source: default/trunk/de.ugoe.cs.swe.bnftools.ebnf/src/de/ugoe/cs/swe/bnftools/Ebnf.xtext

grammar de.ugoe.cs.swe.bnftools.Ebnf hidden(WS, ML_COMMENT, SL_COMMENT)

import "http://www.eclipse.org/emf/2002/Ecore" as ecore

generate ebnf "http://www.ugoe.de/cs/swe/bnftools/Ebnf"

// -----------------------------------------------------------------------------------------------
// Parser Rules
// -----------------------------------------------------------------------------------------------
EtsiBnf:
        'grammar' name=ID
        (       type='/bnf'? ';' 
                (importSection=ImportSection)?
                (bnfEntry+=BnfEntry)+ 
        )
        | 
        (       type='/delta' ';'
                (importSection=ImportSection)?
                (deltaEntry+=DeltaEntry)*
        )
        | 
        (       type='/merge' ';' 
                (importSection=ImportSection)?
                (mergeEntry+=MergeEntry)* 
        )
;

ImportSection:
        (imports+=Import)+
;

BnfEntry:
        sectionheader=SectionHeading | rule=Rule
;

DeltaEntry:
        rule=Rule | sectionheader=SectionHeading | extRule=ExtRule
;

MergeEntry:
        sectionheader=SectionHeading | mergeRule=MergeRule
;

SectionHeading:
        {SectionHeading}
        sectionHeader=SECTIONHEADER
;


Import :
        'import' importURI=STRING 
        ('/' (grammarType='core' | grammarType='package' | grammarType='update'))?
        ('label:' label=ID)? ';'
;

Rule:
        (rulenumber=INT (rulevariant=ID)? '.')?  name=ID  '::=' (definitionList=DefinitionList)? ';'? 
;

ExtRule:
        (rulenumber=INT (rulevariant=ID)? '.')?  name=ID ('(' ruleext=INT ')') '<-' 
        (elements+=Atom | ')' | ']' | '}' | '|' | '(' | '[' | '{' | '*' | '+')* ';'? 
;

MergeRule:
        GlobalCombinator
        | RuleCombinator
        | HookCombinator
;
        
GlobalCombinator:
('global' 'combinator:') logic=LOGIC ';'?
;       

RuleCombinator:
('rule' 'combinator:' name=ID ) logic=LOGIC ('(' LABEL+=STRING ')')* ';'?
;

HookCombinator:
'hook' 'combinator:' name=ID '(' ruleext=INT ')' (logic=LOGIC)? ('(' LABEL+=STRING ')')+ ';'?
;

DefinitionList:
        singleDefinition+=SingleDefinition ('|' singleDefinition+=SingleDefinition)*
;

SingleDefinition:
        (terms+=Term)+
;

Term:
        termAtom=Atom
        | termGroupedSequence=GroupedSequence
        | termOptionalSequence=OptionalSequence
        | termRepeatedSequence=RepeatedSequence
;

Atom:
        atomStringRule=StringRule
        | atomRuleReference=RuleReference
;

RuleReference:
        ruleref=[Rule]
;

StringRule:
        literal=STRING
        | colon=COLON
;

GroupedSequence:
        '(' definitionList+=DefinitionList ')'
;

OptionalSequence:
        '[' definitionList+=DefinitionList ']'
;

RepeatedSequence:
        '{' definitions+=DefinitionList '}' morethanonce?='+'?
;

// -----------------------------------------------------------------------------------------------
// Lexer Rules
// -----------------------------------------------------------------------------------------------

terminal ID             : ('a'..'z'|'A'..'Z'|'_') ('a'..'z'|'A'..'Z'|'0'..'9'|'_')* ;
terminal INT            returns ecore::EInt: ('0'..'9')+;
terminal WS                     : (' '|'\t'|'\r'? '\n')+;
terminal COLON          : '"' '"' '"';
terminal STRING         : '"' !('"')* '"' | "'" !("'")*"'";
terminal SECTIONHEADER: ('a'..'z'|'A'..'Z') ('.'|('0'..'9'))+ (' '|'\t') !('\n'|'\r')* '\r'? '\n';
terminal SL_COMMENT     : '//' !('\n'|'\r')* ('\r'? '\n')?;
terminal ML_COMMENT     : '/*' -> '*/';
//TODO: a more intuitive notation
terminal LOGIC          : '/and' | '/or' | '/andr' | '/orr' | '/any' | '/together' ;