add some char primitives

src/char.c

@@ -0,0 +1,39 @@
+#include "picrin.h"
+
+static pic_value
+pic_char_char_p(pic_state *pic)
+{
+  pic_value v;
+
+  pic_get_args(pic, "o", &v);
+
+  return pic_char_p(v) ? pic_true_value() : pic_false_value();
+}
+
+static pic_value
+pic_char_char_to_integer(pic_state *pic)
+{
+  char c;
+
+  pic_get_args(pic, "c", &c);
+
+  return pic_int_value(c);
+}
+
+static pic_value
+pic_char_integer_to_char(pic_state *pic)
+{
+  int i;
+
+  pic_get_args(pic, "i", &i);
+
+  return pic_char_value(i);
+}
+
+void
+pic_init_char(pic_state *pic)
+{
+  pic_defun(pic, "char?", pic_char_char_p);
+  pic_defun(pic, "char->integer", pic_char_char_to_integer);
+  pic_defun(pic, "integer->char", pic_char_integer_to_char);
+}

src/init.c

@@ -16,6 +16,7 @@ void pic_init_symbol(pic_state *);
 void pic_init_vector(pic_state *);
 void pic_init_blob(pic_state *);
 void pic_init_cont(pic_state *);
+void pic_init_char(pic_state *);
 
 void
 pic_load_stdlib(pic_state *pic)
@@ -81,6 +82,7 @@ pic_init_core(pic_state *pic)
   pic_init_vector(pic); DONE;
   pic_init_blob(pic); DONE;
   pic_init_cont(pic); DONE;
+  pic_init_char(pic); DONE;
 
   pic_load_stdlib(pic); DONE;
 }

src/vm.c

@@ -216,6 +216,24 @@ pic_get_args(pic_state *pic, const char *format, ...)
 	}
       }
       break;
+    case 'c':
+      {
+	char *c;
+	pic_value v;
+
+	c = va_arg(ap, char *);
+	if (i < argc) {
+	  v = GET_OPERAND(pic,i);
+	  if (pic_char_p(v)) {
+	    *c = pic_char(v);
+	  }
+	  else {
+	    pic_error(pic, "pic_get_args: expected char");
+	  }
+	  i++;
+	}
+      }
+      break;
     default:
       {
 	pic_error(pic, "pic_get_args: invalid argument specifier given");