From 15fdbc9c7da469613611ec1f93558d8f8a9648b8 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Tue, 29 Oct 2013 02:49:38 +0900
Subject: [PATCH] add some symbol primitive functions

---
 src/init.c   |  2 ++
 src/symbol.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+)

diff --git a/src/init.c b/src/init.c
index 42c572ea..46fcf0c3 100644
--- a/src/init.c
+++ b/src/init.c
@@ -10,6 +10,7 @@ void pic_init_time(pic_state *);
 void pic_init_system(pic_state *);
 void pic_init_file(pic_state *);
 void pic_init_proc(pic_state *);
+void pic_init_symbol(pic_state *);
 
 void
 pic_load_stdlib(pic_state *pic)
@@ -66,6 +67,7 @@ pic_init_core(pic_state *pic)
   pic_init_system(pic); DONE;
   pic_init_file(pic); DONE;
   pic_init_proc(pic); DONE;
+  pic_init_symbol(pic); DONE;
 
   pic_load_stdlib(pic); DONE;
 }
diff --git a/src/symbol.c b/src/symbol.c
index 7a84641b..b8212ba2 100644
--- a/src/symbol.c
+++ b/src/symbol.c
@@ -30,3 +30,49 @@ pic_symbol_name(pic_state *pic, pic_sym sym)
 {
   return pic->sym_pool[sym];
 }
+
+static pic_value
+pic_symbol_symbol_p(pic_state *pic)
+{
+  pic_value v;
+
+  pic_get_args(pic, "o", &v);
+
+  return pic_bool_value(pic_symbol_p(v));
+}
+
+static pic_value
+pic_symbol_symbol_to_string(pic_state *pic)
+{
+  pic_value v;
+
+  pic_get_args(pic, "o", &v);
+
+  if (! pic_symbol_p(v)) {
+    pic_error(pic, "symbol->string: expected symbol");
+  }
+
+  return pic_str_new_cstr(pic, pic_symbol_name(pic, pic_sym(v)));
+}
+
+static pic_value
+pic_symbol_string_to_symbol(pic_state *pic)
+{
+  pic_value v;
+
+  pic_get_args(pic, "o", &v);
+
+  if (! pic_str_p(v)) {
+    pic_error(pic, "string->symbol: expected string");
+  }
+
+  return pic_symbol_value(pic_intern_cstr(pic, pic_str_ptr(v)->str));
+}
+
+void
+pic_init_symbol(pic_state *pic)
+{
+  pic_defun(pic, "symbol?", pic_symbol_symbol_p);
+  pic_defun(pic, "symbol->string", pic_symbol_symbol_to_string);
+  pic_defun(pic, "string->symbol", pic_symbol_string_to_symbol);
+}