bug#25129: 26.0.50; seq-some function

[Pierre Lorenzon]

Is documentation in following seq-somme function not ambiguous
? One might believe taht it returns the element and not the
test result as it does. Moreover I suspect even if I did not
verify that it was not so in a previous implementation since I
had no error in my code before using seq-some.


I well understand now that I must use seq-find instead of
seq-some but I think that I will not be the only one being
confused by these functions specifications !

In fact there is a very subtle difference between two
documentation : value not equal element .... But what means
value ? Is it obvious taht it means test result ?


Regards

Pierre
>>>  -- Code 

(cl-defgeneric seq-some (pred sequence)
  "Return the first value for which if (PRED element) is non-nil for in 
SEQUENCE."
  (catch 'seq--break
    (seq-doseq (elt sequence)
      (let ((result (funcall pred elt)))
        (when result
          (throw 'seq--break result))))
    nil))

(cl-defgeneric seq-find (pred sequence &optional default)
  "Return the first element for which (PRED element) is non-nil in SEQUENCE.
If no element is found, return DEFAULT.

Note that `seq-find' has an ambiguity if the found element is
identical to DEFAULT, as it cannot be known if an element was
found or not."
  (catch 'seq--break
    (seq-doseq (elt sequence)
      (when (funcall pred elt)
        (throw 'seq--break elt)))
    default))

>>>  -- End Code 









In GNU Emacs 26.0.50.1 (x86_64-unknown-linux-gnu)
 of 2016-11-15 built on jabberwocky
Repository revision: db43613307bb05d0f43d2d5649b5bb2f29876cee
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