//==============================================================================
//	
//	Copyright (c) 2002-
//	Authors:
//	* Dave Parker <david.parker@comlab.ox.ac.uk> (University of Oxford, formerly University of Birmingham)
//	
//------------------------------------------------------------------------------
//	
//	This file is part of PRISM.
//	
//	PRISM is free software; you can redistribute it and/or modify
//	it under the terms of the GNU General Public License as published by
//	the Free Software Foundation; either version 2 of the License, or
//	(at your option) any later version.
//	
//	PRISM is distributed in the hope that it will be useful,
//	but WITHOUT ANY WARRANTY; without even the implied warranty of
//	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//	GNU General Public License for more details.
//	
//	You should have received a copy of the GNU General Public License
//	along with PRISM; if not, write to the Free Software Foundation,
//	Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//	
//==============================================================================

options {
	LOOKAHEAD = 1;
}

PARSER_BEGIN(PrismParser)

package parser;

import java.io.*;
import java.util.ArrayList;

import parser.ast.*;
import prism.PrismLangException;

public class PrismParser
{
	// The modules file associated with properties file being parsed
	private static ModulesFile modulesFile;
	
	// List of keyword strings
	private static ArrayList<String> keywordList = new ArrayList<String>();
	
	//-----------------------------------------------------------------------------------
	// Main method for testing purposes
	//-----------------------------------------------------------------------------------

	public static void main(String[] args)
	{
		PrismParser p = null;
		InputStream str = null;
		String src = null;
		
		try {
			if (args.length == 0) {
				System.out.println("Usage: java parser.PrismParser <switch> [<file>]");
				System.out.println("Where: <switch> = -modulesfile or -mf");
				System.out.println("                  -propertiesfile or -pf");
				System.out.println("                  -expression or -e");
				System.exit(1);
			}
			
			p = new PrismParser();
			str = (args.length > 1) ? new FileInputStream(args[1]) : System.in;
			src = (args.length > 1) ? "file "+args[1] : "stdin";
			System.out.println("Reading from "+src+"...\n");
			
			if (args[0].equals("-modulesfile") || args[0].equals("-mf")) {
				ModulesFile mf = p.parseModulesFile(str);
				System.out.print("Modules file:\n=============\n\n" + mf);
				System.out.print("\nTree:\n=====\n" + mf.toTreeString());
				mf.tidyUp();
				System.out.print("\nAnd after expansion:\n====================\n\n" +mf);
			}
			else if (args[0].equals("-propertiesfile") || args[0].equals("-pf")) {
				PropertiesFile pf = p.parsePropertiesFile(new ModulesFile(), str);
				System.out.print("Properties file:\n================\n\n" + pf);
				System.out.print("\nTree:\n=====\n" + pf.toTreeString());
				pf.tidyUp();
				System.out.print("\nAnd after expansion:\n====================\n\n" + pf);
			}
			else if (args[0].equals("-expression") || args[0].equals("-e")) {
				Expression expr = p.parseSingleExpression(str);
				System.out.println("Expression: " + expr.toString());
				System.out.print("Tree:\n=====\n" + expr.toTreeString());
				expr.typeCheck();
				expr.semanticCheck();
				System.out.println("Type: " + Expression.getTypeString(expr.getType()));
				System.out.println("Eval: " + expr.evaluate(null, null));
			} else {
				System.out.println("Unknown switch"); System.exit(1);
			}
		}
		catch (PrismLangException e) {
			System.out.println("Error in "+src+": " + e.getMessage()+"."); System.exit(1);
		}
		catch (FileNotFoundException e) {
			System.out.println(e); System.exit(1);
		}
	}

	//-----------------------------------------------------------------------------------
	// Methods called by Prism
	//-----------------------------------------------------------------------------------

	// Constructor

	public PrismParser()
	{
		// Call default constructor
		this(System.in);
		// Build a list of strings for keywords
		keywordList.clear();
		for (int i = PrismParserConstants.COMMENT+1; i < PrismParserConstants.NOT; i++) {
			keywordList.add(PrismParserConstants.tokenImage[i].replaceAll("\"", ""));
		}
	}
	
