branch: externals/stream
commit b2f650a8a6ea5234b0810f0a322c510a2525442e
Author: Earl Hyatt <oka...@protonmail.com>
Commit: Stefan Monnier <monn...@iro.umontreal.ca>
Add an implementation of `seq-concatenate` for streams.
* stream.el (stream): Add a method for creating a stream from a stream,
which really just returns the original stream unmodified.
* stream.el (seq-concatenate): Add implementation for streams.
* tests/stream-tests (stream-seq-concatenate-test, stream-seq-mapcat-test):
Add tests for seq-concatenate and seq-mapcat, which by default uses
seq-concatenate.
---
stream.el | 9 +++++++++
tests/stream-tests.el | 21 +++++++++++++++++++++
2 files changed, 30 insertions(+)
diff --git a/stream.el b/stream.el
index dea42b4962..f9210ed324 100644
--- a/stream.el
+++ b/stream.el
@@ -164,6 +164,10 @@ FIRST and REST are forms and REST must return a stream."
(cl-defgeneric stream (src)
"Return a new stream from SRC.")
+(cl-defmethod stream ((stream stream))
+ "Return STREAM unmodified."
+ stream)
+
(cl-defmethod stream ((seq sequence))
"Return a stream built from the sequence SEQ.
SEQ can be a list, vector or string."
@@ -492,6 +496,11 @@ calling this function."
(cl-defmethod seq-copy ((stream stream))
"Return a shallow copy of STREAM."
(stream-delay stream))
+
+(cl-defmethod seq-concatenate ((_type (eql stream)) &rest sequences)
+ "Make a stream which concatenates each sequence in SEQUENCES."
+ (apply #'stream-append (mapcar #'stream sequences)))
+
;;; More stream operations
diff --git a/tests/stream-tests.el b/tests/stream-tests.el
index 997dd8607b..5d3f116d13 100644
--- a/tests/stream-tests.el
+++ b/tests/stream-tests.el
@@ -212,6 +212,27 @@
(and (equal res1 5)
(equal res2 5)))))
+(ert-deftest stream-seq-concatenate-test ()
+ (should (streamp (seq-concatenate 'stream (list 1 2) (vector 3 4) (stream
(list 5 6)))))
+ (should (equal '(1 2 3 4 5 6)
+ (seq-into (seq-concatenate 'stream
+ (list 1 2)
+ (vector 3 4)
+ (stream (list 5 6)))
+ 'list))))
+
+(ert-deftest stream-seq-mapcat-test ()
+ (should (streamp (seq-mapcat #'stream (list (list 1 2)
+ (vector 3 4)
+ (stream (list 5 6)))
+ 'stream)))
+ (should (equal '(1 2 3 4 5 6)
+ (seq-into (seq-mapcat #'stream (list (list 1 2)
+ (vector 3 4)
+ (stream (list 5 6)))
+ 'stream)
+ 'list))))
+
(ert-deftest stream-seq-copy-test ()
(should (streamp (seq-copy (stream-range))))
(should (= 0 (stream-first (seq-copy (stream-range)))))
