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core.cljc
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core.cljc
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(ns schema.core
"A library for data shape definition and validation. A Schema is just Clojure data,
which can be used to document and validate Clojure functions and data.
For example,
(def FooBar {:foo Keyword :bar [Number]}) ;; a schema
(check FooBar {:foo :k :bar [1.0 2.0 3.0]})
==> nil
representing successful validation, but the following all return helpful errors
describing how the provided data fails to measure up to schema FooBar's standards.
(check FooBar {:bar [1.0 2.0 3.0]})
==> {:foo missing-required-key}
(check FooBar {:foo 1 :bar [1.0 2.0 3.0]})
==> {:foo (not (keyword? 1))}
(check FooBar {:foo :k :bar [1.0 2.0 3.0] :baz 1})
==> {:baz disallowed-key}
Schema lets you describe your leaf values using the Any, Keyword, Symbol, Number,
String, and Int definitions below, or (in Clojure) you can use arbitrary Java
classes or primitive casts to describe simple values.
From there, you can build up schemas for complex types using Clojure syntax
(map literals for maps, set literals for sets, vector literals for sequences,
with details described below), plus helpers below that provide optional values,
enumerations, arbitrary predicates, and more.
Assuming you (:require [schema.core :as s :include-macros true]),
Schema also provides macros for defining records with schematized elements
(s/defrecord), and named or anonymous functions (s/fn and s/defn) with
schematized inputs and return values. In addition to producing better-documented
records and functions, these macros allow you to retrieve the schema associated
with the defined record or function. Moreover, functions include optional
*validation*, which will throw an error if the inputs or outputs do not
match the provided schemas:
(s/defrecord FooBar
[foo :- Int
bar :- String])
(s/defn quux :- Int
[foobar :- Foobar
mogrifier :- Number]
(* mogrifier (+ (:foo foobar) (Long/parseLong (:bar foobar)))))
(quux (FooBar. 10 \"5\") 2)
==> 30
(fn-schema quux)
==> (=> Int (record user.FooBar {:foo Int, :bar java.lang.String}) java.lang.Number)
(s/with-fn-validation (quux (FooBar. 10.2 \"5\") 2))
==> Input to quux does not match schema: [(named {:foo (not (integer? 10.2))} foobar) nil]
As you can see, the preferred syntax for providing type hints to schema's defrecord,
fn, and defn macros is to follow each element, argument, or function name with a
:- schema. Symbols without schemas default to a schema of Any. In Clojure,
class (e.g., clojure.lang.String) and primitive schemas (long, double) are also
propagated to tag metadata to ensure you get the type hinting and primitive
behavior you ask for.
If you don't like this style, standard Clojure-style typehints are also supported:
(fn-schema (s/fn [^String x]))
==> (=> Any java.lang.String)
You can directly type hint a symbol as a class, primitive, or simple
schema.
See the docstrings of defrecord, fn, and defn for more details about how
to use these macros."
;; don't exclude def because it's not a var.
(:refer-clojure :exclude [Keyword Symbol Inst atom defprotocol defrecord defn letfn defmethod fn MapEntry ->MapEntry])
(:require
#?(:clj [clojure.pprint :as pprint])
[clojure.string :as str]
#?(:clj [schema.macros :as macros])
[schema.utils :as utils]
[schema.spec.core :as spec :include-macros true]
[schema.spec.leaf :as leaf]
[schema.spec.variant :as variant]
[schema.spec.collection :as collection])
#?(:cljs (:require-macros [schema.macros :as macros]
schema.core)))
#?(:clj (set! *warn-on-reflection* true))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Schema protocol
(clojure.core/defprotocol Schema
(spec [this]
"A spec is a record of some type that expresses the structure of this schema
in a declarative and/or imperative way. See schema.spec.* for examples.")
