Changes from arch/CVS synchronization

ChangeLog

@@ -1,3 +1,7 @@
+2007-06-13  Ludovic Courtès  <ludo@chbouib.org>
+
+	* NEWS: Mention top-level define incompatible change.
+
 2007-06-12  Ludovic Courtès  <ludo@chbouib.org>
 
 	* NEWS: Mention `inet-ntop' bug fix.

NEWS

@@ -12,6 +12,16 @@ Changes in 1.8.2 (since 1.8.1):
 ** set-program-arguments
 ** make-vtable
 
+* Incompatible changes
+
+** The body of a top-level `define' no longer sees the binding being created
+
+In a top-level `define', the binding being created is no longer visible
+from the `define' body.  This breaks code like
+"(define foo (begin (set! foo 1) (+ foo 1)))", where `foo' is now
+unbound in the body.  However, such code was not R5RS-compliant anyway,
+per Section 5.2.1.
+
 * Bugs fixed
 
 ** Fractions were not `equal?' if stored in unreduced form.

ice-9/ChangeLog

@@ -1,3 +1,9 @@
+2007-06-13  Ludovic Courtès  <ludo@chbouib.org>
+
+	* boot-9.scm (module-make-local-var!): Simplified.  No need to
+	check for the value of a same-named imported binding since the
+	newly created variable is systematically assigned afterwards.
+
 2007-01-04  Kevin Ryde  <user42@zip.com.au>
 
 	* boot-9.scm (top-repl): Check (defined? 'SIGBUS) before using that

ice-9/boot-9.scm

@@ -1515,19 +1515,10 @@
 	       (module-modified m)
 	       b)))
 
-      ;; No local variable yet, so we need to create a new one.  That
-      ;; new variable is initialized with the old imported value of V,
-      ;; if there is one.
-      (let ((imported-var (module-variable m v))
-	    (local-var (or (and (module-binder m)
-				((module-binder m) m v #t))
-			   (begin
-			     (let ((answer (make-undefined-variable)))
-			       (module-add! m v answer)
-			       answer)))))
-	(if (and imported-var (not (variable-bound? local-var)))
-	    (variable-set! local-var (variable-ref imported-var)))
-	local-var)))
+      ;; Create a new local variable.
+      (let ((local-var (make-undefined-variable)))
+        (module-add! m v local-var)
+        local-var)))
 
 ;; module-ensure-local-variable! module symbol
 ;;

libguile/ChangeLog

@@ -1,3 +1,9 @@
+2007-06-13  Ludovic Courtès  <ludo@chbouib.org>
+
+	* eval.c (scm_m_define): Updated comment.  Changed order for value
+	evaluation and `scm_sym2var ()' call, which is perfectly valid per
+	R5RS.  This reverts the change dated 2004-04-22 by Dirk Herrmann.
+
 2007-06-12  Ludovic Courtès  <ludo@chbouib.org>
 
 	* socket.c (scm_inet_ntop): In the `AF_INET' case, declare `addr4'

libguile/eval.c

@@ -1213,10 +1213,11 @@ canonicalize_define (const SCM expr)
   return expr;
 }
 
-/* According to section 5.2.1 of R5RS we first have to make sure that the
- * variable is bound, and then perform the (set! variable expression)
- * operation.  This means, that within the expression we may already assign
- * values to variable: (define foo (begin (set! foo 1) (+ foo 1)))  */
+/* According to Section 5.2.1 of R5RS we first have to make sure that the
+   variable is bound, and then perform the `(set! variable expression)'
+   operation.  However, EXPRESSION _can_ be evaluated before VARIABLE is
+   bound.  This means that EXPRESSION won't necessarily be able to assign
+   values to VARIABLE as in `(define foo (begin (set! foo 1) (+ foo 1)))'.  */
 SCM
 scm_m_define (SCM expr, SCM env)
 {
@@ -1226,9 +1227,9 @@ scm_m_define (SCM expr, SCM env)
     const SCM canonical_definition = canonicalize_define (expr);
     const SCM cdr_canonical_definition = SCM_CDR (canonical_definition);
     const SCM variable = SCM_CAR (cdr_canonical_definition);
+    const SCM value = scm_eval_car (SCM_CDR (cdr_canonical_definition), env);
     const SCM location
       = scm_sym2var (variable, scm_env_top_level (env), SCM_BOOL_T);
-    const SCM value = scm_eval_car (SCM_CDR (cdr_canonical_definition), env);
 
     if (SCM_REC_PROCNAMES_P)
       {

test-suite/ChangeLog

@@ -1,3 +1,11 @@
+2007-06-13  Ludovic Courtès  <ludo@chbouib.org>
+
+	* tests/syntax.test (top-level define)[binding is created before
+	expression is evaluated]: Moved to "internal define", using `let'
+	instead of `begin'.  The test was not necessarily valid for
+	top-level defines, according to Section 5.2.1 or R5RS.
+	[redefinition]: New.
+
 2007-06-12  Ludovic Courtès  <ludo@chbouib.org>
 
 	* tests/socket.test: Renamed module to `(test-suite test-socket)'.

test-suite/tests/syntax.test

@@ -725,15 +725,16 @@
 
 (with-test-prefix "top-level define"
 
-  (pass-if "binding is created before expression is evaluated"
-    (= (eval '(begin
-                (define foo
-                  (begin
-                    (set! foo 1)
-                    (+ foo 1)))
-                foo)
-             (interaction-environment))
-       2))
+  (pass-if "redefinition"
+    (let ((m (make-module)))
+      (beautify-user-module! m)
+
+      ;; The previous value of `round' must still be visible at the time the
+      ;; new `round' is defined.  According to R5RS (Section 5.2.1), `define'
+      ;; should behave like `set!' in this case (except that in the case of
+      ;; Guile, we respect module boundaries).
+      (eval '(define round round) m)
+      (eq? (module-ref m 'round) round)))
 
   (with-test-prefix "currying"
 
@@ -780,6 +781,17 @@
                   (eq? 'c (a 2) (a 5))))
           (interaction-environment)))
 
+  (pass-if "binding is created before expression is evaluated"
+    ;; Internal defines are equivalent to `letrec' (R5RS, Section 5.2.2).
+    (= (eval '(let ()
+                (define foo
+                  (begin
+                    (set! foo 1)
+                    (+ foo 1)))
+                foo)
+             (interaction-environment))
+       2))
+
   (pass-if "internal defines with begin"
     (false-if-exception
      (eval '(let ((a identity) (b identity) (c identity))