/*******************************************************************************
 * Copyright (c) 2010 E.D.Willink and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     E.D.Willink - initial API and implementation
 *******************************************************************************/
grammar org.eclipse.ocl.xtext.essentialocl.EssentialOCL with org.eclipse.ocl.xtext.base.Base
import "http://www.eclipse.org/emf/2002/Ecore" as ecore
import "http://www.eclipse.org/ocl/2015/Pivot" as pivot
import "http://www.eclipse.org/ocl/2015/BaseCS" as base
import "http://www.eclipse.org/ocl/2015/EssentialOCLCS"
//generate essentialOCLCST "http://www.eclipse.org/ocl/3.0.0/EssentialOCLCST"
Model returns ContextCS:
	ownedExpression=ExpCS;

/** <<<This is a join point for derived grammars - replace with a more disciplined grammar extensibility>>> */
EssentialOCLReservedKeyword:
	'and'
	| 'else'
	| 'endif'
	| 'if'
	| 'implies'
	| 'in'
	| 'let'
	| 'not'
	| 'or'
	| 'then'
	| 'xor';

/** <<<This is a join point for derived grammars - replace with a more disciplined grammar extensibility>>> */
EssentialOCLUnaryOperatorName:
	'-' | 'not';

/** <<<This is a join point for derived grammars - replace with a more disciplined grammar extensibility>>> */
EssentialOCLInfixOperatorName:
	'*' | '/' | '+' | '-' | '>' | '<' | '>=' | '<=' | '=' | '<>' | 'and' | 'or' | 'xor' | 'implies';

/** <<<This is a join point for derived grammars - replace with a more disciplined grammar extensibility>>> */
EssentialOCLNavigationOperatorName:
	'.' | '->' | '?.' | '?->';

BinaryOperatorName:
	InfixOperatorName | NavigationOperatorName;

InfixOperatorName: 			// Intended to be overrideable
	EssentialOCLInfixOperatorName;

NavigationOperatorName: 	// Intended to be overrideable
	EssentialOCLNavigationOperatorName;

UnaryOperatorName: 			// Intended to be overrideable
	EssentialOCLUnaryOperatorName;

//---------------------------------------------------------------------
//  Names
//---------------------------------------------------------------------
/** <<<This is a join point for derived grammars - replace with a more disciplined grammar extensibility>>> */
EssentialOCLUnrestrictedName returns ecore::EString:
	Identifier;

UnrestrictedName returns ecore::EString: // Intended to be overridden
	EssentialOCLUnrestrictedName;

/** <<<This is a join point for derived grammars - replace with a more disciplined grammar extensibility>>> */
EssentialOCLUnreservedName returns ecore::EString:
	UnrestrictedName
|	CollectionTypeIdentifier
|	PrimitiveTypeIdentifier
|	'Tuple'
;

UnreservedName returns ecore::EString: // Intended to be overridden
	EssentialOCLUnreservedName;

URIPathNameCS returns base::PathNameCS:
	ownedPathElements+=URIFirstPathElementCS ('::' ownedPathElements+=NextPathElementCS)*;

URIFirstPathElementCS returns base::PathElementCS:
	referredElement=[pivot::NamedElement|UnrestrictedName] | {base::PathElementWithURICS} referredElement=[pivot::Namespace|URI];

//---------------------------------------------------------------------
//  Types
//---------------------------------------------------------------------
PrimitiveTypeIdentifier:
	'Boolean'
	| 'Integer'
	| 'Real'
	| 'String'
	| 'UnlimitedNatural'
	| 'OclAny'
	| 'OclInvalid'
	| 'OclVoid';

PrimitiveTypeCS returns base::PrimitiveTypeRefCS:
	name=PrimitiveTypeIdentifier;

CollectionTypeIdentifier returns ecore::EString:
	'Set'
	| 'Bag'
	| 'Sequence'
	| 'Collection'
	| 'OrderedSet';

CollectionTypeCS returns CollectionTypeCS:
	name=CollectionTypeIdentifier ('(' ownedType=TypeExpCS ')')?;

TupleTypeCS returns base::TupleTypeCS:
	name='Tuple' ('(' (ownedParts+=TuplePartCS (',' ownedParts+=TuplePartCS)*)? ')')?;

TuplePartCS returns base::TuplePartCS:
	name=UnrestrictedName ':' ownedType=TypeExpCS;

//---------------------------------------------------------------------
//  Literals
//---------------------------------------------------------------------
CollectionLiteralExpCS returns CollectionLiteralExpCS:
	ownedType=CollectionTypeCS
	'{' (ownedParts+=CollectionLiteralPartCS
	(',' ownedParts+=CollectionLiteralPartCS)*)?
	'}';

CollectionLiteralPartCS returns CollectionLiteralPartCS:
	(ownedExpression=ExpCS ('..' ownedLastExpression=ExpCS)?) | ownedExpression=PatternExpCS;

