problem with declaration grammar?

[Ellery Newcomer]

jerry quinn wrote:
> Ellery Newcomer Wrote:
>>> Maybe I'm missing something.  The grammar shown in http://www.digitalmars.com/d/2.0/declaration.html has the following rules:
>>>
>>> BasicType2:
>>>         *
>>>         [ ]
>>>         [ Expression ]
>>>         [ Expression .. Expression ]
>>>         [ Type ]
>>>         delegate Parameters FunctionAttributesopt
>>>         function Parameters FunctionAttributesopt
>>>
>>> Declarator:
>>>         BasicType2 Declarator DeclaratorSuffixesopt
>>>         BasicType2 Identifier DeclaratorSuffixesopt
>>>
>>> With this definition, I don't see how you can get Declarator->Identifier.
>>>
>>> Jerry
>>>
>> You are correct. BasicType2 can match nothing. It should also be able to 
>> match what it does above multiple times.
> 
> As I'm looking at this further, there seems to be more issues.  In particular, I don't think the grammar can parse:
> 
> int (*x)(char);
> 
> as specified.  Doing so gives (my best attempt)
> 
> Decl -> BasicType Declarators ;
> BasicType -> int
> Declarators -> DeclaratorInitializer
> DeclaratorInitializer -> Declarator
> Declarator -> BasicType2 Identifier DeclaratorSuffixes
> BasicType2 -> NULL (assuming that the grammar should be revised like this)
> Identifier -> BAD PARSE
> 
> 

yeah, if you haven't figured out by now, the grammar is a bunch of hooey.

I spent like a month building an ANTLR grammar based on the above, and 
then realized much of it was garbage.

Then I spent two months going through the source code and rewriting most 
of the rules. Just got done with it a week or two ago :) That was all 
version 1, but it looks the same, so if memory serves the above rules 
should look something like this:

BasicType2_x:
	*
	[ ]
	[ Expression ]
	[ Expression .. Expression ]
	[ Type ]
	delegate Parameters FunctionAttributesopt
	function Paramters FunctionAttributesopt
BasicType2:
	BasicType2_x
	BasicType2 BasicType2_x
	epsilon
Declarator:
	BasicType2 Identifier DeclaratorSuffixesopt
	BasicType2 ( Declarator ) DeclaratorSuffixesopt

Apologies for any BNF misuse