Rewrote large parts of presenter

 * PresentationOptions has gained more fine-tuning options:
   * directivesEnd: specifies when `---` is written. ref flyx#135
   * containers: specifies whether containers use block or flow style
   * suppressAddrs: if set, suppresses output of attributes
   * quoting: specifies how strings should be quoted
   * condenseFlow: specifies whether flow sequences should be on a
     single line
   * explicitKeys: specifies whether mapping keys should always have '?'
 * PresentationStyle is now a list of presets that set
   multiple options in PresentationOptions.
 * Does not output trailing spaces anymore. ref flyx#135
 * Writes compact notation, i.e. a mapping in a sequence starts on the
   line with the sequence's `-`, unless attributes are written
 * Added tests for the presenter
 * Existing code might change behavior because of whitespace, `---` and
   compact notation. The API has been extended so that existing code is
   affected as little as possible.

.gitignore

@@ -6,9 +6,11 @@ test/tserialization
 test/tjson
 test/tparser
 test/tquickstart
+test/tpresenter
 test/*.exe
 test/*.pdb
 test/*.ilk
+test/*.js
 server/server
 bench/jsonBench
 bench/yamlBench
@@ -22,4 +24,8 @@ doc/rstPreproc
 doc/tmp.rst
 doc/**/code
 nimsuggest.log
+server/server_cfg.nim
 result
+vendor
+.vscode
+*.swp

config.nims

@@ -43,6 +43,11 @@ task hintsTests, "Run hints tests":
   --verbosity:0
   setCommand "c", "test/thints"
 
+task presenterTests, "Run presenter tests":
+  --r
+  --verbosity:0
+  setCommand "c", "test/tpresenter"
+
 task documentation, "Generate documentation":
   exec "mkdir -p docout"
   withDir "doc":

doc/snippets/quickstart/00/01-out.yaml

@@ -1,9 +1,7 @@
 %YAML 1.2
 %TAG !n! tag:nimyaml.org,2016:
---- !n!system:seq(tag:nimyaml.org;2016:custom:Person) 
-- 
-  name: Karl Koch
+--- !n!system:seq(tag:nimyaml.org;2016:custom:Person)
+- name: Karl Koch
   age: 23
-- 
-  name: Peter Pan
+- name: Peter Pan
   age: 12

doc/snippets/quickstart/02/00-code.nim

@@ -8,9 +8,10 @@ personList.add(Person(name: "Karl Koch", age: 23))
 personList.add(Person(name: "Peter Pan", age: 12))
 
 var s = newFileStream("out.yaml", fmWrite)
-dump(personList, s, options = defineOptions(
-    style = psCanonical,
-    indentationStep = 3,
-    newlines = nlLF,
-    outputVersion = ov1_1))
+dump(personList, s, tagStyle = tsAll,
+    options = defineOptions(
+      style = psCanonical,
+      indentationStep = 3,
+      newlines = nlLF,
+      outputVersion = ov1_1))
 s.close()

doc/snippets/quickstart/02/01-out.yaml

@@ -1,17 +1,17 @@
 %YAML 1.1
 %TAG !n! tag:nimyaml.org,2016:
---- 
-!n!system:seq(tag:nimyaml.org;2016:custom:Person) [
+--- !n!system:seq(tag:nimyaml.org;2016:custom:Person)
+[
    !n!custom:Person {
-      ? !n!field "name"
-      : !!str "Karl Koch",
-      ? !n!field "age"
-      : !n!system:int32 "23"
+      ?  !n!field "name"
+      :  !!str "Karl Koch",
+      ?  !n!field "age"
+      :  !n!system:int32 "23"
    },
    !n!custom:Person {
-      ? !n!field "name"
-      : !!str "Peter Pan",
-      ? !n!field "age"
-      : !n!system:int32 "12"
+      ?  !n!field "name"
+      :  !!str "Peter Pan",
+      ?  !n!field "age"
+      :  !n!system:int32 "12"
    }
 ]

doc/snippets/quickstart/03/01-out.yaml

@@ -1,11 +1,11 @@
 %YAML 1.2
 %TAG !n! tag:nimyaml.org,2016:
---- !n!custom:NodeObj &a 
+--- !n!custom:NodeObj &a
 name: Node 1
-left: 
+left:
   name: Node 2
   left: !!null ~
-  right: &b 
+  right: &b
     name: Node 3
     left: *a
     right: !!null ~

