diff options
| -rw-r--r-- | lisp/emacs-lisp/seq.el | 13 | ||||
| -rw-r--r-- | test/automated/seq-tests.el | 5 |
2 files changed, 17 insertions, 1 deletions
diff --git a/lisp/emacs-lisp/seq.el b/lisp/emacs-lisp/seq.el index d4a9139758..a17b0a8f1b 100644 --- a/lisp/emacs-lisp/seq.el +++ b/lisp/emacs-lisp/seq.el @@ -48,6 +48,7 @@ ;; - `seq-do' ;; - `seq-p' ;; - `seq-subseq' +;; - `seq-into-sequence' ;; - `seq-copy' ;; - `seq-into' ;; @@ -200,7 +201,17 @@ The result is a sequence of the same type as SEQ." TYPE must be one of following symbols: vector, string or list. \n(fn TYPE SEQUENCE...)" - (apply #'cl-concatenate type seqs)) + (apply #'cl-concatenate type (seq-map #'seq-into-sequence seqs))) + +(cl-defgeneric seq-into-sequence (seq) + "Convert SEQ into a sequence. + +The default implementation is to signal an error if SEQ is not a +sequence, specific functions should be implemented for new types +of seq." + (unless (sequencep seq) + (error "Cannot convert %S into a sequence" seq)) + seq) (cl-defgeneric seq-into (seq type) "Convert the sequence SEQ into a sequence of type TYPE. diff --git a/test/automated/seq-tests.el b/test/automated/seq-tests.el index 163935b543..482daeecb9 100644 --- a/test/automated/seq-tests.el +++ b/test/automated/seq-tests.el @@ -312,5 +312,10 @@ Evaluate BODY for each created sequence. (should (= (seq-min seq) 0)) (should (= (seq-max seq) 5)))) +(ert-deftest test-seq-into-sequence () + (with-test-sequences (seq '(1 2 3)) + (should (eq seq (seq-into-sequence seq))) + (should-error (seq-into-sequence 2)))) + (provide 'seq-tests) ;;; seq-tests.el ends here |