CollectionPatternCS returns CollectionPatternCS:
	ownedType=CollectionTypeCS
	'{' (ownedParts+=PatternExpCS
	(',' ownedParts+=PatternExpCS)*
	('++' restVariableName=Identifier))?
	'}';

ShadowPartCS returns ShadowPartCS:		// PatternPartCS
	referredProperty=[pivot::Property|UnrestrictedName] '='ownedInitExpression=(ExpCS|PatternExpCS);

PatternExpCS:
	patternVariableName=UnrestrictedName? ':' ownedPatternType=TypeExpCS;

LambdaLiteralExpCS returns LambdaLiteralExpCS:
	'Lambda' '{' ownedExpressionCS=ExpCS '}';

PrimitiveLiteralExpCS returns PrimitiveLiteralExpCS:
	NumberLiteralExpCS
	| StringLiteralExpCS
	| BooleanLiteralExpCS
	| UnlimitedNaturalLiteralExpCS
	| InvalidLiteralExpCS
	| NullLiteralExpCS;

TupleLiteralExpCS returns TupleLiteralExpCS:
	'Tuple' '{' ownedParts+=TupleLiteralPartCS (',' ownedParts+=TupleLiteralPartCS)* '}';

TupleLiteralPartCS returns TupleLiteralPartCS:
	name=UnrestrictedName (':' ownedType=TypeExpCS)? '=' ownedInitExpression=ExpCS;

NumberLiteralExpCS returns NumberLiteralExpCS:
	symbol=NUMBER_LITERAL;

StringLiteralExpCS returns StringLiteralExpCS:
	segments+=StringLiteral+;

BooleanLiteralExpCS returns BooleanLiteralExpCS:
	symbol='true'
	| symbol='false';

UnlimitedNaturalLiteralExpCS returns UnlimitedNaturalLiteralExpCS:
	{UnlimitedNaturalLiteralExpCS} '*';

InvalidLiteralExpCS returns InvalidLiteralExpCS:
	{InvalidLiteralExpCS} 'invalid';

NullLiteralExpCS returns NullLiteralExpCS:
	{NullLiteralExpCS} 'null';

TypeLiteralCS returns base::TypedRefCS:
	PrimitiveTypeCS
	| CollectionTypeCS
	| TupleTypeCS;

TypeLiteralWithMultiplicityCS returns base::TypedRefCS:
	TypeLiteralCS ownedMultiplicity=MultiplicityCS?;

TypeLiteralExpCS returns TypeLiteralExpCS:
	ownedType=TypeLiteralWithMultiplicityCS;

TypeNameExpCS returns TypeNameExpCS:
	ownedPathName=PathNameCS (ownedCurlyBracketedClause=CurlyBracketedClauseCS ('{' ownedPatternGuard=ExpCS '}')?)?;

TypeExpCS returns base::TypedRefCS:
	(TypeNameExpCS | TypeLiteralCS | CollectionPatternCS) ownedMultiplicity=MultiplicityCS?;

//---------------------------------------------------------------------
//  Expressions
//---------------------------------------------------------------------
// An ExpCS permits a LetExpCS only in the final term to ensure
//  that let is right associative, whereas infix operators are left associative.
//   a = 64 / 16 / let b : Integer in 8 / let c : Integer in 4 
// is
//   a = (64 / 16) / (let b : Integer in 8 / (let c : Integer in 4 ))
/* An expression elaborates a prefixed expression with zero or more binary operator and expression suffixes.
 * An optionally prefixed let expression is permitted except when suffixed with further expressions.*/
ExpCS returns ExpCS:
//	({InfixExpCS} ownedSource=PrefixedExpCS name=BinaryOperatorName ownedArgument=ExpCS)
//| 	PrefixedExpCS
// the above takes exponential or worse time for backtracking, below is fast
	(PrefixedPrimaryExpCS ({InfixExpCS.ownedLeft=current} name=BinaryOperatorName ownedRight=ExpCS)?)
| 	PrefixedLetExpCS;

/* A prefixed let expression elaborates a let expression with zero or more unary prefix operators. */
PrefixedLetExpCS returns ExpCS:
	({PrefixExpCS} name=UnaryOperatorName ownedRight=PrefixedLetExpCS)
| 	LetExpCS;

/* A prefixed primary expression elaborates a primary expression with zero or more unary prefix operators. */
PrefixedPrimaryExpCS returns ExpCS:
	({PrefixExpCS} name=UnaryOperatorName ownedRight=PrefixedPrimaryExpCS)
| 	PrimaryExpCS;

/* A primary expression identifies the basic expressions from which more complex expressions may be constructed. */
PrimaryExpCS returns ExpCS:
	NestedExpCS
|	IfExpCS
| 	SelfExpCS
| 	PrimitiveLiteralExpCS
| 	TupleLiteralExpCS
| 	CollectionLiteralExpCS
| 	LambdaLiteralExpCS
| 	TypeLiteralExpCS
| 	NameExpCS;