(explain [this]
"Expand this schema to a human-readable format suitable for pprinting,
also expanding class schematas at the leaves. Example:
user> (s/explain {:a s/Keyword :b [s/Int]} )
{:a Keyword, :b [Int]}"))
#?(:clj
(clojure.core/defn register-schema-print-as-explain [t]
(clojure.core/defmethod print-method t [s writer]
(print-method (explain s) writer))
(clojure.core/defmethod pprint/simple-dispatch t [s]
(pprint/write-out (explain s)))))
;; macros/defrecord-schema implements print methods in bb/cljs
#?(:bb nil
:clj (do (register-schema-print-as-explain schema.core.Schema)
(doseq [m [print-method pprint/simple-dispatch]]
(prefer-method m schema.core.Schema clojure.lang.IRecord)
(prefer-method m schema.core.Schema java.util.Map)
(prefer-method m schema.core.Schema clojure.lang.IPersistentMap))))
(clojure.core/defn checker
"Compile an efficient checker for schema, which returns nil for valid values and
error descriptions otherwise."
[schema]
(comp utils/error-val
(spec/run-checker
(clojure.core/fn [s params] (spec/checker (spec s) params)) false schema)))
(clojure.core/defn check
"Return nil if x matches schema; otherwise, returns a value that looks like the
'bad' parts of x with ValidationErrors at the leaves describing the failures.
If you will be checking many datums, it is much more efficient to create
a 'checker' once and call it on each of them."
[schema x]
((checker schema) x))
(clojure.core/defn validator
"Compile an efficient validator for schema."
[schema]
(let [c (checker schema)]
(clojure.core/fn [value]
(when-let [error (c value)]
(macros/error! (utils/format* "Value does not match schema: %s" (pr-str error))
{:schema schema :value value :error error}))
value)))
(clojure.core/defn validate
"Throw an exception if value does not satisfy schema; otherwise, return value.
If you will be validating many datums, it is much more efficient to create
a 'validator' once and call it on each of them."
[schema value]
((validator schema) value))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Platform-specific leaf Schemas
;; On the JVM, a Class itself is a schema. In JS, we treat functions as prototypes so any
;; function prototype checks objects for compatibility. In BB, defrecord classes can also be
;; instances of sci.lang.Type, and the interpreter extends `instance?` to support it as first arg.
(clojure.core/defn instance-precondition [s klass]
(spec/precondition
s
#?(:clj #(instance? klass %)
:cljs #(and (not (nil? %))
(or (identical? klass (.-constructor %))
(js* "~{} instanceof ~{}" % klass))))
#(list 'instance? klass %)))
(defn- -class-spec [this]
(let [pre (instance-precondition this this)]
(if-let [class-schema (utils/class-schema this)]
(variant/variant-spec pre [{:schema class-schema}])
(leaf/leaf-spec pre))))
(defn- -class-explain [this]
(if-let [more-schema (utils/class-schema this)]
(explain more-schema)
(condp = this
#?@(:clj [java.lang.String 'Str])
#?(:clj java.lang.Boolean :cljs js/Boolean) 'Bool
#?(:clj java.lang.Number :cljs js/Number) 'Num
#?@(:clj [java.util.regex.Pattern 'Regex])
#?(:clj java.util.Date :cljs js/Date) 'Inst
#?(:clj java.util.UUID :cljs cljs.core/UUID) 'Uuid
#?(:clj (or #?(:bb (when (instance? sci.lang.Type this)
(symbol (str this))))
(symbol (.getName ^Class this)))
:cljs this))))
(extend-protocol Schema
#?(:clj Class
:cljs function)
(spec [this] (-class-spec this))
(explain [this] (-class-explain this))
#?@(:bb [sci.lang.Type
(spec [this] (-class-spec this))
(explain [this] (-class-explain this))]))
;; On the JVM, the primitive coercion functions (double, long, etc)
;; alias to the corresponding boxed number classes
#?(:clj
(do
(defmacro extend-primitive [cast-sym class-sym]
(let [qualified-cast-sym `(class @(resolve '~cast-sym))]
`(extend-protocol Schema
~qualified-cast-sym
(spec [this#]
(variant/variant-spec spec/+no-precondition+ [{:schema ~class-sym}]))
(explain [this#]
'~cast-sym))))
(extend-primitive double Double)
(extend-primitive float Float)
(extend-primitive long Long)
(extend-primitive int Integer)
(extend-primitive short Short)
(extend-primitive char Character)
(extend-primitive byte Byte)
(extend-primitive boolean Boolean)
(extend-primitive doubles (Class/forName "[D"))
(extend-primitive floats (Class/forName "[F"))
(extend-primitive longs (Class/forName "[J"))
(extend-primitive ints (Class/forName "[I"))
(extend-primitive shorts (Class/forName "[S"))
(extend-primitive chars (Class/forName "[C"))
(extend-primitive bytes (Class/forName "[B"))
(extend-primitive booleans (Class/forName "[Z"))))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Cross-platform Schema leaves
;;; Any matches anything (including nil)
(macros/defrecord-schema AnythingSchema [_]
;; _ is to work around bug in Clojure where eval-ing defrecord with no fields
;; loses type info, which makes this unusable in schema-fn.
