On 28 September 2011 19:44, Kazu Yamamoto
I didn't propose to add 'chop'. I proposed to add 'tailDropWhile'.
I understood that you wanting to be able to define `chop' was the motivation behind this proposal.
For real use, you are right. But to teach list programming to beginners, I think this is necessary. For instance, I would explain how to process String without regular expressions.
I still argue that this is a bad idea. To an extent, functional programmers tend to focus too much on lists as the be-all and end-all of data structures. Whilst lists are great at what they do and generally serve as a good "intermediary" data structure (e.g. converting a Map k a to a Seq (k,a) ), we should not be abusing them to do _everything_. In my opinion, teaching students to do a large amount of "fiddling" with the ends of lists is getting them used to bad habits. If you _really_ need to do a lot of stuff at the end of a list-like data structure, use a Seq or something. If you still want to use this to teach students (maybe because you're building them up to "but in general you shouldn't do this") then provide this function for their use elsewhere (either as something to copy/paste, or an auxiliary library for your class). But I don't think it belongs in Data.List. -- Ivan Lazar Miljenovic Ivan.Miljenovic@gmail.com IvanMiljenovic.wordpress.com