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Input with multiple alternatives [message #1755945]

Thu, 09 March 2017 08:16

Eclipse User

Hello guys.

I have the following problem in my grammar:

This rule overlaps the terminal rule ID, native from Xtext.

terminal FREESTRING:  (('\\')?('a'..'z'|'A'..'Z'|'0'..'9'|','))*;

As a result, my log shows:

Decision can match input such as "RULE_FREESTRING" using multiple alternatives: 1, 2

And now I need to use the ID rule in another rules, so then, the parser can't recognize the input as a ID, as follows:

Env: 'ENV' name=ID ':' value=NL '.';

I've tried to use syntatic predicates, but it does not work:

Env: ('ENV' => name=ID) ':' value=NL '.';

How can I solve this problem?

Thanks in advance!

[Updated on: Thu, 09 March 2017 12:39] by Moderator

Re: Input with multiple alternatives [message #1755947 is a reply to message #1755945]

Thu, 09 March 2017 08:19

Eclipse User

Hi,

you might have a look at the concepts of
- terminal fragments
- datatype rules
- validation

can you please share a minimal complete grammar + sample model

[Updated on: Thu, 09 March 2017 08:48] by Moderator

Re: Input with multiple alternatives [message #1755975 is a reply to message #1755947]

Thu, 09 March 2017 12:49

Eclipse User

Hi, I'll share my entire grammar:

And a sample is:

The system SHALL save all the data;
ENV size: 16Gb.
ENV maxFiles: 32.

So, the problem is in the declaration of these "ENV" variables, the name of these variables is not recognized as ID, and I think that this occurs becose of the rule FREESTRING, wich overlaps the ID rule.

Thanks.

[Updated on: Thu, 09 March 2017 16:43] by Moderator

Re: Input with multiple alternatives [message #1755982 is a reply to message #1755975]

Thu, 09 March 2017 14:10

Eclipse User

well if i write minimal i do that with a reason Sad

and what you try to do is the very hardest thing to do in xtext.

and there a lot very strange concepts in your grammar.
what separates a String primitive from the next one?

Requirements:
	requirements+=Requirement+;

Requirement:
	(root+=Sentence)+ ';' ;
	
Sentence:
	(root+=StringValue)+ & '.'?;

terminal FREESTRING:  (('\\')?('a'..'z'|'A'..'Z'|'0'..'9'|','))*;

NL hidden(WS): FREESTRING ( FREESTRING)*;

StringValue:value=NL;

this problem is there even if you generalize FREESTRING and ID to a common superrule e.g. by loosenin ID

for me that looks very hard to solve without a custom lexer that is more intelligent and knows what is a FREESTRING and what is a ID

Re: Input with multiple alternatives [message #1755987 is a reply to message #1755982]

Thu, 09 March 2017 14:33

Eclipse User

=> I'd first use ID only and solve the grammar problem
And then have a look at the Lexing problem

Re: Input with multiple alternatives [message #1755993 is a reply to message #1755987]

Thu, 09 March 2017 15:17

Eclipse User

Hi, thanks for answer.

Yes, it's a very strange grammar, and I'm just implementing it, I did not created this language. All of this freedom in this grammar has complicated my work many times. Answering your question, what separates a primitive String from the next one is some key word (like SHALL), just it, so I have parts in Natural Language inside of this language (Relax Language).

Is a strange concept, but the language is in this way. And this is the way how I could get do it, I don't know if is the better one.

So, in this case, predicates will not work?

Re: Input with multiple alternatives [message #1755994 is a reply to message #1755993]

Thu, 09 March 2017 15:19

Eclipse User

No I mean

Bla bla bla

One sentence or three sentences

Re: Input with multiple alternatives [message #1755995 is a reply to message #1755994]

Thu, 09 March 2017 15:29

Eclipse User

Bla bla bla will be trated as one sentence.