;; http://dev.clojure.org/jira/browse/CLJ-1093
Schema
(spec [this] (leaf/leaf-spec spec/+no-precondition+))
(explain [this] 'Any))
(def Any
"Any value, including nil."
(AnythingSchema. nil))
;;; eq (to a single allowed value)
(macros/defrecord-schema EqSchema [v]
Schema
(spec [this] (leaf/leaf-spec (spec/precondition this #(= v %) #(list '= v %))))
(explain [this] (list 'eq v)))
(clojure.core/defn eq
"A value that must be (= v)."
[v]
(EqSchema. v))
;;; isa (a child of parent)
(macros/defrecord-schema Isa [h parent]
Schema
(spec [this] (leaf/leaf-spec (spec/precondition this
#(if h
(isa? h % parent)
(isa? % parent))
#(list 'isa? % parent))))
(explain [this] (list 'isa? parent)))
(clojure.core/defn isa
"A value that must be a child of parent."
([parent]
(Isa. nil parent))
([h parent]
(Isa. h parent)))
;;; enum (in a set of allowed values)
(macros/defrecord-schema EnumSchema [vs]
Schema
(spec [this] (leaf/leaf-spec (spec/precondition this #(contains? vs %) #(list vs %))))
(explain [this] (cons 'enum vs)))
(clojure.core/defn enum
"A value that must be = to some element of vs."
[& vs]
(EnumSchema. (set vs)))
;;; pred (matches all values for which p? returns truthy)
(macros/defrecord-schema Predicate [p? pred-name]
Schema
(spec [this] (leaf/leaf-spec (spec/precondition this p? #(list pred-name %))))
(explain [this]
(cond (= p? integer?) 'Int
(= p? keyword?) 'Keyword
(= p? symbol?) 'Symbol
(= p? string?) 'Str
:else (list 'pred pred-name))))
(clojure.core/defn pred
"A value for which p? returns true (and does not throw).
Optional pred-name can be passed for nicer validation errors."
([p?] (pred p? (symbol (utils/fn-name p?))))
([p? pred-name]
(when-not (ifn? p?)
(macros/error! (utils/format* "Not a function: %s" p?)))
(Predicate. p? pred-name)))
;;; protocol (which value must `satisfies?`)
(clojure.core/defn protocol-name [protocol]
(-> protocol meta :proto-sym))
;; In cljs, satisfies? is a macro so we must precompile (partial satisfies? p)
;; and put it in metadata of the record so that equality is preserved, along with the name.
(macros/defrecord-schema Protocol [p]
Schema
(spec [this]
(leaf/leaf-spec
(spec/precondition
this
(:proto-pred (meta this))
#(list 'satisfies? (protocol-name this) %))))
(explain [this] (list 'protocol (protocol-name this))))
;; The cljs version is macros/protocol by necessity, since cljs `satisfies?` is a macro.
#?(:clj
(defmacro protocol
"A value that must satisfy? protocol p.
Internally, we must make sure not to capture the value of the protocol at
schema creation time, since that's impossible in cljs and breaks later
extends in Clojure.
A macro for cljs sake, since `satisfies?` is a macro in cljs."
[p]
`(with-meta (->Protocol ~p)
{:proto-pred #(satisfies? ~p %)
:proto-sym '~p})))
;;; regex (validates matching Strings)
(extend-protocol Schema
#?(:clj java.util.regex.Pattern
:cljs js/RegExp)
(spec [this]
(leaf/leaf-spec
(some-fn
(spec/simple-precondition this string?)
