add attribute information to closure objects

include/picrin/proc.h

@@ -31,6 +31,7 @@ struct pic_proc {
     struct pic_irep *irep;
   } u;
   struct pic_env *env;
+  struct pic_dict *attr;
 };
 
 #define PIC_PROC_KIND_FUNC 1
@@ -50,6 +51,8 @@ struct pic_proc *pic_proc_new_irep(pic_state *, struct pic_irep *, struct pic_en
 
 pic_sym pic_proc_name(struct pic_proc *);
 
+struct pic_dict *pic_proc_attr(pic_state *, struct pic_proc *);
+
 /* closed variables accessor */
 void pic_proc_cv_init(pic_state *, struct pic_proc *, size_t);
 int pic_proc_cv_size(pic_state *, struct pic_proc *);

src/gc.c

@@ -381,6 +381,9 @@ gc_mark_object(pic_state *pic, struct pic_object *obj)
     if (proc->env) {
       gc_mark_object(pic, (struct pic_object *)proc->env);
     }
+    if (proc->attr) {
+      gc_mark_object(pic, (struct pic_object *)proc->attr);
+    }
     if (pic_proc_irep_p(proc)) {
       gc_mark_object(pic, (struct pic_object *)proc->u.irep);
     }

src/proc.c

@@ -6,6 +6,7 @@
 #include "picrin/pair.h"
 #include "picrin/proc.h"
 #include "picrin/irep.h"
+#include "picrin/dict.h"
 
 struct pic_proc *
 pic_proc_new(pic_state *pic, pic_func_t func, const char *name)
@@ -19,6 +20,7 @@ pic_proc_new(pic_state *pic, pic_func_t func, const char *name)
   proc->u.func.f = func;
   proc->u.func.name = pic_intern_cstr(pic, name);
   proc->env = NULL;
+  proc->attr = NULL;
   return proc;
 }
 
@@ -31,6 +33,7 @@ pic_proc_new_irep(pic_state *pic, struct pic_irep *irep, struct pic_env *env)
   proc->kind = PIC_PROC_KIND_IREP;
   proc->u.irep = irep;
   proc->env = env;
+  proc->attr = NULL;
   return proc;
 }
 
@@ -46,6 +49,15 @@ pic_proc_name(struct pic_proc *proc)
   UNREACHABLE();
 }
 
+struct pic_dict *
+pic_proc_attr(pic_state *pic, struct pic_proc *proc)
+{
+  if (proc->attr == NULL) {
+    proc->attr = pic_dict_new(pic);
+  }
+  return proc->attr;
+}
+
 void
 pic_proc_cv_init(pic_state *pic, struct pic_proc *proc, size_t cv_size)
 {