pyparsing-users

[Pyparsing] Proposed notational shortcut for setResultsName

[Paul M. <pa...@al...>]

After the posts on c.l.py from Paul Boddie and Steven Bethard, it got me to
thinking about how to supply a notational shortcut to make
setResultsName'ing easier.  I've added this post to the pyparsing wiki Home
page Discussion (http://pyparsing.wikispaces.com/message/view/home/606302):
------------
I got to thinking after some postings on comp.lang.python about adding a
notational short cut for setResultsName. I really want to encourage people
to use named elements in their grammar, but that method name is just long
and ugly, and grammar-cluttering.

So how about adding a shortcut for setResultsName, using getitem? With this
short cut, this code:

    userdata = Word(alphas).setResultsName("name") +
Word(nums+"-").setResultsName("socsecno")

could be written as:

    userdata = Word(alphas)["name"] + Word(nums+"-")["socsecno"]

Any comments? Alternatives?
------------

I'm inclined to make this change, but I'd like a little feedback from those
who are using pyparsing.  I've not gotten any replies yet, so I'm trying the
other pyparsing communication channels (short of intruding on c.l.py).

If you have any comments, please reply here, or add them to the Wiki
discussion.

Thanks!
-- Paul

Re: [Pyparsing] Proposed notational shortcut for setResultsName

[Ralph C. <ra...@in...>]

Hi Paul,

> So how about adding a shortcut for setResultsName, using getitem? With this
> short cut, this code:
> 
>     userdata = Word(alphas).setResultsName("name") +
> Word(nums+"-").setResultsName("socsecno")
> 
> could be written as:
> 
>     userdata = Word(alphas)["name"] + Word(nums+"-")["socsecno"]

It just seems odd to use getitem to "set" something, i.e. the results
name.  What about having "_" as an attribute function instead so it
isn't too obtrusive?

    userdata = Word(alphas)._("name") + Word(nums+"-")._("socsecno")

Or

    userdata = Word(alphas, n = "name") + Word(nums+"-", n = "socsecno")

Cheers,


Ralph.