diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 959c200a..f8de1cf6 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -1,4 +1,19 @@
-Jsone  (2021-11-17)
+Jsone 4.5.0 (2022-12-25)
+========================
+
+Features
+--------
+
+- Added a $default case to the switch operator (#455)
+
+
+Improved Documentation
+----------------------
+
+- Replaced the documentation site with a new, more usable and ineractive version
+
+
+Jsone 4.4.3 (2021-11-17)
 ===================
 
 Features
@@ -7,6 +22,9 @@ Features
 - The JSON-e GitHub repository has been moved to https://github.com/json-e/json-e. (#430)
 
 
+Jsone 4.4.2 (2021-11-12)
+===================
+
 Bugfixes
 --------
 
diff --git a/js/package.json b/js/package.json
index 7670342e..ef830e82 100644
--- a/js/package.json
+++ b/js/package.json
@@ -1,6 +1,6 @@
 {
   "name": "json-e",
-  "version": "4.4.3",
+  "version": "4.5.0",
   "description": "json parameterization module inspired from json-parameterization",
   "main": "./src/index.js",
   "browser": "./dist/index.js",
diff --git a/py/jsone/newsfragments/455.feature b/py/jsone/newsfragments/455.feature
deleted file mode 100644
index fee4e6d5..00000000
--- a/py/jsone/newsfragments/455.feature
+++ /dev/null
@@ -1 +0,0 @@
-Added a $default case to the switch operator
\ No newline at end of file
diff --git a/py/setup.py b/py/setup.py
index 92a8a23c..2ac134e1 100644
--- a/py/setup.py
+++ b/py/setup.py
@@ -2,7 +2,7 @@
 import os
 from setuptools import setup, find_packages
 
-version = "4.4.3"
+version = "4.5.0"
 
 description='A data-structure parameterization system written for embedding context in JSON objects'
 
diff --git a/rs/Cargo.lock b/rs/Cargo.lock
index 000e32ed..88d352b2 100644
--- a/rs/Cargo.lock
+++ b/rs/Cargo.lock
@@ -53,7 +53,7 @@ checksum = "b71991ff56294aa922b450139ee08b3bfc70982c6b2c7562771375cf73542dd4"
 
 [[package]]
 name = "json-e"
-version = "4.4.3"
+version = "4.5.0"
 dependencies = [
  "anyhow",
  "chrono",
diff --git a/rs/Cargo.toml b/rs/Cargo.toml
index b19582cc..200f835e 100644
--- a/rs/Cargo.toml
+++ b/rs/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "json-e"
-version = "4.4.3"
+version = "4.5.0"
 authors = ["owlishDeveloper <bugzeeeeee@gmail.com>", "Alex Lopez <alex.lopez.zorzano@gmail.com>"]
 edition = "2018"
 license = "MPL-2.0"
diff --git a/rs/specification.yml b/rs/specification.yml
new file mode 100644
index 00000000..5e6c894f
--- /dev/null
+++ b/rs/specification.yml
@@ -0,0 +1,5396 @@
+################################################################################
+# ### Specification for json-e
+# This document specifies the json-e template language through a series of
+# test cases on the form: `{title, context, template, result, error, panic}`
+# where `jsone.render(template, context) = result` and title is short name
+# for the test case. If the `error` property is specified as `true`, no result
+# needs to be specified, as the test case must throw an error. If the `panic`
+# property is specified as `true`, the test case is expected to throw an error
+# about invalid usage, typically invalid context.
+#
+# Comments explaining the test cases is encouraged, additionally entries with
+# {section: '...'} is encouraged to separate sections.
+#
+# Test conditions:
+#   1) Time at test time is expected to be '2017-01-19T16:27:20.974Z'
+################################################################################
+---
+section:  Initial Minimal Subset
+---
+title:    Identity
+context:  {}
+template: {key: [1,2,{key2: 'val', key3: 1}, true], f: false}
+result:   {key: [1,2,{key2: 'val', key3: 1}, true], f: false}
+---
+title:    fromNow
+context:  {}
+template: {$fromNow: ''}
+result:   '2017-01-19T16:27:20.974Z'
+---
+title:    fromNow 2 days 3 hours
+context:  {}
+template: {$fromNow: '2 days 3 hours'}
+result:   '2017-01-21T19:27:20.974Z'
+---
+title:    $eval without context
+context:  {}
+template: {$eval: '1 + 2'}
+result:   3
+---
+title:    $eval
+context:  {key: ['value', 1, 2, true, {}]}
+template: {$eval: 'key'}
+result:   ['value', 1, 2, true, {}]
+---
+title:    $json
+context:  {}
+template: {$json: [1,2,true,{},[]]}
+result:   '[1,2,true,{},[]]'
+---
+title:    $json alphabetical
+context:  {}
+template: {$json: {'Z':null,'q':1,'a':{'c':45,'b':['9',8,{}]},'r':true}}
+result:   '{"Z":null,"a":{"b":["9",8,{}],"c":45},"q":1,"r":true}'
+---
+title:    string interpolation
+context:  {key: 'world', num: 1}
+template: {message: 'hello ${key}', 'k-${num}': true}
+result:   {message: 'hello world', 'k-1': true}
+---
+title:    string interpolation with object evaluation
+context:  {key: 'world', num: 1}
+template: {message: 'hello ${{a: "world"}.a}', 'k-${{a: 1}.a + {a: 0}.a}': true}
+result:   {message: 'hello world', 'k-1': true}
+---
+title: multiple string interpolation (1)
+context:  {a: 'hello', b: 'world'}
+template: {message: '${a} ${b}'}
+result:   {message: 'hello world'}
+---
+title: multiple string interpolation (2)
+context:  {a: 'hello', b: 'world'}
+template: {message: '${a}$$${b}'}
+result:   {message: 'hello$${b}'}
+---
+title: multiple string interpolation (3)
+context:  {a: 'hello', b: 'world'}
+template: {message: '${a}##${b}'}
+result:   {message: 'hello##world'}
+---
+title: string interpolation escapes
+context:  {}
+template: {message: 'a literal $${in a string}'}
+result:   {message: 'a literal ${in a string}'}
+---
+title: string interpolation escapes with more $
+context:  {x: 'a'}
+template: ['${x}', '$${x}', '$$${x}', '$$$${x}', '$$$$${x}']
+result:   ['a', '${x}', '$${x}', '$$${x}', '$$$${x}']
+---
+title: string interpolation of keys
+context: {name: 'foo', value: 'bar'}
+template: {"tc_${name}": "${value}"}
+result: {"tc_foo": "bar"}
+---
+title: string interpolation with unbalanced }
+context:  {}
+template: {message: 'tricky ${"}}}}"}'}
+result:   {message: 'tricky }}}}'}
+---
+title:    can't interpolate arrays
+context:  {key: [1,2,3]}
+template: {message: 'hello ${key}'}
+error:    "TemplateError at template.message: interpolation of 'key' produced an array or object"
+---
+title:    can't interpolate objects
+context:  {key: {}}
+template: 'hello ${key}'
+error:    "TemplateError: interpolation of 'key' produced an array or object"
+---
+title:    booleans interpolate
+context:  {t: true, f: false}
+template: '${t} or ${f}: yeast is a bacterium'
+result:   'true or false: yeast is a bacterium'
+---
+title:    numbers interpolate
+context:  {round: 3, decimal: 3.75}
+template: '${round}, really ${decimal}'
+result:   '3, really 3.75'
+---
+title:    nulls interpolate
+context:  {nothing: null}
+template: 'big pile of ${nothing}'
+result:   'big pile of '
+---
+title: invalid context
+context: {'a b c': 1}
+template: {}
+error: 'TemplateError: top level keys of context must follow /[a-zA-Z_][a-zA-Z0-9_]*/'
+panic: true
+################################################################################
+---
+section:  $if operator
+---
+title:    $if-then-else, true
+context:  {cond: true}
+template: {$if: 'cond', then: 1, else: 2}
+result:   1
+---
+title:    $if-then-else, false
+context:  {cond: false}
+template: {$if: 'cond', then: 1, else: 2}
+result:   2
+---
+title:    $if-then in array, true
+context:  {cond: true}
+template: [0, {$if: 'cond', then: 1}]
+result:   [0, 1]
+---
+title:    $if-then in array, false
+context:  {cond: false}
+template: [0, {$if: 'cond', then: 1}]
+result:   [0] # missing else branch should return a delete-marker
+---
+title:    $if-then in object, true
+context:  {cond: true}
+template: {key: {$if: 'cond', then: 1}, k2: 3}
+result:   {key: 1, k2: 3}
+---
+title:    $if-then in object, false
+context:  {cond: false}
+template: {key: {$if: 'cond', then: 1}, k2: 3}
+result:   {k2: 3} # missing else branch should return a delete-marker
+---
+title:    $if -> delete-marker, true
+context:  {cond: true}
+template: {key: {$if: 'cond'}, k2: 3}
+result:   {k2: 3} # missing then/else branches should return a delete-marker
+---
+title:    $if -> delete-marker, false
+context:  {cond: false}
+template: {key: {$if: 'cond'}, k2: 3}
+result:   {k2: 3} # missing then/else branches should return a delete-marker
+---
+title: $if->then, then => $eval, true
+context: {key: {b: 1}}
+template: {$if: 'true', then: {$eval: 'key'}}
+result: {b: 1}
+---
+title: $if->else, else => $eval, false
+context: {key: {b: 1}}
+template: {$if: 'false', else: {$eval: 'key'}}
+result: {b: 1}
+---
+title: $if->then, then => ${}, true
+context: {key: 'one'}
+template: {$if: 'true', then: '${key}'}
+result: 'one'
+---
+title: $if->else, else => ${}, false
+context: {key: 'one'}
+template: {$if: 'false', else: '${key}'}
+result: 'one'
+---
+title: $if->then, then => object, true
+context: {cond: true}
+template: {$if: 'cond', then: {key: 'hello world'}}
+result: {key: 'hello world'}
+---
+title: $if->else, else => object, false
+context: {cond: false}
+template: {$if: 'cond', else: {key: 'hello world'}}
+result: {key: 'hello world'}
+---
+title: $if->then, then => object, $eval, true
+context: {cond: true, key: 'hello world'}
+template: {$if: 'cond', then: {key: {$eval: 'key'}}}
+result: {key: 'hello world'}
+---
+title: $if->else, else => object, $eval, false
+context: {cond: false, key: 'hello world'}
+template: {$if: 'cond', else: {key: {$eval: 'key'}}}
+result: {key: 'hello world'}
+---
+title: $if->then, then => object, interpolation, true
+context: {cond: true, key: 'world'}
+template: {$if: 'cond', then: {key: 'hello ${key}'}}
+result: {key: 'hello world'}
+---
+title: $if->else, else => object, interpolation, false
+context: {cond: false, key: 'world'}
+template: {$if: 'cond', else: {key: 'hello ${key}'}}
+result: {key: 'hello world'}
+---
+title: $if->then->else, empty string
+context: {cond: "", key: 'world'}
+template: {$if: 'cond', then: "t", else: "f"}
+result: f
+---
+title: $if->then->else, nonempty string
+context: {cond: "stuff", key: 'world'}
+template: {$if: 'cond', then: "t", else: "f"}
+result: t
+---
+title: $if->then->else, string "0"  # once upon a time, this was false in PHP.. maybe still is
+context: {cond: "0", key: 'world'}
+template: {$if: 'cond', then: "t", else: "f"}
+result: t
+---
+title: $if->then->else, zero
+context: {cond: 0, key: 'world'}
+template: {$if: 'cond', then: "t", else: "f"}
+result: f
+---
+title: $if->then->else, one
+context: {cond: 1, key: 'world'}
+template: {$if: 'cond', then: "t", else: "f"}
+result: t
+---
+title: $if->then->else, null
+context: {cond: null, key: 'world'}
+template: {$if: 'cond', then: "t", else: "f"}
+result: f
+---
+title: $if->then->else, empty array
+context: {cond: [], key: 'world'}
+template: {$if: 'cond', then: "t", else: "f"}
+result: f
+---
+title: $if->then->else, nonempty array
+context: {cond: [1, 2], key: 'world'}
+template: {$if: 'cond', then: "t", else: "f"}
+result: t
+---
+title: $if->then->else, empty object
+context: {cond: {}, key: 'world'}
+template: {$if: 'cond', then: "t", else: "f"}
+result: f
+---
+title: $if->then->else, nonempty object
+context: {cond: {a: 2}, key: 'world'}
+template: {$if: 'cond', then: "t", else: "f"}
+result: t
+---
+title: $if->then->else, function
+context: {}
+template: {$if: 'min', then: "t", else: "f"}
+result: t
+---
+title:    $if->then evaluating to nothing at the top level is null
+context:  {cond: false}
+template: {$if: 'cond', then: "t"}
+result:   null
+---
+title:    $if-then-else with undefined properties
+context:  {cond: true}
+template: {$if: 'cond', then: 1, foo: 'bar', else: 2, bing: 'baz'}
+error:    'TemplateError: $if has undefined properties: bing foo'
+################################################################################
+---
+section:  escape operators
+---
+title:    escape $eval
+context:  {}
+template: {$$eval: "1+2"}
+result:   {$eval: "1+2"}
+---
+title:    escape $flatten
+context:  {}
+template: {$$flatten: [[1, 2], [3, 4], [5]]}
+result:   {$flatten: [[1, 2], [3, 4], [5]]}
+---
+title:    escape $fromNow
+context:  {}
+template: {$$fromNow: "2 days"}
+result:   {$fromNow: "2 days"}
+---
+title:    escape $if
+context:  {}
+template: {$$if: false}
+result:   {$if: false}
+---
+title:    escape $json
+context:  {}
+template: {$$json: [1, 2, 3]}
+result:   {$json: [1, 2, 3]}
+---
+title:    escape $let
+context:  {}
+template: {$$let: {ts: 100, foo: 200}, in: [{$$eval: "ts+foo"}]}
+result:   {$let: {ts: 100, foo: 200}, in: [{$eval: "ts+foo"}]}
+---
+title:    escape $map
+context:  {}
+template: {$$map: [2, 4, 6], each(x): {$$eval: "x + a"}}
+result:   {$map: [2, 4, 6], each(x): {$eval: "x + a"}}
+---
+title:    escape $match
+context:  {x: 1}
+template: {$$match: [{'x == 1': 2}]}
+result:   {$match: [{'x == 1': 2}]}
+---
+title:    escape $switch
+context:  {x: 1}
+template: {$$switch: [{'x == 1': 2}]}
+result:   {$switch: [{'x == 1': 2}]}
+---
+title:    escape $merge
+context:  {}
+template: {$$merge: [{a: 1}, {a: 2}]}
+result:   {$merge: [{a: 1}, {a: 2}]}
+---
+title:    escape $reverse
+context:  {}
+template: {$$reverse: [3, 2, 1]}
+result:   {$reverse: [3, 2, 1]}
+---
+title:    escape $sort
+context:  {}
+template: {$$sort: [3, 2, 1]}
+result:   {$sort: [3, 2, 1]}
+---
+title:    reserved $-keywords
+context:  {}
+template: {$nothing: 1}
+error:    'TemplateError: $<identifier> is reserved; use $$<identifier>'
+---
+title:    escape non-json-e operator
+context:  {}
+template: {$$nothing: 1}
+result:   {$nothing: 1}
+################################################################################
+---
+section:  $flatten
+---
+title:    simple flatten
+context:  {}
+template: {$flatten: [[1, 2], [3, 4], [5]]}
+result:   [1, 2, 3, 4, 5]
+---
+title:    flatten empty array
+context:  {}
+template: {$flatten: []}
+result:   []
+---
+title:    flatten empty array of arrays
+context:  {}
+template: {$flatten: [[]]}
+result:   []
+---
+title:    flatten evaluated value
+context:  {}
+template: {$flatten: {$eval: '[[1], [2, 3]]'}}
+result:   [1, 2, 3]
+---
+title:    flatten null
+context:  {}
+template: {$flatten: null}
+error:    'TemplateError: $flatten value must evaluate to an array'
+---
+title:    flatten an object
+context:  {}
+template: {$flatten: {a: 1, b: 2}}
+error:    'TemplateError: $flatten value must evaluate to an array'
+---
+title:    flatten an array of strings
+context:  {}
+template: {$flatten: ["a", "b"]}
+result:   ["a", "b"]
+---
+title:    flatten an array of numbers
+context:  {}
+template: {$flatten: [1, 2]}
+result:   [1, 2]
+---
+title:    flatten mixed types
+context:  {}
+template: {$flatten: [[1, 2], [['a', 'b']], [{}], [[]]]}
+result:   [1, 2, ['a', 'b'], {}, []]
+---
+title:    flatten mixed levels
+context:  {}
+template: {$flatten: [[1, [2, 3]], [4], 5]}
+result:   [1, [2, 3], 4, 5]
+---
+title:    flatten with undefined properties
+context:  {}
+template: {$flatten: {$eval: '[[1], [2, 3]]'}, foo: 'bar'}
+error: 'TemplateError: $flatten has undefined properties: foo'