	// Parse modules file
	
	public ModulesFile parseModulesFile(InputStream str) throws PrismLangException { return parseModulesFile(str, 0); }
	
	public ModulesFile parseModulesFile(InputStream str, int typeOverride) throws PrismLangException
	{
		ModulesFile mf = null;
		
		// (Re)start parser
		ReInit(str);
		// Parse
		try {
			mf = ModulesFile();
		}
		catch (ParseException e) {
			throw generateSyntaxError(e);
		}
		// Override type of model if requested
		if (typeOverride != 0) {
			mf.setType(typeOverride);
		}
		
		return mf;
	}
	
	// Parse properties file (pass ModulesFile in to get at its constants)
	
	public PropertiesFile parsePropertiesFile(ModulesFile mf, InputStream str) throws PrismLangException
	{ return parsePropertiesFile(mf, str, false); }
	
	public PropertiesFile parsePropertiesFile(ModulesFile mf, InputStream str, boolean strict) throws PrismLangException
	{
		PropertiesFile pf = null;
		
		// (Re)start parser
		ReInit(str);
		modulesFile = mf;
		// Parse
		try {
			pf = strict ? PropertiesFile() : PropertiesFileSemicolonless();
		}
		catch (ParseException e) {
			throw generateSyntaxError(e);
		}

		return pf;
	}
	
	// Parse a single expression
	
	public Expression parseSingleExpression(InputStream str) throws PrismLangException
	{
		Expression expr = null;
		
		// (Re)start parser
		ReInit(str);
		// Parse
		try {
			expr = SingleExpression();
		}
		catch (ParseException e) {
			throw generateSyntaxError(e);
		}
		return expr;
	}
	
	// Parse a for loop
	
	public ForLoop parseForLoop(InputStream str) throws PrismLangException
	{
		ForLoop fl = null;
		
		// (Re)start parser
		ReInit(str);
		// Parse
		try {
			fl = ForLoop();
		}
		catch (ParseException e) {
			throw generateSyntaxError(e);
		}
		return fl;
	}
	
	//-----------------------------------------------------------------------------------
	// Some utility methods
	//-----------------------------------------------------------------------------------
	
	// Get comment block (including white space)
	// preceding a token and remove "//" characters
	
	public static String getPrecedingCommentBlock(Token firstToken)
	{
		String comment = "", s;
		Token t = firstToken;
		
		// extract any comment from the previous lines of the file
		if (t.specialToken != null) {
			// trace back thru special tokens
			t = t.specialToken;
			while (t.specialToken != null) t = t.specialToken;
			// ignore initial white space
			while (t != null && t.kind == PrismParserConstants.WHITESPACE) t = t.next;
			// concatenate special tokens
			while (t != null) {
				s = t.image;
				// strip any nasty carriage returns
				s = s.replaceAll("\r", "");
				// remove "//" and preceding/subsequent spaces/tabs from comments
				if (t.kind == PrismParserConstants.COMMENT) {
					while (comment.length() > 0 && (""+comment.charAt(comment.length()-1)).matches("[ \t]"))
						comment = comment.substring(0,comment.length()-1);
					s = s.substring(2);
					s = s.replaceFirst("[ \t]*", "");
				}
				comment += s;
				t = t.next;
			}
		}
		// remove final new line (if present)
		if (comment.length() > 0 && (comment.charAt(comment.length()-1) == '\n'))
			comment = comment.substring(0,comment.length()-1);
		
		return comment;
	}
	
	// Add "//"s into comment block
	
	public static String slashCommentBlock(String comment)
	{
		int i;
		String s, res = "";
		// break into lines
		while ((i = comment.indexOf("\n")) != -1) {
			s = comment.substring(0, i);
			comment = comment.substring(i+1);
			// add "//" to non-empty lines
			if (s.trim().length()>0) res += "// " + s;
			res += "\n";
		}
		// deal with any trailing characters (with no new line ending them)
		if (comment.trim().length()>0) res += "// " + comment + "\n";
		return res;
	}
	
