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Add basic list matching

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Scott Richmond 2022-05-19 19:27:32 -04:00
parent a899ee776d
commit 9984a6c8ec
1 changed files with 28 additions and 1 deletions
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29
src/ludus/interpreter.clj
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@ -43,6 +43,28 @@
(recur (dec i) (merge ctx (:ctx match?)))
{:success false :reason (str "Could not match " pattern " with " value)})))))))
(defn- match-list [pattern value ctx-vol]
(cond
(not (vector? value)) {:success false :reason "Could not match non-list value to list"}
(= ::data/tuple (first value)) {:success false :reason "Could not match tuple value to list pattern"}
;; TODO: fix this with splats
(not (= (count (:members pattern)) (count value)))
{:success false :reason "Cannot match lists of different lengths"}
(= 0 (count (:members pattern)) (count value)) {:success true :ctx {}}
:else (let [members (:members pattern)]
(loop [i (dec (count members))
ctx {}]
(if (> 0 i)
{:success true :ctx ctx}
(let [match? (match (nth members i) (nth value i) ctx-vol)]
(if (:success match?)
(recur (dec i) (merge ctx (:ctx match?)))
{:success false :reason (str "Could not match " pattern " with " value)})))))))
(defn- match [pattern value ctx-vol]
(let [ctx @ctx-vol]
(case (::ast/type pattern)
@ -63,6 +85,8 @@
::ast/tuple (match-tuple pattern value ctx-vol)
::ast/list (match-list pattern value ctx-vol)
(throw (ex-info "Unknown pattern on line " {:pattern pattern})))))
(defn- update-ctx [ctx new-ctx]
@ -407,10 +431,13 @@
(println (ex-message e))
(pp/pprint (ex-data e)))))
(comment
(do
(def source "
let [1, 2, x] = [1, 2, 3]
x
")