add pic_equal_p

src/bool.c

@@ -1,6 +1,27 @@
 #include <string.h>
 
 #include "picrin.h"
+#include "picrin/pair.h"
+
+bool
+pic_equal_p(pic_state *pic, pic_value x, pic_value y)
+{
+  enum pic_tt type;
+
+  if (pic_eqv_p(x, y))
+    return true;
+
+  type = pic_type(x);
+  if (type != pic_type(y))
+    return false;
+  switch (type) {
+  case PIC_TT_PAIR:
+    return pic_equal_p(pic, pic_car(pic, x), pic_car(pic, y))
+      && pic_equal_p(pic, pic_cdr(pic, x), pic_cdr(pic, y));
+  default:
+    return false;
+  }
+}
 
 static pic_value
 pic_bool_eq_p(pic_state *pic)
@@ -22,6 +43,16 @@ pic_bool_eqv_p(pic_state *pic)
   return pic_bool_value(pic_eqv_p(x, y));
 }
 
+static pic_value
+pic_bool_equal_p(pic_state *pic)
+{
+  pic_value x, y;
+
+  pic_get_args(pic, "oo", &x, &y);
+
+  return pic_bool_value(pic_equal_p(pic, x, y));
+}
+
 /* TODO: replace it with native opcode */
 static pic_value
 pic_bool_not(pic_state *pic)
@@ -48,6 +79,7 @@ pic_init_bool(pic_state *pic)
 {
   pic_defun(pic, "eq?", pic_bool_eq_p);
   pic_defun(pic, "eqv?", pic_bool_eqv_p);
+  pic_defun(pic, "equal?", pic_bool_equal_p);
 
   pic_defun(pic, "not", pic_bool_not);
   pic_defun(pic, "boolean?", pic_bool_boolean_p);