	// Test a string to see if it is a PRISM language keyword
	
	public static boolean isKeyword(String s)
	{
		return keywordList.contains(s);
	}
	
	/**
	 * Set the tab size used by the lexer/parser.
	 */
	public void setTabSize(int size) 
	{
		SimpleCharStream.setTabSize(size);   
	}
	
	/**
	 * Get the tab size used by the lexer/parser.
	 */
	public int getTabSize()
	{
		return SimpleCharStream.getTabSize(0);
	}
	
	/**
	 * Split a single argument ExpressionFunc object into two expressions.
	 */
	protected ExpressionPair splitExpressionFunc(ExpressionFunc func)
	{
		ExpressionPair expr = new ExpressionPair();
		
		return expr;
	}
	
	/**
	 * Generate a syntax error (PrismLangException) from a ParseException.
	 */
	protected PrismLangException generateSyntaxError(ParseException e)
	{
		Token t;
		if (e == null || e.currentToken == null) return new PrismLangException("Syntax error");
		else if (e.currentToken.next == null) {
			ExpressionIdent tmp = new ExpressionIdent(e.currentToken.image);
			tmp.setPosition(e.currentToken);
			return new PrismLangException("Syntax error", tmp);
		} else {
			ExpressionIdent tmp = new ExpressionIdent(e.currentToken.next.image);
			tmp.setPosition(e.currentToken.next);
			return new PrismLangException("Syntax error", tmp);
		}
	}
	
	//-----------------------------------------------------------------------------------
	// A few classes for temporary storage of bits of the AST
	//-----------------------------------------------------------------------------------
	
	static class TimeBound { public Expression lBound = null; public Expression uBound = null; }
	
	static class ExpressionPair { public Expression expr1 = null; public Expression expr2 = null; }
}

//-----------------------------------------------------------------------------------

PARSER_END(PrismParser)

// Token definitions follow
// Note that PrismSyntaxHighlighter makes assumptions about the ordering of these