/* A name expression is a generalised rule for expressions that start with a name and which may be followed by square, round or
 * curly bracket clauses and optionally an @pre as well.*/
NameExpCS returns NameExpCS:
	ownedPathName=PathNameCS ownedSquareBracketedClauses+=SquareBracketedClauseCS*
	ownedRoundBracketedClause=RoundBracketedClauseCS? ownedCurlyBracketedClause=CurlyBracketedClauseCS? (isPre?='@' 'pre')?;

/* A curly bracket clause is a generalized rule for the literal arguments of collections, maps, tuples and shadows.*/
CurlyBracketedClauseCS:
	{CurlyBracketedClauseCS} '{'
		( ((ownedParts+=ShadowPartCS (',' ownedParts+=ShadowPartCS)*))?
		| (value=StringLiteral)
		) '}'
	;
	
/* A curly bracket clause is a generalized rule for template specialisations and operations arguments.*/
RoundBracketedClauseCS:
	{RoundBracketedClauseCS} '(' (
		ownedArguments+=NavigatingArgCS (ownedArguments+=NavigatingCommaArgCS)*
		(ownedArguments+=NavigatingSemiArgCS (ownedArguments+=NavigatingCommaArgCS)*)?
		(ownedArguments+=NavigatingBarArgCS (ownedArguments+=NavigatingCommaArgCS)*)*
		)? ')'
	;

/* A square bracket clause is a generalized rule for association class qualifiers and roles.*/
SquareBracketedClauseCS:
	'[' ownedTerms+=ExpCS (',' ownedTerms+=ExpCS)* ']';

/* A navigating argument is a generalized rule for the first argument in a round bracket clause. This is typically the first operation
 * parameter or an iterator. */
NavigatingArgCS returns NavigatingArgCS:
	(ownedNameExpression=NavigatingArgExpCS ((':' ownedType=TypeExpCS ('=' ownedInitExpression=ExpCS)?) | ('in' ownedInitExpression=ExpCS))?)
	| (':' ownedType=TypeExpCS);	// Type-less init is an illegal infix expression

/* A navigating bar argument is a generalized rule for a bar-prefixed argument in a round bracket clause. This is typically the body of an iteration. */
NavigatingBarArgCS returns NavigatingArgCS:
	prefix='|' ownedNameExpression=NavigatingArgExpCS (':' ownedType=TypeExpCS ('=' ownedInitExpression=ExpCS)?)?;	// Type-less init is an illegal infix expression

/* A navigating comma argument is a generalized rule for non-first argument in a round bracket clause. These are typically non-first operation
 * parameters or a second iterator. */
NavigatingCommaArgCS returns NavigatingArgCS:
	prefix=',' ownedNameExpression=NavigatingArgExpCS ((':' ownedType=TypeExpCS ('=' ownedInitExpression=ExpCS)?) | ('in' ownedInitExpression=ExpCS))?;	// Type-less init is an illegal infix expression

/* A navigating semi argument is a generalized rule for a semicolon prefixed argument in a round bracket clause. This is typically an iterate accumulator. */
NavigatingSemiArgCS returns NavigatingArgCS:
	prefix=';' ownedNameExpression=NavigatingArgExpCS (':' ownedType=TypeExpCS ('=' ownedInitExpression=ExpCS)?)?;	// Type-less init is an illegal infix expression

NavigatingArgExpCS returns ExpCS: // Intended to be overridden
	ExpCS
	//	'?'	-- defined by Complete OCL
;

IfExpCS returns IfExpCS:
	'if' ownedCondition=(ExpCS|PatternExpCS)
	'then' ownedThenExpression=ExpCS
//	ifThenExpressions+=IfThenExpCS
	(ownedIfThenExpressions+=ElseIfThenExpCS)*
	'else' ownedElseExpression=ExpCS
	'endif';
//IfThenExpCS returns IfThenExpCS:
//	'if' condition=ExpCS
//	'then' thenExpression=ExpCS
//;
ElseIfThenExpCS returns IfThenExpCS:
	'elseif' ownedCondition=ExpCS
	'then' ownedThenExpression=ExpCS
;

LetExpCS returns LetExpCS:
	'let' ownedVariables+=LetVariableCS (',' ownedVariables+=LetVariableCS)*
	'in' ownedInExpression=ExpCS;

LetVariableCS returns LetVariableCS:
	name=UnrestrictedName ownedRoundBracketedClause=RoundBracketedClauseCS? (':' ownedType=TypeExpCS)? '=' ownedInitExpression=ExpCS;

NestedExpCS returns NestedExpCS:
	'(' ownedExpression=ExpCS ')';

SelfExpCS returns SelfExpCS:
	{SelfExpCS} 'self';