(spec/precondition this #(re-find this %) #(list 're-find (explain this) %)))))
(explain [this]
#?(:clj (symbol (str "#\"" this "\""))
:cljs (symbol (str "#\"" (.slice (str this) 1 -1) "\"")))))
;;; Cross-platform Schemas for atomic value types
(def Str
"Satisfied only by String.
Is (pred string?) and not js/String in cljs because of keywords."
#?(:clj java.lang.String :cljs (pred string? 'string?)))
(def Bool
"Boolean true or false"
#?(:clj java.lang.Boolean :cljs js/Boolean))
(def Num
"Any number"
#?(:clj java.lang.Number :cljs js/Number))
(def Int
"Any integral number"
(pred integer? 'integer?))
(def Keyword
"A keyword"
(pred keyword? 'keyword?))
(def Symbol
"A symbol"
(pred symbol? 'symbol?))
(def Regex
"A regular expression"
#?(:clj java.util.regex.Pattern
:cljs (reify Schema ;; Closure doesn't like if you just def as js/RegExp
(spec [this]
(leaf/leaf-spec
(spec/precondition this #(instance? js/RegExp %) #(list 'instance? 'js/RegExp %))))
(explain [this] 'Regex))))
(def Inst
"The local representation of #inst ..."
#?(:clj java.util.Date :cljs js/Date))
(def Uuid
"The local representation of #uuid ..."
#?(:clj java.util.UUID :cljs cljs.core/UUID))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Variant schemas (and other unit containers)
;;; maybe (nil)
(macros/defrecord-schema Maybe [schema]
Schema
(spec [this]
(variant/variant-spec
spec/+no-precondition+
[{:guard nil? :schema (eq nil)}
{:schema schema}]))
(explain [this] (list 'maybe (explain schema))))
(clojure.core/defn maybe
"A value that must either be nil or satisfy schema"
[schema]
(Maybe. schema))
;;; named (schema elements)
(macros/defrecord-schema NamedSchema [schema name]
Schema
(spec [this]
(variant/variant-spec
spec/+no-precondition+
[{:schema schema :wrap-error #(utils/->NamedError name %)}]))
(explain [this] (list 'named (explain schema) name)))
(clojure.core/defn named
"A value that must satisfy schema, and has a name for documentation purposes."
[schema name]
(NamedSchema. schema name))
;;; either (satisfies this schema or that one)
(macros/defrecord-schema Either [schemas]
Schema
(spec [this]
(variant/variant-spec
spec/+no-precondition+
(for [s schemas]
{:guard (complement (checker s)) ;; since the guard determines which option we check against
:schema s})
#(list 'some-matching-either-clause? %)))
(explain [this] (cons 'either (map explain schemas))))
(clojure.core/defn ^{:deprecated "1.0.0"} either
"A value that must satisfy at least one schema in schemas.
Note that `either` does not work properly with coercion
DEPRECATED: prefer `conditional` or `cond-pre`
WARNING: either does not work with coercion. It is also slow and gives
bad error messages. Please consider using `conditional` and friends
instead; they are more efficient, provide better error messages,
and work with coercion."
[& schemas]
(Either. schemas))
;;; conditional (choice of schema, based on predicates on the value)
(macros/defrecord-schema ConditionalSchema [preds-and-schemas error-symbol]
Schema
(spec [this]
(variant/variant-spec
spec/+no-precondition+
(for [[p s] preds-and-schemas]
{:guard p :schema s})
#(list (or error-symbol
(if (= 1 (count preds-and-schemas))
(symbol (utils/fn-name (ffirst preds-and-schemas)))
'some-matching-condition?))
%)))
(explain [this]
(cons 'conditional
(concat
(mapcat (clojure.core/fn [[pred schema]] [(symbol (utils/fn-name pred)) (explain schema)])
preds-and-schemas)
(when error-symbol [error-symbol])))))
(clojure.core/defn conditional
"Define a conditional schema. Takes args like cond,
(conditional pred1 schema1 pred2 schema2 ...),
and checks the first schemaX where predX (an ordinary Clojure function
that returns true or false) returns true on the value.
Unlike cond, throws if the value does not match any condition.
:else may be used as a final condition in the place of (constantly true).