// Skip (but store) all other white space

SPECIAL_TOKEN :
{
	<WHITESPACE: (" "|"\t"|"\n"|"\r")>
}

// Skip (but store) comments

SPECIAL_TOKEN :
{
	<COMMENT: "//" (~["\n","\r"])* ("\n"|"\r"|"\r\n")>
}

// Tokens

TOKEN :
{
	// Keywords
	< BOOL:				"bool" >
|	< CONST:			"const" >
|	< CTMC:				"ctmc" >
|	< C:				"C" >
|	< DOUBLE:			"double" >
|	< DTMC:				"dtmc" >
|	< ENDINIT:			"endinit" >
|	< ENDMODULE:		"endmodule" >
|	< ENDREWARDS:		"endrewards" >
|	< ENDSYSTEM:		"endsystem" >
|	< FALSE:			"false" >
|	< FORMULA:			"formula" >
|	< FUNC:				"func" >
|	< F:				"F" >
|	< GLOBAL:			"global" >
|	< G:				"G" >
|	< INIT:				"init" >
|	< I:				"I" >
|	< INT:				"int" >
|	< LABEL:			"label" >
|	< MAX:				"max" >
|	< MDP:				"mdp" >
|	< MIN:				"min" >
|	< MODULE:			"module" >
|	< X:				"X" >
|	< NONDETERMINISTIC:	"nondeterministic" >
|	< PMAX:				"Pmax" >
|	< PMIN:				"Pmin" >
|	< P:				"P" >
|	< PROBABILISTIC:	"probabilistic" >
|	< PROB:				"prob" >
|	< RATE:				"rate" >
|	< REWARDS:			"rewards" >
|	< RMAX:				"Rmax" >
|	< RMIN:				"Rmin" >
|	< R:				"R" >
|	< S:				"S" >
|	< STOCHASTIC:		"stochastic" >
|	< SYSTEM:			"system" >
|	< TRUE:				"true" >
|	< U:				"U" >
|	< W:				"W" >
	// Punctuation, etc.
	// Note that "NOT" must be the first item of punctuation in this list
	// (PrismSyntaxHighlighter relies on this fact)
|	< NOT:			"!" >
|	< AND:			"&" >
|	< OR:			"|" >
|	< IMPLIES:		"=>" >
|	< RARROW:		"->" >
|	< COLON:		":" >
|	< SEMICOLON:	";" >
|	< COMMA:		"," >
|	< DOTS:			".." >
|	< LPARENTH:		"(" >
|	< RPARENTH:		")" >
|	< LBRACKET: 	"[" >
|	< RBRACKET:		"]" >
|	< LBRACE:		"{" >
|	< RBRACE:		"}" >
|	< EQ:			"=" >
|	< NE:			"!=" >
|	< LT:			"<" >
|	< GT:			">" >
|	< LE:			"<=" >
|	< GE:			">=" >
|	< PLUS:			"+" >
|	< MINUS:		"-" >
|	< TIMES:		"*" >
|	< DIVIDE:		"/" >
|	< PRIME:		"'" >
|	< RENAME:		"<-" >
|	< QMARK:		"?" >
|	< DQUOTE:		"\"" >
	// Regular expressions
|	< REG_INT:			(["1"-"9"](["0"-"9"])*)|("0") >
|	< REG_DOUBLE:		(["0"-"9"])*(".")?(["0"-"9"])+(["e","E"](["-","+"])?(["0"-"9"])+)? >
|	< REG_IDENTPRIME:	["_","a"-"z","A"-"Z"](["_","a"-"z","A"-"Z","0"-"9"])*"'" >
|	< REG_IDENT:		["_","a"-"z","A"-"Z"](["_","a"-"z","A"-"Z","0"-"9"])* >
|	< PREPROC:			"#"(~["#"])*"#" >
	// Special catch-all token for lexical errors
	// (this allows us to throw our usual exceptions in this case)
|	< LEXICAL_ERROR: ~[] >
}

//-----------------------------------------------------------------------------------
// Top-level productions
//-----------------------------------------------------------------------------------

// Modules file

ModulesFile ModulesFile() throws PrismLangException :
{
	int type = 0;
	int typeCount = 0;
	Token typeDupe = null;
	Declaration global;
	Module m = null;
	RenamedModule rm = null;
	RewardStruct rs = null;
	Expression init = null;
	int initCount = 0;
	Expression initDupe = null;
	SystemDefn sys = null;
	int sysCount = 0;
	SystemDefn sysDupe = null;
	ModulesFile mf = new ModulesFile();
	Token begin = null;
}
{
	( { begin = getToken(1); }
	// Model type
	( type=ModulesFileType() { typeCount++; if (typeCount == 2) typeDupe = getToken(0); } ) |
	// Formula/label/constant definition
	FormulaDef(mf.getFormulaList()) | LabelDef(mf.getLabelList()) | ConstantDef(mf.getConstantList()) |
	// Global variable
	global = GlobalDecl() { mf.addGlobal(global); } |
	// Renamed module (lookahead to distinguish from normal module)
	LOOKAHEAD(<MODULE> Identifier() <EQ>) rm = RenamedModule() { mf.addRenamedModule(rm); } |
	// Module
	m = Module() { mf.addModule(m); } | 
	// Reward structure
	rs = RewardStruct() { mf.addRewardStruct(rs); } |
	// Initial states ("init...endinit" construct)
	init = Init() { mf.setInitialStates(init); initCount++; if (initCount == 2) initDupe = init; } |
	// System definition ("system...endsystem" construct)
	sys = SystemEndsystem() { mf.setSystemDefn(sys); sysCount++; if (sysCount == 2) sysDupe = sys; }
	)* <EOF>
	{
		// Check for multiple instances of some items
		if (typeDupe != null) {
			ExpressionIdent tmp = new ExpressionIdent(typeDupe.image);
			tmp.setPosition(typeDupe);
			throw new PrismLangException("There were multiple model type declarations", tmp);
		}
		if (initDupe != null) {
			throw new PrismLangException("There were multiple init...endinit constructs", initDupe);
		}
		if (sysDupe != null) {
			throw new PrismLangException("There were multiple system...endsystem constructs", sysDupe);
		}
		
