From 0e3c047c3fa3ef7d3e7168314bf6fdb0ba15443d Mon Sep 17 00:00:00 2001
From: Kaz Kyheku <kaz@kylheku.com>
Date: Mon, 24 Feb 2020 23:03:08 -0800
Subject: New function: assq and rassq.
TXR Lisp is henceforth a dialect in which
(cdr (assq key a-list))
works exactly as shown, without substitution of
assql or assoc.
* eval.c (eval_init): Register assq and rassq intrinsics.
* lib.c (assq, rassq): New functions.
* lib.h (assq, rassq): Declared.
* txr.1: Documented.
* tests/012/ashwin.tl: New file.
* tests/012/ashwin.expected: New file.
---
lib.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
(limited to 'lib.c')
diff --git a/lib.c b/lib.c
index 011da356..dc9f28d3 100644
--- a/lib.c
+++ b/lib.c
@@ -8178,6 +8178,20 @@ val assql(val key, val list)
return nil;
}
+val assq(val key, val list)
+{
+ list = nullify(list);
+
+ while (list) {
+ val elem = car(list);
+ if (eq(car(elem), key))
+ return elem;
+ list = cdr(list);
+ }
+
+ return nil;
+}
+
val rassoc(val key, val list)
{
list = nullify(list);
@@ -8206,6 +8220,20 @@ val rassql(val key, val list)
return nil;
}
+val rassq(val key, val list)
+{
+ list = nullify(list);
+
+ while (list) {
+ val elem = car(list);
+ if (eq(cdr(elem), key))
+ return elem;
+ list = cdr(list);
+ }
+
+ return nil;
+}
+
val acons(val car, val cdr, val list)
{
return cons(cons(car, cdr), list);
--
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