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-rw-r--r--libguile/srfi-1.c18
-rw-r--r--libguile/srfi-1.h1
-rw-r--r--module/srfi/srfi-1.scm11
3 files changed, 11 insertions, 19 deletions
diff --git a/libguile/srfi-1.c b/libguile/srfi-1.c
index 39291a439..1651bcd5b 100644
--- a/libguile/srfi-1.c
+++ b/libguile/srfi-1.c
@@ -575,24 +575,6 @@ SCM_DEFINE (scm_srfi1_delete_duplicates_x, "delete-duplicates!", 1, 1, 0,
}
#undef FUNC_NAME
-SCM_DEFINE (scm_srfi1_find_tail, "find-tail", 2, 0, 0,
- (SCM pred, SCM lst),
- "Return the first pair of @var{lst} whose @sc{car} satisfies the\n"
- "predicate @var{pred}, or return @code{#f} if no such element is\n"
- "found.")
-#define FUNC_NAME s_scm_srfi1_find_tail
-{
- SCM_VALIDATE_PROC (SCM_ARG1, pred);
-
- for ( ; scm_is_pair (lst); lst = SCM_CDR (lst))
- if (scm_is_true (scm_call_1 (pred, SCM_CAR (lst))))
- return lst;
- SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (lst), lst, SCM_ARG2, FUNC_NAME, "list");
-
- return SCM_BOOL_F;
-}
-#undef FUNC_NAME
-
SCM_DEFINE (scm_srfi1_length_plus, "length+", 1, 0, 0,
(SCM lst),
"Return the length of @var{lst}, or @code{#f} if @var{lst} is\n"
diff --git a/libguile/srfi-1.h b/libguile/srfi-1.h
index fa21dc42a..3faaaa428 100644
--- a/libguile/srfi-1.h
+++ b/libguile/srfi-1.h
@@ -33,7 +33,6 @@ SCM_INTERNAL SCM scm_srfi1_delete (SCM x, SCM lst, SCM pred);
SCM_INTERNAL SCM scm_srfi1_delete_x (SCM x, SCM lst, SCM pred);
SCM_INTERNAL SCM scm_srfi1_delete_duplicates (SCM lst, SCM pred);
SCM_INTERNAL SCM scm_srfi1_delete_duplicates_x (SCM lst, SCM pred);
-SCM_INTERNAL SCM scm_srfi1_find_tail (SCM pred, SCM lst);
SCM_INTERNAL SCM scm_srfi1_length_plus (SCM lst);
SCM_INTERNAL SCM scm_srfi1_lset_difference_x (SCM equal, SCM lst, SCM rest);
SCM_INTERNAL SCM scm_srfi1_list_copy (SCM lst);
diff --git a/module/srfi/srfi-1.scm b/module/srfi/srfi-1.scm
index e5b28e777..1fc7a0e26 100644
--- a/module/srfi/srfi-1.scm
+++ b/module/srfi/srfi-1.scm
@@ -731,6 +731,17 @@ the list returned."
head
(loop (cdr lst)))))))
+(define (find-tail pred lst)
+ "Return the first pair of @var{lst} whose @sc{car} satisfies the
+predicate @var{pred}, or return @code{#f} if no such element is found."
+ (check-arg procedure? pred find)
+ (let loop ((lst lst))
+ (and (not (null? lst))
+ (let ((head (car lst)))
+ (if (pred head)
+ lst
+ (loop (cdr lst)))))))
+
(define (take-while pred ls)
"Return a new list which is the longest initial prefix of LS whose
elements all satisfy the predicate PRED."