More efficient than either, since only one schema must be checked.
An optional final argument can be passed, a symbol to appear in
error messages when none of the conditions match."
[& preds-and-schemas]
(macros/assert!
(and (seq preds-and-schemas)
(or (even? (count preds-and-schemas))
(symbol? (last preds-and-schemas))))
"Expected even, nonzero number of args (with optional trailing symbol); got %s"
(count preds-and-schemas))
(ConditionalSchema.
(vec
(for [[pred schema] (partition 2 preds-and-schemas)]
(do (macros/assert! (ifn? pred) (str "Conditional predicate " pred " must be a function"))
[(if (= pred :else) (constantly true) pred) schema])))
(if (odd? (count preds-and-schemas)) (last preds-and-schemas))))
;; cond-pre (conditional based on surface type)
(clojure.core/defprotocol HasPrecondition
(precondition [this]
"Return a predicate representing the Precondition for this schema:
the predicate returns true if the precondition is satisfied.
(See spec.core for more details)"))
(extend-protocol HasPrecondition
schema.spec.leaf.LeafSpec
(precondition [this]
(complement (.-pre ^schema.spec.leaf.LeafSpec this)))
schema.spec.variant.VariantSpec
(precondition [^schema.spec.variant.VariantSpec this]
(every-pred
(complement (.-pre this))
(apply some-fn
(for [{:keys [guard schema]} (.-options this)]
(if guard
(every-pred guard (precondition (spec schema)))
(precondition (spec schema)))))))
schema.spec.collection.CollectionSpec
(precondition [this]
(complement (.-pre ^schema.spec.collection.CollectionSpec this))))
(macros/defrecord-schema CondPre [schemas]
Schema
(spec [this]
(variant/variant-spec
spec/+no-precondition+
(for [s schemas]
{:guard (precondition (spec s))
:schema s})
#(list 'matches-some-precondition? %)))
(explain [this]
(cons 'cond-pre
(map explain schemas))))
(clojure.core/defn cond-pre
"A replacement for `either` that constructs a conditional schema
based on the schema spec preconditions of the component schemas.
Given a datum, the preconditions for each schema (which typically
check just the outermost class) are tested against the datum in turn.
The first schema whose precondition matches is greedily selected,
and the datum is validated against that schema. Unlike `either`,
a validation failure is final (and there is no backtracking to try
other schemas that might match).
Thus, `cond-pre` is only suitable for schemas with mutually exclusive
preconditions (e.g., s/Int and s/Str). If this doesn't hold
(e.g. {:a s/Int} and {:b s/Str}), you must use `conditional` instead
and provide an explicit condition for distinguishing the cases.
EXPERIMENTAL"
[& schemas]
(CondPre. schemas))
;; constrained (post-condition on schema)
(macros/defrecord-schema Constrained [schema postcondition post-name]
Schema
(spec [this]
(variant/variant-spec
spec/+no-precondition+
[{:schema schema}]
nil
(spec/precondition this postcondition #(list post-name %))))
(explain [this]
(list 'constrained (explain schema) post-name)))
(clojure.core/defn constrained
"A schema with an additional post-condition. Differs from `conditional`
with a single schema, in that the predicate checked *after* the main
schema. This can lead to better error messages, and is often better
suited for coercion."
([s p?] (constrained s p? (symbol (utils/fn-name p?))))
([s p? pred-name]
(when-not (ifn? p?)
(macros/error! (utils/format* "Not a function: %s" p?)))
(Constrained. s p? pred-name)))
;;; both (satisfies this schema and that one)
(macros/defrecord-schema Both [schemas]
Schema
(spec [this] this)
(explain [this] (cons 'both (map explain schemas)))
HasPrecondition
(precondition [this]
(apply every-pred (map (comp precondition spec) schemas)))
spec/CoreSpec
(subschemas [this] schemas)
(checker [this params]
(reduce
(clojure.core/fn [f t]
(clojure.core/fn [x]
(let [tx (t x)]
(if (utils/error? tx)
tx
(f (or tx x))))))
(map #(spec/sub-checker {:schema %} params) (reverse schemas)))))
(clojure.core/defn ^{:deprecated "1.0.0"} both
"A value that must satisfy every schema in schemas.
