Mojo: Mojom: Disallow trailing commas in parameter lists.

Mojo: Mojom: Disallow trailing commas in parameter lists.

Also:
* Using len(p) to figure out which rule was matched is janky. Instead,
  use different functions (for the parameter list things).
* Change the grammar so that parameters get appended to the back of
  parameter lists, rather than inserted at the front.

R=jamesr@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=281110

[viettrungluu, 2014-07-02 18:28:53]

(Dependent on https://codereview.chromium.org/366873007/.)

[jamesr, 2014-07-02 22:03:01]

based on what it does to the tests lgtm, but is there anywhere that documents
what the suffixes mean to PLY if they have a special meaning? if so can you put
a reference in the comments? if they don't have a special meaning then i've no
idea how this works...

https://codereview.chromium.org/364003002/diff/20001/mojo/public/tools/bindin...
File mojo/public/tools/bindings/pylib/mojom/parse/parser.py (right):

https://codereview.chromium.org/364003002/diff/20001/mojo/public/tools/bindin...
mojo/public/tools/bindings/pylib/mojom/parse/parser.py:180: def
p_parameter_list_1(self, p):
do _1 / _2 have any particular meaning? i'd expect naively for this to mean
"with one parameter" and "with two parameters" but that clearly isn't the case.
can we name these something else?

[viettrungluu, 2014-07-02 23:08:19]

On 2014/07/02 22:03:01, jamesr wrote:
> based on what it does to the tests lgtm, but is there anywhere that documents
> what the suffixes mean to PLY if they have a special meaning? if so can you
put
> a reference in the comments? if they don't have a special meaning then i've no
> idea how this works...

ply doesn't care very much about a function's name, only about its docstring.
(See http://www.dabeaz.com/ply/ply.html#ply_nn25 -- you can not only have
multiple functions for the same LHS, but you can also have a single function
that has multiple LHSes.)

> 
>
https://codereview.chromium.org/364003002/diff/20001/mojo/public/tools/bindin...
> File mojo/public/tools/bindings/pylib/mojom/parse/parser.py (right):
> 
>
https://codereview.chromium.org/364003002/diff/20001/mojo/public/tools/bindin...
> mojo/public/tools/bindings/pylib/mojom/parse/parser.py:180: def
> p_parameter_list_1(self, p):
> do _1 / _2 have any particular meaning? i'd expect naively for this to mean
> "with one parameter" and "with two parameters" but that clearly isn't the
case.
> can we name these something else?

(I was following the pattern in
https://github.com/eliben/pycparser/blob/master/pycparser/c_parser.py, which is
a project linked to as an example on the ply page. I'll come up with more
descriptive names.)

[viettrungluu, 2014-07-02 23:12:51]

On 2014/07/02 23:08:19, viettrungluu wrote:
> On 2014/07/02 22:03:01, jamesr wrote:
> > based on what it does to the tests lgtm, but is there anywhere that
documents
> > what the suffixes mean to PLY if they have a special meaning? if so can you
> put
> > a reference in the comments? if they don't have a special meaning then i've
no
> > idea how this works...
> 
> ply doesn't care very much about a function's name, only about its docstring.
> (See http://www.dabeaz.com/ply/ply.html#ply_nn25 -- you can not only have
> multiple functions for the same LHS, but you can also have a single function
> that has multiple LHSes.)
> 
> > 
> >
>
https://codereview.chromium.org/364003002/diff/20001/mojo/public/tools/bindin...
> > File mojo/public/tools/bindings/pylib/mojom/parse/parser.py (right):
> > 
> >
>
https://codereview.chromium.org/364003002/diff/20001/mojo/public/tools/bindin...
> > mojo/public/tools/bindings/pylib/mojom/parse/parser.py:180: def
> > p_parameter_list_1(self, p):
> > do _1 / _2 have any particular meaning? i'd expect naively for this to mean
> > "with one parameter" and "with two parameters" but that clearly isn't the
> case.
> > can we name these something else?
> 
> (I was following the pattern in
> https://github.com/eliben/pycparser/blob/master/pycparser/c_parser.py, which
is
> a project linked to as an example on the ply page. I'll come up with more
> descriptive names.)

On second thought, I think I prefer naming them after the LHS of the rule; it
makes it clear that there are multiple functions handling the same LHS (and
avoids confusion about what rule a function is handling). I'll add a comment
explaining this at the top.

[viettrungluu, 2014-07-02 23:34:07]

Committed patchset #3 manually as r281110 (presubmit successful).