May 24, 2016
3:42 p.m.
On Tue, May 24, 2016 at 5:59 PM, Michel Desmoulin
<desmoulinmichel@gmail.com> wrote:
> What about making it a function ?
>
> Pattern matching is complex, it can be like a mini language inside the
> language, just like regex.
>
> To match text we do:
>
> import re
> re.match('pattern', 'string')
>
> We could do the same for matching structures:
>
> from inspect import match
>
> def do(stuff):
> m = match(stuff): # m implements __call__
> if m('whatever mini language you like'):
> return foo
> if m('again'):
> return m.thing_your_extracted
>
Or with methods:
m = match(stuff)
if m.by_type(SomeType):
# handle SomeType
elif m.by_attrs('x', 'y'):
# do things with stuff.x and stuff.y
elif m.by_len(3):
x,y,z = stuff
# do things with x, y, z
> Pros:
>
> - no need for a new syntax
> - very explicit
> - use well know constructs
> - we can easily start experimenting with the matching language in a lib
> in Pypy
+ can be extended easily
>
> Cons:
>
> - much more verbose;
> - debugging your mini language and handling error is not as good;
+ probably slower
+ need to separately get the desired attributes/elements after matching.
-- Koos