DEPRECATED: prefer 'conditional' with a single condition
instead, or `constrained`.
When used with coercion, coerces each schema in sequence."
[& schemas]
(Both. schemas))
(clojure.core/defn if
"if the predicate returns truthy, use the if-schema, otherwise use the else-schema"
[pred if-schema else-schema]
(conditional pred if-schema (constantly true) else-schema))
;;; Recursive schemas
;; Supports recursively defined schemas by using the level of indirection offered by by
;; Clojure and ClojureScript vars.
(clojure.core/defn var-name [v]
(let [{:keys [ns name]} (meta v)]
(symbol (str #?(:clj (ns-name ns)
:cljs ns)
"/" name))))
(macros/defrecord-schema Recursive [derefable]
Schema
(spec [this] (variant/variant-spec spec/+no-precondition+ [{:schema @derefable}]))
(explain [this]
(list 'recursive
(if #?(:clj (var? derefable)
:cljs (instance? Var derefable))
(list 'var (var-name derefable))
#?(:clj
(format "%s@%x"
(.getName (class derefable))
(System/identityHashCode derefable))
:cljs
'...)))))
(clojure.core/defn recursive
"Support for (mutually) recursive schemas by passing a var that points to a schema,
e.g (recursive #'ExampleRecursiveSchema)."
[schema]
(macros/assert! #?(:clj (instance? clojure.lang.IDeref schema)
:cljs (satisfies? IDeref schema))
"Not an IDeref: %s" schema)
(Recursive. schema))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Atom schema
(defn- atom? [x]
#?(:clj (instance? clojure.lang.Atom x)
:cljs (satisfies? IAtom x)))
(macros/defrecord-schema Atomic [schema]
Schema
(spec [this]
(collection/collection-spec
(spec/simple-precondition this atom?)
clojure.core/atom
[(collection/one-element true schema (clojure.core/fn [item-fn coll] (item-fn @coll) nil))]
(clojure.core/fn [_ xs _] (clojure.core/atom (first xs)))))
(explain [this] (list 'atom (explain schema))))
(clojure.core/defn atom
"An atom containing a value matching 'schema'."
[schema]
(->Atomic schema))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Map Schemas
;; A map schema is itself a Clojure map, which can provide value schemas for specific required
;; and optional keys, as well as a single, optional schema for additional key-value pairs.
;; Specific keys are mapped to value schemas, and given as either:
;; - (required-key k), a required key (= k)
;; - a keyword, also a required key
;; - (optional-key k), an optional key (= k)
;; For example, {:a Int (optional-key :b) String} describes a map with key :a mapping to an
;; integer, an optional key :b mapping to a String, and no other keys.
;; There can also be a single additional key, itself a schema, mapped to the schema for
;; corresponding values, which applies to all key-value pairs not covered by an explicit
;; key.
;; For example, {Int String} is a mapping from integers to strings, and
;; {:a Int Int String} is a mapping from :a to an integer, plus zero or more additional
;; mappings from integers to strings.
;;; Definitions for required and optional keys, and single entry validators
(clojure.core/defrecord RequiredKey [k])
(clojure.core/defn required-key
"A required key in a map"
[k]
(if (keyword? k)
k
(RequiredKey. k)))
(clojure.core/defn required-key? [ks]
(or (keyword? ks)
(instance? RequiredKey ks)))
(clojure.core/defrecord OptionalKey [k])
(clojure.core/defn optional-key
"An optional key in a map"
[k]
(OptionalKey. k))
(clojure.core/defn optional-key? [ks]
(instance? OptionalKey ks))
(clojure.core/defn explicit-schema-key [ks]
(cond (keyword? ks) ks
(instance? RequiredKey ks) (.-k ^RequiredKey ks)
(optional-key? ks) (.-k ^OptionalKey ks)
:else (macros/error! (utils/format* "Bad explicit key: %s" ks))))
(clojure.core/defn specific-key? [ks]
(or (required-key? ks)
(optional-key? ks)))
(clojure.core/defn map-entry-ctor [[k v :as coll]]
#?(:clj (clojure.lang.MapEntry. k v)
:cljs (cljs.core.MapEntry. k v nil)))
;; A schema for a single map entry.