+################################################################################
+---
+section:  $flattenDeep
+---
+title:    simple flattenDeep
+context:  {}
+template: {$flattenDeep: [[1, [2, [3]]]]}
+result:   [1, 2, 3]
+---
+title:    flattenDeep empty array
+context:  {}
+template: {$flattenDeep: []}
+result:   []
+---
+title:    evaluated value
+context:  {}
+template: {$flattenDeep: {$eval: '[[1], [2, [3]]]'}}
+result:   [1, 2, 3]
+---
+title:    flattenDeep empty array of arrays
+context:  {}
+template: {$flattenDeep: [[]]}
+result:   []
+---
+title:    flattenDeep null
+context:  {}
+template: {$flattenDeep: null}
+error:    'TemplateError: $flattenDeep value must evaluate to an array'
+---
+title:    flattenDeep an object
+context:  {}
+template: {$flattenDeep: {a: 1, b: 2}}
+error:    'TemplateError: $flattenDeep value must evaluate to an array'
+---
+title:    flattenDeep an array of strings
+context:  {}
+template: {$flattenDeep: ["a", "b"]}
+result:   ["a", "b"]
+---
+title:    flattenDeep an array of numbers
+context:  {}
+template: {$flattenDeep: [1, 2]}
+result:   [1, 2]
+---
+title:    flattenDeep mixed types
+context:  {}
+template: {$flattenDeep: [[1, 2], [['a', 'b']], [{}], [[]]]}
+result:   [1, 2, 'a', 'b', {}]
+---
+title:    flattenDeep mixed levels
+context:  {}
+template: {$flattenDeep: [[1, [2, 3]], [4], 5]}
+result:   [1, 2, 3, 4, 5]
+---
+title:    flattenDeep with undefined properties
+context:  {}
+template: {$flattenDeep: [[1, [2, 3]], [4], 5], foo: 'bar'}
+error: 'TemplateError: $flattenDeep has undefined properties: foo'
+################################################################################
+---
+section:  $fromNow
+---
+title:    $fromNow 1 hour
+context:  {}
+template: {$fromNow: '1 hour'}
+result:   '2017-01-19T17:27:20.974Z'
+---
+title:    $fromNow 2 hours
+context:  {}
+template: {$fromNow: '2 hours'}
+result:   '2017-01-19T18:27:20.974Z'
+---
+title:    $fromNow 3h
+context:  {}
+template: {$fromNow: '3h'}
+result:   '2017-01-19T19:27:20.974Z'
+---
+title:    $fromNow 1 hours
+context:  {}
+template: {$fromNow: '1 hours'}
+result:   '2017-01-19T17:27:20.974Z'
+---
+title:    $fromNow -1 hour
+context:  {}
+template: {$fromNow: '-1 hour'}
+result:   '2017-01-19T15:27:20.974Z'
+---
+title:    $fromNow 1 m
+context:  {}
+template: {$fromNow: '1 m'}
+result:   '2017-01-19T16:28:20.974Z'
+---
+title:    $fromNow 1m
+context:  {}
+template: {$fromNow: '1m'}
+result:   '2017-01-19T16:28:20.974Z'
+---
+title:    $fromNow 12 min
+context:  {}
+template: {$fromNow: '12 min'}
+result:   '2017-01-19T16:39:20.974Z'
+---
+title:    $fromNow 12min
+context:  {}
+template: {$fromNow: '12min'}
+result:   '2017-01-19T16:39:20.974Z'
+---
+title:    $fromNow 11m
+context:  {}
+template: {$fromNow: '11m'}
+result:   '2017-01-19T16:38:20.974Z'
+---
+title:    $fromNow 11 m
+context:  {}
+template: {$fromNow: '11 m'}
+result:   '2017-01-19T16:38:20.974Z'
+---
+title:    $fromNow 1 day
+context:  {}
+template: {$fromNow: '1 day'}
+result:   '2017-01-20T16:27:20.974Z'
+---
+title:    $fromNow 2 days
+context:  {}
+template: {$fromNow: '2 days'}
+result:   '2017-01-21T16:27:20.974Z'
+---
+title:    $fromNow 1 second
+context:  {}
+template: {$fromNow: '1 second'}
+result:   '2017-01-19T16:27:21.974Z'
+---
+title:    $fromNow 1 week
+context:  {}
+template: {$fromNow: '1 week'}
+result:   '2017-01-26T16:27:20.974Z'
+---
+title:    $fromNow 1 month
+context:  {}
+template: {$fromNow: '1 month'}
+result:   '2017-02-18T16:27:20.974Z'
+---
+title:    $fromNow 30 mo
+context:  {}
+template: {$fromNow: '30 mo'}
+result:   '2019-07-08T16:27:20.974Z'
+---
+title:    $fromNow -30 mo
+context:  {}
+template: {$fromNow: '-30 mo'}
+result:   '2014-08-03T16:27:20.974Z'
+---
+title:    $fromNow 1 year
+context:  {}
+template: {$fromNow: '1 year'}
+result:   '2018-01-19T16:27:20.974Z'
+---
+title:    $fromNow of non-string
+context:  {}
+template: {$fromNow: 13}
+error:    'TemplateError: $fromNow expects a string'
+---
+title:    $fromNow with eval
+context:  {ttl: 24}
+template: {$fromNow: {$eval: 'str(ttl) + " hours"'}}
+result:   '2017-01-20T16:27:20.974Z'
+---
+title:    $fromNow with redefined `now`
+context:  {}
+template: {$let: {now: '2019-01-01T01:00:00.123Z'}, in: {$fromNow: '3 mo'}}
+result:   '2019-04-01T01:00:00.123Z'
+---
+title:    $fromNow with reference
+context:  {when: '2019-01-01T01:00:00.123Z'}
+template: {$fromNow: '3 mo', from: {$eval: when}}
+result:   '2019-04-01T01:00:00.123Z'
+---
+title:    $fromNow with undefined properties
+context:  {now: '2019-01-01T01:00:00.123Z'}
+template: {$fromNow: '3 mo', from: {$eval: now}, foo: 'bar'}
+error: 'TemplateError: $fromNow has undefined properties: foo'
+################################################################################
+---
+section:  $json
+---
+title:    wrap expressions with $eval
+context:  {a: 1, b: 2}
+template: {$json: {$eval: 'a + b + 7'}}
+result:   '10'
+---
+title:    unwrap expressions not evaluated
+context:  {a: 1, b: 2}
+template: {$json: 'a + b + 7'}
+result:   '"a + b + 7"'
+---
+title:    $eval inside array
+context:  {a: 1, b: 2}
+template: {$json: [2, 5, {$eval: 'a + b + 7'}]}
+result:   '[2,5,10]'
+---
+title:    representation of various unicode codepoints are consistent
+context:  {}
+template: {$json: ["\x10", "Z", "\u0103","\U0001F809"]}
+result:   "[\"\\u0010\",\"Z\",\"\u0103\",\"\U0001F809\"]"
+---
+title:    sorting pairs by unicode key strings sorts lexically by codepoint
+context:  {}
+template: {$json: {"\u3347\u0050": 1, "\uE1FF\u0100": 2, "\u0055\u0045": 3}}
+result:   "{\"\u0055\u0045\":3,\"\u3347\u0050\":1,\"\uE1FF\u0100\":2}"
+---
+title:    sorting pairs by unicode key strings sorts lexically by codepoint, even with chars above base plane
+context:  {}
+template: {$json: {"\U0001F809\u732b":'hey', "Z\U00010000P": 1, "\U000E1FFF\u0103": 2, "UaE": 3}}
+result:   "{\"UaE\":3,\"Z\U00010000P\":1,\"\U0001F809\u732b\":\"hey\",\"\U000E1FFF\u0103\":2}"
+---
+title:    $json with undefined properties
+context:  {}
+template: {$json: [1,2,true,{},[]], foo: 'bar'}
+error:    'TemplateError: $json has undefined properties: foo'
+---
+title:    $json can be evaluated to null without an error
+context:  {input: null}
+template: {$json: { '$eval': 'input' } }
+result: 'null'
+################################################################################
+---
+section: accessing nested objects => context
+---
+title: $eval
+context:  {key: {key2: ['value', 1, 2, true, {}]}}
+template: {$eval: 'key.key2'}
+result:   ['value', 1, 2, true, {}]
+---
+title:    $json
+context:  {key: {key2: [1,2,true,{},[]]}}
+template: {$json: {$eval: 'key.key2'}}
+result:   '[1,2,true,{},[]]'
+################################################################################
+---
+section: string interpolation
+---
+title: string interpolation
+context: {key: {key2: 'world', key3: 1}}
+template: {message: 'hello ${key.key2}', 'k-${key.key3}': true}
+result:   {message: 'hello world', 'k-1': true}
+---
+title: string interpolation, first character
+context: {somevalue: 13}
+template: {message: '${somevalue}'}
+result:   {message: '13'}
+---
+title: no string interpolation with $$
+context: {somevalue: 13}
+template: {message: '$${somevalue}'}
+result:   {message: '${somevalue}'}
+################################################################################
+---
+section: $let
+---
+title:    simple let
+template: {$let: {ts: 100, foo: 200,}, in: [{$eval: "ts+foo"}, {$eval: "ts-foo"}, {$eval: "ts*foo"}]}
+context:  {}
+result:   [300, -100, 20000]
+---
+title:    let with evaluated values
+template: {$let: {thirty: {$eval: "10 + 20"}}, in: {$eval: "thirty+5"}}
+context:  {}
+result:   35
+---
+title:    let with evaluated context
+template: {$let: {$eval: '{"thirty": 10 + 20}'}, in: {$eval: "thirty+5"}}
+context:  {}
+result:    35
+---
+title:    context overriding
+template: {$let: {x: 20}, in: {$eval: "x + y"}}
+context:  {x: 10, 'y': 1}
+result:   21
+---
+title:    nested let
+template: {$let: {x: 20,'y': 10}, in: {$let: {x: 30}, in: {$eval: "x + y + z"}}}
+context:  {x: 1,'y': 2, z: 3}
+result:   43
+---
+title:    let with undefined properties
+template: {$let: {x: 1,'y': 2}, a: {$eval: "x + y"}}
+context:  {}
+error:    'TemplateError: $let has undefined properties: a'
+---
+title:    let array
+template: {$let: [1, 2], in: {$eval: "1 + 2"}}
+context:  {}
+error:    'TemplateError: $let value must be an object'
+---
+title:    let null
+template: {$let: null, in: {$eval: "1 + 2"}}
+context:  {}
+error:    'TemplateError: $let value must be an object'
+---
+title:    checking name begin with number
+context:  {}
+template: {$let: {ab: 100, bb: 200, 2b: 5}, in: [{$eval: "ab+bb"}, {$eval: "ab-bb"}, {$eval: "ab*bb"}]}
+error:    'TemplateError: top level keys of $let must follow /[a-zA-Z_][a-zA-Z0-9_]*/'
+---
+title:    checking space in variable name
+context:  {}
+template: {$let: {ab: 100, bb: 200, "a b": 10}, in: [{$eval: "ab+bb"}, {$eval: "ab-bb"}, {$eval: "ab*bb"}]}
+error:    'TemplateError: top level keys of $let must follow /[a-zA-Z_][a-zA-Z0-9_]*/'
+---
+title:    checking special character in variable name
+context:  {}
+template: {$let: {ab: 100, bb: 200, "a.b": 10}, in: [{$eval: "ab+bb"}, {$eval: "ab-bb"}, {$eval: "ab*bb"}]}
+error:    'TemplateError: top level keys of $let must follow /[a-zA-Z_][a-zA-Z0-9_]*/'
+---
+title:    checking integrity of operation $let with exact result
+context:  {}
+template: {$let: {ts: 100, foo: 200}, in: [{$eval: "ts+foo"}, {$eval: "ts-foo"}, {$eval: "ts*foo"}]}
+result:   [300, -100, 20000]
+---
+title:    checking $let and $reverse operator integrity
+context:  {}
+template: {$let: {x: [1, 2, 3]}, in: [$reverse: {$eval: "x"}]}
+result:   [[ 3, 2, 1 ]]
+---
+title:    checking $let with $if without else
+context:  {c: 'itm'}
+template: {$let: {a: {$if: 'c == "item"', then: 'value'}}, in: {a: '${a}'}}
+error:    'InterpreterError at template.a: unknown context value a'
+---
+title:    let with a value of $if-then-else
+template: {$let: {$if: something == 3, then: {a: 10, b: 20}, else: {a: 20, b: 10}}, in: {$eval: 'a + b'}}
+context:  {'something': 3}
+result:   30
+---
+title:    let with a rendered key
+template: {$let: {"first_${name}": 1, "second_${name}": 2}, in: {$eval: "first_prize + second_prize"}}
+context:  {name: "prize"}
+result:   3
+---
+title:    let using values from the parent context
+template: {$let: {"b": {$eval: "a + 10"}}, in: {$eval: "a + b"}}
+context:  {a: 5}
+result:   20
+---
+title:    let with a non-object rendered value (array)
+template: {$let: {$eval: "[1, 2]"}, in: "uhoh"}
+context:  {}
+error:    'TemplateError: $let value must be an object'
+---
+title:    let with a non-object rendered value (string)
+template: {$let: "${name}", in: "uhoh"}
+context:  {name: "fido"}
+error:    'TemplateError: $let value must be an object'
+---
+title:    let with a non-object rendered value (boolean)
+template: {$let: {$eval: "true"}, in: "uhoh"}
+context:  {}
+error:    'TemplateError: $let value must be an object'
+---
+title:    fromNow with redefined `now`
+context:  {}
+template: {$let: {now: '2017-01-01T01:00:00.123Z'}, in: {$eval: "fromNow('1 day')"}}
+result:   '2017-01-02T01:00:00.123Z'
+---
+title: defined with empty variable from a let expression
+context: {}
+template: {$let: {var: 10}, in: {$if: "defined('var')", then: 't', else: 'f'}}
+result: t
+---
+title: $let with nested redefinitions of builtins
+context: {}
+template:
+  $let: {lowercase: {$eval: uppercase}}
+  in:
+    $let: {var: 10}
+    in:
+      $if: "defined('var')"
+      then: "${lowercase('t')}"  # lowercase should be redefined as uppercase
+      else: "${lowercase('f')}"
+result: T
+---
+title: $let with nested redefinitions of builtins
+context: {}
+template:
+  $let: {fromNow: {$eval: uppercase}}
+  in:
+    $let: {var: 10}
+    in:
+      $if: "defined('var')"
+      then: "${fromNow('1 hour')}"
+      else: "f"
+result: '1 HOUR'
+################################################################################
+---
+section:  $map
+---
+title:    simple map
+context:  {a: 1}
+template:
+  $map: [2, 4, 6]
+  each(x): {$eval: 'x + a'}
+result:   [3, 5, 7]
+---
+title:    map to objects
+context:  {a: 1}
+template:
+  $map: [2, 4, 6]
+  each(x):
+    asText: '${x + a}'
+    integer: {$eval: 'x + a'}
+result:
+ - {asText: '3', integer: 3}
+ - {asText: '5', integer: 5}
+ - {asText: '7', integer: 7}
+---
+title:    complex identifier
+context:  {a: 1}
+template:
+  $map: [2, 4, 6]
+  each(my_identifier97): {$eval: 'my_identifier97 + a'}
+result:   [3, 5, 7]
+---
+title:    must wrap expressions with $eval
+context:  {a: 1}
+template:
+  $map: [2, 4, 6]
+  each(my_identifier97): 'my_identifier97 + a'
+result:   ['my_identifier97 + a', 'my_identifier97 + a', 'my_identifier97 + a']
+---
+title:    can take from objects
+context:  {a: 1}
+template:
+  $map: [{k: 1}, {k: 2}, {k: 3}]
+  each(y): {$eval: 'y.k'}
+result:   [1, 2, 3]
+---
+title:    value is rendered
+context:  {a: 1}
+template:
+  $map: {$eval: '[{k: 1}, {k: 2}, {k: 3}]'}
+  each(y): {$eval: 'y.k'}
+result:   [1, 2, 3]
+---
+title:    can make objects too
+context:  {a: 1}
+template:
+  $map: [{k: 1}, {k: 2}, {k: 3}]
+  each(y):
+    k: {$eval: 'y.k + 1'}
+    v: 'before=${y.k}'
+result:
+  - k: 2
+    v: 'before=1'
+  - k: 3
+    v: 'before=2'
+  - k: 4
+    v: 'before=3'
+---
+title:    respects delete-marker from $if
+context:  {a: 1}
+template:
+  $map: [{k: 1}, {k: 2}, {k: 3}]
+  each(y):
+    $if: 'y.k != 2'
+    then: {$eval: 'y.k'}
+result: [1, 3]
+---
+title:    $map works on object
+context:  {}
+template:
+  $map: {a: 1, b: 2, c: 3}
+  each(y): {'${y.key}x': {$eval: 'y.val + 1'}}
+result: {ax: 2, bx: 3, cx: 4}
+---
+title:    $map each(value,key) on object
+context:  {}
+template:
+  $map: {a: 1, b: 2, c: 3}
+  each(v,k): {'${k}x': {$eval: 'v + 1'}}
+result: {ax: 2, bx: 3, cx: 4}
+---
+title:    $map can add new keys to object
+context:  {}
+template:
+  $map: {a: 1, b: 2, c: 3}
+  each(y): {'${y.key}': {$eval: 'y.val'}, '${y.key}x': {$eval: 'y.val + 1'}}
+result: {a: 1, b: 2, c: 3, ax: 2, bx: 3, cx: 4}
+---
+title:    $map array index variable
+context: {}
+template:
+  $map: ['a', 'b', 'c']
+  each(y,i): '${y}-${i}'
+result: ['a-0','b-1','c-2']
+---
+title:    $map no args
+context:  {}
+template:
+  $map: "a, b, c"
+  each(): {$eval: 'y.k'}
+error: 'TemplateError: $map has undefined properties: each()'
+---
+title:    $map too many args
+context:  {}
+template:
+  $map: "a, b, c"
+  each(k,v,i): {$eval: 'y.k'}
+error: 'TemplateError: $map has undefined properties: each(k,v,i)'
+---
+title:    $map requires an array, not string
+context:  {}
+template:
+  $map: "a, b, c"
+  each(y): {$eval: 'y.k'}
+error: 'TemplateError: $map value must evaluate to an array or object'
+---
+title:    $map requires an array, not number
+context:  {}
+template:
+  $map: 10.1
