* eval.c (eval_init): New gensym function registered.

* lib.c (gensym_counter): New variable.
(gensymv): New function.
(obj_init): Initialize gensym_counter.

* lib.h (gensym_counter, gensymv): Declared.

4 files changed, 26 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index bab15280..56554371 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2012-01-01  Kaz Kylheku  <kaz@kylheku.com>
+
+	* eval.c (eval_init): New gensym function registered.
+
+	* lib.c (gensym_counter): New variable.
+	(gensymv): New function.
+	(obj_init): Initialize gensym_counter.
+
+	* lib.h (gensym_counter, gensymv): Declared.
+
 2011-12-30  Kaz Kylheku  <kaz@kylheku.com>
 
 	* match.c (counter_k): New keyword symbol variable.
diff --git a/eval.c b/eval.c
index e5672f24..163f9135 100644
--- a/eval.c
+++ b/eval.c
@@ -1331,6 +1331,7 @@ void eval_init(void)
   reg_var(intern(lit("*keyword-package*"), user_package), keyword_package);
   reg_var(intern(lit("*system-package*"), user_package), system_package);
   reg_fun(intern(lit("make-sym"), user_package), func_n1(make_sym));
+  reg_fun(intern(lit("gensym"), user_package), func_n0v(gensymv));
   reg_fun(intern(lit("make-package"), user_package), func_n1(make_package));
   reg_fun(intern(lit("find-package"), user_package), func_n1(find_package));
   reg_fun(intern(lit("intern"), user_package), func_n2(intern));
diff --git a/lib.c b/lib.c
index a1663217..c5afc004 100644
--- a/lib.c
+++ b/lib.c
@@ -84,6 +84,8 @@ val null_list;
 
 val identity_f, equal_f, eql_f, eq_f, car_f, cdr_f;
 
+val gensym_counter;
+
 val prog_string;
 
 static val env_list;
@@ -1633,6 +1635,15 @@ val make_sym(val name)
   return obj;
 }
 
+val gensymv(val args)
+{
+  uses_or2;
+  gensym_counter = plus(gensym_counter, one);
+  val prefix = or2(car(args), lit("g"));
+  val name = format(nil, lit("~a~,04a"), prefix, gensym_counter, nao);
+  return make_sym(name);
+}
+
 val make_package(val name)
 {
   if (find_package(name)) {
@@ -3273,6 +3284,7 @@ static void obj_init(void)
   identity_f = func_n1(identity);
   car_f = func_n1(car);
   cdr_f = func_n1(cdr);
+  gensym_counter = zero;
   prog_string = string(progname);
 }
 
diff --git a/lib.h b/lib.h
index 6b3bf0a9..4c8d6e69 100644
--- a/lib.h
+++ b/lib.h
@@ -298,6 +298,8 @@ extern val null_list; /* (nil) */
 
 extern val identity_f, equal_f, eql_f, eq_f, car_f, cdr_f;
 
+extern val gensym_counter;
+
 extern const wchar_t *progname;
 extern val prog_string;
 
@@ -443,6 +445,7 @@ val span_str(val str, val set);
 val compl_span_str(val str, val set);
 val break_str(val str, val set);
 val make_sym(val name);
+val gensymv(val args);
 val make_package(val name);
 val find_package(val name);
 val intern(val str, val package);