New seq-contains-p predicate (Bug#34852)

* lisp/emacs-lisp/seq.el (seq-contains-p): New predicate function.  It
is a replacement for seq-contains which cannot be used as a predicate
when a sequence contains nil values as it returns the element found.
(seq-contains): Make obsolete.

* test/lisp/emacs-lisp/seq-tests.el (test-seq-contains-p):
(test-seq-intersection-with-nil, test-seq-set-equal-p-with-nil,
test-difference-with-nil): Add regression tests.

* doc/lispref/sequences.texi (Sequence Functions): Document
seq-contains-p.
This commit is contained in:
Nicolas Petton 2019-03-20 21:44:01 +01:00
parent 093d3e78d2
commit 287cc58f39
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3 changed files with 45 additions and 9 deletions

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@ -356,6 +356,7 @@ found or not."
count))
(cl-defgeneric seq-contains (sequence elt &optional testfn)
(declare (obsolete seq-contains-p "27.1"))
"Return the first element in SEQUENCE that is equal to ELT.
Equality is defined by TESTFN if non-nil or by `equal' if nil."
(seq-some (lambda (e)
@ -363,11 +364,20 @@ Equality is defined by TESTFN if non-nil or by `equal' if nil."
e))
sequence))
(cl-defgeneric seq-contains-p (sequence elt &optional testfn)
"Return non-nil if SEQUENCE contains an element equal to ELT.
Equality is defined by TESTFN if non-nil or by `equal' if nil."
(catch 'seq--break
(seq-doseq (e sequence)
(when (funcall (or testfn #'equal) e elt)
(throw 'seq--break t)))
nil))
(cl-defgeneric seq-set-equal-p (sequence1 sequence2 &optional testfn)
"Return non-nil if SEQUENCE1 and SEQUENCE2 contain the same elements, regardless of order.
Equality is defined by TESTFN if non-nil or by `equal' if nil."
(and (seq-every-p (lambda (item1) (seq-contains sequence2 item1 testfn)) sequence1)
(seq-every-p (lambda (item2) (seq-contains sequence1 item2 testfn)) sequence2)))
(and (seq-every-p (lambda (item1) (seq-contains-p sequence2 item1 testfn)) sequence1)
(seq-every-p (lambda (item2) (seq-contains-p sequence1 item2 testfn)) sequence2)))
(cl-defgeneric seq-position (sequence elt &optional testfn)
"Return the index of the first element in SEQUENCE that is equal to ELT.
@ -385,7 +395,7 @@ Equality is defined by TESTFN if non-nil or by `equal' if nil."
TESTFN is used to compare elements, or `equal' if TESTFN is nil."
(let ((result '()))
(seq-doseq (elt sequence)
(unless (seq-contains result elt testfn)
(unless (seq-contains-p result elt testfn)
(setq result (cons elt result))))
(nreverse result)))
@ -410,7 +420,7 @@ negative integer or 0, nil is returned."
"Return a list of the elements that appear in both SEQUENCE1 and SEQUENCE2.
Equality is defined by TESTFN if non-nil or by `equal' if nil."
(seq-reduce (lambda (acc elt)
(if (seq-contains sequence2 elt testfn)
(if (seq-contains-p sequence2 elt testfn)
(cons elt acc)
acc))
(seq-reverse sequence1)
@ -420,7 +430,7 @@ Equality is defined by TESTFN if non-nil or by `equal' if nil."
"Return a list of the elements that appear in SEQUENCE1 but not in SEQUENCE2.
Equality is defined by TESTFN if non-nil or by `equal' if nil."
(seq-reduce (lambda (acc elt)
(if (not (seq-contains sequence2 elt testfn))
(if (not (seq-contains-p sequence2 elt testfn))
(cons elt acc)
acc))
(seq-reverse sequence1)