Merge pull request #539 from justinethier/issue-537-apply-in-icyc

Issue 537 apply in icyc

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 Bug Fixes
 
+- Fixed a bug in `apply` where an error may be raised when processing quoted sub-expressions. For example the following would throw an error: `(apply cons '(5 (1 2)))`. Thanks to @srgx for the bug report!
 - Fixed a beta expansion optimization bug where code such as the following would cause the compiler to hang. Thanks to Yorick Hardy for the bug report:
 
       (define (compile-forever x) x (compile-forever x))

scheme/eval.sld

@@ -89,17 +89,26 @@
       ((analyze exp *global-environment* rename-env '()) *global-environment*)
       ((analyze exp (car env) rename-env '()) (car env))))
 
+;; Called from the C runtime to support apply
 (define (eval-from-c exp . _env)
   (let ((env (if (null? _env) *global-environment* (car _env))))
     (eval (wrapc exp) env)))
 
-;; Expressions received from C code are already evaluated, but sometimes too much so.
-;; Try to wrap 
+;; Helper function for eval-from-c
+;; 
+;; Expressions received from C code are already evaluated, 
+;; however any quoted expressions will have the quotes
+;; stripped off. This is a problem for expressions that
+;; aren't self evaluating - like (1 2) - so we re-quote
+;; the expressions here so a subsequent eval will work.
+;;
 (define (wrapc exp)
   (cond 
     ((application? exp)
      (cond
-       ((compound-procedure? (car exp))
+       ((or (primitive-procedure? (car exp)) 
+            (compound-procedure? (car exp))
+            (procedure? (car exp)))
         (cons 
           (car exp)
           (map