change eval interface: eval takes an expression and an environment

macroexpand should be done in the context in which the expansion is
running. As of now I only changed c interface of eval but should change
the scheme interface as well ASAP.

extlib/benz/codegen.c

@@ -1420,7 +1420,7 @@ pic_codegen(pic_state *pic, pic_value obj)
 }
 
 struct pic_proc *
-pic_compile(pic_state *pic, pic_value obj, struct pic_lib *lib)
+pic_compile(pic_state *pic, pic_value obj, struct pic_env *env)
 {
   struct pic_irep *irep;
   size_t ai = pic_gc_arena_preserve(pic);
@@ -1436,7 +1436,7 @@ pic_compile(pic_state *pic, pic_value obj, struct pic_lib *lib)
 #endif
 
   /* macroexpand */
-  obj = pic_macroexpand(pic, obj, lib);
+  obj = pic_macroexpand(pic, obj, env);
 #if DEBUG
   fprintf(stdout, "## macroexpand completed\n");
   pic_debug(pic, obj);

extlib/benz/eval.c

@@ -5,13 +5,13 @@
 #include "picrin.h"
 
 pic_value
-pic_eval(pic_state *pic, pic_value program, struct pic_lib *lib)
+pic_eval(pic_state *pic, pic_value program, struct pic_env *env)
 {
   struct pic_proc *proc;
 
-  proc = pic_compile(pic, program, lib);
+  proc = pic_compile(pic, program, env);
 
-  return pic_apply(pic, proc, pic_nil_value());
+  return pic_apply0(pic, proc);
 }
 
 static pic_value
@@ -26,7 +26,7 @@ pic_eval_eval(pic_state *pic)
   if (lib == NULL) {
     pic_errorf(pic, "no library found: ~s", spec);
   }
-  return pic_eval(pic, program, lib);
+  return pic_eval(pic, program, lib->env);
 }
 
 void

extlib/benz/include/picrin.h

@@ -215,9 +215,9 @@ pic_value pic_apply3(pic_state *, struct pic_proc *, pic_value, pic_value, pic_v
 pic_value pic_apply4(pic_state *, struct pic_proc *, pic_value, pic_value, pic_value, pic_value);
 pic_value pic_apply5(pic_state *, struct pic_proc *, pic_value, pic_value, pic_value, pic_value, pic_value);
 pic_value pic_apply_trampoline(pic_state *, struct pic_proc *, pic_value);
-pic_value pic_eval(pic_state *, pic_value, struct pic_lib *);
-struct pic_proc *pic_compile(pic_state *, pic_value, struct pic_lib *);
-pic_value pic_macroexpand(pic_state *, pic_value, struct pic_lib *);
+pic_value pic_eval(pic_state *, pic_value, struct pic_env *);
+struct pic_proc *pic_compile(pic_state *, pic_value, struct pic_env *);
+pic_value pic_macroexpand(pic_state *, pic_value, struct pic_env *);
 
 struct pic_lib *pic_make_library(pic_state *, pic_value);
 struct pic_lib *pic_find_library(pic_state *, pic_value);

extlib/benz/include/picrin/value.h

@@ -184,6 +184,7 @@ struct pic_blob;
 struct pic_proc;
 struct pic_port;
 struct pic_error;
+struct pic_env;
 
 /* set aliases to basic types */
 typedef pic_value pic_list;

extlib/benz/lib.c

@@ -299,7 +299,7 @@ pic_lib_define_library(pic_state *pic)
     pic->lib = lib;
 
     for (i = 0; i < argc; ++i) {
-      pic_void(pic_eval(pic, argv[i], pic->lib));
+      pic_void(pic_eval(pic, argv[i], pic->lib->env));
     }
 
     pic->lib = prev;

extlib/benz/load.c

@@ -13,7 +13,7 @@ pic_load_port(pic_state *pic, struct pic_port *port)
     size_t ai = pic_gc_arena_preserve(pic);
 
     while (! pic_eof_p(form = pic_read(pic, port))) {
-      pic_eval(pic, form, pic->lib);
+      pic_eval(pic, form, pic->lib->env);
 
       pic_gc_arena_restore(pic, ai);
     }

extlib/benz/macro.c

@@ -299,7 +299,7 @@ macroexpand_defmacro(pic_state *pic, pic_value expr, struct pic_env *env)
   val = pic_cadr(pic, pic_cdr(pic, expr));
 
   pic_try {
-    val = pic_eval(pic, val, pic->lib);
+    val = pic_eval(pic, val, env);
   } pic_catch {
     pic_errorf(pic, "macroexpand error while definition: %s", pic_errmsg(pic));
   }
@@ -403,9 +403,8 @@ macroexpand(pic_state *pic, pic_value expr, struct pic_env *env)
 }
 
 pic_value
-pic_macroexpand(pic_state *pic, pic_value expr, struct pic_lib *lib)
+pic_macroexpand(pic_state *pic, pic_value expr, struct pic_env *env)
 {
-  struct pic_lib *prev;
   pic_value v;
 
 #if DEBUG
@@ -414,17 +413,12 @@ pic_macroexpand(pic_state *pic, pic_value expr, struct pic_lib *lib)
   puts("");
 #endif
 
-  /* change library for macro-expansion time processing */
-  prev = pic->lib;
-  pic->lib = lib;
+  /* expansion can fail with non-local exit so env->defer should be cleared every time */
+  env->defer = pic_nil_value();
 
-  lib->env->defer = pic_nil_value(); /* the last expansion could fail and leave defer field old */
+  v = macroexpand(pic, expr, env);
 
-  v = macroexpand(pic, expr, lib->env);
-
-  macroexpand_deferred(pic, lib->env);
-
-  pic->lib = prev;
+  macroexpand_deferred(pic, env);
 
 #if DEBUG
   puts("after expand:");

extlib/benz/read.c

@@ -153,7 +153,7 @@ read_eval(pic_state *pic, struct pic_port *port, int PIC_UNUSED(c))
 
   form = read(pic, port, next(port));
 
-  return pic_eval(pic, form, pic->lib);
+  return pic_eval(pic, form, pic->lib->env);
 }
 
 static pic_value