Re: Input with multiple alternatives [message #1755996 is a reply to message #1755995]

Thu, 09 March 2017 15:31

Eclipse User

So what separates two sentences?

Re: Input with multiple alternatives [message #1755998 is a reply to message #1755996]

Thu, 09 March 2017 15:53

Eclipse User

The dot charactere "."

Sentence:
	(root+=General)+ & '.'?;

Re: Input with multiple alternatives [message #1755999 is a reply to message #1755998]

Thu, 09 March 2017 15:54

Eclipse User

Why the &

Re: Input with multiple alternatives [message #1756000 is a reply to message #1755999]

Thu, 09 March 2017 15:55

Eclipse User

And why is the dot optional

Re: Input with multiple alternatives [message #1756001 is a reply to message #1756000]

Thu, 09 March 2017 16:10

Eclipse User

The & charactere was added, because without it, an error occurs:

5962 [main] ERROR mf.mwe2.launch.runtime.Mwe2Launcher - Problems running workflow br.edu.unipampa.lesa.relaxEditor.GenerateRelax:
[ERROR]: GeneratorException: (Element: -UNKNOWN-; Reported by: XtextGenerator)

...

Caused by: java.io.FileNotFoundException: /home/paulo/workspaces/dsl/br.edu.unipampa.lesa.relaxEditor/../br.edu.unipampa.lesa.relaxEditor/src-gen/br/edu/unipampa/lesa/relaxEditor/parser/antlr/internal/InternalRelaxLexer.java (Arquivo ou diretório não encontrado)

I do not know why it happend.

And dot is optional, because one requirement may contain just one sentence.

Re: Input with multiple alternatives [message #1756003 is a reply to message #1756001]

Thu, 09 March 2017 16:27

Eclipse User

The system SHALL save all the data;

how should that be parseable?

after the Primitive there must be an until ?

Requirements:
	(requirements+=Requirement ';')+;
	
	Properties:
	property=Env|Mon|Dep|Rel
;

Env: ('ENV' => name=FREESTRING) ':' value=NL '.';
Mon: ('MON' => name=FREESTRING) ':' value=NL '.';
Rel: 'REL:' mon=[Mon]'-'env=[Env] '.';
Dep: 'DEP:' NL '.';

Requirement:
	(root+=General ('.' root+=General)* '.'?)  (properties+=Properties)*;
	
//declaramos tipos ainda nao existentes
terminal BOOLEAN returns ecore::EBoolean:'true'|'false';
//a primeira parte eh o escape
terminal FREESTRING:  (('\\')?('a'..'z'|'A'..'Z'|'0'..'9'|','))*;

//Natural Language, trechos que serao em LN
NL hidden(WS): FREESTRING ( FREESTRING)*;

//Essa eh a regra mae da gramatica, ja tratando a recursividade a esquerda 
General:
	rest = Rest =>({UntilOperator.left=current}('UNTIL'|'until') right=General)*;

//aqui se encontram as demais regras da gramatica
Rest:
	rule = Primitive|ShallOperator|MayOperator|EventuallyOperator|BeforeOperator|AfterOperator|InOperator|AsCloseOperator|AsOperator
;
// tipos primitivos, como boleanos (previstos na gramatica original) e os trechos em LN
Primitive:
	BooleanValue | StringValue
;
//novamente os operadores primitivos
BooleanValue:value=BOOLEAN;
StringValue:value=NL;

//aqui sao tratados todos os operandos (exceto o UNTIL) 
ShallOperator:
	('SHALL'|'shall') elements=General;

MayOperator:
	("MAY"|'may') action1=General ('OR' 'MAY'|'or' 'may') action2=General;

EventuallyOperator:
	('EVENTUALLY'|'eventually') element=General;

BeforeOperator:
	('BEFORE'|'before') event=NL;// other=General;

AfterOperator:
	('AFTER'|'after') event=NL;// other=General;

InOperator:
	('IN'|'in') t=NL; //other=General;
	
