modules: save fn docstring in prototype

sex-modules.scm

@@ -8,6 +8,7 @@
   (chicken process-context)
   (chicken string)
   fmt
+  matchable
   reader
   srfi-1
   utils)
@@ -71,22 +72,33 @@
      (list)
      raw-forms)))
 
+(define (public-fn-interface form)
+  ;; (pub fn name args ret . body) -> prototype, keeping a docstring so
+  ;; the importer can emit it above the declaration
+  (match form
+    (('pub 'fn name args ret)
+     form)
+    (('pub 'fn name args ret ('comment . _) . rest)
+     (public-fn-interface `(pub fn ,name ,args ,ret ,@rest)))
+    (('pub 'fn name args ret (? string? doc) . _)
+     `(pub fn ,name ,args ,ret ,doc))
+    (('pub 'fn name args ret . _)
+     `(pub fn ,name ,args ,ret))))
+
 ;;; TODO: use semen facilities to analyze modules
 (define (process-public-interface-form form acc)
-  (case (car form)
-    ((pub)
-     (case (cadr form)
-       ;; A function is reduced to a prototype and keeps its `pub', so
-       ;; the importing unit declares it with external linkage
-       ((fn)
-        (cons (copy-form-source! form (take form 5)) acc))
-       ;; A variable becomes an `extern' declaration
-       ((var)
-        (cons (copy-form-source! form (cons 'extern (take (cdr form) 3))) acc))
-       ((define defmacro enum import include struct typedef union)
-        (cons (copy-form-source! form (cdr form)) acc))
-       (else (sex-error form "pub must be followed by a definition" form))))
-    (else acc)))
+  (match form
+    ;; Reduced to a prototype, still `pub', so the importer declares it
+    ;; with external linkage
+    (('pub 'fn . _)
+     (cons (copy-form-source! form (public-fn-interface form)) acc))
+    (('pub 'var name type . _)
+     (cons (copy-form-source! form `(extern var ,name ,type)) acc))
+    (('pub (or 'define 'defmacro 'enum 'import 'include 'struct 'typedef 'union) . _)
+     (cons (copy-form-source! form (cdr form)) acc))
+    (('pub . _)
+     (sex-error form "pub must be followed by a definition" form))
+    (_ acc)))
 
 (define (load-persistent-module-paths)
   (let ((sex-module-path-env-var