+  each(y): {$eval: 'y.k'}
+error: 'TemplateError: $map value must evaluate to an array or object'
+---
+title:    $map requires an array, not null
+context:  {}
+template:
+  $map: null
+  each(y): {$eval: 'y.k'}
+error: 'TemplateError: $map value must evaluate to an array or object'
+---
+title:    map with undefined properties
+context:  {a: 1}
+template:
+  $map: [2, 4, 6]
+  each(x): {$eval: 'x + a'}
+  foo: 'bar'
+error: 'TemplateError: $map has undefined properties: foo'
+---
+title:    $map as object and each(identifier) as array
+context:  {}
+template:
+  $map: {"hello": 5, "test": 9}
+  each(x): ['${x.key}', {$eval: 'x.val+1'}]
+error: 'TemplateError: $map on objects expects each(x) to evaluate to an object'
+################################################################################
+---
+section: $match operator
+---
+title:    $match, 2 matches, ordered by lexcial sorting of property names
+context:  {cond: 3}
+template: {$match: {'cond == 3': 2, 'cond == 5': 3, 'cond < 5 && cond > 0': 4, 'true': 17}}
+result:   [4, 2, 17]
+---
+title:    $match, no matches
+context:  {cond: 3}
+template: {$match: {'cond > 5': 2, 'cond == 5': 3, 'cond == 4 || cond < 1': 4}}
+result:   []
+---
+title:    $match, 1 match in array
+context:  {cond: 3}
+template: [0, $match: {'cond == 3': 2, 'cond == 5': 3}]
+result:   [0, [2]]
+---
+title:    $match, 0 matches in array
+context:  {cond: 3}
+template: [0, $match: {'cond > 3': 2, 'cond == 5': 3}]
+result:   [0, []]
+---
+title:    $match, 1 match in object
+context:  {cond: 3}
+template: {key: 0, banana: {$match: {'cond == 3': 2, 'cond == 5': 3}}}
+result:   {key: 0, banana: [2]}
+---
+title:    $match, 0 matches in object
+context:  {cond: 3}
+template: {key: 0, banana: {$match: {'cond > 3': 2, 'cond == 5': 3}}}
+result:   {key: 0, banana: []}
+---
+title:    $match, is not an object
+context:  {cond: 3}
+template: {$match: [{'cond < 5 && cond > 0': 2}]}
+error:    'TemplateError: $match can evaluate objects only'
+---
+title:    $match, value that also needs evaluation
+context:  {cond: 3, ifcond: false}
+template: {$match: {'cond == 3': {$if: 'ifcond', then: "t", else: "f"}}}
+result:   ["f"]
+################################################################################
+---
+section: $switch operator
+---
+title:    $switch, 1 match
+context:  {cond: 3}
+template: {$switch: {'cond == 3': 2, 'cond == 5': 3}}
+result: 2
+---
+title:    $switch, 2 matches
+context:  {cond: 3}
+template: {$switch: {'cond == 3': 2, 'cond > 1': 3}}
+error:    'TemplateError: $switch can only have one truthy condition'
+---
+title:    $switch, no matches
+context:  {cond: 3}
+template: {$switch: {'cond > 5': 2, 'cond == 5': 3, 'cond == 4 || cond < 1': 4}}
+result:   null
+---
+title:    $switch, 1 match in array
+context:  {cond: 3}
+template: [0, $switch: {'cond == 3': 2, 'cond == 5': 3}]
+result:   [0, 2]
+---
+title:    $switch, 0 matches in array
+context:  {cond: 3}
+template: [0, $switch: {'cond > 3': 2, 'cond == 5': 3}]
+result:   [0]
+---
+title:    $switch, 1 match in object
+context:  {cond: 3}
+template: {key: 0, banana: {$switch: {'cond == 3': 2, 'cond == 5': 3}}}
+result:   {key: 0, banana: 2}
+---
+title:    $switch, 0 matches in object
+context:  {cond: 3}
+template: {key: 0, banana: {$switch: {'cond > 3': 2, 'cond == 5': 3}}}
+result:   {key: 0}
+---
+title:    $switch, is not an object
+context:  {cond: 3}
+template: {$switch: [{'cond < 5 && cond > 0': 2}]}
+error:    'TemplateError: $switch can evaluate objects only'
+---
+title:    $switch, value that also needs evaluation
+context:  {cond: 3, ifcond: false}
+template: {$switch: {'cond == 3': {$if: 'ifcond', then: "t", else: "f"}}}
+result:   "f"
+---
+title:    $switch, fallback to $default
+context:  {cond: 4}
+template: {$switch: {'cond == 3': 1, $default: 'fallback'}}
+result:   "fallback"
+---
+title:    $switch, $default value that also needs evaluation
+context:  {cond: 4, ifcond: false}
+template: {$switch: {'cond == 3': 1, $default: {$if: 'ifcond', then: "t", else: "f"}}}
+result:   "f"
+---
+title:    $switch, $default with 1 match in object
+context:  {cond: 3}
+template: {$switch: {'cond == 3': 1, $default: 'fallback'}}
+result:   1
+###############################################################################
+---
+section:  $merge
+---
+title:    simple merge
+context:  {}
+template: {$merge: [{a: 1, b: 1}, {b: 2, c: 3}, {d: 4}]}
+result:   {a: 1, b: 2, c: 3, d: 4}
+---
+title:    value is evaluated
+context:  {defaults: {d: 4}}
+template: {$merge: [{a: 1, b: 1}, {b: 2, c: 3}, {$eval: defaults}]}
+result:   {a: 1, b: 2, c: 3, d: 4}
+---
+title:    merge empty array
+context:  {}
+template: {$merge: []}
+result:   {}
+---
+title:    merge empty array with empty object
+context:  {}
+template: {$merge: [{}]}
+result:   {}
+---
+title:    merge null
+context:  {}
+template: {$merge: null}
+error: 'TemplateError: $merge value must evaluate to an array of objects'
+---
+title: $merge [null]
+template: {$merge: [null]}
+context: {}
+error: 'TemplateError: $merge value must evaluate to an array of objects'
+---
+title: merge with undefined properties
+template: {$merge: [{a: 1}, {b: 2, c: 3}, {d: 4}], foo: "bar", bing: "baz"}
+context: {}
+error: 'TemplateError: $merge has undefined properties: bing foo'
+################################################################################
+---
+section:  $mergeDeep
+---
+title:    simple non-deep mergeDeep matches merge
+context:  {}
+template: {$mergeDeep: [{a: 1, b: 1}, {b: 2, c: 3}, {d: 4}]}
+result:   {a: 1, b: 2, c: 3, d: 4}
+---
+title:    deep merge of lists appends
+context:  {}
+template: {$mergeDeep: [{a: [1, 2]}, {a: [3, 4]}]}
+result:   {a: [1, 2, 3, 4]}
+---
+title:    deep merge of objects merges
+context:  {}
+template: {$mergeDeep: [{a: {x: 1,'y': 2}}, {a: {'y': 3, z: 4}}]}
+result:   {a: {x: 1,'y': 3, z: 4}}
+---
+title:    very deep merge
+context:  {}
+template:
+  $mergeDeep:
+    - task:
+        payload:
+          command: [a, b]
+    - task:
+        extra:
+          foo: bar
+    - task:
+        payload:
+          command: [c]
+result:
+  task:
+    extra:
+      foo: bar
+    payload:
+      command: [a, b, c]
+---
+title:    value is evaluated
+context:  {defaults: {d: 4}}
+template: {$mergeDeep: [{a: 1, b: 1}, {b: 2, c: 3}, {$eval: defaults}]}
+result:   {a: 1, b: 2, c: 3, d: 4}
+---
+title:    mergeDeep empty array
+context:  {}
+template: {$mergeDeep: []}
+result:   {}
+---
+title:    mergeDeep empty array with empty object
+context:  {}
+template: {$mergeDeep: [{}]}
+result:   {}
+---
+title:    mergeDeep null
+context:  {}
+template: {$mergeDeep: null}
+error: 'TemplateError: $mergeDeep value must evaluate to an array of objects'
+---
+title: $mergeDeep [null]
+template: {$mergeDeep: [null]}
+context: {}
+error: 'TemplateError: $mergeDeep value must evaluate to an array of objects'
+---
+title: mergeDeep with undefined properties
+template: {$mergeDeep: [{a: {x: 1,'y': 2}}, {a: {'y': 3, z: 4}}], foo: "bar", bing: "baz"}
+context: {}
+error: 'TemplateError: $mergeDeep has undefined properties: bing foo'
+################################################################################
+---
+section:  $sort
+---
+title:    simple sort
+context:  {}
+template: {$sort: [3, 4, 1, 2]}
+result:   [1, 2, 3, 4]
+---
+title:    simple sort of strings (shortest first)
+context:  {}
+template: {$sort: ['android', 'aardvark', 'add', 'adderall']}
+result:   ['aardvark', 'add', 'adderall', 'android']
+---
+title:    simple sort of multi-digit numbers
+context:  {}
+template: {$sort: [111, 22, 3]}
+result:   [3, 22, 111]
+---
+title:    sort of mixed array
+context:  {}
+template: {$sort: [1, "2", 2, 3, "111", "112"]}
+error:    true
+---
+title:    simple sort with $eval
+context:  {array: [3, 4, 1, 2]}
+template: {$sort: {$eval: 'array'}}
+result:   [1, 2, 3, 4]
+---
+title:    sort by, returning number
+context:  {}
+template:
+  $sort: [{a: 20}, {a: 10, b: []}, {a: 3}]
+  by(x): 'x.a'
+result:   [{a: 3}, {a: 10, b: []}, {a: 20}]
+---
+title:    sort by, returning string
+context:  {}
+template:
+  $sort: [{s: 'android'}, {s: 'add'}, {s: 'adderall'}]
+  by(x): 'x.s'
+result: [{s: 'add'}, {s: 'adderall'}, {s: 'android'}]
+---
+title:    cannot sort objects without by
+context:  {}
+template:
+  $sort: [{a: 2}, {a: 1, b: []}, {a: 3}]
+error: 'TemplateError: $sorted values to be sorted must have the same type'
+---
+title:    by cannot return objects
+context:  {}
+template:
+  $sort: [{a: 2}, {a: 1, b: []}, {a: 3}]
+  by(x): x
+error: 'TemplateError: $sorted values to be sorted must have the same type'
+---
+title:    cannot sort arrays without by
+context:  {}
+template:
+  $sort: [[1,2,3], [4,5], [], [8,9,10]]
+error: 'TemplateError: $sorted values to be sorted must have the same type'
+---
+title:    by cannot return arrays
+context:  {}
+template:
+  $sort: [[1,2,3], [4,5], [], [8,9,10]]
+  by(x): x
+error: 'TemplateError: $sorted values to be sorted must have the same type'
+---
+title:    cannot sort nulls
+context:  {}
+template: {$sort: [null, null]}
+error: 'TemplateError: $sorted values to be sorted must have the same type'
+---
+title:    cannot sort nulls, even with by
+context:  {}
+template: {$sort: [null, null], 'by(x)': 'x'}
+error: 'TemplateError: $sorted values to be sorted must have the same type'
+---
+title:    cannot sort booleans
+context:  {}
+template: {$sort: [false, true]}
+error: 'TemplateError: $sorted values to be sorted must have the same type'
+---
+title:    cannot sort booleans, even with by
+context:  {}
+template: {$sort: [false, true], 'by(x)': 'x'}
+error: 'TemplateError: $sorted values to be sorted must have the same type'
+---
+title:    cannot sort numbers and strings together
+context:  {}
+template: {$sort: [1, 'a']}
+error: 'TemplateError: $sorted values to be sorted must have the same type'
+---
+title:    cannot sort numbers and strings together even with by
+context:  {}
+template: {$sort: [1, 'a'], 'by(x)': 'x'}
+error: 'TemplateError: $sorted values to be sorted must have the same type'
+---
+title:    sort requires an array (string)
+context:  {}
+template:
+  $sort:  "some string"
+error: 'TemplateError: $sorted values to be sorted must have the same type'
+---
+title:    sort requires an array (number)
+context:  {}
+template:
+  $sort:  34
+error: 'TemplateError: $sorted values to be sorted must have the same type'
+---
+title:    sort requires an array (object)
+context:  {}
+template:
+  $sort:  {k: 1, b: 4, x: 8}
+error: 'TemplateError: $sorted values to be sorted must have the same type'
+---
+title:    sort requires an array (null)
+context:  {}
+template:
+  $sort:  null
+error: 'TemplateError: $sorted values to be sorted must have the same type'
+---
+title:    sort with undefined properties
+context:  {}
+template:
+  $sort: [{s: 'android'}, {s: 'add'}, {s: 'adderall'}]
+  by(x): 'x.s'
+  foo:   'bar'
+error: 'TemplateError: $sort has undefined properties: foo'
+
+################################################################################
+---
+section:  $reverse
+---
+title:    simple reverse
+context:  {}
+template: {$reverse: [3, 4, 1, 2]}
+result:   [2, 1, 4, 3]
+---
+title:    value is rendered
+context:  {}
+template: {$reverse: {$eval: '[99, 999, 9]'}}
+result:   [9, 999, 99]
+---
+title:    reverse of an object
+context:  {}
+template: {$reverse: {a: 1}}
+error: 'TemplateError: $reverse value must evaluate to an array of objects'
+---
+title:    reverse of null
+context:  {}
+template: {$reverse: null}
+error: 'TemplateError: $reverse value must evaluate to an array of objects'
+---
+title:    reverse of a string
+context:  {}
+template: {$reverse: 'foo'}
+error: 'TemplateError: $reverse value must evaluate to an array of objects'
+---
+title:    reverse of a number
+context:  {}
+template: {$reverse: 1}
+error: 'TemplateError: $reverse value must evaluate to an array of objects'
+---
+title:    reverse of a boolean
+context:  {}
+template: {$reverse: true}
+error: 'TemplateError: $reverse value must evaluate to an array of objects'
+---
+title:    simple reverse with $eval
+context:  {key: [3, 4, 1, 2]}
+template: {$reverse: {$eval: 'key'}}
+result:   [2, 1, 4, 3]
+---
+title:    simple reverse + $sort # with this we can sort in reverse order
+context:  {}
+template: {$reverse: {$sort: [3, 4, 1, 2]}}
+result:   [4, 3, 2, 1]
+---
+title: reverse with undefined properties
+template: {$reverse: [3, 4, 1, 2], foo: "bar", bing: "baz"}
+context: {}
+error: 'TemplateError: $reverse has undefined properties: bing foo'
+################################################################################
+---
+section: $eval
+---
+title: $eval of $eval
+context: {}
+template: {$eval: {$eval: '"13"'}}
+error: 'TemplateError: $eval must be given a string expression'
+---
+title: $eval with undefined properties
+context: {}
+template: {$eval: '13', wrong: 'a + b'}
+error: 'TemplateError: $eval has undefined properties: wrong'
+---
+title: $eval of an array
+context: {key1: 1, key2: 2}
+template: {$eval: ['key1', 'key2']}
+error: 'TemplateError: $eval must be given a string expression'
+---
+title: $eval of an object
+context: {key1: 1, key2: 2}
+template: {$eval: {k: 'key1'}}
+error: 'TemplateError: $eval must be given a string expression'
+---
+title: $eval of null
+context: {}
+template: {$eval: null}
+error: 'TemplateError: $eval must be given a string expression'
+---
+title: $eval of a number
+context: {}
+template: {$eval: 11}
+error: 'TemplateError: $eval must be given a string expression'
+---
+title: $eval of a boolean
+context: {}
+template: {$eval: true}
+error: 'TemplateError: $eval must be given a string expression'
+################################################################################
+---
+section: builtins
+---
+title: min (1)
+context: {key1: 1, key2: 2}
+template: {$eval: 'min(key1, key2)'}
+result: 1
+---
+title: min (2)
+context: {key1: 1, key2: 2}
+template: {$eval: 'min(1, key2)'}
+result: 1
+---
+title: min (3)
+context: {key1: 1, key2: 2}
+template: {$eval: 'min(key1, 2)'}
+result: 1
+---
+title: min (4)
+context: {key1: 1, key2: 2}
+template: {$eval: 'min(1, 2)'}
+result: 1
+---
+title: min (5)
+context: {key1: 1, key2: 2}
+template: {$eval: 'min(2, 1)'}
+result: 1
+---
+title: min (6)
+context: {key1: 1, key2: 2}
+template: {$eval: 'min(2, 1, 3, 4, 5)'}
+result: 1
+---
+title: min - TypeError
+context: {}
+template: {$eval: 'min("11")'}
+error: 'BuiltinError: invalid arguments to builtin: min'
+---
+title: min (7)
+context: {}
+template: {$eval: 'min()'}
+error: 'BuiltinError: invalid arguments to builtin: min: expected at least 1 arguments'
+---
+title: max (1)
+context: {key1: 1, key2: 2}
+template: {$eval: 'max(key1, key2)'}
+result: 2
+---
+title: max (2)
+context: {key1: 1, key2: 2}
+template: {$eval: 'max(1, key2)'}
+result: 2
+---
+title: max (3)
+context: {key1: 1, key2: 2}
