nspredicate.grammar

/*
A Grammar for Apple's NSPredicate String Format Syntax

See: http://developer.apple.com/documentation/Cocoa/Conceptual/Predicates/Articles/pSyntax.html

*/

@wordState = '#';
@wordChars = '.' '[' ']';

@symbols = '==' '>=' '=>' '<=' '=<' '!=' '<>' '&&' '||';

@start = expr;

// Expressions
    expr                 = orTerm orOrTerm*;
    orOrTerm             = or orTerm;
    orTerm               = andTerm andAndTerm*;
    andAndTerm           = and andTerm;
    andTerm              = primaryExpr | compoundExpr; 
    compoundExpr         = '('! expr ')'!;
    primaryExpr          = predicate | negatedPredicate;
    negatedPredicate     = not predicate;

    predicate      = boolPredicate | comparisonPredicate | stringTestPredicate | collectionTestPredicate;


// values
    value   = keyPath | string | num | bool | array;

    string  = QuotedString;
    num     = Number;
    bool    = true | false;
    true    = 'true'!;
    false   = 'false'!;

// arrays
    array               = '{' arrayContentsOpt '}'!;
    arrayContentsOpt    = Empty | arrayContents;
    arrayContents       = value commaValue*;
    commaValue          = ','! value;


// keyPaths
    keyPath = Word;

//    keyPath        = key dotKey*;
//    key            = name memberAccess?;
//    name           = Word;
//    dotKey         = '.' key;
//    memberAccess   = '[' (num | 'FIRST' | 'LAST' | 'SIZE') ']';


// Comparison Tests
    comparisonPredicate     = numComparisonPredicate | collectionComparisonPredicate;

    numComparisonPredicate  = numComparisonValue comparisonOp numComparisonValue;
    numComparisonValue      = keyPath | num;

    comparisonOp            = eq | gt | lt | gtEq | ltEq | notEq | between;

    eq      = '=' | '==';
    gt      = '>';
    lt      = '<';
    gtEq    = '>=' | '=>';
    ltEq    = '<=' | '=<';
    notEq   = '!=' | '<>';
    between = 'BETWEEN';

// breaking these out to make the assembler callbacks simpler
    collectionComparisonPredicate   = collectionLtPredicate | collectionGtPredicate | collectionLtEqPredicate | collectionGtEqPredicate | collectionEqPredicate | collectionNotEqPredicate;
    
    collectionLtPredicate           = aggregateOp collection lt value;
    collectionGtPredicate           = aggregateOp collection gt value;
    collectionLtEqPredicate         = aggregateOp collection ltEq value;
    collectionGtEqPredicate         = aggregateOp collection gtEq value;
    collectionEqPredicate           = aggregateOp collection eq value;
    collectionNotEqPredicate        = aggregateOp collection notEq value;
    


// Boolean Value Predicates
    boolPredicate  = truePredicate | falsePredicate;

    truePredicate  = 'TRUEPREDICATE'!;
    falsePredicate = 'FALSEPREDICATE'!;



// Compound Expressions
    and = 'AND'! | '&&'!;
    or  = 'OR'!  | '||'!;
    not = 'NOT'! | '!'!;



// String Tests
    stringTestPredicate = string stringTestOp value;

    stringTestOp = beginswith | contains | endswith | like | matches;

    beginswith  = 'BEGINSWITH';
    contains    = 'CONTAINS';
    endswith    = 'ENDSWITH';
    like        = 'LIKE';
    matches     = 'MATCHES';


// Collection Tests
    collectionTestPredicate = value in collection;
    collection              = keyPath | array;
    in                      = 'IN'!;


// Aggregate Operators
    aggregateOp = any | some | all | none;
    any         = 'ANY';
    some        = 'SOME';
    all         = 'ALL';
    none        = 'NONE';