refactor var. c api no longer supports converters.

include/picrin/var.h

@@ -12,16 +12,15 @@ extern "C" {
 struct pic_var {
   PIC_OBJECT_HEADER
   pic_value value;
-  struct pic_proc *conv;
 };
 
 #define pic_var_p(o) (pic_type(o) == PIC_TT_VAR)
 #define pic_var_ptr(o) ((struct pic_var *)pic_ptr(o))
 
-struct pic_var *pic_var_new(pic_state *, pic_value, struct pic_proc *);
+struct pic_var *pic_var_new(pic_state *, pic_value);
 
-struct pic_proc *pic_wrap_var(pic_state *, struct pic_var *);
+pic_value pic_var_ref(pic_state *, const char *);
-struct pic_var *pic_unwrap_var(pic_state *, struct pic_proc *);
+void pic_var_set(pic_state *, const char *, pic_value);
 
 #if defined(__cplusplus)
 }

piclib/built-in.scm

@@ -410,10 +410,34 @@
   (import (scheme base)
           (scheme cxr)
           (picrin macro)
-          (picrin core-syntax))
+          (picrin core-syntax)
+          (picrin var))
 
-  ;; reopen (pircin parameter)
+  (define (single? x)
-  ;; see src/var.c
+    (and (list? x) (= (length x) 1)))
+
+  (define (double? x)
+    (and (list? x) (= (length x) 2)))
+
+  (define (%make-parameter init conv)
+    (let ((var (make-var (conv init))))
+      (lambda args
+        (cond
+         ((null? args)
+          (var-ref var))
+         ((single? args)
+          (var-set! var (conv (car args))))
+         ((double? args)
+          (var-set! var ((cadr args) (car args))))
+         (else
+          (error "invalid arguments for parameter"))))))
+
+  (define (make-parameter init . conv)
+    (let ((conv
+           (if (null? conv)
+               (lambda (x) x)
+               (car conv))))
+      (%make-parameter init conv)))
 
   (define-syntax parameterize
     (er-macro-transformer
@@ -432,11 +456,12 @@
               ,@bindings
               (,(r 'let) ((,(r 'result) (begin ,@body)))
                 ,@(map (lambda (var)
-                         `(,(r 'parameter-set!) ,var ,(r (gensym var))))
+                         `(,var ,(r (gensym var)) (,(r 'lambda) (x) x)))
                        vars)
                 ,(r 'result))))))))
 
-  (export parameterize))
+  (export make-parameter
+          parameterize))
 
 ;;; Record Type
 (define-library (picrin record)

src/gc.c

@@ -476,9 +476,6 @@ gc_mark_object(pic_state *pic, struct pic_object *obj)
   case PIC_TT_VAR: {
     struct pic_var *var = (struct pic_var *)obj;
     gc_mark(pic, var->value);
-    if (var->conv) {
-      gc_mark_object(pic, (struct pic_object *)var->conv);
-    }
     break;
   }
   case PIC_TT_IREP: {

src/var.c

@@ -14,158 +14,100 @@ var_ref(pic_state *pic, struct pic_var *var)
 }
 
 static void
-var_set_force(pic_state *pic, struct pic_var *var, pic_value value)
+var_set(pic_state *pic, struct pic_var *var, pic_value value)
 {
   UNUSED(pic);
   var->value = value;
 }
 
-static void
-var_set(pic_state *pic, struct pic_var *var, pic_value value)
-{
-  if (var->conv) {
-    value = pic_apply1(pic, var->conv, value);
-  }
-  var_set_force(pic, var, value);
-}
-
 struct pic_var *
-pic_var_new(pic_state *pic, pic_value init, struct pic_proc *conv /* = NULL */)
+pic_var_new(pic_state *pic, pic_value init)
 {
   struct pic_var *var;
 
   var = (struct pic_var *)pic_obj_alloc(pic, sizeof(struct pic_var), PIC_TT_VAR);
-  var->value = pic_undef_value();
+  var->value = init;
-  var->conv = conv;
-
-  var_set(pic, var, init);
 
   return var;
 }
 
-static pic_value
+pic_value
-var_call(pic_state *pic)
+pic_var_ref(pic_state *pic, const char *name)
 {
-  struct pic_proc *proc;
+  pic_value v;
   struct pic_var *var;
-  pic_value v;
-  int c;
 
-  proc = pic_get_proc(pic);
+  v = pic_ref(pic, name);
 
