[news.eclipse.technology.dltk] Re: ASTNode sourceStart and sourceEnd - r

["Chuck Doucette" <cdoucette@xxxxxxxxxxx>]

Thank you for the information.

I followed the model in the Example Python parser since that's the tutorial 
that was recommended to follow (although the parser was not specifically 
discussed in the tutorial).

I will look at the source code for TCL and Ruby and see what they do 
instead.

Chuck

"Andrei Sobolev" <haiodo@xxxxxxxxx> wrote in message 
news:g09l3j$omi$1@xxxxxxxxxxxxxxxxxxxx
> Hi Chuck,
>
> In the beginning of DLTK and Python support, ASTNode class was constructor 
> with ANTLR Token parameters.
> Then we move to Eclipse, we removed ANTLR dependency from core and created 
> this wrapper class. It is only used from
> Python parser. Better idea it is not to use it at all, as we do in Tcl and 
> Ruby.
>
> I suppose for some problems you described we have for some Python 
> statements.
>
> I suppose better idea for you is not to use DLTKToken at all. I've marked 
> this class as deprecated in HEAD.
>
> Best regards,
> Andrei Sobolev.
>
>> Every DLTKToken has the members:
>> line
>> column
>> text (from which you can get text.length())
>>
>> Please note that line is *never* read.
>>
>>
>> ASTNode has the members:
>> sourceStart
>> sourceEnd
>>
>> These are initialized in the constructor to be:
>>
>> protected ASTNode(DLTKToken token) {
>>   this.sourceStart = token.getColumn();
>>   String tokenValue = token.getText();
>>   if (tokenValue != null) {
>>     this.sourceEnd = this.sourceStart + tokenValue.length();
>>   }
>> }
>>
>> If this node is all on the first line, this makes sense.
>> If the node does not start on the first line or spans multiple lines, 
>> this
>> doesn't make sense.
>
>> Somehow you need to determine a running offset from the start of the 
>> source
>> module.
>> I don't see where/how that is done.
>>
>> Later, in ASTNode, is getSourceRange:
>>
>> protected ISourceRange getSourceRange() {
>>    return new SourceRange(this.sourceStart(), this.sourceEnd() -
>> this.sourceStart() + 1);
>> }
>>
>> Here's what the documentation for ISourceRange says:
>> A source range defines an element's source coordinates relative to its
>> source buffer.
>>
>> int getOffset()
>>           Returns the 0-based index of the first character of the source
>> code for this element, relative to the source buffer in which this 
>> element
>> is contained.
>>
>> int getLength()
>>           Returns the number of characters of the source code for this
>> element, relative to the source buffer in which this element is 
>> contained.
>>
>>
>