+template: {$eval: 'max(key1, 2)'}
+result: 2
+---
+title: max (4)
+context: {key1: 1, key2: 2}
+template: {$eval: 'max(1, 2)'}
+result: 2
+---
+title: max (5)
+context: {key1: 1, key2: 2}
+template: {$eval: 'max(2, 1)'}
+result: 2
+---
+title: max (6)
+context: {key1: 1, key2: 2}
+template: {$eval: 'max(2, 1, 3, 4, 5)'}
+result: 5
+---
+title: max - TypeError
+context: {}
+template: {$eval: 'max("12")'}
+error: 'BuiltinError: invalid arguments to builtin: max'
+---
+title: max (7)
+context: {}
+template: {$eval: 'max()'}
+error: 'BuiltinError: invalid arguments to builtin: max: expected at least 1 arguments'
+---
+title: sqrt (1)
+context: {key: 4}
+template: {$eval: 'sqrt(key)'}
+result: 2
+---
+title: sqrt (2)
+context: {}
+template: {$eval: 'sqrt(9)'}
+result: 3
+---
+title: sqrt - TypeError
+context: {}
+template: {$eval: 'sqrt("nine")'}
+error: 'BuiltinError: invalid arguments to builtin: sqrt'
+---
+title: ceil (1)
+context: {key: 1.1}
+template: {$eval: 'ceil(key)'}
+result: 2
+---
+title: ceil (2)
+context: {}
+template: {$eval: 'ceil(2.003)'}
+result: 3
+---
+title: ceil (3)
+context: {key: 1}
+template: {$eval: 'ceil(key)'}
+result: 1
+---
+title: ceil (4)
+context: {key: 1.0}
+template: {$eval: 'ceil(key)'}
+result: 1
+---
+title: ceil - TypeError
+context: {}
+template: {$eval: 'ceil(true)'}
+error: 'BuiltinError: invalid arguments to builtin: ceil'
+---
+title: floor (1)
+context: {key: 1.1}
+template: {$eval: 'floor(key)'}
+result: 1
+---
+title: floor (2)
+context: {}
+template: {$eval: 'floor(2.003)'}
+result: 2
+---
+title: floor (3)
+context: {key: 1}
+template: {$eval: 'floor(key)'}
+result: 1
+---
+title: floor (4)
+context: {key: 1.0}
+template: {$eval: 'floor(key)'}
+result: 1
+---
+title: floor - TypeError
+context: {key: null}
+template: {$eval: 'floor(key)'}
+error: 'BuiltinError: invalid arguments to builtin: floor'
+---
+title: abs (1)
+context: {key: -1.1}
+template: {$eval: 'abs(key)'}
+result: 1.1
+---
+title: abs (2)
+context: {}
+template: {$eval: 'abs(-1.1)'}
+result: 1.1
+---
+title: abs (3)
+context: {key: -1}
+template: {$eval: 'abs(key)'}
+result: 1
+---
+title: abs (4)
+context: {key: -1.0}
+template: {$eval: 'abs(key)'}
+result: 1
+---
+title: abs (5)
+context: {}
+template: {$eval: 'abs(-1)'}
+result: 1
+---
+title: abs (6)
+context: {}
+template: {$eval: 'abs(-1.0)'}
+result: 1
+---
+title: abs (7)
+context: {key: 1.1}
+template: {$eval: 'abs(key)'}
+result: 1.1
+---
+title: abs (8)
+context: {}
+template: {$eval: 'abs(1.1)'}
+result: 1.1
+---
+title: abs (9)
+context: {key: 1}
+template: {$eval: 'abs(key)'}
+result: 1
+---
+title: abs (10)
+context: {key: 1.0}
+template: {$eval: 'abs(key)'}
+result: 1
+---
+title: abs (11)
+context: {}
+template: {$eval: 'abs(1)'}
+result: 1
+---
+title: abs (12)
+context: {}
+template: {$eval: 'abs(1.0)'}
+result: 1
+---
+title: abs - TypeError
+context: {}
+template: {$eval: 'abs({})'}
+error: 'BuiltinError: invalid arguments to builtin: abs'
+---
+title: lowercase (1)
+context: {key: 'HEllo'}
+template: {$eval: 'lowercase(key)'}
+result: 'hello'
+---
+title: lowercase (2)
+context: {}
+template: {$eval: 'lowercase("HEllo")'}
+result: 'hello'
+---
+title: TypeError lowercase (1)
+context: {key: {}}
+template: {$eval: 'lowercase(key)'}
+error: 'BuiltinError: invalid arguments to builtin: lowercase'
+---
+title: TypeError lowercase (2)
+context: {}
+template: {$eval: 'lowercase({})'}
+error: 'BuiltinError: invalid arguments to builtin: lowercase'
+---
+title: TypeError lowercase (3)
+context: {key: []}
+template: {$eval: 'lowercase(key)'}
+error: 'BuiltinError: invalid arguments to builtin: lowercase'
+---
+title: TypeError lowercase (4)
+context: {}
+template: {$eval: 'lowercase([])'}
+error: 'BuiltinError: invalid arguments to builtin: lowercase'
+---
+title: TypeError lowercase (5)
+context: {key: 1}
+template: {$eval: 'lowercase(key)'}
+error: 'BuiltinError: invalid arguments to builtin: lowercase'
+---
+title: TypeError lowercase (6)
+context: {}
+template: {$eval: 'lowercase(1)'}
+error: 'BuiltinError: invalid arguments to builtin: lowercase'
+---
+title: uppercase (1)
+context: {key: 'HEllo'}
+template: {$eval: 'uppercase(key)'}
+result: 'HELLO'
+---
+title: uppercase (2)
+context: {}
+template: {$eval: 'uppercase("HEllo")'}
+result: 'HELLO'
+---
+title: TypeError uppercase (1)
+context: {key: {}}
+template: {$eval: 'uppercase(key)'}
+error: 'BuiltinError: invalid arguments to builtin: uppercase'
+---
+title: TypeError uppercase (2)
+context: {}
+template: {$eval: 'uppercase({})'}
+error: 'BuiltinError: invalid arguments to builtin: uppercase'
+---
+title: TypeError uppercase (3)
+context: {key: []}
+template: {$eval: 'uppercase(key)'}
+error: 'BuiltinError: invalid arguments to builtin: uppercase'
+---
+title: TypeError uppercase (4)
+context: {}
+template: {$eval: 'uppercase([])'}
+error: 'BuiltinError: invalid arguments to builtin: uppercase'
+---
+title: TypeError uppercase (5)
+context: {key: 1}
+template: {$eval: 'uppercase(key)'}
+error: 'BuiltinError: invalid arguments to builtin: uppercase'
+---
+title: TypeError uppercase (6)
+context: {}
+template: {$eval: 'uppercase(1)'}
+error: 'BuiltinError: invalid arguments to builtin: uppercase'
+---
+title: len (1)
+context: {key: [1,2,3]}
+template: {$eval: 'len(key)'}
+result: 3
+---
+title: len (2)
+context: {key: [1,2,3]}
+template: {$eval: 'len([1, 2, 3])'}
+result: 3
+---
+title: len (3)
+context: {key: 'abc'}
+template: {$eval: 'len(key)'}
+result: 3
+---
+title: len of grinning face unicode character
+context: {key: "\U0001F601"}
+template: {$eval: 'len(key)'}
+result: 1
+---
+title: len (4)
+context: {key: [1,2,3]}
+template: {$eval: 'len("abc")'}
+result: 3
+---
+title: TypeError len (1)
+context: {key: {}}
+template: {$eval: 'len(key)'}
+error: 'BuiltinError: invalid arguments to builtin: len'
+---
+title: TypeError len (2)
+context: {}
+template: {$eval: 'len({})'}
+error: 'BuiltinError: invalid arguments to builtin: len'
+---
+title: TypeError len (3)
+context: {key: 1}
+template: {$eval: 'len(key)'}
+error: 'BuiltinError: invalid arguments to builtin: len'
+---
+title: TypeError len (4)
+context: {}
+template: {$eval: 'len(1)'}
+error: 'BuiltinError: invalid arguments to builtin: len'
+---
+title: str (1)
+context: {key: 1}
+template: {$eval: 'str(key)'}
+result: '1'
+---
+title: str (2)
+context: {}
+template: {$eval: 'str(1)'}
+result: '1'
+---
+title: str (3)
+context: {key: 'hello'}
+template: {$eval: 'str(key)'}
+result: 'hello'
+---
+title: str (4)
+context: {}
+template: {$eval: 'str("hello")'}
+result: 'hello'
+---
+title: str (3)
+context: {key: 'hello'}
+template: {$eval: 'str(key)'}
+result: 'hello'
+---
+title: str (4)
+context: {}
+template: {$eval: 'str("hello")'}
+result: 'hello'
+---
+title: str (5)
+context: {key: true}
+template: {$eval: 'str(key)'}
+result: 'true'
+---
+title: str (6)
+context: {}
+template: {$eval: 'str(true)'}
+result: 'true'
+---
+title: str (key) with null
+context: {x: null}
+template: {$eval: 'str(x)'}
+result: 'null'
+---
+title: str (7)
+context: {key: false}
+template: {$eval: 'str(key)'}
+result: 'false'
+---
+title: str (8)
+context: {}
+template: {$eval: 'str(false)'}
+result: 'false'
+---
+title: str (9)
+context: {val: 24}
+template: {$eval: 'str(val)'}
+result: '24'
+---
+title: str (unicode)
+context: {val: "let's make a ☃"}
+template: {$eval: 'str(val)'}
+result: "let's make a ☃"
+---
+title: str({})
+context: {}
+template: {$eval: 'str({})'}
+error: 'BuiltinError: invalid arguments to builtin: str'
+---
+title: str({a:10})
+context: {}
+template: {$eval: 'str({a:10})'}
+error: 'BuiltinError: invalid arguments to builtin: str'
+---
+title: str([1, 2, 3])
+context: {}
+template: {$eval: 'str([1, 2, 3])'}
+error: 'BuiltinError: invalid arguments to builtin: str'
+---
+title: str(key) with array
+context: {key: [1, 2, 3]}
+template: {$eval: 'str(key)'}
+error: 'BuiltinError: invalid arguments to builtin: str'
+---
+title:    number
+context:  {round: "3"}
+template: {foo: {$eval: number(round)}}
+result:   {foo: 3}
+---
+title:    number (with point)
+context:  {round: "3.5"}
+template: {foo: {$eval: number(round)}}
+result:   {foo: 3.5}
+---
+title:    negative number
+context:  {round: "-14"}
+template: {foo: {$eval: number(round)}}
+result:   {foo: -14}
+---
+title:    negative number (with point)
+context:  {round: "-14.15"}
+template: {foo: {$eval: number(round)}}
+result:   {foo: -14.15}
+---
+title:    number zero
+context:  {round: "0"}
+template: {foo: {$eval: number(round)}}
+result:   {foo: 0}
+---
+title:    giving a number to number fails
+context:  {round: 0}
+template: {foo: {$eval: number(round)}}
+error: true
+---
+title:    giving a bool to number fails
+context:  {round: false}
+template: {foo: {$eval: number(round)}}
+error: true
+---
+title:    giving null to number fails
+context:  {round: null}
+template: {foo: {$eval: number(round)}}
+error: true
+---
+title:    giving an array to number fails
+context:  {round: [1]}
+template: {foo: {$eval: number(round)}}
+error: true
+---
+title:    giving an object to number fails
+context:  {round: {one: 1}}
+template: {foo: {$eval: number(round)}}
+error: true
+---
+title: strip space
+context: {}
+template: {$eval: "strip('  abc   ')"}
+result: 'abc'
+---
+title: strip mixed whitspace
+context: {}
+template: {$eval: "strip(' \f\n\r\t\vabc \f\n\r\t\v')"}
+result: 'abc'
+---
+title: rstrip space
+context: {}
+template: {$eval: "rstrip('  abc   ')"}
+result: '  abc'
+---
+title: rstrip mixed whitspace
+context: {}
+template: {$eval: "rstrip(' \f\n\r\t\vabc \f\n\r\t\v')"}
+result: " \f\n\r\t\vabc"
+---
+title: lstrip space
+context: {}
+template: {$eval: "lstrip('  abc   ')"}
+result: 'abc   '
+---
+title: lstrip mixed whitspace
+context: {}
+template: {$eval: "lstrip(' \f\n\r\t\vabc \f\n\r\t\v')"}
+result: "abc \f\n\r\t\v"
+---
+title: split string with delimiter
+context: {}
+template: {$eval: "split('left:right', ':')"}
+result: ['left', 'right']
+---
+title: split string without delimiter
+context: {}
+template: {$eval: "split('spellme', '')"}
+result: ['s', 'p', 'e', 'l', 'l', 'm', 'e']
+---
+title: split with empty string
+context: {}
+template: {$eval: "split('', ':')"}
+result: ['']
+---
+title: split string with no match
+context: {}
+template: {$eval: "split('no semicolon', ':')"}
+result: ['no semicolon']
+---
+title: split with number delimiter
+context: {}
+template: {$eval: "split('left1right', 1)"}
+result: ['left', 'right']
+---
+title: split error with object
+context: {}
+template: {$eval: "split({})"}
+error: 'BuiltinError: invalid arguments to builtin: split'
+---
+title: split error with array
+context: {}
+template: {$eval: "split([])"}
+error: 'BuiltinError: invalid arguments to builtin: split'
+---
+title: join with string separator
+context: {}
+template: {$eval: "join(['join', 'me'], ' ')"}
+result: "join me"
+---
+title: join with same
+context: {}
+template: {$eval: "join([',', ','], ',')"}
+result: ",,,"
+---
+title: join with number separator
+context: {}
+template: {$eval: "join([1, 3], 2)"}
+result: "123"
+---
+title: join with strings separated with number
+context: {}
+template: {$eval: "join(['one', 'three'], 2)"}
+result: "one2three"
+---
+title: join with numbers separated with string
+context: {}
+template: {$eval: "join([1, 3], 'two')"}
+result: "1two3"
+---
+title: join with string
+context: {}
+template: {$eval: "join('cannot join string')"}
+error: "BuiltinError: invalid arguments to builtin: join"
+---
+title: join with object
+context: {}
+template: {$eval: "join({})"}
+error: "BuiltinError: invalid arguments to builtin: join"
+---
+title: join with boolean
+context: {}
+template: {$eval: "join(false)"}
+error: "BuiltinError: invalid arguments to builtin: join"
+---
+title:    fromNow
+context:  {}
+template: {$eval: fromNow("")}
+result:   '2017-01-19T16:27:20.974Z'
+---
+title:    fromNow - 2 days 3 hours
+context:  {}
+template: {$eval: fromNow("2 days 3 hours")}
+result:   '2017-01-21T19:27:20.974Z'
+---
+title:    fromNow with reference
+context:  {}
+template: {$eval: "fromNow('1 day', '2017-01-01T01:00:00.123Z')"}
+result:   '2017-01-02T01:00:00.123Z'
+---
+title:    fromNow - TypeError
+context:  {}
+template: {$eval: fromNow(13)}
+error: 'BuiltinError: invalid arguments to builtin: fromNow'
+---
+title:    typeof str
+context:  {}
+template: {$eval: typeof('abc')}
+result: string
+---
+title:    typeof number (int)
+context:  {}
+template: {$eval: typeof(4)}
+result: number
+---
+title:    typeof number (float)
+context:  {}
+template: {$eval: typeof(4.0)}
+result: number
+---
+title:    typeof boolean (true)
+context:  {}
+template: {$eval: typeof(true)}
+result: boolean
+---
+title:    typeof boolean (false)
+context:  {}
+template: {$eval: typeof(false)}
+result: boolean
+---
+title:    typeof array (empty)
+context:  {}
+template: {$eval: 'typeof([])'}
+result: array
+---
+title:    typeof array
+context:  {}
+template: {$eval: 'typeof([1, 2, 3])'}
+result: array
+---
+title:    typeof object
+context:  {}
+template: {$eval: 'typeof({})'}
+result: object
+---
+title:    typeof null
+context:  {x: null}
+template: {$eval: 'typeof(x)'}
+result: 'null'
+---
+title:    typeof null, interpolated
+context:  {x: null}
+template: "${typeof(x)}"
+result: 'null'
+---
+title:    typeof null in if
+context:  {}
+template: {$if: 'typeof(null) == "null"', then: 'foo', else: 'bar'}
+result: foo
+---
+title:    typeof function
+context:  {}
+template: {$eval: 'typeof(typeof)'}
+result: function
+---
+title: override builtin (1), uppercase
+context: {uppercase: 1}
+template: {$eval: 'uppercase + 1'}
+result: 2
+---
+title: override builtin (2), min
+context: {min: 'hello world!'}
+template: {$eval: 'min'}
+result: 'hello world!'
+---
+title: 'defined without context variable'
+context: {}
+template: {$if: "defined('var')", then: 't', else: 'f'}
+result: f
+---
+title: 'defined with empty string as context variable'
+context: {var: ""}
+template: {$if: "defined('var')", then: 't', else: 'f'}
+result: t
+################################################################################
+---
+section:  expression language - basics
+---
+title:    missing right square bracket
+context:  {bar: "mystring"}
+template: {foo: '${bar[2:}'}
+error:   "SyntaxError at template.foo: Found: } token, expected one of: !, (, +, -, [, false, identifier, null, number, string, true, {"
+---
+title:    decimal literal
+context:  {}
+template: {$eval: '10.5'}
+result:   10.5
+---
+title:    hex literal
+context:  {}
+template: {$eval: '0xff'}
+error:    'SyntaxError: Found: xff token, expected one of: !=, &&, (, *, **, +, -, ., /, <, <=, ==, >, >=, [, in, ||'
+---
+title:    string literal with single quote
+context:  {}
+template: {$eval: "'three!'"}
+result: 'three!'
+---
+title:    string literal with double quote
+context:  {}
+template: {$eval: '"three!"'}
+result: 'three!'