//Frquencia ou Quantidade f or q
AsCloseOperator:
	('AS' 'CLOSE' 'AS' 'POSSIBLE' 'TO'|'as' 'close' 'as' 'possible' 'to') ForQ=NL //other=General 
;
//quebramos todos os operadores AS
AsOperator:
	AsEarlyOperator|AsLateOperator|AsManyOperator|AsFewOperator;

AsEarlyOperator:
	('AS' 'EARLY' 'AS' 'POSSIBLE'|'as' 'early' 'as' 'possible') value=General;
AsLateOperator:
	('AS' 'LATE' 'AS' 'POSSIBLE'|'as' 'late' 'as' 'possible') value=General;
AsManyOperator:
	('AS' 'MANY'|'as' 'many') (element=NL)? ('AS' 'POSSIBLE'|'as' 'possible') value=General;
AsFewOperator:
	('AS' 'FEW'|'as' 'few') (element=NL)? ('AS' 'POSSIBLE'|'as' 'possible') value=General;

Re: Input with multiple alternatives [message #1756004 is a reply to message #1756003]

Thu, 09 March 2017 16:29

Eclipse User

Which again. The question

What goes in which sentence

Re: Input with multiple alternatives [message #1756005 is a reply to message #1756004]

Thu, 09 March 2017 16:40

Eclipse User

Ok, Christian thanks for your time, this is a strange grammar, and I really don't know how to implement all os these strange things in Xtext.

If you want to see the original grammar, here is https://www.eclipse.org/forums/index.php?t=getfile&id=27544&

Thanks anyway.

Re: Input with multiple alternatives [message #1756006 is a reply to message #1756005]

Thu, 09 March 2017 17:12

Eclipse User

thus this original grammar have a name?

maybe you can try something like this

Requirements:
(requirements+=Requirement ';')+ (properties+=Properties)*;

Properties:
property=Env|Mon|Dep|Rel
;

Env: ('ENV' => name=FREESTRING) ':' value=NL '.';
Mon: ('MON' => name=FREESTRING) ':' value=NL '.';
Rel: 'REL:' mon=[Mon]'-'env=[Env] '.';
Dep: 'DEP:' x=NL '.';

Requirement:
(root+=General ('.' root+=General)* '.'?) ;
//declaramos tipos ainda nao existentes
terminal BOOLEAN returns ecore::EBoolean:'true'|'false';
//a primeira parte eh o escape

//Natural Language, trechos que serao em LN
NL hidden(WS): FREESTRING+;

//Essa eh a regra mae da gramatica, ja tratando a recursividade a esquerda
General:
rest = Rest =>({UntilOperator.left=current}('UNTIL'|'until') right=Rest)*;

//aqui se encontram as demais regras da gramatica
Rest:
(=>primitives+=Primitive* (shall=ShallOperator|may=MayOperator)?)
;
// tipos primitivos, como boleanos (previstos na gramatica original) e os trechos em LN
Primitive:
BooleanValue | StringValue
;
//novamente os operadores primitivos
BooleanValue:value=BOOLEAN;
StringValue:value=FREESTRING;

terminal FREESTRING:
(('\\')? ('a'..'z' | 'A'..'Z' | '0'..'9' | ','))*;

//aqui sao tratados todos os operandos (exceto o UNTIL)
ShallOperator:
=>('SHALL'|'shall') elements=General;

MayOperator:
=>("MAY"|'may') action1=General ('OR' 'MAY'|'or' 'may') action2=General;

Re: Input with multiple alternatives [message #1756007 is a reply to message #1756006]

Thu, 09 March 2017 17:22

Eclipse User

Thanks, I'll try it.

This grammar defines the Relax Language, wich is a language for requirements specification for Self-Adaptive Systems, so the grammars and all of this, is not my domain area. It is a new language, without tool supporting, the authors just have defined the grammar and semantics. It is an academic work yet.

[Updated on: Thu, 09 March 2017 17:44] by Moderator

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