Adding typecase macro.

* lisplib.c (type_set_entries, type_instantiate): New static
functions.
(lisplib_init): Register new functions in dl_table.

* share/txr/stdlib/type.tl: New file, providing typecase

* txr.1: Documented typecase.

1 files changed, 16 insertions, 0 deletions

diff --git a/lisplib.c b/lisplib.c
index cb4fdb48..09e0386f 100644
--- a/lisplib.c
+++ b/lisplib.c
@@ -242,6 +242,21 @@ static val except_instantiate(val set_fun)
   return nil;
 }
 
+static val type_set_entries(val dlt, val fun)
+{
+  val name[] = { lit("typecase"), nil };
+  set_dlt_entries(dlt, name, fun);
+  return nil;
+}
+
+static val type_instantiate(val set_fun)
+{
+  funcall1(set_fun, nil);
+  load(format(nil, lit("~a/type.tl"), stdlib_path, nao));
+  return nil;
+}
+
+
 
 val dlt_register(val dlt,
                  val (*instantiate)(val),
@@ -264,6 +279,7 @@ void lisplib_init(void)
   dlt_register(dl_table, with_stream_instantiate, with_stream_set_entries);
   dlt_register(dl_table, hash_instantiate, hash_set_entries);
   dlt_register(dl_table, except_instantiate, except_set_entries);
+  dlt_register(dl_table, type_instantiate, type_set_entries);
 }
 
 val lisplib_try_load(val sym)