add chicken-import support to sex

also fix unquoting to single atom processing wrongly in walk-sex-tree

example/test-list.sex

@@ -3,7 +3,12 @@
 (include stdbool.h)
 (include stdio.h)
 
-(load "list.seh")
+(chicken-import srfi-1 brev-separate)                 ; list routines, e.g. fold
+
+(chicken-load "list.seh")
+
+(define (imports-test a b c)
+  (fold + 0 (list 1 2 3 a b c)))
 
 (struct foo
   ((float a)
@@ -16,9 +21,8 @@
 ,(length-list-T '(int) #f)
 ,(is-empty-list-T '(int) #f)
 
-
 (extern fn void puk ((int a) (float b)))
-(fn bool bar () false)
+(fn int bar () ,(imports-test 10 20 30))
 (pub fn void baz () true)
 
 (extern var int i)

sex-mode.el

@@ -28,7 +28,8 @@ All commands in `lisp-mode-shared-map' are inherited by this map.")
     (list
      ;; Declarations
      (list (concat "("
-                   (regexp-opt '("extern"
+                   (regexp-opt '("chicken-import"
+                                 "extern"
                                  "include"
                                  "fn"
                                  "pub"

sexc.scm

@@ -111,22 +111,27 @@
     (else (error "Pub what?"))))
 
 (define (walk-sex-tree form acc)
-  (case (car form)
-    ((fn) (walk-function form #t acc))
-    ((extern) (walk-extern form acc))
-    ((pub) (walk-public form acc))
-    ((struct union) (walk-struct form acc))
-    ((unquote) (fold (fn (walk-sex-tree x y))
-                     acc
-                     (eval (cadr form))))
+  (if (list? form)
+      (case (car form)
+        ((fn) (walk-function form #t acc))
+        ((extern) (walk-extern form acc))
+        ((pub) (walk-public form acc))
+        ((struct union) (walk-struct form acc))
+        ((unquote) (fold (fn (walk-sex-tree x y))
+                         acc
+                         (eval (cadr form))))
 
-    (else (append (walk-generic form (list)) acc))))
+        (else (append (walk-generic form (list)) acc)))
+      ;; only for unquote support
+      (list (list (atom-to-fmt-c form)))))
 
 (define (process-form form acc)
   (case (car form)
     ((define) (eval form) acc)
     ((template) (eval form) acc)
     ((load) (eval form) acc)
+    ((chicken-import)
+     (eval (cons 'import (cdr form))) acc)
     (else
      (walk-sex-tree form acc))))