Re: ASCII Name and URL Elements (2nd)

[Roger H. <rog...@mi...>]

On 14 May, 2007, at 17:23, James W. Walker wrote:

> On May 14, 2007, at 2:21 AM, Roger Holmes wrote:
>
>>
>> On 14 May, 2007, at 00:32, James W. Walker wrote:
>>
>>>
>>> On May 12, 2007, at 9:10 AM, Stefan Huber wrote:
>>>
>>>> Please ignore the previous mail. So once again...
>>>>
>>>> "Apple Computer, Inc.:NameElement" and "Apple Computer, Inc.:
>>>> URLElement" are not very parser friendly.
>>>>
>>>> The problem is in E3FFR_3DMF_Text.c/
>>>> e3fformat_3dmf_text_readobjecttype.
>>>> E3FileFormat_GenericReadText_ReadUntilChars with argument blank =
>>>> true cannot read object types with blanks in their name. So the
>>>> parser tries to handle an object "Apple" and runs into trouble.
>>>
>>> I wish Apple had published a formal grammar for ASCII 3DMF.  It is
>>> not clear to me how the parser is supposed to know where an object
>>> type ends, or how to tell the difference between a label and an
>>> object type.
>>
>> I agree. But here, can't we just read everything up to the colon?
>
> That takes you to the middle of the name element object type.  Then
> what?

 From the only two samples so far mentioned, the spaces are only in  
the first part of the name element object type. The rest is a normal  
identifier terminated by white space or any non alpha-numeric character.

> It appears that in a label, the colon should always be
> followed by a line break.  So, if it's not followed by a line break,
> we continue reading up to the open parenthesis?

A parser or any lexical analyser does not need to apply the same  
rules to a symbol in all circumstances. A label can have different  
rules to a name element object type. Any compiler can treat a colon  
in a comment differently from a colon in a statement.