		// Set type (default is MDP)
		switch (type) {
			case PROBABILISTIC:
			case DTMC:
				mf.setType(ModulesFile.PROBABILISTIC); break;
			case NONDETERMINISTIC:
			case MDP:
				mf.setType(ModulesFile.NONDETERMINISTIC); break;
			case STOCHASTIC:
			case CTMC:
				mf.setType(ModulesFile.STOCHASTIC); break;
			default : mf.setType(ModulesFile.NONDETERMINISTIC); break;
		}
		
		// Return completed ModulesFile object
		mf.setPosition(begin != null? begin: getToken(0), getToken(0));
		return mf;
	}
}

// Properties file

PropertiesFile PropertiesFile() throws PrismLangException :
{
	PropertiesFile pf = new PropertiesFile(modulesFile);
	Expression expr;
	Token begin = null, t = null;
}
{
	{ begin = getToken(1); }
	(
		// Semi-colon terminated property
		( { t = getToken(1); } expr = Property() { pf.addProperty(expr, getPrecedingCommentBlock(t)); } (<SEMICOLON>)+ )
	|
		// Label/constant definition
		( LabelDef(pf.getLabelList()) ) | ( ConstantDef(pf.getConstantList()) )
	)* <EOF>
	{ pf.setPosition(begin, getToken(0)); return pf; }
}

// Properties file with optional semicolons - beware of potential ambiguities

PropertiesFile PropertiesFileSemicolonless() throws PrismLangException :
{
	PropertiesFile pf = new PropertiesFile(modulesFile);
	Expression expr;
	Token begin = null, t = null;
}
{
	{ begin = getToken(1); }
	(
		// Semi-colon terminated property
		( { t = getToken(1); } expr = Property() (<SEMICOLON>)* { pf.addProperty(expr, getPrecedingCommentBlock(t)); } )
	|
		// Label/constant definition
		( LabelDef(pf.getLabelList()) ) | ( ConstantDef(pf.getConstantList()) )
	)* <EOF>
	{ pf.setPosition(begin, getToken(0)); return pf; }
}

// Property expression (used above)

Expression Property() :
{
	Expression expr;
}
{
	// Note that we jump in a few levels down in the Expression hierarchy
	// (more precisely, we skip the temporal operators, which can't occur at the top-level)
	// (this avoids some common parsing errors for semicolon-less files)
	expr = ExpressionITE(true, false) { return expr; }
}

// A single expression

Expression SingleExpression() :
{
	Expression ret;
}
{
	( ret = Expression(false, false) <EOF> ) { return ret; }
}

//-----------------------------------------------------------------------------------
// Modules file stuff (a few bits of which are reused for property files)
//-----------------------------------------------------------------------------------

// Keyword denoting model type

int ModulesFileType() :
{
}
{
	( <DTMC>|<PROBABILISTIC> | <MDP>|<NONDETERMINISTIC> | <CTMC>|<STOCHASTIC> )
	{ return getToken(0).kind; }
}

// Formula definition

void FormulaDef(FormulaList formulaList) :
{
	ExpressionIdent name = null;
	Expression expr = null;
}
{
	( <FORMULA> name = IdentifierExpression() <EQ> expr = Expression(false, false) <SEMICOLON> )
	{ formulaList.addFormula(name, expr); }
}

// Label definition

void LabelDef(LabelList labelList) throws PrismLangException :
{
	ExpressionIdent name = null;
	Expression expr = null;
}
{
	// Lookahead required because of the error handling clause below
	LOOKAHEAD(<LABEL> <DQUOTE>) <LABEL> ( <DQUOTE> name = IdentifierExpression() <DQUOTE> <EQ> expr = Expression(false, false) <SEMICOLON> )
	{ labelList.addLabel(name, expr); }
	// Error handling
	| LOOKAHEAD(<LABEL>) ( <LABEL> name = IdentifierExpression() ) { throw new PrismLangException("Label names must be enclosed in double-quotes", name); }
}

