* lisplib.c (ifa_set_entries): Add conda.

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

* tests/012/ifa.tl: Adding test for conda.

* txr.1: Documenting conda.

1 files changed, 34 insertions, 0 deletions

diff --git a/txr.1 b/txr.1
index e3a61513..f043344d 100644
--- a/txr.1
+++ b/txr.1
@@ -10941,6 +10941,40 @@ form.
   -> (4)
 .cble
 
+.coNP Macro @ conda
+.synb
+.mets (conda >> {( test << form *)}*)
+.syne
+.desc
+The
+.code conda
+operator provides a multi-branching conditional evaluation of
+forms, similarly to the
+.code cond
+operator. Enclosed in the cond form are groups of forms expressed as lists.
+Each group must be a list of at least one form.
+
+The
+.code conda
+operator is anaphoric: it expands into a nested structure of zero or more
+.code ifa
+invocations, according to these patterns:
+
+.cble
+  (conda) -> nil
+  (conda (x y ...) ...) -> (ifa x (progn y ...) (conda z ...))
+.cblk
+
+Thus,
+.code conda
+inherits all the restrictions on the
+.meta test
+expressions from
+.codn ifa ,
+as well as the anaphoric
+.code it
+variable feature.
+
 .coNP Macro @ dotimes
 .synb
 .mets (dotimes >> ( var < count-form <> [ result-form ]) << body-form *)