(macros/defrecord-schema MapEntry [key-schema val-schema]
Schema
(spec [this]
(collection/collection-spec
spec/+no-precondition+
map-entry-ctor
[(collection/one-element true key-schema (clojure.core/fn [item-fn e] (item-fn (key e)) e))
(collection/one-element true val-schema (clojure.core/fn [item-fn e] (item-fn (val e)) nil))]
(clojure.core/fn [[k] [xk xv] _]
(if-let [k-err (utils/error-val xk)]
[k-err 'invalid-key]
[k (utils/error-val xv)]))))
(explain [this]
(list
'map-entry
(explain key-schema)
(explain val-schema))))
(clojure.core/defn map-entry [key-schema val-schema]
(MapEntry. key-schema val-schema))
(clojure.core/defn find-extra-keys-schema [map-schema]
(let [key-schemata (remove specific-key? (keys map-schema))]
(macros/assert! (< (count key-schemata) 2)
"More than one non-optional/required key schemata: %s"
(vec key-schemata))
(first key-schemata)))
(clojure.core/defn- explain-kspec [kspec]
(if (specific-key? kspec)
(if (keyword? kspec)
kspec
(list (cond (required-key? kspec) 'required-key
(optional-key? kspec) 'optional-key)
(explicit-schema-key kspec)))
(explain kspec)))
(defn- map-elements [this]
(let [extra-keys-schema (find-extra-keys-schema this)]
(let [duplicate-keys (->> (dissoc this extra-keys-schema)
keys
(group-by explicit-schema-key)
vals
(filter #(> (count %) 1))
(apply concat)
(mapv explain-kspec))]
(macros/assert! (empty? duplicate-keys)
"Schema has multiple variants of the same explicit key: %s" duplicate-keys))
(let [without-extra-keys-schema (dissoc this extra-keys-schema)]
(concat
(for [[k v] without-extra-keys-schema]
(let [rk (explicit-schema-key k)
required? (required-key? k)]
(collection/one-element
required? (map-entry (eq rk) v)
(clojure.core/fn [item-fn m]
(let [e (find m rk)]
(cond e (item-fn e)
required? (item-fn (utils/error [rk 'missing-required-key])))
(if e
(dissoc #?(:clj (if (instance? clojure.lang.PersistentStructMap m) (into {} m) m)
:cljs m)
rk)
m))))))
(when extra-keys-schema
(let [specific-keys (set (map explicit-schema-key (keys without-extra-keys-schema)))
[ks vs] (find this extra-keys-schema)
restricted-ks (constrained ks #(not (contains? specific-keys %)))]
[(collection/all-elements (map-entry restricted-ks vs))]))))))
(defn- map-error []
(clojure.core/fn [_ elts extra]
(into {} (concat (keep utils/error-val elts) (for [[k _] extra] [k 'disallowed-key])))))
(defn- map-spec [this]
(collection/collection-spec
(spec/simple-precondition this map?)
#(into {} %)
(map-elements this)
(map-error)))
(clojure.core/defn- map-explain [this]
(into {} (for [[k v] this] [(explain-kspec k) (explain v)])))
(extend-protocol Schema
#?(:clj clojure.lang.APersistentMap
:cljs cljs.core.PersistentArrayMap)
(spec [this] (map-spec this))
(explain [this] (map-explain this))
#?(:cljs cljs.core.PersistentHashMap)
#?(:cljs (spec [this] (map-spec this)))
#?(:cljs (explain [this] (map-explain this))))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Set schemas
;; A set schema is a Clojure set with a single element, a schema that all values must satisfy
(extend-protocol Schema
#?(:clj clojure.lang.APersistentSet
:cljs cljs.core.PersistentHashSet)
(spec [this]
(macros/assert! (= (count this) 1) "Set schema must have exactly one element")
(collection/collection-spec
(spec/simple-precondition this set?)
set
[(collection/all-elements (first this))]
(clojure.core/fn [_ xs _] (set (keep utils/error-val xs)))))
(explain [this] (set [(explain (first this))])))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Queue schemas
;; A queue schema is satisfied by PersistentQueues containing values that all satisfy
;; a specific sub-schema.
