add pic_sc (syntactic closure) structure

include/picrin/macro.h

@@ -25,6 +25,15 @@ struct pic_syntax {
   struct pic_proc *macro;
 };
 
+struct pic_sc {
+  PIC_OBJECT_HEADER
+  pic_value expr;
+  struct pic_senv *senv;
+};
+
+#define pic_sc(v) ((struct pic_sc *)pic_ptr(v))
+#define pic_sc_p(v) (pic_type(v) == PIC_TT_SC)
+
 #define pic_syntax(v) ((struct pic_syntax *)pic_ptr(v))
 #define pic_syntax_p(v) (pic_type(v) == PIC_TT_SYNTAX)
 

include/picrin/value.h

@@ -91,7 +91,8 @@ enum pic_tt {
   PIC_TT_ENV,
   PIC_TT_CONT,
   PIC_TT_SENV,
-  PIC_TT_SYNTAX
+  PIC_TT_SYNTAX,
+  PIC_TT_SC
 };
 
 #define PIC_OBJECT_HEADER			\

src/codegen.c

@@ -663,7 +663,8 @@ codegen(codegen_state *state, pic_value obj, bool tailpos)
   case PIC_TT_PORT:
   case PIC_TT_ERROR:
   case PIC_TT_SENV:
-  case PIC_TT_SYNTAX: {
+  case PIC_TT_SYNTAX:
+  case PIC_TT_SC: {
     pic_error(pic, "invalid expression given");
   }
   }

src/gc.c

@@ -284,6 +284,12 @@ gc_mark_object(pic_state *pic, struct pic_object *obj)
     }
     break;
   }
+  case PIC_TT_SC: {
+    struct pic_sc *sc = (struct pic_sc *)obj;
+    gc_mark(pic, sc->expr);
+    gc_mark_object(pic, (struct pic_object *)sc->senv);
+    break;
+  }
   case PIC_TT_NIL:
   case PIC_TT_BOOL:
   case PIC_TT_FLOAT:
@@ -420,6 +426,9 @@ gc_finalize_object(pic_state *pic, struct pic_object *obj)
   case PIC_TT_SYNTAX: {
     break;
   }
+  case PIC_TT_SC: {
+    break;
+  }
   case PIC_TT_NIL:
   case PIC_TT_BOOL:
   case PIC_TT_FLOAT:

src/macro.c

@@ -111,6 +111,12 @@ macroexpand(pic_state *pic, pic_value expr, struct pic_senv *senv)
   int ai = pic_gc_arena_preserve(pic);
 
   switch (pic_type(expr)) {
+  case PIC_TT_SC: {
+    struct pic_sc *sc;
+
+    sc = pic_sc(expr);
+    return macroexpand(pic, sc->expr, sc->senv);
+  }
   case PIC_TT_SYMBOL: {
     struct xh_entry *e;
     while (senv) {

src/port.c

@@ -103,6 +103,9 @@ write(pic_state *pic, pic_value obj)
   case PIC_TT_SYNTAX:
     printf("#<senv %p>", pic_ptr(obj));
     break;
+  case PIC_TT_SC:
+    printf("#<sc %p>", pic_ptr(obj));
+    break;
   }
 }