Re: [PATCH] Gnu Elpa: stream.el: Add some more basic stream operations

[Michael Heerdegen]

Yuri Khan <address@hidden> writes:

> You’re right, drop-until is not a good match for this semantics. By
> the way, how would you describe the required behavior without going
> operational (mirroring the implementation)?

If you asking the question implies that you find the semantics not
trivially clear, maybe the following simpler (even superior) approach
would be much better: Add an optional integer type argument to
`seq-drop-while' and `seq-take-while' that allows to shift the index by
the specified amount (as far as possible):

#+begin_src emacs-lisp
(cl-defgeneric seq-drop-while (pred sequence &optional less)
  (seq-drop sequence (- (seq--count-successive pred sequence) (or less 0))))

(cl-defgeneric seq-take-while (pred sequence &optional more)
  (seq-take sequence (+ (seq--count-successive pred sequence) (or more 0))))
#+end_src


Michael.