* parser.y: Allow the (. expr) syntax to denote expr.

* eval.h: Declare existing lambda_s extern variable.

* lib.c (obj_print, obj_pprint): print (lambda sym ...)
as (lambda (. sym) ...) and (lambda sym) as (lambda (. sym)).

* txr.1: document it.

1 files changed, 28 insertions, 0 deletions

diff --git a/lib.c b/lib.c
index 7037585f..0c257102 100644
--- a/lib.c
+++ b/lib.c
@@ -5213,8 +5213,22 @@ val obj_print(val obj, val out)
           put_char(chr('('), out);
         }
 
+        if (sym == lambda_s && cdr(obj) && symbolp(second(obj))) {
+          obj_print(sym, out);
+          if (second(obj)) {
+            put_string(lit(" (. "), out);
+            obj_print(second(obj), out);
+            put_char(chr(')'), out);
+          } else {
+            put_string(lit(" ()"), out);
+          }
+          iter = (cdr(obj));
+          goto finish;
+        }
+
         for (iter = obj; consp(iter); iter = cdr(iter)) {
           obj_print(car(iter), out);
+finish:
           if (nilp(cdr(iter))) {
             put_char(closepar, out);
           } else if (consp(cdr(iter))) {
@@ -5379,8 +5393,22 @@ val obj_pprint(val obj, val out)
           put_char(chr('('), out);
         }
 
+        if (sym == lambda_s && cdr(obj) && symbolp(second(obj))) {
+          obj_print(sym, out);
+          if (second(obj)) {
+            put_string(lit(" (. "), out);
+            obj_print(second(obj), out);
+            put_char(chr(')'), out);
+          } else {
+            put_string(lit(" ()"), out);
+          }
+          iter = (cdr(obj));
+          goto finish;
+        }
+
         for (iter = obj; consp(iter); iter = cdr(iter)) {
           obj_pprint(car(iter), out);
+finish:
           if (nilp(cdr(iter))) {
             put_char(closepar, out);
           } else if (consp(cdr(iter))) {