// Constant definition

void ConstantDef(ConstantList constantList) :
{
	int type = Expression.INT;
	ExpressionIdent name = null;
	Expression expr = null;
}
{
	// Constant (allow omission of "int" and use of "rate"/"prob" for backwards compatability)
	(( <CONST> ( <INT> { type=Expression.INT; } | <DOUBLE> { type=Expression.DOUBLE; } | <BOOL> { type=Expression.BOOLEAN; } )? )
	| (<RATE> | <PROB> ) { type=Expression.DOUBLE; } )
	// Name and (optional) initial value
	name = IdentifierExpression()
	( <EQ> expr = Expression(false, false) )? <SEMICOLON>
	{ constantList.addConstant(name, expr, type); }
}

// Global variable declaration

Declaration GlobalDecl() :
{
	Declaration decl = null;
}
{
	( <GLOBAL> decl = Declaration() )
	{ return decl; }
}

// Variable declaration

Declaration Declaration() :
{
	String name = null;
	Expression low = null, high = null, init = null;
	Declaration decl;
	Token begin = null;
}
{
	( { begin = getToken(1);} name = Identifier() <COLON>
	// Integer-range variable declaration
	(( <LBRACKET> low = Expression(false, false) <DOTS> high = Expression(false, false) <RBRACKET> ( <INIT> init = Expression(false, false) )? <SEMICOLON>
	{ decl = new Declaration(name, low, high, init); } )
	// Boolean variable declaration
	| ( <BOOL> ( <INIT> init = Expression(false, false) )? <SEMICOLON> { return new Declaration(name, init); } )))
	{ decl.setPosition(begin, getToken(0)); return decl; }
}

// Module

Module Module() :
{
	String name = null;
	Declaration var = null;
	Command comm = null;
	Module module = null;
	Token begin = null;
}
{
	begin = <MODULE> name = Identifier() { module = new Module(name); }
	( var = Declaration() { module.addDeclaration(var); } )*
	( comm = Command() { module.addCommand(comm); } )*
	<ENDMODULE>
	{ module.setPosition(begin, getToken(0)); return module; }
}

// Command

Command Command() :
{
	String synch = null;
	Expression guard = null;
	Updates updates = null;
	Command comm = new Command();
	Token begin = null;
}
{
	// Synchronisation action-label
	begin = <LBRACKET> ( synch = Identifier() { comm.setSynch(synch); } )? <RBRACKET>
	// Guard/updates
	guard = Expression(false, false) { comm.setGuard(guard); } <RARROW> updates = Updates() { comm.setUpdates(updates); } <SEMICOLON>
	{ comm.setPosition(begin, getToken(0)); return comm; }
}

// Updates

Updates Updates() :
{
	Expression prob;
	Update update;
	Updates updates = new Updates();
	Token begin = null;
}
{
	{ begin = getToken(1); }
	(
		// Single update with probability 1
		// (lookahead required because update and probability can both start with "(")
		LOOKAHEAD(Update()) update = Update()
		{ updates.addUpdate(null, update); }
	|
		// Several probabilistic updates
		( prob = Expression(false, false) <COLON> update = Update() { updates.addUpdate(prob, update); }
		( <PLUS> prob = Expression(false, false) <COLON> update = Update() { updates.addUpdate(prob, update); } )* )
	)
	{ updates.setPosition(begin, getToken(0)); return updates; }
}

Update Update() :
{
	Update update = new Update();
	Token begin = null;
}
{
	{ begin = getToken(1); }
	// Conjunction of update elements
	(( UpdateElement(update) ( <AND> UpdateElement(update) )* )
	// Empty conjunction: true
	| <TRUE> )
	{ update.setPosition(begin, getToken(0)); return update; }
}

void UpdateElement(Update update) :
{
	ExpressionIdent var = null;
	Expression expr = null;
}
{
	<LPARENTH> var = IdentifierPrime() <EQ> expr = Expression(false, false) <RPARENTH> { update.addElement(var, expr); }
}

