Allow last var to be omitted in whilet.

* eval.c (me_whilet): insert gensym if last var is missing.
Warn if init-form looks like a variable.

* txr.1: Documented by copy and paste from iflet.

1 files changed, 17 insertions, 0 deletions

diff --git a/txr.1 b/txr.1
index e1ef3748..0ef550de 100644
--- a/txr.1
+++ b/txr.1
@@ -13757,6 +13757,23 @@ loop is thus terminated by an explicit
 a return value can be specified. Under normal termination, the return value is
 .codn nil .
 
+In the syntax, a small convenience is permitted. Instead of the last
+.cblk
+.meti >> ( sym << init-form )
+.cble
+it is permissible for the syntax
+.cblk
+.meti <> ( init-form )
+.cble
+to appear, the
+.meta sym
+being omitted. A machine-generated variable is substituted
+in place of the missing
+.meta sym
+and that variable is then initialized from
+.meta init-form
+and used as the basis of the test.
+
 .TP* Examples:
 .cblk
   ;; read lines of text from *std-input* and print them,