+---
+title:    string literal escape with backslash (not supported)
+context:  {}
+template: {$eval: '"backslash\\"maybe"'}
+error:    'SyntaxError: Found: maybe token, expected one of: !=, &&, (, *, **, +, -, ., /, <, <=, ==, >, >=, [, in, ||'
+---
+title:    string literal escape with doubling (not supported)
+context:  {}
+template: {$eval: '"doubled""maybe"'}
+error:    'SyntaxError: Found: "maybe" token, expected one of: !=, &&, (, *, **, +, -, ., /, <, <=, ==, >, >=, [, in, ||'
+---
+title:    boolean literals
+context:  {}
+template: {$eval: '[true, false]'}
+result: [true, false]
+---
+title:    null literal
+context:  {}
+template: {$eval: '[null, null]'}
+result: [null, null]
+---
+title:    leading zeroes (not octal)
+context:  {}
+template: {$eval: '0777'}
+result: 777
+---
+title:    addition
+context:  {a: 1, b: 2}
+template: {$eval: 'a + b + 7'}
+result:   10
+---
+title:    multiplication
+context:  {a: 3, b: 2}
+template: {$eval: 'a * b * 3'}
+result:   18
+---
+title:    string concatenation
+context:  {a: 3, b: 2}
+template: {$eval: '"a" + "b"'}
+result:   'ab'
+---
+title:    $eval must take string
+context:  {a: 3, b: 2}
+template: {$eval: ['a', 'b']}
+error:    'TemplateError: $eval must be given a string expression'
+---
+title: array access [index]
+context: {a: [1,2,3,4]}
+template: {$eval: 'a[0]'}
+result: 1
+---
+title: array access [index]
+context: {a: [1,2,3,4]}
+template: {$eval: 'a[2]'}
+result: 3
+---
+title: array access [-index]
+context: {a: [1,2,3,4]}
+template: {$eval: 'a[-1]'}
+result: 4
+---
+title: array access [-index]
+context: {a: [1,2,3,4]}
+template: {$eval: 'a[-2]'}
+result: 3
+---
+title: array slicing [begin:end], [begin, end)
+context: {a: [1,2,3,4]}
+template: {$eval: 'a[0:2]'}
+result: [1,2]
+---
+title: array slicing [begin:], [begin, end)
+context: {a: [1,2,3,4]}
+template: {$eval: 'a[0:]'}
+result: [1,2,3,4]
+---
+title: array slicing [begin:], [begin, end)
+context: {a: [1,2,3,4]}
+template: {$eval: 'a[1:]'}
+result: [2,3,4]
+---
+title: array slicing [-begin:], [begin, end)
+context: {a: [1,2,3,4]}
+template: {$eval: 'a[-3:]'}
+result: [2,3,4]
+---
+title: array slicing [-begin:-end], [begin, end)
+context: {a: [1,2,3,4]}
+template: {$eval: 'a[-3:-1]'}
+result: [2,3]
+---
+title: array slicing [:end], [begin, end)
+context: {a: [1,2,3,4]}
+template: {$eval: 'a[:3]'}
+result: [1,2,3]
+---
+title: array slicing [:-end], [begin, end)
+context: {a: [1,2,3,4]}
+template: {$eval: 'a[:-2]'}
+result: [1,2]
+---
+title: array slice partially out of range
+context: {a: [1,2,3,4]}
+template: {$eval: 'a[2:10]'}
+result: [3,4]
+---
+title: array slice completely out of range
+context: {a: [1,2,3,4]}
+template: {$eval: 'a[8:10]'}
+result: []
+---
+title: array slice negative out of range
+context: {a: [1,2,3,4]}
+template: {$eval: 'a[2:-10]'}
+result: []
+---
+title: array slice negative range
+context: {a: [1,2,3,4]}
+template: {$eval: 'a[2:-3]'}
+result: []
+---
+title: array slice reverse range
+context: {a: [1,2,3,4]}
+template: {$eval: 'a[3:2]'}
+result: []
+---
+title: function min(contextValue, contextValue)
+context: {a: 1, b: 2}
+template: {$eval: 'min(a, b)'}
+result: 1
+---
+title: function max(contextValue, contextValue)
+context: {a: 1, b: 2}
+template: {$eval: 'max(a, b)'}
+result: 2
+---
+title: function min(contextValue, value)
+context: {a: 1, b: 2}
+template: {$eval: 'min(a, -1)'}
+result: -1
+---
+title: function max(contextValue, value)
+context: {a: 1, b: 2}
+template: {$eval: 'max(a, 3)'}
+result: 3
+---
+title: identifier beginning with in
+context: {input: 6}
+template: {$eval: 'input + 1'}
+result: 7
+---
+title: identifier beginning with true / false
+context: {true_facts: true, false_lies: false}
+template: {$eval: 'true_facts || false_lies'}
+result: true
+---
+title: identifier beginning with null
+context: {null_hypothesis: "no difference"}
+template: {$eval: 'null_hypothesis'}
+result: "no difference"
+################################################################################
+---
+section: expression language - arithmetic
+---
+title: 'addition'
+context: {a: 1, b: 2}
+template: {$eval: 'a + b + 7'}
+result: 10
+---
+title: 'multiplication'
+context: {a: 3, b: 2}
+template: {$eval: 'a * b * 3'}
+result: 18
+---
+title: 'division (1)'
+context: {a: 3, b: 2}
+template: {$eval: 'a / b'}
+result: 1.5
+---
+title: 'division (2)'
+context: {a: 3.0, b: 2.0}
+template: {$eval: 'a / b'}
+result: 1.5
+---
+title: 'division (3)'
+context: {a: 3, b: 2}
+template: {$eval: 'b / a'}
+result: 0.6666666666666666
+---
+title: 'division (4)'
+context: {a: 3.0, b: 2.0}
+template: {$eval: 'b / a'}
+result: 0.6666666666666666
+---
+title: 'exponentiation (1)'
+context: {a: 2, b: 3}
+template: {$eval: 'a ** b'}
+result: 8
+---
+title: 'exponentiation (2)'
+context: {a: 2, b: 3}
+template: {$eval: 'a ** b + 2'}
+result: 10
+---
+title: 'exponentiation (3)'
+context: {a: 2, b: 3}
+template: {$eval: 'a ** b * 2'}
+result: 16
+---
+title: 'exponentiation (4)'
+context: {a: 2, b: 3}
+template: {$eval: 'a * a ** b'}
+result: 16
+---
+title: 'exponentiation, right associativity (1)'
+context: {a: 2, b: 3}
+template: {$eval: 'a ** a ** b == a ** (a ** b)'}
+result: true
+---
+title: 'exponentiation, right associativity (2)'
+context: {a: 2, b: 3}
+template: {$eval: 'a ** a ** b'}
+result: 256
+---
+title: 'exponentiation, right associativity (3)'
+context: {a: 2, b: 3}
+template: {$eval: '2 ** 2 ** 3 == 2 ** (2 ** 3)'}
+result: true
+---
+title: 'exponentiation, right associativity (4)'
+context: {a: 2, b: 3}
+template: {$eval: '2 ** 2 ** 3'}
+result: 256
+---
+title: 'unary negation'
+context: {a: 2}
+template: {$eval: '-a'}
+result: -2
+---
+title: 'unary plus'
+context: {a: 2}
+template: {$eval: '+a'}
+result: 2
+################################################################################
+---
+section: expression language - operator type errors
+---
+title: 'addition of strings to numbers'
+context: {a: 'a', b: 1}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of strings to null'
+context: {a: 'a', b: null}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of strings to booleans'
+context: {a: 'a', b: true}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of strings to objects'
+context: {a: 'a', b: {x: 1}}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of strings to arrays'
+context: {a: 'a', b: [1, 2]}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'subtraction of strings from strings'
+context: {a: 'a', b: 'b'}
+template: {$eval: 'a-b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of strings from numbers'
+context: {a: 'a', b: 1}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of strings from null'
+context: {a: 'a', b: null}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of strings from booleans'
+context: {a: 'a', b: true}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of strings from objects'
+context: {a: 'a', b: {x: 1}}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of strings from arrays'
+context: {a: 'a', b: [1, 2]}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'multiplication of strings to strings'
+context: {a: 'a', b: 'b'}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of strings to numbers'
+context: {a: 'a', b: 1}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of strings to null'
+context: {a: 'a', b: null}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of strings to booleans'
+context: {a: 'a', b: true}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of strings to objects'
+context: {a: 'a', b: {x: 1}}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of strings to arrays'
+context: {a: 'a', b: [1, 2]}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'division of strings by strings'
+context: {a: 'a', b: 'b'}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of strings by numbers'
+context: {a: 'a', b: 1}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of strings by null'
+context: {a: 'a', b: null}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of strings by booleans'
+context: {a: 'a', b: true}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of strings by objects'
+context: {a: 'a', b: {x: 1}}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of strings by arrays'
+context: {a: 'a', b: [1, 2]}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'exponentiation of strings by strings'
+context: {a: 'a', b: 'b'}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of strings by numbers'
+context: {a: 'a', b: 1}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of strings by null'
+context: {a: 'a', b: null}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of strings by booleans'
+context: {a: 'a', b: true}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of strings by objects'
+context: {a: 'a', b: {x: 1}}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of strings by arrays'
+context: {a: 'a', b: [1, 2]}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'unary negation of string'
+context: {a: 'a'}
+template: {$eval: '-a'}
+error: 'InterpreterError: unary - expects number'
+---
+title: 'unary plus of string'
+context: {a: 'a'}
+template: {$eval: '+a'}
+error: 'InterpreterError: unary + expects number'
+---
+title:    'unary negation of true'
+template: {$eval: '-true'}
+context:  {}
+error:    'InterpreterError: unary - expects number'
+---
+title:    'unary plus of true'
+template: {$eval: '+true'}
+context:  {}
+error:    'InterpreterError: unary + expects number'
+---
+title:    'unary negation of false'
+template: {$eval: '-false'}
+context:  {}
+error:    'InterpreterError: unary - expects number'
+---
+title:    'unary plus of false'
+template: {$eval: '+false'}
+context:  {}
+error:    'InterpreterError: unary + expects number'
+---
+title:    'unary negation of null'
+template: {$eval: '-null'}
+context:  {}
+error:    'InterpreterError: unary - expects number'
+---
+title:    'unary plus of null'
+template: {$eval: '+null'}
+context:  {}
+error:    'InterpreterError: unary + expects number'
+---
+title: 'addition of numbers to strings'
+context: {a: 13, b: 'b'}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of numbers to null'
+context: {a: 13, b: null}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of numbers to booleans'
+context: {a: 13, b: true}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of numbers to objects'
+context: {a: 13, b: {x: 1}}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of numbers to arrays'
+context: {a: 13, b: [1, 2]}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'subtraction of numbers from strings'
+context: {a: 13, b: 'b'}
+template: {$eval: 'a-b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of numbers from null'
+context: {a: 13, b: null}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of numbers from booleans'
+context: {a: 13, b: true}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of numbers from objects'
+context: {a: 13, b: {x: 1}}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of numbers from arrays'
+context: {a: 13, b: [1, 2]}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'multiplication of numbers to strings'
+context: {a: 13, b: 'b'}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of numbers to null'
+context: {a: 13, b: null}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of numbers to booleans'
+context: {a: 13, b: true}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of numbers to objects'
+context: {a: 13, b: {x: 1}}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of numbers to arrays'
+context: {a: 13, b: [1, 2]}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'division of numbers by strings'
+context: {a: 13, b: 'b'}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of numbers by null'
+context: {a: 13, b: null}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of numbers by booleans'
+context: {a: 13, b: true}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of numbers by objects'
+context: {a: 13, b: {x: 1}}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of numbers by arrays'
+context: {a: 13, b: [1, 2]}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'exponentiation of numbers by strings'
+context: {a: 13, b: 'b'}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of numbers by null'
+context: {a: 13, b: null}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of numbers by booleans'
+context: {a: 13, b: true}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of numbers by objects'
+context: {a: 13, b: {x: 1}}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of numbers by arrays'
+context: {a: 13, b: [1, 2]}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'addition of null to strings'
+context: {a: null, b: 'a'}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of null to numbers'
+context: {a: null, b: 1}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of null to null'
+context: {a: null, b: null}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of null to booleans'
+context: {a: null, b: true}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of null to objects'
+context: {a: null, b: {x: 1}}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of null to arrays'
+context: {a: null, b: [1, 2]}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'subtraction of null from strings'
+context: {a: null, b: 'b'}
+template: {$eval: 'a-b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of null from numbers'
+context: {a: null, b: 1}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of null from null'
+context: {a: null, b: null}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of null from booleans'
+context: {a: null, b: true}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of null from objects'
+context: {a: null, b: {x: 1}}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of null from arrays'
+context: {a: null, b: [1, 2]}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'multiplication of null to strings'
+context: {a: null, b: 'b'}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of null to numbers'
+context: {a: null, b: 1}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of null to null'
+context: {a: null, b: null}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of null to booleans'
+context: {a: null, b: true}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of null to objects'
+context: {a: null, b: {x: 1}}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of null to arrays'
+context: {a: null, b: [1, 2]}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'division of null by strings'
+context: {a: null, b: 'b'}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of null by numbers'
+context: {a: null, b: 1}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of null by null'
+context: {a: null, b: null}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of null by booleans'
+context: {a: null, b: true}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of null by objects'
+context: {a: null, b: {x: 1}}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of null by arrays'
+context: {a: null, b: [1, 2]}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'exponentiation of null by strings'
+context: {a: null, b: 'b'}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of null by numbers'
+context: {a: null, b: 1}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of null by null'
+context: {a: null, b: null}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of null by booleans'
+context: {a: null, b: true}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of null by objects'
+context: {a: null, b: {x: 1}}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of null by arrays'
+context: {a: null, b: [1, 2]}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'unary negation of null'
+context: {a: null}
+template: {$eval: '-a'}
+error: 'InterpreterError: unary - expects number'
+---
+title: 'unary plus of null'
+context: {a: null}
+template: {$eval: '+a'}
+error: 'InterpreterError: unary + expects number'
+---
+title: 'addition of boolean to strings'
+context: {a: true, b: 'a'}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of boolean to numbers'
+context: {a: true, b: 1}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of boolean to null'
+context: {a: true, b: null}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of boolean to booleans'
+context: {a: true, b: true}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of boolean to objects'
+context: {a: true, b: {x: 1}}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of boolean to arrays'
+context: {a: true, b: [1, 2]}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'subtraction of boolean from strings'
+context: {a: true, b: 'b'}
+template: {$eval: 'a-b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of boolean from numbers'
+context: {a: true, b: 1}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of boolean from null'
+context: {a: true, b: null}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of boolean from booleans'
+context: {a: true, b: true}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of boolean from objects'
+context: {a: true, b: {x: 1}}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of boolean from arrays'
+context: {a: true, b: [1, 2]}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'multiplication of boolean to strings'
+context: {a: true, b: 'b'}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of boolean to numbers'
+context: {a: true, b: 1}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of boolean to null'
+context: {a: true, b: null}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of boolean to booleans'
+context: {a: true, b: true}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of boolean to objects'
+context: {a: true, b: {x: 1}}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of boolean to arrays'
+context: {a: true, b: [1, 2]}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'division of boolean by strings'
+context: {a: true, b: 'b'}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of boolean by numbers'
+context: {a: true, b: 1}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of boolean by null'
+context: {a: true, b: null}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of boolean by booleans'
+context: {a: true, b: true}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of boolean by objects'
+context: {a: true, b: {x: 1}}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of boolean by arrays'
+context: {a: true, b: [1, 2]}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'exponentiation of boolean by strings'
+context: {a: true, b: 'b'}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of boolean by numbers'
+context: {a: true, b: 1}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of boolean by null'
+context: {a: true, b: null}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of boolean by booleans'
+context: {a: true, b: true}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of boolean by objects'
+context: {a: true, b: {x: 1}}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of boolean by arrays'
+context: {a: true, b: [1, 2]}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'unary negation of boolean'