doc/snippets/quickstart/04/01-in.yaml

@@ -5,7 +5,7 @@ name: Node 1
 left:
   name: Node 2
   left: ~
-  right: &b 
+  right: &b
     name: Node 3
     left: *a
     right: ~

doc/snippets/quickstart/05/01-out.yaml

@@ -1,6 +1,6 @@
 %YAML 1.2
 %TAG !n! tag:nimyaml.org,2016:
---- !Mob 
+--- !Mob
 !n!field level: !n!system:int32 42
 !n!field experience: !n!system:int32 1800
 !n!field drops: !Drops [!!str Sword of Mob Slaying]

doc/snippets/quickstart/06/00-code.nim

@@ -9,5 +9,5 @@ personList.add(Person(name: "Peter Pan", age: 12))
 
 var s = newFileStream("out.yaml", fmWrite)
 dump(personList, s,
-      options = defineOptions(style = psJson))
+    options = defineOptions(style = psJson))
 s.close()

doc/snippets/quickstart/06/01-out.yaml

@@ -1,4 +1,3 @@
-
 [
   {
     "name": "Karl Koch",

test/commonTestUtils.nim

@@ -71,4 +71,30 @@ template ensure*(input: var YamlStream,
       printDifference(expected[i], token)
       fail()
       break
-    i.inc()
+    i.inc()
+
+template assertStringEqual*(expected, actual: string) =
+  if expected != actual:
+    # if they are unequal, walk through the strings and check each
+    # character for a better error message
+    if expected.len != actual.len:
+      echo "Expected and actual string's length differs.\n"
+      echo "Expected length: ", expected.len, "\n"
+      echo "Actual length: ", actual.len, "\n"
+    # check length up to smaller of the two strings
+    for i in countup(0, min(expected.high, actual.high)):
+      if expected[i] != actual[i]:
+        echo "string mismatch at character #", i, "(expected:\'",
+         expected[i], "\', was \'", actual[i], "\'):\n"
+        echo "expected:\n", expected, "\nactual:\n", actual, "\n"
+        assert(false)
+    # if we haven't raised an assertion error here, the problem is that
+    # one string is longer than the other
+    let minInd = min(expected.len, actual.len) # len instead of high to continue
+                                               # after shorter string
+    if expected.high > actual.high:
+      echo "Expected continues with: '", expected[minInd .. ^1], "'"
+      assert false
+    else:
+      echo "Actual continues with: '", actual[minInd .. ^1], "'"
+      assert false

test/tests.nim

@@ -5,7 +5,7 @@
 #    distribution, for details about the copyright.
 
 {.warning[UnusedImport]: off.}
-import tlex, tjson, tserialization, tparser, tquickstart, tannotations, thints
+import tlex, tjson, tserialization, tparser, tquickstart, tannotations, thints, tpresenter
 
