fed-sx-m1: Step 3b substrate fix #3 — atom_to_list/integer_to_list as Erlang charlists; list_to_* accept both (+9 net eval, 759/759)

lib/erlang/transpile.sx

@@ -821,16 +821,30 @@
         (len (get v :elements))
         (error "Erlang: tuple_size: not a tuple")))))
 
+(define er-string->charlist
+  (fn (s)
+    (let ((cs (string->list s)) (out (er-mk-nil)))
+      (for-each
+        (fn (i)
+          (set! out (er-mk-cons
+                      (char->integer (nth cs (- (- (len cs) 1) i)))
+                      out)))
+        (range 0 (len cs)))
+      out)))
+
 (define
   er-bif-atom-to-list
   (fn
     (vs)
     (let
       ((v (er-bif-arg1 vs "atom_to_list")))
+      ;; Standard Erlang: atom_to_list/1 returns an Erlang charlist
+      ;; (list of integer char codes). Was: SX string of :name —
+      ;; unusable from Erlang-land for [Char|T] / ++ / binary segments.
       (if
         (er-atom? v)
-        (get v :name)
-        (error "Erlang: atom_to_list: not an atom")))))
+        (er-string->charlist (get v :name))
+        (raise (er-mk-error-marker (er-mk-atom "badarg")))))))
 
 (define
   er-bif-list-to-atom
@@ -838,10 +852,11 @@
     (vs)
     (let
       ((v (er-bif-arg1 vs "list_to_atom")))
-      (if
-        (= (type-of v) "string")
-        (er-mk-atom v)
-        (error "Erlang: list_to_atom: not a string")))))
+      ;; Accept Erlang charlist (cons of ints) or SX string.
+      (let ((s (er-source-to-string v)))
+        (cond
+          (= s nil) (raise (er-mk-error-marker (er-mk-atom "badarg")))
+          :else (er-mk-atom s))))))
 
 ;; ── lists module ─────────────────────────────────────────────────
 (define
@@ -1597,10 +1612,12 @@
     (vs)
     (let
       ((v (er-bif-arg1 vs "integer_to_list")))
+      ;; Standard Erlang: integer_to_list/1 returns an Erlang charlist
+      ;; (e.g. integer_to_list(42) -> [$4, $2] -> [52, 50]).
       (cond
         (not (= (type-of v) "number"))
         (raise (er-mk-error-marker (er-mk-atom "badarg")))
-        :else (str v)))))
+        :else (er-string->charlist (str v))))))
 
 (define
   er-bif-list-to-integer
@@ -1608,15 +1625,14 @@
     (vs)
     (let
       ((v (er-bif-arg1 vs "list_to_integer")))
-      (cond
-        (not (= (type-of v) "string"))
-        (raise (er-mk-error-marker (er-mk-atom "badarg")))
-        :else (let
-          ((n (parse-number v)))
-          (cond
-            (= n nil)
-            (raise (er-mk-error-marker (er-mk-atom "badarg")))
-            :else n))))))
+      ;; Accept Erlang charlist (cons of ints) or SX string.
+      (let ((s (er-source-to-string v)))
+        (cond
+          (= s nil) (raise (er-mk-error-marker (er-mk-atom "badarg")))
+          :else (let ((n (parse-number s)))
+            (cond
+              (= n nil) (raise (er-mk-error-marker (er-mk-atom "badarg")))
+              :else n)))))))
 
 (define
   er-bif-is-function