+context: {a: true}
+template: {$eval: '-a'}
+error: 'InterpreterError: unary - expects number'
+---
+title: 'unary plus of boolean'
+context: {a: true}
+template: {$eval: '+a'}
+error: 'InterpreterError: unary + expects number'
+---
+title: 'addition of object to strings'
+context: {a: {x: 10}, b: 'a'}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of object to numbers'
+context: {a: {x: 10}, b: 1}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of object to null'
+context: {a: {x: 10}, b: null}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of object to booleans'
+context: {a: {x: 10}, b: true}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of object to objects'
+context: {a: {x: 10}, b: {x: 1}}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of object to arrays'
+context: {a: {x: 10}, b: [1, 2]}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'subtraction of object from strings'
+context: {a: {x: 10}, b: 'b'}
+template: {$eval: 'a-b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of object from numbers'
+context: {a: {x: 10}, b: 1}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of object from null'
+context: {a: {x: 10}, b: null}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of object from booleans'
+context: {a: {x: 10}, b: true}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of object from objects'
+context: {a: {x: 10}, b: {x: 1}}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of object from arrays'
+context: {a: {x: 10}, b: [1, 2]}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'multiplication of object to strings'
+context: {a: {x: 10}, b: 'b'}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of object to numbers'
+context: {a: {x: 10}, b: 1}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of object to null'
+context: {a: {x: 10}, b: null}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of object to booleans'
+context: {a: {x: 10}, b: true}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of object to objects'
+context: {a: {x: 10}, b: {x: 1}}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of object to arrays'
+context: {a: {x: 10}, b: [1, 2]}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'division of object by strings'
+context: {a: {x: 10}, b: 'b'}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of object by numbers'
+context: {a: {x: 10}, b: 1}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of object by null'
+context: {a: {x: 10}, b: null}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of object by booleans'
+context: {a: {x: 10}, b: true}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of object by objects'
+context: {a: {x: 10}, b: {x: 1}}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of object by arrays'
+context: {a: {x: 10}, b: [1, 2]}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'exponentiation of object by strings'
+context: {a: {x: 10}, b: 'b'}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of object by numbers'
+context: {a: {x: 10}, b: 1}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of object by null'
+context: {a: {x: 10}, b: null}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of object by booleans'
+context: {a: {x: 10}, b: true}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of object by objects'
+context: {a: {x: 10}, b: {x: 1}}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of object by arrays'
+context: {a: {x: 10}, b: [1, 2]}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'unary negation of object'
+context: {a: {x: 10}}
+template: {$eval: '-a'}
+error: 'InterpreterError: unary - expects number'
+---
+title: 'unary plus of object'
+context: {a: {x: 10}}
+template: {$eval: '+a'}
+error: 'InterpreterError: unary + expects number'
+---
+title: 'addition of array to strings'
+context: {a: [1, 2], b: 'a'}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of array to numbers'
+context: {a: [1, 2], b: 1}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of array to null'
+context: {a: [1, 2], b: null}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of array to booleans'
+context: {a: [1, 2], b: true}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of array to objects'
+context: {a: [1, 2], b: {x: 1}}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'addition of array to arrays'
+context: {a: [1, 2], b: [1, 2]}
+template: {$eval: 'a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'subtraction of array from strings'
+context: {a: [1, 2], b: 'b'}
+template: {$eval: 'a-b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of array from numbers'
+context: {a: [1, 2], b: 1}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of array from null'
+context: {a: [1, 2], b: null}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of array from booleans'
+context: {a: [1, 2], b: true}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of array from objects'
+context: {a: [1, 2], b: {x: 1}}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'subtraction of array from arrays'
+context: {a: [1, 2], b: [1, 2]}
+template: {$eval: 'a - b'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'multiplication of array to strings'
+context: {a: [1, 2], b: 'b'}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of array to numbers'
+context: {a: [1, 2], b: 1}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of array to null'
+context: {a: [1, 2], b: null}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of array to booleans'
+context: {a: [1, 2], b: true}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of array to objects'
+context: {a: [1, 2], b: {x: 1}}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'multiplication of array to arrays'
+context: {a: [1, 2], b: [1, 2]}
+template: {$eval: 'a * b'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'division of array by strings'
+context: {a: [1, 2], b: 'b'}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of array by numbers'
+context: {a: [1, 2], b: 1}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of array by null'
+context: {a: [1, 2], b: null}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of array by booleans'
+context: {a: [1, 2], b: true}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of array by objects'
+context: {a: [1, 2], b: {x: 1}}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'division of array by arrays'
+context: {a: [1, 2], b: [1, 2]}
+template: {$eval: 'a / b'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'exponentiation of array by strings'
+context: {a: [1, 2], b: 'b'}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of array by numbers'
+context: {a: [1, 2], b: 1}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of array by null'
+context: {a: [1, 2], b: null}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of array by booleans'
+context: {a: [1, 2], b: true}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of array by objects'
+context: {a: [1, 2], b: {x: 1}}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'exponentiation of array by arrays'
+context: {a: [1, 2], b: [1, 2]}
+template: {$eval: 'a ** b'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'unary negation of array'
+context: {a: [1, 2]}
+template: {$eval: '-a'}
+error: 'InterpreterError: unary - expects number'
+---
+title: 'unary plus of array'
+context: {a: [1, 2]}
+template: {$eval: '+a'}
+error: 'InterpreterError: unary + expects number'
+################################################################################
+---
+section: expression language - logic
+---
+title: 'logical not (1)'
+context: {tt: true, ff: false}
+template: {$eval: '!tt'}
+result: false
+---
+title: 'logical not (2)'
+context: {tt: true, ff: false}
+template: {$eval: '!ff'}
+result: true
+---
+title: 'or operator (1)'
+context: {tt: true, ff: false}
+template: {$eval: 'tt || tt'}
+result: true
+---
+title: 'or operator (2)'
+context: {tt: true, ff: false}
+template: {$eval: 'tt || ff'}
+result: true
+---
+title: 'or operator (3)'
+context: {tt: true, ff: false}
+template: {$eval: 'ff || tt'}
+result: true
+---
+title: 'or operator (4)'
+context: {tt: true, ff: false}
+template: {$eval: 'ff || ff'}
+result: false
+---
+title: 'and operator (1)'
+context: {tt: true, ff: false}
+template: {$eval: 'tt && tt'}
+result: true
+---
+title: 'and operator (2)'
+context: {tt: true, ff: false}
+template: {$eval: 'tt && ff'}
+result: false
+---
+title: 'and operator (3)'
+context: {tt: true, ff: false}
+template: {$eval: 'ff && tt'}
+result: false
+---
+title: 'and operator (4)'
+context: {tt: true, ff: false}
+template: {$eval: 'ff && ff'}
+result: false
+---
+title: 'and operator with not operator'
+context: {tt: true, ff: false}
+template: {$eval: 'tt && !ff'}
+result: true
+---
+title: 'or operator with not operator'
+context: {tt: true, ff: false}
+template: {$eval: 'ff || !ff'}
+result: true
+---
+title: 'complex logical operation (1)'
+context: {}
+template: {$eval: "4 < 6 && 2 == 1 + 1"}
+result: true
+---
+title: 'complex logical operation (2)'
+context: {}
+template: {$eval: "!(4 < 6) && 2 == 1 + 1"}
+result: false
+---
+title: 'complex logical operation (3)'
+context: {}
+template: {$eval: "2 == 1 + 1 && 4 < 6"}
+result: true
+---
+title: 'complex logical operation (4)'
+context: {}
+template: {$eval: "4 >= 6 || 2 == 1 + 1"}
+result: true
+---
+title: 'string not'
+context: {a: 'abc'}
+template: {$eval: "!a"}
+result: false
+---
+title: 'empty string not'
+context: {a: ''}
+template: {$eval: "!a"}
+result: true
+---
+title: 'number not'
+context: {a: 123}
+template: {$eval: "!a"}
+result: false
+---
+title: 'zero not'
+context: {a: 0}
+template: {$eval: "!a"}
+result: true
+---
+title: 'null not'
+context: {a: null}
+template: {$eval: "!a"}
+result: true
+---
+title: 'object not'
+context: {a: {x: 1}}
+template: {$eval: "!a"}
+result: false
+---
+title: 'empty object not'
+context: {a: {}}
+template: {$eval: "!a"}
+result: true
+---
+title: 'array not'
+context: {a: [1, 2]}
+template: {$eval: "!a"}
+result: false
+---
+title: 'empty array not'
+context: {a: []}
+template: {$eval: "!a"}
+result: true
+---
+title: 'function not'
+context: {}
+template: {$eval: "!min"}
+result: false
+---
+title: 'string and string'
+context: {a: 'abc', b: 'abc'}
+template: {$eval: "a && b"}
+result: true
+---
+title: 'string or string'
+context: {a: 'abc', b: 'abc'}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'string and number'
+context: {a: 'abc', b: 123}
+template: {$eval: "a && b"}
+result: true
+---
+title: 'string or number'
+context: {a: 'abc', b: 123}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'string and null'
+context: {a: 'abc', b: null}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'string or null'
+context: {a: 'abc', b: null}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'string and boolean'
+context: {a: 'abc', b: true}
+template: {$eval: "a && b"}
+result: true
+---
+title: 'string or boolean'
+context: {a: 'abc', b: true}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'string and object'
+context: {a: 'abc', b: {}}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'string or object'
+context: {a: 'abc', b: {}}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'string and array'
+context: {a: 'abc', b: []}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'string or array'
+context: {a: 'abc', b: []}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'number and string'
+context: {a: 345, b: 'abc'}
+template: {$eval: "a && b"}
+result: true
+---
+title: 'number or string'
+context: {a: 345, b: 'abc'}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'number and number'
+context: {a: 345, b: 123}
+template: {$eval: "a && b"}
+result: true
+---
+title: 'number or number'
+context: {a: 345, b: 123}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'number and null'
+context: {a: 345, b: null}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'number or null'
+context: {a: 345, b: null}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'number and boolean'
+context: {a: 345, b: true}
+template: {$eval: "a && b"}
+result: true
+---
+title: 'number or boolean'
+context: {a: 345, b: true}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'number and object'
+context: {a: 345, b: {}}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'number or object'
+context: {a: 345, b: {}}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'number and array'
+context: {a: 345, b: []}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'number or array'
+context: {a: 345, b: []}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'null and string'
+context: {a: null, b: 'abc'}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'null or string'
+context: {a: null, b: 'abc'}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'null and number'
+context: {a: null, b: 123}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'null or number'
+context: {a: null, b: 123}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'null and null'
+context: {a: null, b: null}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'null or null'
+context: {a: null, b: null}
+template: {$eval: "a || b"}
+result: false
+---
+title: 'null and boolean'
+context: {a: null, b: true}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'null or boolean'
+context: {a: null, b: true}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'null and object'
+context: {a: null, b: {}}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'null or object'
+context: {a: null, b: {}}
+template: {$eval: "a || b"}
+result: false
+---
+title: 'null and array'
+context: {a: null, b: []}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'null or array'
+context: {a: null, b: []}
+template: {$eval: "a || b"}
+result: false
+---
+title: 'boolean and string'
+context: {a: true, b: 'abc'}
+template: {$eval: "a && b"}
+result: true
+---
+title: 'boolean or string'
+context: {a: true, b: 'abc'}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'boolean and number'
+context: {a: true, b: 123}
+template: {$eval: "a && b"}
+result: true
+---
+title: 'boolean or number'
+context: {a: true, b: 123}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'boolean and null'
+context: {a: true, b: null}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'boolean or null'
+context: {a: true, b: null}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'boolean and boolean'
+context: {a: true, b: true}
+template: {$eval: "a && b"}
+result: true
+---
+title: 'boolean or boolean'
+context: {a: true, b: true}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'boolean and object'
+context: {a: true, b: {}}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'boolean or object'
+context: {a: true, b: {}}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'boolean and array'
+context: {a: true, b: []}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'boolean or array'
+context: {a: true, b: []}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'object and string'
+context: {a: {}, b: 'abc'}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'object or string'
+context: {a: {}, b: 'abc'}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'object and number'
+context: {a: {}, b: 123}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'object or number'
+context: {a: {}, b: 123}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'object and null'
+context: {a: {}, b: null}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'object or null'
+context: {a: {}, b: null}
+template: {$eval: "a || b"}
+result: false
+---
+title: 'object and boolean'
+context: {a: {}, b: true}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'object or boolean'
+context: {a: {}, b: true}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'object and object'
+context: {a: {}, b: {}}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'object or object'
+context: {a: {}, b: {}}
+template: {$eval: "a || b"}
+result: false
+---
+title: 'object and array'
+context: {a: {}, b: []}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'object or array'
+context: {a: {}, b: []}
+template: {$eval: "a || b"}
+result: false
+---
+title: 'array and string'
+context: {a: [], b: 'abc'}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'array or string'
+context: {a: [], b: 'abc'}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'array and number'
+context: {a: [], b: 123}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'array or number'
+context: {a: [], b: 123}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'array and null'
+context: {a: [], b: null}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'array or null'
+context: {a: [], b: null}
+template: {$eval: "a || b"}
+result: false
+---
+title: 'array and boolean'
+context: {a: [], b: true}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'array or boolean'
+context: {a: [], b: true}
+template: {$eval: "a || b"}
+result: true
+---
+title: 'array and object'
+context: {a: [], b: {}}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'array or object'
+context: {a: [], b: {}}
+template: {$eval: "a || b"}
+result: false
+---
+title: 'array and array'
+context: {a: [], b: []}
+template: {$eval: "a && b"}
+result: false
+---
+title: 'array or array'
+context: {a: [], b: []}
+template: {$eval: "a || b"}
+result: false
+---
+title: 'short-circuit evaluation for and'
+context: {}
+template: {$eval: "false && b"}
+result: false
+---
+title: 'short-circuit evaluation for or'
+context: {}
+template: {$eval: "true || b"}
+result: true
+################################################################################
+---
+section: expression language - string operations
+---
+title: 'string concatenation (1)'
+context: {a: 3, b: 2}
+template: {$eval: '"a" + "b"'}
+result: 'ab'
+---
+title: 'TypeError: string + number (1)'
+context: {a: 3, b: 2}
+template: {$eval: '"a" + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'TypeError: string + number (2)'
+context: {a: 3, b: 2}
+template: {$eval: '"" + a + b'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'TypeError: string + number (3)'
+context: {a: 3, b: 2}
+template: {$eval: '"" + (a + b)'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'TypeError: number + string (4)'
+context: {a: 3, b: 2}
+template: {$eval: '(a + b) + "abc"'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'string indexing (1)'
+context: {key: '12345'}
+template: {$eval: 'key[1]'}
+result: '2'
+---
+title: 'string indexing (2)'
+context: {key: '12345'}
+template: {$eval: 'key[-2]'}
+result: '4'
+---
+title: 'string indexing (3)'
+context: {}
+template: {$eval: '"12345"[1]'}
+result: '2'
+---
+title: 'string indexing (4)'
+context: {}
+template: {$eval: '"12345"[-2]'}
+result: '4'
+---
+title: 'string indexing (noninteger)'
+context: {}
+template: {$eval: '"12345"[2.5]'}
+error: 'InterpreterError: should only use integers to access arrays or strings'
+---
+title: 'string slicing (1)'
+context: {key: '12345'}
+template: {$eval: 'key[1:-1]'}
+result: '234'
+---
+title: 'string slicing (2)'
+context: {key: '12345'}
+template: {$eval: 'key[-2:]'}
+result: '45'
+---
+title: 'string slicing (noninteger first index)'
+context: {key: '12345'}
+template: {$eval: 'key[1.5:3]'}
