[antlr-interest] .g vs .g4

[Kirby Bohling]

On Mon, Nov 7, 2011 at 12:01 PM, Terence Parr <parrt at cs.usfca.edu> wrote:
> yeah, maybe forcing tool to do .g4 is good otherwise why use it. .g4 means v4. .g means v3 (er…and v2).
> Ter

   Please don't do that.  If I want to call that file "foobar.g", or
"silly" what does it matter?  Have a declaration inside of the file if
need be, or be one of the wonderful handful and just add it as part of
the documentation at the top of the grammar?  When it doesn't work, I
promise, I'll get around to reading the docs at the top.

Every time I have a tool which refuses to do my bidding it just ends
up getting in my way.  What if I want to pipe it in over stdin so
there is no file name?  Virtually every time I write or use a tool
with tight constraints, later on I come across the counter example
where it is a big work around to get where I want to be because a tool
decided to dictate minor details.  It really irritates me that unzip
thinks the file _has_ to be named .zip, .z, or .Z.  I _know_ it is a
zip file, just unzip the thing, stop guessing at the file name.

Should the community say it is a best practice?  Absolutely, but I'm
really happy that the C/C++ pre-processor doesn't force me to name the
files "foo.h", or "foo.hpp" to get them to work.  At the very least,
put in the flags/switches for "expert mode", which will override any
of the magic auto-detection, so when I tell it what to, it just does
it.  I have no idea in what context that'll be useful, but in my
experience, there's always one.

Kirby


> On Nov 7, 2011, at 9:59 AM, Jim Idle wrote:
>
>> We started down this path with v3 and never really took it anywhere. I
>> would be in favor of using .g4 only.
>>
>> Jim
>>
>>> -----Original Message-----
>>> From: antlr-interest-bounces at antlr.org [mailto:antlr-interest-
>>> bounces at antlr.org] On Behalf Of Terence Parr
>>> Sent: Sunday, November 06, 2011 9:56 AM
>>> To: Eric
>>> Cc: antlr-interest Interest
>>> Subject: Re: [antlr-interest] .g vs .g4
>>>
>>> Hi Eric,I think we are going to allow .g as well.   Rather than a
>>> property in the grammar file itself that identifies the version, I
>>> think we were going to use the file extension for this reason. all v3
>>> grammars will be .g and people building v4 grammar should name them .g4
>>> Ter
>>> On Nov 6, 2011, at 9:29 AM, Eric wrote:
>>>
>>>>
>>>>
>>>> On Sun, Nov 6, 2011 at 12:22 PM, Terence Parr <parrt at cs.usfca.edu>
>>> wrote:
>>>> Hi, Sam Harwell and I are talking about the file extension for new
>>> ANTLR 4. We think it makes good sense to use .g4 to distinguish the new
>>> grammars. They're mostly compatible except that there is no need for
>>> syntactic predicates and .g4 allows immediate left recursion. I think
>>> it will reduce confusion about what version of ANTLR is necessary to
>>> compile a grammar.
>>>>
>>>> Ter
>>>>
>>>> List: http://www.antlr.org/mailman/listinfo/antlr-interest
>>>> Unsubscribe: http://www.antlr.org/mailman/options/antlr-
>>> interest/your-email-address
>>>>
>>>>
>>>> Hi Ter,
>>>>
>>>> Will v4 require the file type to be .g4, or will it accept .g and
>>> .g4?
>>>>
>>>> My preference is for .g4 only.
>>>>
>>>> Also, will there be a property in the grammar file that identifies
>>> the minimum version or required version. I think it would help for
>>> obvious reasons such as when a user post a grammar needing help or an
>>> example grammar is given.
>>>>
>>>> Thanks, Eric
>>>>
>>>>
>>>
>>>
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>
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