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Problem with quoted string that should be split [message #1608452]

Mon, 09 February 2015 09:28

Eclipse User

Hi, first post of probably many.

I am using XText to define a DSL that needs to understand both:

base myPrefix:myName;

and

base "myPrefix:myName";

"myPrefix" is optional and should map to "namespace" in the ecore model, "myName" is mandatory and should map to "name" in the ecore model

I have tried without success both to have a terminal rule for a quoted string and also to hide all quotes with the "hidden" keyword.

What I try with now is to have a terminal rule eat the whole string and have a value converter split it into namespace and name, but so far no success with that either...

So any suggestions for way forward is highly appreciated! Let me know if I should clarify anything.

Thanks, Fredrik

Re: Problem with quoted string that should be split [message #1608503 is a reply to message #1608452]

Mon, 09 February 2015 10:08

Eclipse User

Hi,

just to clear semantics:

is it really two pointers? or is it a pointer by a (optionally) qualified name? if so you could use a datatype rule like

NAME: STRING | ID ":" ID; //+ a value converter that does the validation

if it really are 2 different pointer it will be very tricky (if you want to keep the normal strings as well)

Re: Problem with quoted string that should be split [message #1608865 is a reply to message #1608503]

Mon, 09 February 2015 15:26

Eclipse User

Hi, thanks for your quick answer.

Yes, two pointers unfortunately, the parser rule looks like this currently:

Base returns dsl::Base: 
	'base' (namespace=[dsl::Prefix]':')?name=StringPatternToSplit ';'
;

This works for unqouted strings, and also for quoted strings if I make a terminal rule to eat the quotes and hide them. However that solution breaks the dsl in other places. The basic problem is that the language needs to allow anything betweet quotes, so if I grab only the quotes with a terminal rule I need to handle everything in between specifically.

I also tried to make a terminal rule to grab quoted strings that contained "{" and/or "}" but failed. Is this possible and if so do you have any pointers on how to do it?

Thanks, Fredrik

Re: Problem with quoted string that should be split [message #1608962 is a reply to message #1608865]

Mon, 09 February 2015 16:58

Eclipse User

Hi,

sounds you want to have context sensual lexing. this can be done if you use a custom lexer in xtext. there should be some threads on that in the forum.

Re: Problem with quoted string that should be split [message #1609617 is a reply to message #1608962]

Tue, 10 February 2015 03:22

Eclipse User

Hi,

Ok, I will have a look at that,

Thanks for the pointer!
Regards, Fredrik

Re: Problem with quoted string that should be split [message #1609636 is a reply to message #1609617]

Tue, 10 February 2015 03:35

Eclipse User

another search term may be "external lexer"

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