+error: 'InterpreterError: cannot perform interval access with non-integers'
+---
+title: 'string slicing (noninteger second index)'
+context: {key: '12345'}
+template: {$eval: 'key[1:3.5]'}
+error: 'InterpreterError: cannot perform interval access with non-integers'
+---
+title: 'string slicing (noninteger indexes)'
+context: {key: '12345'}
+template: {$eval: 'key[1.5:3.5]'}
+error: 'InterpreterError: cannot perform interval access with non-integers'
+---
+title: 'string slicing type error (1)'
+context: {key: '12345'}
+template: {$eval: 'key["a":]'}
+error: 'InterpreterError: cannot perform interval access with non-integers'
+---
+title: 'string slicing type error (2)'
+context: {key: '12345'}
+template: {$eval: 'key[:"a"]'}
+error: 'InterpreterError: cannot perform interval access with non-integers'
+---
+title: 'string length attribute is an error'
+context: {key: '12345'}
+template: {$eval: 'key.length'}
+error: 'InterpreterError: infix: . expects objects'
+---
+title: 'string length attribute is an error even by index'
+context: {key: '12345'}
+template: {$eval: 'key["length"]'}
+error: 'InterpreterError: should only use integers to access arrays or strings'
+---
+title: 'other string attributes are not set'
+context: {key: 'abc'}
+template: {$eval: 'key.toUpperCase()'}
+error: 'InterpreterError: infix: . expects objects'
+---
+title: 'non-identifier after dot'
+context: {key: {}}
+template: {$eval: 'key.{'}
+error: 'SyntaxError: Found: { token, expected one of: identifier'
+################################################################################
+---
+section: expression language - property access
+---
+title: 'property with numeric value'
+context: {key: 1}
+template: {$eval: 'key'}
+result: 1
+---
+title: 'property with string value'
+context: {key: 'a'}
+template: {$eval: 'key'}
+result: 'a'
+---
+title: 'property with boolean value'
+context: {key: true}
+template: {$eval: 'key'}
+result: true
+---
+title: 'property with object value'
+context: {key: {a: 1}}
+template: {$eval: 'key'}
+result: {a: 1}
+---
+title: 'property with null value'
+context: {key: 'null'}
+template: {$eval: 'key'}
+result: 'null'
+---
+title: 'missing property'
+context: {key: {a: 1}}
+template: {$eval: 'key.b'}
+error: 'InterpreterError: object has no property "b"'
+---
+title: 'missing property by name'
+context: {key: {a: 1}}
+template: {$eval: 'key["b"]'}
+result: null
+---
+title: 'single property access with object value'
+context: {key: {key2: 3}}
+template: {$eval: 'key.key2'}
+result: 3
+---
+title: 'nested property access with object value'
+context: {key: {key2: {key3: {a: 1}}}}
+template: {$eval: 'key.key2.key3'}
+result: {a: 1}
+---
+title: 'nested property access with numeric value'
+context: {key: {key2: {key3: 1}}}
+template: {$eval: 'key["key2"]["key3"]'}
+result: 1
+---
+title: 'nested property access with dot following ]'
+context: {key: {key2: {key3: 1}}}
+template: {$eval: 'key["key2"].key3'}
+result: 1
+---
+title: 'nested property with object in parentheses'
+context: {key: {key2: true}}
+template: {$eval: '(key)["key2"]'}
+result: true
+---
+title: 'nested property with object expression'
+context: {keyid: 1, keys: [false, {key2: true}]}
+template: {$eval: '(keys[keyid])["key2"]'}
+result: true
+---
+title: 'property access with expression value'
+context: {key: abc, values: {abc: 2, def: 3}}
+template: {$eval: 'values[key]'}
+result: 2
+---
+title: 'property access with number'
+context:
+  obj: {'13': 15}
+  key: 13 # note that this is the number 13, yet the object key is a string as required by JSON
+template: {$eval: 'obj[key]'}
+error: 'InterpreterError: object keys must be strings'
+---
+title: 'property of number'
+context: {key: 123}
+template: {$eval: 'key.valueOf'}
+error: 'InterpreterError: infix: . expects objects'
+---
+title: 'property of null'
+context: {key: null}
+template: {$eval: 'key.foo'}
+error: 'InterpreterError: infix: . expects objects'
+---
+title: 'property of boolean'
+context: {key: null}
+template: {$eval: 'key.valueOf'}
+error: 'InterpreterError: infix: . expects objects'
+---
+title: 'property of array'
+context: {key: []}
+template: {$eval: 'key.valueOf'}
+error: 'InterpreterError: infix: . expects objects'
+---
+title: 'non-identifier after dot'
+context: {key: {}}
+template: {$eval: 'key.{'}
+error: 'SyntaxError: Found: { token, expected one of: identifier'
+################################################################################
+---
+section: expression language - array access
+---
+title: 'numeric'
+context: {key: [1,2,3,4,5]}
+template: {$eval: 'key[0]'}
+result: 1
+---
+title: 'numeric, nonzero index'
+context: {key: [1,2,3,4,5]}
+template: {$eval: 'key[2]'}
+result: 3
+---
+title: 'numeric, noninteger index'
+context: {key: [1,2,3,4,5]}
+template: {$eval: 'key[2.5]'}
+error: 'InterpreterError: should only use integers to access arrays or strings'
+---
+title: 'arithemtic with results'
+context: {key: [1,2,3,4,5]}
+template: {$eval: 'key[0] + key[1] + key[2] + key[3] + key[4]'}
+result: 15
+---
+title: 'string index'
+context: {key: [1,2,3,4,5]}
+template: {$eval: 'key["a"]'}
+error: 'InterpreterError: should only use integers to access arrays or strings'
+---
+title: 'too-large index'
+context: {key: [1,2,3,4,5]}
+template: {$eval: 'key[999]'}
+error: 'InterpreterError: index out of bounds'
+---
+title: 'negative index'
+context: {key: [1,2,3,4,5]}
+template: {$eval: 'key[-1]'}
+result: 5
+---
+title: 'nested, in property accesses'
+context: {key: {key2: {key3: [1,2,3,4,5]}}}
+template: {$eval: 'key.key2.key3[0]'}
+result: 1
+---
+title: 'nested, in property access by string'
+context: {key: {key2: {key3: [1,2,3,4,5]}}}
+template: {$eval: 'key["key2"]["key3"][0]'}
+result: 1
+---
+title: 'nested, nonzero index'
+context: {key: {key2: {key3: [1,2,3,4,5]}}}
+template: {$eval: 'key.key2.key3[2]'}
+result: 3
+---
+title: 'nested, nonzero index, in property access by string'
+context: {key: {key2: {key3: [1,2,3,4,5]}}}
+template: {$eval: 'key["key2"]["key3"][2]'}
+result: 3
+---
+title: 'nested, with arithmetic'
+context: {key: {key2: {key3: [1,2,3,4,5]}}}
+template: {$eval: 'key.key2.key3[0] + key.key2.key3[1] + key.key2.key3[2] + key.key2.key3[3] + key.key2.key3[4]'}
+result: 15
+---
+title: 'nested, with arithmetic, in property access by string'
+context: {key: {key2: {key3: [1,2,3,4,5]}}}
+template: {$eval: 'key["key2"]["key3"][0] + key["key2"]["key3"][1] + key["key2"]["key3"][2] + key["key2"]["key3"][3] + key["key2"]["key3"][4]'}
+result: 15
+---
+title: 'indexing number'
+context: {key: 123}
+template: {$eval: 'key[2]'}
+error: 'InterpreterError: infix: "[..]" expects object, array, or string'
+---
+title: 'indexing null'
+context: {key: null}
+template: {$eval: 'key[2]'}
+error: 'InterpreterError: infix: "[..]" expects object, array, or string'
+---
+title: 'indexing boolean'
+context: {key: true}
+template: {$eval: 'key[2]'}
+error: 'InterpreterError: infix: "[..]" expects object, array, or string'
+---
+title: 'indexing object'
+context: {key: {x: 10}}
+template: {$eval: 'key[2]'}
+error: 'InterpreterError: object keys must be strings'
+---
+title: 'array length property is an error'
+context: {key: [1, 3, 5]}
+template: {$eval: 'key.length'}
+error: 'InterpreterError: infix: . expects objects'
+---
+title: 'array length property is an error even by index'
+context: {key: [1, 3, 5]}
+template: {$eval: 'key["length"]'}
+error: 'InterpreterError: should only use integers to access arrays or strings'
+---
+title: 'other array attributes are not available'
+context: {key: [5, 3, 1]}
+template: {$eval: 'key.sort'}
+error: 'InterpreterError: infix: . expects objects'
+################################################################################
+---
+section: expression language - array slicing
+---
+title: 'array slicing (full slice)'
+context: {key: [1,2,3,4,5]}
+template: {$eval: 'key[0:5]'}
+result: [1,2,3,4,5]
+---
+title: 'array slicing (prefix)'
+context: {key: [1,2,3,4,5]}
+template: {$eval: 'key[0:3]'}
+result: [1,2,3]
+---
+title: 'array slicing (negative indices)'
+context: {key: [1,2,3,4,5]}
+template: {$eval: 'key[-5:-1]'}
+result: [1,2,3,4]
+---
+title: 'array slicing (noninteger first index)'
+context: {key: [1,2,3,4,5]}
+template: {$eval: 'key[2.5: 4]'}
+error: true
+---
+title: 'array slicing (noninteger last index)'
+context: {key: [1,2,3,4,5]}
+template: {$eval: 'key[2: 3.5]'}
+error: true
+---
+title: 'array slicing (noninteger indexes)'
+context: {key: [1,2,3,4,5]}
+template: {$eval: 'key[2.5: 3.5]'}
+error: true
+---
+title: 'array slicing (floor)'
+context: {key: [1,2,3,4,5]}
+template: {$eval: 'key[:floor(len(key)/2)]'}
+result: [1, 2]
+---
+title: 'array slicing (no end index)'
+context: {key: [1,2,3,4,5]}
+template: {$eval: 'key[-4:]'}
+result: [2,3,4,5]
+---
+title: 'array slicing (no start index)'
+context: {key: [1,2,3,4,5]}
+template: {$eval: 'key[:-3]'}
+result: [1,2]
+---
+title: 'array slicing type error (1)'
+context: {key: [1,2,3,4,5]}
+template: {$eval: 'key["a":]'}
+error: true
+---
+title: 'array slicing type error (2)'
+context: {key: [1,2,3,4,5]}
+template: {$eval: 'key[:"a"]'}
+error: true
+---
+title: 'array slicing type error (3)'
+context: {key: [1,2,3,4,5]}
+template: {$eval: 'key["a":"b"]'}
+error: true
+---
+title: 'array slicing type error (4)'
+context: {key: [1,2,3,4,5]}
+template: {$eval: 'key[1:"a"]'}
+error: true
+---
+title: 'array slicing type error (5)'
+context: {key: [1,2,3,4,5]}
+template: {$eval: 'key["a":2]'}
+error: true
+---
+title: 'slicing number'
+context: {key: 123}
+template: {$eval: 'key[2:]'}
+error: true
+---
+title: 'slicing null'
+context: {key: null}
+template: {$eval: 'key[2:]'}
+error: true
+---
+title: 'slicing boolean'
+context: {key: true}
+template: {$eval: 'key[2:]'}
+error: true
+---
+title: 'slicing object'
+context: {key: {x: 10}}
+template: {$eval: 'key[2:]'}
+error: true
+################################################################################
+---
+section: expression language - function calls
+---
+title: 'function call (1)'
+context: {a: 3, b: 2}
+template: {$eval: 'min(a, b)'}
+result: 2
+---
+title: 'function call (2)'
+context: {a: 3, b: 2}
+template: {$eval: 'min(3, b)'}
+result: 2
+---
+title: 'function call (3)'
+context: {a: 3, b: 2}
+template: {$eval: 'min(a, 2)'}
+result: 2
+---
+title: 'function call (4)'
+context: {a: 3, b: 2}
+template: {$eval: 'min(3, 2)'}
+result: 2
+---
+title: 'function call (5)'
+context: {a: 3, b: 2}
+template: {$eval: 'max(a, b)'}
+result: 3
+---
+title: 'function call (6)'
+context: {a: 3, b: 2}
+template: {$eval: 'max(3, b)'}
+result: 3
+---
+title: 'function call (7)'
+context: {a: 3, b: 2}
+template: {$eval: 'max(a, 2)'}
+result: 3
+---
+title: 'function call (8)'
+context: {a: 3, b: 2}
+template: {$eval: 'max(3, 2)'}
+result: 3
+---
+title: 'function call (9)'
+context: {a: 3, b: 2}
+template: {$eval: 'min(a, b) + max(a, b)'}
+result: 5
+---
+title: 'function call (10)'
+context: {a: 3, b: 2}
+template: {$eval: 'min(3, b) + max(3, b)'}
+result: 5
+---
+title: 'function call (11)'
+context: {a: 3, b: 2}
+template: {$eval: 'min(a, 2) + max(a, 2)'}
+result: 5
+---
+title: 'function call (12)'
+context: {a: 3, b: 2}
+template: {$eval: 'min(3, 2) + max(3, 2)'}
+result: 5
+---
+title: 'function call (13)'
+context: {}
+template: {$let: {functions: [{$eval: min}, {$eval: max}]}, in: {$eval: 'functions[1](2, 3)'}}
+result: 3
+---
+title: 'function call (14)'
+context: {}
+template: {$eval: '[max,min][1](5, 1)'}
+result: 1
+---
+title: 'function name is not callable'
+context: {function: "hi"}
+template: {$eval: "function(10)"}
+error: "InterpreterError: hi is not callable"
+---
+title: 'parenthesized function expression'
+context: {}
+template: {$eval: "(min)(10, 20)"}
+result: 10
+---
+title: 'dotted function expression'
+context: {}
+template: {$let: {negated: {max: {$eval: min}, min: {$eval: max}}}, in: {$eval: "(negated.min)(10, 20)"}}
+result: 20
+################################################################################
+---
+section: expression language - in operator
+---
+title: 'in operator on string, success (1)'
+context: {}
+template: {$eval: '"abc" in "aabc"'}
+result: true
+---
+title: 'in operator on string, failure (2)'
+context: {}
+template: {$eval: '"efg" in "aabc"'}
+result: false
+---
+title: 'in operator on string, success (3)'
+context: {key: 'aabc'}
+template: {$eval: '"abc" in key'}
+result: true
+---
+title: 'in operator on string, failure (4)'
+context: {key: 'aabc'}
+template: {$eval: '"efg" in key'}
+result: false
+---
+title: 'in operator on string, failure (5)'
+context: {key: 'aabc'}
+template: {$eval: '"2" in key'}
+result: false
+---
+title: 'in operator on array, success (1)'
+context: {}
+template: {$eval: '"abc" in [1, "abc", "def"]'}
+result: true
+---
+title: 'in operator on array, success (2)'
+context: {}
+template: {$eval: '1 in [1, "abc", "def"]'}
+result: true
+---
+title: 'in operator on array, success (3)'
+context: {key: [1, 'abc', 'def']}
+template: {$eval: '"abc" in key'}
+result: true
+---
+title: 'in operator on array, success (3)'
+context: {key: [1, 'abc', 'def']}
+template: {$eval: '1 in key'}
+result: true
+---
+title: 'in operator on array, failure (1)'
+context: {}
+template: {$eval: '"efg" in [1, "abc", "def"]'}
+result: false
+---
+title: 'in operator on array, failure (2)'
+context: {}
+template: {$eval: '2 in [1, "abc", "def"]'}
+result: false
+---
+title: 'in operator on array, failure (2)'
+context: {key: [1, 'abc', 'def']}
+template: {$eval: '"efg" in key'}
+result: false
+---
+title: 'in operator on array, failure (4)'
+context: {key: [1, 'abc', 'def']}
+template: {$eval: '2 in key'}
+result: false
+---
+title: 'in operator on object, success (1)'
+context: {}
+template: {$eval: '"a" in {"a": 1, b: 2}'}
+result: true
+---
+title: 'in operator on object, success (2)'
+context: {key: {a: 1, b: 2}}
+template: {$eval: '"a" in key'}
+result: true
+---
+title: 'in operator on object, success (3)'
+context: {}
+template: {$eval: '"3.4" in {"3.4": 1, "b": 2}'}
+result: true
+---
+title: 'in operator on object, failure (1)'
+context: {}
+template: {$eval: '"c" in {a: 1, "b": 2}'}
+result: false
+---
+title: 'in operator on object, failure (2)'
+context: {key: {a: 1, b: 2}}
+template: {$eval: '"c" in key'}
+result: false
+---
+title: 'in operator on object, failure (3)'
+context: {}
+template: {$eval: '"a" in {"3": 1, "b": 2}'}
+result: false
+---
+title: 'in operator on object, failure (4)'
+context: {}
+template: {$eval: '"3.4" in {"3": 1, "b": 2}'}
+result: false
+---
+title: 'TypeError: in operator on Object, error (1)'
+context: {key: {a: 1, b: 2}}
+template: {$eval: '[] in key'}
+error: true
+---
+title: 'TypeError: in operator on Object, error (2)'
+context: {key: {a: 1, b: 2}}
+template: {$eval: '{} in key'}
+error: true
+---
+title: 'TypeError: in operator on Object, error (3)'
+context: {key: {a: 1, b: 2}}
+template: {$eval: '1 in key'}
+error: true
+---
+title: 'TypeError: in operator on Array, Array not found'
+context: {key: [2,3,4]}
+template: {$eval: '[] in key'}
+result: false
+---
+title: 'TypeError: in operator on String, error (1)'
+context: {key: 'hello world!'}
+template: {$eval: '[] in key'}
+error: true
+---
+title: 'TypeError: in operator on String, error (2)'
+context: {key: 'hello world!'}
+template: {$eval: '{} in key'}
+error: true
+---
+title: 'TypeError: in operator on String, error (3)'
+context: {key: 'hello world!'}
+template: {$eval: '1 in key'}
+error: true
+---
+title: 'TypeError: in operator on Array, object not found'
+context: {key: [2,3,4]}
+template: {$eval: '{} in key'}
+result: false
+---
+title: 'no type conversion from num to string in array'
+context: {}
+template: {$eval: '5 in ["5", "five"]'}
+result: false
+---
+title: 'no type conversion from string to num in array'
+context: {}
+template: {$eval: '"5" in [5]'}
+result: false
+---
+title: 'cannot search for num in object'
+context: {}
+template: {$eval: '5 in {"5": "five"}'}
+error: true
+---
+title: 'deep equality, object on left side, found'
+context: {}
+template: {$eval: '{a: 45} in ["string", 46, {a: 45}]'}
+result: true
+---
+title: 'deep equality, object on left side, not found'
+context: {}
+template: {$eval: '{a: {b: 13}} in ["string", 46, {a: {b: 14}}]'}
+result: false
+---
+title: 'deep equality, Array on left side, found'
+context: {}
+template: {$eval: '[44, 45] in ["string", 46, [44, 45]]'}
+result: true
+---
+title: 'deep equality, Array on left side, not found'
+context: {}
+template: {$eval: '[44, 45] in ["string", 46, [44]]'}
+result: false
+---
+title: 'precedence of in over ||'
+context: {a: 'a', b: 'ab'}
+template: {$eval: "a in b || true"}
+result: true
+---
+title: 'precedence of in over &&'
+context: {a: 'a', b: 'bc'}
+template: {$eval: "a in b && true"}
+result: false
+---
+title: 'compare precedence of in and =='
+context: {a: 'a', b: 'ab', x: 5,'y': 7 }
+template: {$eval: "a in b || x==y"}
+result: true
+################################################################################
+---
+section: expression language - comparisons
+---
+title: 'equality (1)'
+context: {a: 1, b: 1}
+template: {$eval: '1 == 1'}
+result: true
+---
+title: 'equality (2)'
+context: {a: 1, b: 1}
+template: {$eval: '1 == 2'}
+result: false
+---
+title:    equality (3)
+context:  {}
+template: {$eval: '4 == 3.2 + 0.8'}
+result:   true
+---
+title: 'equality (4)'
+context: {a: 1, b: 1}
+template: {$eval: 'a == b'}
+result: true
+---
+title: 'equality (5)'
+context: {a: 1, b: 2}
+template: {$eval: 'a == b'}
+result: false
+---
+title:    object equality, true
+context:  {a: {x: 1,'y': 2}, b: {x: 1,'y': 2}}
+template: {$eval: 'a == b'}
+result:   true
+---
+title:    object equality, false
+context:  {a: {x: 1,'y': 2}, b: {x: 2,'y': 2}}
+template: {$eval: 'a == b'}
+result:   false
+---
+title:    object in-equality, true
+context:  {a: {x: 1,'y': 2}, b: {x: 2,'y': 2}}
+template: {$eval: 'a != b'}
+result:   true
+---
+title:    object in-equality, false
+context:  {a: {x: 1,'y': 2}, b: {x: 1,'y': 2}}
+template: {$eval: 'a != b'}
+result:   false
+---
+title:    complex object equality, true
+context:  {a: {x: 1,'y': {e: {g: {one: 1}}}}, b: {x: 1,'y': {e: {g: {one: 1}}}}}
+template: {$eval: 'a == b'}
+result:   true
+---
+title:    complex object equality, false
+context:  {a: {x: 1,'y': {e: {g: {one: 1}}}}, b: {x: 1,'y': {e: {g: {two: 2}}}}}
+template: {$eval: 'a == b'}
+result:   false
+---
+title:    complex object in-equality, true
+context:  {a: {x: 1,'y': {e: {g: {one: 1}}}}, b: {x: 1,'y': {e: {g: {two: 2}}}}}
+template: {$eval: 'a != b'}
+result:   true
+---
+title:    complex object in-equality, false
+context:  {a: {x: 1,'y': {e: {g: {one: 1}}}}, b: {x: 1,'y': {e: {g: {one: 1}}}}}
+template: {$eval: 'a != b'}
+result:   false
+---
+title: 'in-equality (1)'
+context: {a: 1, b: 1}
+template: {$eval: '1 != 1'}
+result: false
+---
+title: 'in-equality (2)'
+context: {a: 1, b: 1}
+template: {$eval: '1 != 2'}
+result: true
+---
+title: 'in-equality (3)'
+context: {a: 1, b: 1}
+template: {$eval: 'a != b'}
+result: false
+---
+title: 'in-equality (4)'
+context: {a: 1, b: 2}
+template: {$eval: 'a != b'}
+result: true
+---
+title: 'less than (1)'
+context: {a: 1, b: 2}
+template: {$eval: '1 < 2'}
+result: true
+---
+title: 'less than (2)'