 when not defined(gcArc) or defined(gcOrc):
   import tdom

test/tpresenter.nim

@@ -0,0 +1,84 @@
+import ../yaml
+import unittest, strutils
+import commonTestUtils
+
+proc inputSingle(events: varargs[Event]): BufferYamlStream =
+  result = newBufferYamlStream()
+  result.put(startStreamEvent())
+  result.put(startDocEvent())
+  for event in events: result.put(event)
+  result.put(endDocEvent())
+  result.put(endStreamEvent())
+
+let minimalOptions = defineOptions(outputVersion = ovNone)
+
+proc assertOutput(
+    input: YamlStream, expected: string,
+    options: PresentationOptions = minimalOptions) =
+  var output = present(input, options)
+  assertStringEqual expected, output
+
+suite "Presenter":
+  test "Scalar with tag":
+    var input = inputSingle(scalarEvent("droggeljug", yTagString))
+    assertOutput(input, "--- !!str\ndroggeljug\n")
+
+  test "Scalar without tag":
+    var input = inputSingle(scalarEvent("droggeljug"))
+    assertOutput(input, "droggeljug\n")
+
+  test "Compact flow sequence":
+    var input = inputSingle(startSeqEvent(), scalarEvent("1"), scalarEvent("2"), endSeqEvent())
+    assertOutput(input, "[1, 2]\n")
+
+  test "Forced block sequence":
+    var input = inputSingle(startSeqEvent(), scalarEvent("1"), scalarEvent("2"), endSeqEvent())
+    assertOutput(input, "- 1\n- 2\n", defineOptions(outputVersion = ovNone, containers = cBlock))
+
+  test "Forced multiline flow sequence":
+    var input = inputSingle(startSeqEvent(), scalarEvent("1"), scalarEvent("2"), endSeqEvent())
+    assertOutput(input, "[\n  1,\n  2\n]\n", defineOptions(outputVersion = ovNone, condenseFlow = false))
+
+  test "Compact flow mapping":
+    var input = inputSingle(startMapEvent(), scalarEvent("1"), scalarEvent("2"), endMapEvent())
+    assertOutput(input, "{1: 2}\n", defineOptions(outputVersion = ovNone, containers = cFlow))
+
+  test "Simple block mapping":
+    var input = inputSingle(startMapEvent(), scalarEvent("1"), scalarEvent("2"), endMapEvent())
+    assertOutput(input, "1: 2\n", defineOptions(outputVersion = ovNone))
+
+  test "Forced multiline flow mapping":
+    var input = inputSingle(startMapEvent(), scalarEvent("1"), scalarEvent("2"), endMapEvent())
+    assertOutput(input, "{\n  1: 2\n}\n", defineOptions(outputVersion = ovNone, condenseFlow = false, containers = cFlow))
+
+  test "Forced JSON mapping":
+    var input = inputSingle(startMapEvent(), scalarEvent("1"), scalarEvent("2"), endMapEvent())
+    assertOutput(input, "{\n  \"1\": 2\n}\n", defineOptions(outputVersion = ovNone, condenseFlow = false, containers = cFlow, quoting = sqJson))
+
+  test "Nested flow sequence":
+    var input = inputSingle(startMapEvent(), scalarEvent("a"), startSeqEvent(), scalarEvent("1"), scalarEvent("2"), endSeqEvent(), endMapEvent())
+    assertOutput(input, "a: [1, 2]\n")
+
+  test "Nested block sequence":
+    var input = inputSingle(startMapEvent(), scalarEvent("a"), startSeqEvent(), scalarEvent("1"), scalarEvent("2"), endSeqEvent(), endMapEvent())
+    assertOutput(input, "a:\n  - 1\n  - 2\n", defineOptions(outputVersion = ovNone, containers = cBlock))
+
+  test "Compact notation: mapping in sequence":
+    var input = inputSingle(startSeqEvent(), scalarEvent("a"), startMapEvent(), scalarEvent("1"), scalarEvent("2"),   
+        scalarEvent("3"), scalarEvent("4"), endMapEvent(), endSeqEvent())
+    assertOutput(input, "- a\n- 1: 2\n  3: 4\n")
+
+  test "No compact notation: sequence in mapping":
+    var input = inputSingle(startMapEvent(), scalarEvent("a"), startSeqEvent(), scalarEvent("1"), endSeqEvent(), endMapEvent())
+    assertOutput(input, "a:\n  - 1\n", defineOptions(outputVersion = ovNone, containers = cBlock))
+
+  test "Compact notation with 4 spaces indentation":
+    var input = inputSingle(startSeqEvent(), scalarEvent("a"), startMapEvent(), scalarEvent("1"), scalarEvent("2"),   
+        scalarEvent("3"), scalarEvent("4"), endMapEvent(), endSeqEvent())
+    assertOutput(input, "-   a\n-   1: 2\n    3: 4\n", defineOptions(outputVersion = ovNone, indentationStep = 4))
+
+  test "Compact notation with 4 spaces indentation, more complex input":
+    var input = inputSingle(startMapEvent(), scalarEvent("root"), startSeqEvent(), scalarEvent("a"),
+        startMapEvent(), scalarEvent("1"), scalarEvent("2"), scalarEvent("3"), scalarEvent("4"), endMapEvent(),
+        endSeqEvent(), endMapEvent())
+    assertOutput(input, "root:\n    -   a\n    -   1: 2\n        3: 4\n", defineOptions(outputVersion = ovNone, indentationStep = 4))