On 02/21/2014 11:43 PM, Masklinn wrote:
On 2014-02-21, at 23:00 , spir <denis.spir@gmail.com> wrote:
Also, I don't find the idea of having a builtin construct for such hacks a good idea. Libs for which this may be practicle can return self --end of the story.
That has two issues though:
1. it makes chainability a decision of the library author, the library user gets to have no preference. This means e.g. you can't create a tree of elements in ElementTree in a single expression (AFAIK Element does not take children parameters). With cascading, the user can "chain" a library whose author did not choose to support chaining (in fact with cascading no author would ever need to support chaining again).
I agree with you, here...
2. where a return value can make sense (and be useful) the author *must* make a choice. No way to chain `dict.pop()` since it returns the popped value, even if `pop` was only used for its removal-with-shut-up properties. With cascading the user can have his cake and eat it: he gets the return value if he wants it, and can keep "chaining" if he does not care.
... not there (if I understand you well; not quite 100% sure). In fact, I find this point rather a counter-argument, something to avoid (again, if I understand). What I mean is that executing given methods should have consistent effect; also, you should use the right method for the right task: if you don't want a stack's top item _and_ have it removed, then don't use 'pop', otherwise you are misleading readers (including yourself maybe, later) (note 'pop' is just a convenience utility for this very case; we could just read and remove in 2 steps). d