c06af7c9f4
ifn? (jolt-1vx) is the canonical IFn set in the overlay: fns, keywords,
symbols, maps (sorted included), sets, vectors, and vars — NOT lists. The
seed version said true for lists and false for struct maps and vars.
Mutable-mode caveat documented (vectors and lists share the array repr
there). 13 predicate rows.
Multimethod dispatch (jolt-heo) now collects EVERY isa-matching method key
and picks the dominant one — x dominates y when prefer-method'd over it or
(isa? x y) — and two matches with no dominant is an ambiguity ERROR, as in
Clojure. It used to take whichever key the table yielded first, silently
ignoring prefer-method. The prefers store upgrades to Clojure's
{x -> set-of-dominated} shape, shared between the dispatch closure and
prefer-method-setup via the var; prefers becomes a macro over a setup fn
(the store lives on the VAR — the multifn value can't carry it, so the old
fn read {} forever). 6 multimethod rows + the conformance row updated to
the canonical shape (335x3).
The reader (jolt-ou8) kept the pending KEY when a comment or #_ sits in a
map's VALUE slot: the old code dropped both, desyncing kv pairing — the
real value became the next key and the closing brace landed in value
position ('Unmatched closing brace'). Selmer's deps.edn (a '; for
development (REPL, etc)' comment between key and value) now parses; 6
reader rows incl. nested commented maps.
Gate: jpm exit 0, conformance 335x3, all tests passed.
48 lines
3.3 KiB
Text
48 lines
3.3 KiB
Text
# Specification: multimethods & hierarchies.
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(use ../support/harness)
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(defspec "multimethods / dispatch"
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["dispatch on value" "\"two\""
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"(do (defmulti f identity) (defmethod f 1 [_] \"one\") (defmethod f 2 [_] \"two\") (f 2))"]
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["dispatch on keyword fn" "\"circle\""
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"(do (defmulti area :shape) (defmethod area :circle [_] \"circle\") (area {:shape :circle}))"]
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[":default method" "\"other\""
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"(do (defmulti f identity) (defmethod f 1 [_] \"one\") (defmethod f :default [_] \"other\") (f 99))"]
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["no match throws" :throws
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"(do (defmulti f identity) (defmethod f 1 [_] \"one\") (f 99))"]
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["multiple args" "5"
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"(do (defmulti g (fn [a b] a)) (defmethod g :add [_ b] b) (g :add 5))"]
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["get-method" "\"one\""
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"(do (defmulti f identity) (defmethod f 1 [_] \"one\") ((get-method f 1) 1))"]
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["remove-method" :throws
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"(do (defmulti f identity) (defmethod f 1 [_] \"one\") (remove-method f 1) (f 1))"])
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(defspec "multimethods / hierarchies"
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["derive + isa?" "true" "(do (derive ::child ::parent) (isa? ::child ::parent))"]
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["isa? reflexive" "true" "(isa? ::x ::x)"]
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["isa? unrelated" "false" "(do (derive ::a ::b) (isa? ::a ::c))"]
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["parents" "true" "(do (derive ::c ::p) (contains? (parents ::c) ::p))"]
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["ancestors" "true" "(do (derive ::c ::p) (derive ::p ::g) (contains? (ancestors ::c) ::g))"]
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["descendants" "true" "(do (derive ::c ::p) (contains? (descendants ::p) ::c))"]
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["dispatch via hierarchy" "\"animal\""
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"(do (derive ::dog ::animal) (defmulti speak identity) (defmethod speak ::animal [_] \"animal\") (speak ::dog))"]
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["custom :default key" ":unknown"
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"(do (defmulti classify :type :default :other) (defmethod classify :a [_] :alpha) (defmethod classify :other [_] :unknown) (classify {:type :zzz}))"]
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["explicit :hierarchy" "\"a\""
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"(do (def h (derive (make-hierarchy) ::dog ::animal)) (defmulti snd identity :hierarchy h) (defmethod snd ::animal [_] \"a\") (snd ::dog))"])
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# prefer-method breaks isa-dispatch ties; ambiguity without a preference is
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# an ERROR (jolt-heo — this used to silently take an arbitrary method).
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(defspec "multimethods / prefer-method"
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["preference picks the winner" ":rect"
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"(do (derive :p/sq :p/rect) (derive :p/sq :p/shape) (defmulti pm1 identity) (defmethod pm1 :p/rect [x] :rect) (defmethod pm1 :p/shape [x] :shape) (prefer-method pm1 :p/rect :p/shape) (pm1 :p/sq))"]
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["reverse preference" ":shape"
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"(do (derive :q/sq :q/rect) (derive :q/sq :q/shape) (defmulti pm2 identity) (defmethod pm2 :q/rect [x] :rect) (defmethod pm2 :q/shape [x] :shape) (prefer-method pm2 :q/shape :q/rect) (pm2 :q/sq))"]
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["ambiguity throws" :throws
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"(do (derive :r/sq :r/rect) (derive :r/sq :r/shape) (defmulti pm3 identity) (defmethod pm3 :r/rect [x] :rect) (defmethod pm3 :r/shape [x] :shape) (pm3 :r/sq))"]
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["isa dominance needs no preference" ":child"
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"(do (derive :s/c :s/p) (defmulti pm4 identity) (defmethod pm4 :s/c [x] :child) (defmethod pm4 :s/p [x] :parent) (pm4 :s/c))"]
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["prefers map shape" "true"
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"(do (defmulti pm5 identity) (defmethod pm5 :a [x] 1) (defmethod pm5 :b [x] 2) (prefer-method pm5 :a :b) (contains? (get (prefers pm5) :a) :b))"]
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["exact match needs no preference" ":exact"
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"(do (derive :t/sq :t/rect) (defmulti pm6 identity) (defmethod pm6 :t/sq [x] :exact) (defmethod pm6 :t/rect [x] :parent) (pm6 :t/sq))"])
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