From cf411fd62a522972510f3866d2069d9dc111b06f Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Tue, 9 Jun 2015 22:36:04 +0900
Subject: [PATCH] lazy export

---
 extlib/benz/lib.c       | 20 +++++++++++---------
 piclib/picrin/macro.scm | 28 ++++++++++++++--------------
 2 files changed, 25 insertions(+), 23 deletions(-)

diff --git a/extlib/benz/lib.c b/extlib/benz/lib.c
index 9c5468bf..1ac5b879 100644
--- a/extlib/benz/lib.c
+++ b/extlib/benz/lib.c
@@ -73,7 +73,7 @@ import_table(pic_state *pic, pic_value spec, struct pic_dict *imports)
   struct pic_lib *lib;
   struct pic_dict *table;
   pic_value val, tmp, prefix, it;
-  pic_sym *sym, *id, *tag;
+  pic_sym *sym, *id, *tag, *nick;
   xh_entry *iter;
 
   table = pic_make_dict(pic);
@@ -122,8 +122,15 @@ import_table(pic_state *pic, pic_value spec, struct pic_dict *imports)
   if (! lib) {
     pic_errorf(pic, "library not found: ~a", spec);
   }
-  pic_dict_for_each (sym, lib->exports, iter) {
-    pic_dict_set(pic, imports, sym, pic_dict_ref(pic, lib->exports, sym));
+  pic_dict_for_each (nick, lib->exports, iter) {
+    pic_sym *realname, *rename;
+
+    realname = pic_sym_ptr(pic_dict_ref(pic, lib->exports, nick));
+
+    if ((rename = pic_find_rename(pic, lib->env, realname)) == NULL) {
+      pic_errorf(pic, "attempted to export undefined variable '~s'", pic_obj_value(realname));
+    }
+    pic_dict_set(pic, imports, nick, pic_obj_value(rename));
   }
 }
 
@@ -148,7 +155,6 @@ export(pic_state *pic, pic_value spec)
 {
   pic_sym *sRENAME = pic_intern_cstr(pic, "rename");
   pic_value a, b;
-  pic_sym *rename;
 
   if (pic_sym_p(spec)) {        /* (export a) */
     a = b = spec;
@@ -165,15 +171,11 @@ export(pic_state *pic, pic_value spec)
       goto fail;
   }
 
-  if ((rename = pic_find_rename(pic, pic->lib->env, pic_sym_ptr(a))) == NULL) {
-    pic_errorf(pic, "export: symbol not defined %s", pic_symbol_name(pic, pic_sym_ptr(a)));
-  }
-
 #if DEBUG
   printf("* exporting %s as %s\n", pic_symbol_name(pic, pic_sym_ptr(b)), pic_symbol_name(pic, rename));
 #endif
 
-  pic_dict_set(pic, pic->lib->exports, pic_sym_ptr(b), pic_obj_value(rename));
+  pic_dict_set(pic, pic->lib->exports, pic_sym_ptr(b), a);
 
   return;
 
diff --git a/piclib/picrin/macro.scm b/piclib/picrin/macro.scm
index 985b5d94..e11d4eb7 100644
--- a/piclib/picrin/macro.scm
+++ b/piclib/picrin/macro.scm
@@ -1,6 +1,19 @@
 (define-library (picrin macro)
   (import (picrin base))
 
+  (export identifier?
+          identifier=?
+          make-identifier
+          make-syntactic-closure
+          close-syntax
+          capture-syntactic-environment
+          sc-macro-transformer
+          rsc-macro-transformer
+          er-macro-transformer
+          ir-macro-transformer
+          ;; strip-syntax
+          define-macro)
+
   ;; assumes no derived expressions are provided yet
 
   (define (walk proc expr)
@@ -125,17 +138,4 @@
            (list (r 'define-macro) (car formal)
                  (cons (r 'lambda)
                        (cons (cdr formal)
-                             body)))))))
-
-  (export identifier?
-          identifier=?
-          make-identifier
-          make-syntactic-closure
-          close-syntax
-          capture-syntactic-environment
-          sc-macro-transformer
-          rsc-macro-transformer
-          er-macro-transformer
-          ir-macro-transformer
-          ;; strip-syntax
-          define-macro))
+                             body))))))))