(clojure.core/defn queue? [x]
(instance?
#?(:clj clojure.lang.PersistentQueue
:cljs cljs.core/PersistentQueue)
x))
(clojure.core/defn as-queue [col]
(reduce
conj
#?(:clj clojure.lang.PersistentQueue/EMPTY
:cljs cljs.core/PersistentQueue.EMPTY)
col))
(macros/defrecord-schema Queue [schema]
Schema
(spec [this]
(collection/collection-spec
(spec/simple-precondition this queue?)
as-queue
[(collection/all-elements schema)]
(clojure.core/fn [_ xs _] (as-queue (keep utils/error-val xs)))))
(explain [this] (list 'queue (explain schema))))
(clojure.core/defn queue
"Defines a schema satisfied by instances of clojure.lang.PersistentQueue
(clj.core/PersistentQueue in ClojureScript) whose values satisfy x."
[x]
(Queue. x))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Sequence Schemas
;; A sequence schema looks like [one* optional* rest-schema?].
;; one matches a single required element, and must be the output of 'one' below.
;; optional matches a single optional element, and must be the output of 'optional' below.
;; Finally, rest-schema is any schema, which must match any remaining elements.
;; (if optional elements are present, they must be matched before the rest-schema is applied).
(clojure.core/defrecord One [schema optional? name])
(clojure.core/defn one
"A single required element of a sequence (not repeated, the implicit default)"
([schema name]
(One. schema false name)))
(clojure.core/defn optional
"A single optional element of a sequence (not repeated, the implicit default)"
([schema name]
(One. schema true name)))
(clojure.core/defn parse-sequence-schema
"Parses and validates a sequence schema, returning a vector in the form
[singles multi] where singles is a sequence of 'one' and 'optional' schemas
and multi is the rest-schema (which may be nil). A valid sequence schema is
a vector in the form [one* optional* rest-schema?]."
[s]
(let [[required more] (split-with #(and (instance? One %) (not (:optional? %))) s)
[optional more] (split-with #(and (instance? One %) (:optional? %)) more)]
(macros/assert!
(and (<= (count more) 1) (not-any? #(instance? One %) more))
"%s is not a valid sequence schema; %s%s%s" s
"a valid sequence schema consists of zero or more `one` elements, "
"followed by zero or more `optional` elements, followed by an optional "
"schema that will match the remaining elements.")
[(concat required optional) (first more)]))
(extend-protocol Schema
#?(:clj clojure.lang.APersistentVector
:cljs cljs.core.PersistentVector)
(spec [this]
(collection/collection-spec
(spec/precondition
this
(clojure.core/fn [x] (or (nil? x) (sequential? x) #?(:clj (instance? java.util.List x))))
#(list 'sequential? %))
vec
(let [[singles multi] (parse-sequence-schema this)]
(reduce
(clojure.core/fn [more ^One s]
(if-not (.-optional? s)
(cons
(collection/one-element
true (named (.-schema s) (.-name s))
(clojure.core/fn [item-fn x]
(if-let [x (seq x)]
(do (item-fn (first x))
(rest x))
(do (item-fn
(macros/validation-error
(.-schema s) ::missing
(list 'present? (.-name s))))
nil))))
more)
[(collection/optional-tail
(named (.-schema s) (.-name s))
(clojure.core/fn [item-fn x]
(when-let [x (seq x)]
(item-fn (first x))
(rest x)))
more)]))
(when multi
[(collection/all-elements multi)])
(reverse singles)))
(clojure.core/fn [_ elts extra]
(let [head (mapv utils/error-val elts)]
(cond-> head
(seq extra) (conj (utils/error-val (macros/validation-error nil extra (list 'has-extra-elts? (count extra))))))))))
(explain [this]
(let [[singles multi] (parse-sequence-schema this)]
(cond-> (mapv (clojure.core/fn [^One s]
(list (if (.-optional? s) 'optional 'one) (explain (:schema s)) (:name s)))
singles)
multi (conj (explain multi))))))
(clojure.core/defn pair
"A schema for a pair of schemas and their names"
[first-schema first-name second-schema second-name]
[(one first-schema first-name)
(one second-schema second-name)])