From dd108fe76bf8c124ec7d68ed0a346c54c01ad182 Mon Sep 17 00:00:00 2001
From: Kaz Kylheku <kaz@kylheku.com>
Date: Tue, 21 Jan 2014 06:18:34 -0800
Subject: * lib.c (car, cdr, ldiff): Extend to handle vectors and strings.
Thereby, numerous previously list-only operations in TXR Lisp now magically
handle strings and vectors.
* txr.1: Documented.
---
lib.c | 36 +++++++++++++++++++++++++++++++++---
1 file changed, 33 insertions(+), 3 deletions(-)
(limited to 'lib.c')
diff --git a/lib.c b/lib.c
index cbc50869..6e162c22 100644
--- a/lib.c
+++ b/lib.c
@@ -203,6 +203,16 @@ val car(val cons)
cons->lc.func = nil;
return cons->lc.car;
}
+ case VEC:
+ if (zerop(cons->v.vec[vec_length]))
+ return nil;
+ return cons->v.vec[0];
+ case STR:
+ case LIT:
+ case LSTR:
+ if (zerop(length_str(cons)))
+ return nil;
+ return chr_str(cons, zero);
default:
type_mismatch(lit("~s is not a cons"), cons, nao);
}
@@ -223,6 +233,13 @@ val cdr(val cons)
cons->lc.func = nil;
return cons->lc.cdr;
}
+ case VEC:
+ case STR:
+ case LIT:
+ case LSTR:
+ if (le(length(cons), one))
+ return nil;
+ return sub(cons, one, t);
default:
type_mismatch(lit("~s is not a cons"), cons, nao);
}
@@ -611,9 +628,22 @@ val ldiff(val list1, val list2)
{
list_collect_decl (out, ptail);
- while (list1 && list1 != list2) {
- list_collect (ptail, car(list1));
- list1 = cdr(list1);
+ switch (type(list2)) {
+ case STR:
+ case LIT:
+ case LSTR:
+ case VEC:
+ while (list1 && !equal(list1, list2)) {
+ list_collect (ptail, car(list1));
+ list1 = cdr(list1);
+ }
+ break;
+ default:
+ while (list1 && list1 != list2) {
+ list_collect (ptail, car(list1));
+ list1 = cdr(list1);
+ }
+ break;
}
return out;
--
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