+context: {a: 1, b: 2}
+template: {$eval: '2 < 1'}
+result: false
+---
+title: 'less than (3)'
+context: {a: 1, b: 2}
+template: {$eval: '"a" < "b"'}
+result: true
+---
+title: 'less than (4)'
+context: {a: 1, b: 2}
+template: {$eval: '"b" < "a"'}
+result: false
+---
+title: 'less than (5)'
+context: {a: 1, b: 2}
+template: {$eval: 'a < b'}
+result: true
+---
+title: 'less than (6)'
+context: {a: 1, b: 2}
+template: {$eval: 'b < a'}
+result: false
+---
+title: 'greater than (1)'
+context: {a: 1, b: 2}
+template: {$eval: '2 > 1'}
+result: true
+---
+title: 'greater than (2)'
+context: {a: 1, b: 2}
+template: {$eval: '1 > 2'}
+result: false
+---
+title: 'greater than (3)'
+context: {a: 1, b: 2}
+template: {$eval: '"b" > "a"'}
+result: true
+---
+title: 'greater than (4)'
+context: {a: 1, b: 2}
+template: {$eval: '"a" > "b"'}
+result: false
+---
+title: 'greater than (5)'
+context: {a: 1, b: 2}
+template: {$eval: 'b > a'}
+result: true
+---
+title: 'greater than (6)'
+context: {a: 1, b: 2}
+template: {$eval: 'a > b'}
+result: false
+---
+title: 'less than equal (1)'
+context: {a: 1, b: 2}
+template: {$eval: "a <= b"}
+result: true
+---
+title: 'less than equal (2)'
+context: {a: 1, b: 1}
+template: {$eval: "a <= b"}
+result: true
+---
+title: 'less than equal (3)'
+context: {a: 1, b: 2}
+template: {$eval: "b <= a"}
+result: false
+---
+title: 'less than equal (4)'
+context: {a: 1, b: 1}
+template: {$eval: "b <= a"}
+result: true
+---
+title: 'greater than equal (1)'
+context: {a: 1, b: 2}
+template: {$eval: "b >= a"}
+result: true
+---
+title: 'greater than equal (2)'
+context: {a: 1, b: 1}
+template: {$eval: "a >= b"}
+result: true
+---
+title: 'greater than equal (3)'
+context: {a: 1, b: 2}
+template: {$eval: "a >= b"}
+result: false
+---
+title: 'greater than equal (4)'
+context: {a: 1, b: 1}
+template: {$eval: "a >= b"}
+result: true
+---
+title: 'deep object equality'
+context:
+    a: {left: 1, right: {left: 2, right: 3}}
+    b: {left: 1, right: {left: 2, right: 3}}
+template: {$eval: "a == b"}
+result: true
+---
+title: 'boolean equality'
+context: {}
+template: {$eval: "true == true"}
+result: true
+---
+title: 'null equality'
+context: {a: null, b:  null}
+template: {$eval: "a == b"}
+result: true
+---
+title: 'string equality'
+context: {a: 'xyz', b:  'xyz'}
+template: {$eval: "a == b"}
+result: true
+---
+title: 'deep object inequality'
+context:
+    a: {left: 1, right: {left: 2, right: 3}}
+    b: {left: 1, right: {left: 3, right: 2}}
+template: {$eval: "a != b"}
+result: true
+---
+title: 'deep array equality'
+context:
+    a: [1, [2, 3]]
+    b: [1, [2, 3]]
+template: {$eval: "a == b"}
+result: true
+---
+title: 'deep array inequality'
+context:
+    a: [1, [2, 3]]
+    b: [1, [3, 2]]
+template: {$eval: "a != b"}
+result: true
+---
+title: ordering of string and string
+context: {a: 'abc', b: 'def'}
+template: {$eval: 'a < b'}
+result: true
+---
+title: ordering of string and number
+context: {a: 'abc', b: 27}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of string and null
+context: {a: 'abc', b: null}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of string and boolean
+context: {a: 'abc', b: true}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of string and object
+context: {a: 'abc', b: {}}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of string and array
+context: {a: 'abc', b: []}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of number and string
+context: {a: 123, b: 'def'}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of number and number
+context: {a: 123, b: 27}
+template: {$eval: 'a < b'}
+result: false
+---
+title: ordering of number and null
+context: {a: 123, b: null}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of number and boolean
+context: {a: 123, b: true}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of number and object
+context: {a: 123, b: {}}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of number and array
+context: {a: 123, b: []}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of null and string
+context: {a: null, b: 'def'}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of null and number
+context: {a: null, b: 27}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of null and null
+context: {a: null, b: null}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of null and boolean
+context: {a: null, b: true}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of null and object
+context: {a: null, b: {}}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of null and array
+context: {a: null, b: []}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of boolean and string
+context: {a: true, b: 'def'}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of boolean and number
+context: {a: true, b: 27}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of boolean and null
+context: {a: true, b: null}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of boolean and boolean
+context: {a: true, b: true}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of boolean and object
+context: {a: true, b: {}}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of boolean and array
+context: {a: true, b: []}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of object and string
+context: {a: {}, b: 'def'}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of object and number
+context: {a: {}, b: 27}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of object and null
+context: {a: {}, b: null}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of object and boolean
+context: {a: {}, b: true}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of object and object
+context: {a: {}, b: {}}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of object and array
+context: {a: {}, b: []}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of array and string
+context: {a: [], b: 'def'}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of array and number
+context: {a: [], b: 27}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of array and null
+context: {a: [], b: null}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of array and boolean
+context: {a: [], b: true}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of array and array
+context: {a: [], b: {}}
+template: {$eval: 'a < b'}
+error: true
+---
+title: ordering of array and array
+context: {a: [], b: []}
+template: {$eval: 'a < b'}
+error: true
+---
+title: equality of string and string
+context: {a: 'abc', b: 'def'}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of string and number
+context: {a: 'abc', b: 27}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of string and null
+context: {a: 'abc', b: null}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of string and boolean
+context: {a: 'abc', b: true}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of string and object
+context: {a: 'abc', b: {}}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of string and array
+context: {a: 'abc', b: []}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of number and string
+context: {a: 123, b: 'def'}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of number and number
+context: {a: 123, b: 27}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of number and null
+context: {a: 123, b: null}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of number and boolean
+context: {a: 123, b: true}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of number and object
+context: {a: 123, b: {}}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of number and array
+context: {a: 123, b: []}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of null and string
+context: {a: null, b: 'def'}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of null and number
+context: {a: null, b: 27}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of null and null
+context: {a: null, b: null}
+template: {$eval: 'a == b'}
+result: true
+---
+title: equality of null and boolean
+context: {a: null, b: true}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of null and object
+context: {a: null, b: {}}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of null and array
+context: {a: null, b: []}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of boolean and string
+context: {a: true, b: 'def'}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of boolean and number
+context: {a: true, b: 27}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of boolean and null
+context: {a: true, b: null}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of boolean and boolean
+context: {a: true, b: true}
+template: {$eval: 'a == b'}
+result: true
+---
+title: equality of boolean and object
+context: {a: true, b: {}}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of boolean and array
+context: {a: true, b: []}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of object and string
+context: {a: {}, b: 'def'}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of object and number
+context: {a: {}, b: 27}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of object and null
+context: {a: {}, b: null}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of object and boolean
+context: {a: {}, b: true}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of object and object
+context: {a: {}, b: {}}
+template: {$eval: 'a == b'}
+result: true
+---
+title: equality of object and array
+context: {a: {}, b: []}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of array and string
+context: {a: [], b: 'def'}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of array and number
+context: {a: [], b: 27}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of array and null
+context: {a: [], b: null}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of array and boolean
+context: {a: [], b: true}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of array and object
+context: {a: [], b: {}}
+template: {$eval: 'a == b'}
+result: false
+---
+title: equality of array and array
+context: {a: [], b: []}
+template: {$eval: 'a == b'}
+result: true
+---
+title: equality of functions
+context: {}
+template: {$eval: 'min == min'}
+result: true
+---
+title: inequality of functions
+context: {}
+template: {$eval: 'min == max'}
+result: false
+---
+title: equality of function and string
+context: {}
+template: {$eval: 'min == "min"'}
+result: false
+---
+title: equality of function and number
+context: {}
+template: {$eval: 'min == 13'}
+result: false
+################################################################################
+---
+section: expression language - compound literals
+---
+title: 'parse list (1)'
+context: {}
+template: {$eval: '[1,2,3,4]'}
+result: [1,2,3,4]
+---
+title: 'parse list (2)'
+context: {}
+template: {$eval: '[1,2,3,4][0]'}
+result: 1
+---
+title: 'parse list (3)'
+context: {}
+template: {$eval: '[1,2,3,4][0:-1]'}
+result: [1,2,3]
+---
+title: 'parse list (4)'
+context: {}
+template: {$eval: '[1,2,3,4'}
+error: true
+---
+title: 'parse object (1)'
+context: {key: 1}
+template: {$eval: '{a: key, "b": key + 1}'}
+result: {a: 1, b: 2}
+---
+title: 'parse object (2)'
+context: {key: 1}
+template: {$eval: '{"a": key, b: key + 1}'}
+result: {a: 1, b: 2}
+---
+title: 'parse object (3)'
+context: {key: 1}
+template: {$eval: '{"a": key, "b": key + 1}'}
+result: {a: 1, b: 2}
+---
+title: 'parse object (4)'
+context: {key: 1}
+template: {$eval: '{"a": key, b: [key,key+1,key+2]}'}
+result: {a: 1, b: [1,2,3]}
+---
+title: 'parse object (5)'
+context: {key: 1}
+template: {$eval: '{a: key, "b": [key,key+1,key+2]}'}
+result: {a: 1, b: [1,2,3]}
+---
+title: 'parse object (6)'
+context: {key: 1}
+template: {$eval: '{"a": key, "b": [key,key+1,key+2]}'}
+result: {a: 1, b: [1,2,3]}
+---
+title: 'parse object (7)'
+context: {key: 1}
+template: {$eval: '{a: key, b: [key,key+1,key+2]}'}
+result: {a: 1, b: [1,2,3]}
+---
+title: 'parse object (8)'
+context: {key: 1}
+template: {$eval: '{a: key, b: min(key + 1, 1)}'}
+result: {a: 1, b: 1}
+---
+title: 'parse object (9)'
+context: {key: 1}
+template: {$eval: '{"a": key, b: min(key + 1, 1)}'}
+result: {a: 1, b: 1}
+---
+title: 'parse object (10)'
+context: {key: 1}
+template: {$eval: '{a: key, "b": min(key + 1, 1)}'}
+result: {a: 1, b: 1}
+---
+title: 'parse object (11)'
+context: {key: 1}
+template: {$eval: '{"a": key, "b": min(key + 1, 1)}'}
+result: {a: 1, b: 1}
+---
+title: 'parse object (12)'
+context: {key: 1}
+template: {$eval: '{a: key, b: key + 1'}
+error: true
+################################################################################
+---
+section: expression language - errors
+---
+title: 'unary - type error'
+context: {key: 'hello'}
+template: {$eval: '-key'}
+error: 'InterpreterError: unary - expects number'
+---
+title: 'unary + type error'
+context: {key: 'hello'}
+template: {$eval: '+key'}
+error: 'InterpreterError: unary + expects number'
+---
+title: 'undefined variable'
+context: {key: 'hello'}
+template: {$eval: 'key2'}
+error: 'InterpreterError: unknown context value key2'
+---
+title: 'missing closing parenthesis'
+context: {key1: 1, key2: 1}
+template: {$eval: 'key1 + (key2 + key1'}
+error: true
+---
+title: 'missing opening parenthesis'
+context: {key1: 1, key2: 1}
+template: {$eval: 'key1 + key2 + key1)'}
+error: true
+---
+title: 'missing closing "'
+context: {}
+template: {$eval: '"hello'}
+error: true
+---
+title: 'missing opening "'
+context: {}
+template: {$eval: 'hello"'}
+error:  "SyntaxError: Unexpected input for 'hello\"' at '\"'"
+---
+title: 'Infix + type error'
+context: {}
+template: {$eval: 'true + false'}
+error: 'InterpreterError: infix: + expects numbers/strings + numbers/strings'
+---
+title: 'Infix - type error'
+context: {}
+template: {$eval: '"hello" - 3'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'Infix * type error'
+context: {}
+template: {$eval: '"hello" * 3'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'Infix / type error'
+context: {}
+template: {$eval: '"hello" / 3'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'Infix - type error'
+context: {}
+template: {$eval: '3 - "hello"'}
+error: 'InterpreterError: infix: - expects number - number'
+---
+title: 'Infix * type error'
+context: {}
+template: {$eval: '3 * "hello"'}
+error: 'InterpreterError: infix: * expects number * number'
+---
+title: 'Infix / type error'
+context: {}
+template: {$eval: '3 / "hello"'}
+error: 'InterpreterError: infix: / expects number / number'
+---
+title: 'Infix ** type error'
+context: {}
+template: {$eval: '"hello" ** 3'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'Infix ** type error'
+context: {}
+template: {$eval: '3 ** "hello"'}
+error: 'InterpreterError: infix: ** expects number ** number'
+---
+title: 'Infix < type error'
+context: {}
+template: {$eval: '"hello" < 3'}
+error: 'InterpreterError: infix: < expects numbers/strings < numbers/strings'
+---
+title: 'Infix > type error'
+context: {}
+template: {$eval: '"hello" > 3'}
+error: 'InterpreterError: infix: > expects numbers/strings > numbers/strings'
+---
+title: 'Infix <= type error'
+context: {}
+template: {$eval: '"hello" <= 3'}
+error: 'InterpreterError: infix: <= expects numbers/strings <= numbers/strings'
+---
+title: 'Infix >= type error'
+context: {}
+template: {$eval: '"hello" >= 3'}
+error: 'InterpreterError: infix: >= expects numbers/strings >= numbers/strings'
+---
+title: 'Infix < type error'
+context: {}
+template: {$eval: '3 < "hello"'}
+error: 'InterpreterError: infix: < expects numbers/strings < numbers/strings'
+---
+title: 'Infix > type error'
+context: {}
+template: {$eval: '3 > "hello"'}
+error: 'InterpreterError: infix: > expects numbers/strings > numbers/strings'
+---
+title: 'Infix <= type error'
+context: {}
+template: {$eval: '3 <= "hello"'}
+error: 'InterpreterError: infix: <= expects numbers/strings <= numbers/strings'
+---
+title: 'Infix >= type error'
+context: {}
+template: {$eval: '3 >= "hello"'}
+error: 'InterpreterError: infix: >= expects numbers/strings >= numbers/strings'
+---
+title: 'Infix access array or string with non-integer type error'
+context: {extra: {attributes: 'a string!'}}
+template: {$if: "extra.attributes['someattr'] == 'x'", then: true}
+error: 'InterpreterError: should only use integers to access arrays or strings'
+---
+title: 'Nested error has appropriate message'
+context: {}
+template: {foo: [1, {"123": [{$eval: 10}]}]}
+error: 'TemplateError at template.foo[1]["123"][0]: $eval must be given a string expression'
+---
+title: 'object with missing value '
+context: {}
+template: {$eval: '{a: 1, "b": }'}
+error:   "SyntaxError: Found: } token, expected one of: !, (, +, -, [, false, identifier, null, number, string, true, {"
+---
+title: 'object missing key and value after comma'
+context: {}
+template: {$eval: '{a: 1,'}
+error:   "SyntaxError: Unexpected end of input"
+---
+title: 'list with missing first value'
+context: {}
+template: {$eval: '[,2,3]'}
+error:   "SyntaxError: Found: , token, expected one of: !, (, +, -, [, false, identifier, null, number, string, true, {"
+---
+title: 'list with missing value'
+context: {}
+template: {$eval: '[1,,3]'}
+error:   "SyntaxError: Found: , token, expected one of: !, (, +, -, [, false, identifier, null, number, string, true, {"
+---
+title: 'empty brackets in property access'
+context: {a: "0123456789"}
+template: {$eval: 'a[]'}
+error:   "SyntaxError: Found: ] token, expected one of: !, (, +, -, [, false, identifier, null, number, string, true, {"
+---
+title: 'function call with missing closing bracket'
+context: {}
+template: {$eval: 'max(2, 0'}
+error:   "SyntaxError: Unexpected end of input"
+---
+title: 'function call with missing argument in brackets'
+context: {}
+template: {$eval: 'max(, 0)'}
+error:   "SyntaxError: Found: , token, expected one of: !, (, +, -, [, false, identifier, null, number, string, true, {"
+---
+title: 'uncalled function'
+context: {}
+template: {$eval: 'fromNow'}
+error:   "TemplateError: evaluated template contained uncalled functions"
+---
+title: 'list expression with uncalled functions'
+context: {}
+template: {$eval: '[min, max]'}
+error:   "TemplateError: evaluated template contained uncalled functions"
+---
+title: 'list with uncalled function inside'
+context: {}
+template: [{$eval: 'min'}]
+error:   "TemplateError: evaluated template contained uncalled functions"
+---
+title: 'object containing uncalled function'
+context: {}
+template: {maximum: {$eval: 'max'}}
+error:   "TemplateError: evaluated template contained uncalled functions"
+---
+title: 'deep data structure with uncalled functions'
+context: {}
+template: [{minimum: {$eval: 'min'}}, {maximum: {$eval: 'max'}}]
+error:   "TemplateError: evaluated template contained uncalled functions"
+---
+title: '$json with an uncalled function'
+context: {}
+template: {$json: {$eval: 'lowercase'}}
+error:   "TemplateError: evaluated template contained uncalled functions"
+---
+title: '$json with deep uncalled functions'
+context: {}
+template: {$json: [{minimum: {$eval: 'min'}}, {maximum: {$eval: 'max'}}]}
+error:   "TemplateError: evaluated template contained uncalled functions"
+################################################################################
+---
+section: Regression tests
+---
+title: issue 354
+template: {$eval: 'max(3, 2)'}
+context: {}
+result: 3