-  c = pic_get_args(pic, "|o", &v);
+  pic_assert_type(pic, v, var);
-  if (c == 0) {
-    var = pic_var_ptr(proc->env->regs[0]);
-    return var_ref(pic, var);
-  }
-  else if (c == 1) {
-    var = pic_var_ptr(proc->env->regs[0]);
 
-    var_set(pic, var, v);
+  var = pic_var_ptr(v);
-    return pic_none_value();
+
-  }
+  return var_ref(pic, var);
-  else {
-    pic_abort(pic, "logic flaw");
-  }
-  UNREACHABLE();
 }
 
-struct pic_proc *
+void
-pic_wrap_var(pic_state *pic, struct pic_var *var)
+pic_var_set(pic_state *pic, const char *name, pic_value value)
-{
-  struct pic_proc *proc;
-
-  proc = pic_proc_new(pic, var_call, "<var-procedure>");
-  pic_proc_cv_init(pic, proc, 1);
-  pic_proc_cv_set(pic, proc, 0, pic_obj_value(var));
-  return proc;
-}
-
-struct pic_var *
-pic_unwrap_var(pic_state *pic, struct pic_proc *proc)
 {
   pic_value v;
+  struct pic_var *var;
 
-  if (! pic_proc_func_p(proc)) {
+  v = pic_ref(pic, name);
-    goto typeerror;
-  }
-  if (pic_proc_cv_size(pic, proc) != 1) {
-    goto typeerror;
-  }
-  v = pic_proc_cv_ref(pic, proc, 0);
-  if (! pic_var_p(v)) {
-    goto typeerror;
-  }
-  return pic_var_ptr(v);
 
- typeerror:
+  pic_assert_type(pic, v, var);
-  pic_errorf(pic, "expected parameter, but got ~s", v);
+
+  var = pic_var_ptr(v);
+
+  var_set(pic, var, value);
 }
 
 static pic_value
-pic_var_make_parameter(pic_state *pic)
+pic_var_make_var(pic_state *pic)
 {
-  struct pic_proc *conv = NULL;
-  struct pic_var *var;
   pic_value init;
 
-  pic_get_args(pic, "o|l", &init, &conv);
+  pic_get_args(pic, "o", &init);
 
-  var = pic_var_new(pic, init, conv);
+  return pic_obj_value(pic_var_new(pic, init));
-  return pic_obj_value(pic_wrap_var(pic, var));
 }
 
 static pic_value
-pic_var_parameter_ref(pic_state *pic)
+pic_var_var_ref(pic_state *pic)
 {
-  struct pic_proc *proc;
   struct pic_var *var;
+  pic_value v;
 
-  pic_get_args(pic, "l", &proc);
+  pic_get_args(pic, "o", &v);
+
+  pic_assert_type(pic, v, var);
+
+  var = pic_var_ptr(v);
 
-  var = pic_unwrap_var(pic, proc);
   return var_ref(pic, var);
 }
 
 static pic_value
-pic_var_parameter_set(pic_state *pic)
+pic_var_var_set(pic_state *pic)
 {
-  struct pic_proc *proc;
   struct pic_var *var;
-  pic_value v;
+  pic_value v, val;
 
-  pic_get_args(pic, "lo", &proc, &v);
+  pic_get_args(pic, "oo", &v, &val);
+
+  pic_assert_type(pic, v, var);
+
+  var = pic_var_ptr(v);
+  var_set(pic, var, val);
 
-  var = pic_unwrap_var(pic, proc);
-  /* no convert */
-  var_set_force(pic, var, v);
   return pic_none_value();
 }
 
-static pic_value
-pic_var_parameter_converter(pic_state *pic)
-{
-  struct pic_proc *proc;
-  struct pic_var *var;
-
-  pic_get_args(pic, "l", &proc);
-
-  var = pic_unwrap_var(pic, proc);
-  if (var->conv) {
-    return pic_obj_value(var->conv);
-  }
-  else {
-    return pic_false_value();
-  }
-}
-
 void
 pic_init_var(pic_state *pic)
 {
-  pic_deflibrary ("(picrin parameter)") {
+  pic_deflibrary ("(picrin var)") {
-    pic_defun(pic, "make-parameter", pic_var_make_parameter);
+    pic_defun(pic, "make-var", pic_var_make_var);
-    pic_defun(pic, "parameter-ref", pic_var_parameter_ref);
+    pic_defun(pic, "var-ref", pic_var_var_ref);
-    pic_defun(pic, "parameter-set!", pic_var_parameter_set); /* no convert */
+    pic_defun(pic, "var-set!", pic_var_var_set);
-    pic_defun(pic, "parameter-converter", pic_var_parameter_converter);
   }
 }