Adding whena macro.

We have ifa and conda; whena is conspicuously absent.

* lisplib.c (ifa_set_entries): Add autoload entry for whena.

* share/txr/stdlib/ifa.tl (whena): New macro.

* txr.1: Documented whena.

1 files changed, 3 insertions, 1 deletions

diff --git a/lisplib.c b/lisplib.c
index abdd8c1c..d5f0d1d1 100644
--- a/lisplib.c
+++ b/lisplib.c
@@ -106,7 +106,9 @@ static val ver_instantiate(val set_fun)
 
 static val ifa_set_entries(val dlt, val fun)
 {
-  val name[] = { lit("ifa"), lit("conda"), lit("condlet"), nil };
+  val name[] = {
+    lit("ifa"), lit("whena"), lit("conda"), lit("condlet"), nil
+  };
   set_dlt_entries(dlt, name, fun);
   return nil;
 }