Fix #585: clj->js (#591)

Author: borkdude

CHANGELOG.md

@@ -2,7 +2,11 @@
 
 [Squint](https://github.com/squint-cljs/squint): Light-weight ClojureScript dialect
 
-## v0.8.126 (2024-11-29)
+## v0.8.128 (2024-12-02)
+
+- [#585](https://github.com/squint-cljs/squint/issues/585): fix `clj->js` to realize lazy seqs into arrays
+
+## v0.8.127 (2024-11-29)
 
 - [#586](https://github.com/squint-cljs/squint/issues/586): support extending protocol to `nil`
 

package.json

@@ -2,7 +2,7 @@
   "name": "squint-cljs",
   "type": "module",
   "sideEffects": false,
-  "version": "0.8.126",
+  "version": "0.8.127",
   "files": [
     "core.js",
     "src/squint/core.js",

resources/squint/core.edn

@@ -33,6 +33,7 @@
   bounded_count
   butlast
   cat
+  clj__GT_js
   coll_QMARK_
   comp
   compare

src/squint/compiler.cljc

@@ -45,7 +45,6 @@
                          'squint-compiler-html
                          'squint.impl/deref
                          'require 'squint.defclass/defclass* 'squint.defclass/super*
-                         'clj->js
                          'squint.impl/for-of
                          'squint.impl/defonce]))
 
@@ -128,9 +127,6 @@
 (defmethod emit-special 'js/typeof [_ env [_ form]]
   (emit-return (str "typeof " (emit form (expr-env env))) env))
 
-(defmethod emit-special 'clj->js [_ env [_ form]]
-  (emit form env))
-
 (defmethod emit-special 'deftype* [_ env [_ t fields pmasks body]]
   (let [fields (map munge fields)]
     (str "var " (munge t) " = " (format "function %s {

src/squint/core.js

@@ -1056,6 +1056,17 @@ export function vector_QMARK_(x) {
 }
 
 export function mapv(...args) {
+  if (args.length === 2) {
+    const [f, coll] = args;
+    if (coll instanceof LazyIterable) {
+      var ret = [];
+      for (const x of coll) {
+        ret.push(f(x));
+      }
+      return ret;
+    }
+    return into([], map(f), coll);
+  }
   return [...map(...args)];
 }
 
@@ -2731,3 +2742,21 @@ export class Delay {
     }
   }
 }
+
+function clj__GT_js_(x, seen) {
+  // we need to protect against circular objects
+  if (seen.has(x)) return x;
+  seen.add(x);
+  if (map_QMARK_(x)) {
+    return update_vals(x, x => clj__GT_js_(x, seen));
+  }
+
+  if (coll_QMARK_(x)) {
+    return mapv(x => clj__GT_js_(x, seen), x);
+  }
+  return x;
+}
+
+export function clj__GT_js(x) {
+  return clj__GT_js_(x, new Set());
+}

test/squint/compiler_test.cljs

@@ -2333,5 +2333,13 @@ new Foo();")
   (is (eq [true true false]
           (jsv! "[(map? {}) (map? (new Map [])) (map? [])]"))))
 
+(deftest clj->js-test
+  (is (eq [2 3 4]
+          (jsv! "(clj->js (map inc [1 2 3]))")))
+  (is (eq {:a [2 3 4]}
+          (jsv! "(clj->js {:a (map inc [1 2 3])})")))
+  (is (eq [2 3 4]
+          (jsv! "(def x {:a 1 :b (map inc [1 2 3])}) (set! (.-a x) x) (:b (clj->js x))"))))
+
 (defn init []
   (t/run-tests 'squint.compiler-test 'squint.jsx-test 'squint.string-test 'squint.html-test))