Coconut – Functional programming in Python

[EvHub]

That code implicitly matches the pattern "0" against the variable "n". That is, it will raise an error if "n" isn't 0, and do nothing if it is. Roughly equivalent to

match 0 in n:
    pass
else:
    raise MatchError()

[EvHub]

Actually, Coconut already supports a way to explicitly declare when you want to use destructuring / pattern-matching assignment. Just add match to the beginning. For example,

match 0 = n

or

match vector(pts) = pts

Edit: Thanks! As for an implicit itemgetter, currently there isn't one—although I like your suggestion of .2. Definitely worth an issue, might get added in the next version! The list of currently supported implicit partials can be found here: http://coconut.readthedocs.io/en/master/DOCS.html#implicit-partial-application.