// Module renaming

RenamedModule RenamedModule() :
{
	String name = null, base = null;
	RenamedModule rm = null;
	Token begin = null;
}
{
	begin = <MODULE> name = Identifier() <EQ> base = Identifier() { rm = new RenamedModule(name, base); }
	<LBRACKET> Rename(rm) ( <COMMA> Rename(rm) )* <RBRACKET> <ENDMODULE>
	{ rm.setPosition(begin, getToken(0)); return rm; }
}

void Rename(RenamedModule rm) :
{
	String id1 = null, id2 = null;
}
{
	// NB: have to explicitly include keywords for functions because they can be renamed
	(( id1=Identifier() | <MIN> { id1="min"; } | <MAX> { id1="max"; } )
	<EQ>
	( id2=Identifier() | <MIN> { id2="min"; } | <MAX> { id2="max"; } ))
	{
		rm.addRename(id1, id2);
	}
}

// Reward structure

RewardStruct RewardStruct() :
{
	String name = null, s = null;
	Expression guard = null, value = null;
	RewardStruct rs = new RewardStruct();
	RewardStructItem rsi;
	Token begin = null, begin2 = null;
}
{
	begin = <REWARDS>
	// Optional name
	// (lookahead required so not misdetected as an ExpressionLabel)
	// (which would not be allowed to appear here anyway)
	( LOOKAHEAD(<DQUOTE>) <DQUOTE> name = Identifier() <DQUOTE> { rs.setName(name); } )?
	// Reward structure items
	( { begin2 = getToken(1); } ( <LBRACKET> { s = ""; } ( s=Identifier() )? <RBRACKET> )?
	guard = Expression(false, false) <COLON> value = Expression(false, false) <SEMICOLON>
	{ rsi = new RewardStructItem(s, guard, value); rsi.setPosition(begin2, getToken(0)); rs.addItem(rsi); } )*
	<ENDREWARDS>
	{ rs.setPosition(begin, getToken(0)); return rs; }
}
	
// Initial states ("init...endinit" construct)

Expression Init() :
{
	Expression expr = null;
}
{
	<INIT> expr = Expression(false, false) <ENDINIT> { return expr; }
}

// System definition ("system...endsystem" construct)

SystemDefn SystemEndsystem() :
{
	SystemDefn ret;
}
{
	<SYSTEM> ( ret = SystemDefn() ) <ENDSYSTEM>
	{ return ret; }
}

// System definition component

SystemDefn SystemDefn() :
{
	SystemDefn ret;
}
{
	ret = SystemFullParallel()
	{ return ret; }
}

// System definition component (full parallel)

SystemDefn SystemFullParallel() :
{
	SystemDefn sys1 = null, sys2 = null;
	SystemFullParallel par = null;
	Token begin;
}
{
	{ begin = getToken(1); }
	sys1 = SystemInterleaved()
	( { par = new SystemFullParallel(); par.addOperand(sys1); } ( LOOKAHEAD(<OR> <OR>) <OR> <OR> sys2 = SystemParallel() { par.addOperand(sys2); } )* )
	{
		if (par==null) {
			return sys1;
		}
		else {
			par.setPosition(begin, getToken(0));
			return par;
		}
	}
}

// System definition component (interleaved parallel)

SystemDefn SystemInterleaved() :
{
	SystemDefn sys1 = null, sys2 = null;
	SystemInterleaved par = null;
	Token begin;
}
{
	{ begin = getToken(1); }
	sys1 = SystemParallel()
	( { par = new SystemInterleaved(); par.addOperand(sys1); } ( LOOKAHEAD(<OR> <OR> <OR>) <OR> <OR> <OR>  sys2 = SystemFullParallel() { par.addOperand(sys2); } )* )
	{
		if (par==null) {
			return sys1;
		}
		else {
			par.setPosition(begin, getToken(0));
			return par;
		}
	}
}

// System definition component (parallel over set of actions)

SystemDefn SystemParallel() :
{
	SystemDefn sys1 = null, sys2 = null;
	SystemParallel par = null;
	String s;
	Token begin;
}
{
	{ begin = getToken(1); }
	sys1 = SystemHideRename()
	( LOOKAHEAD(<OR> <LBRACKET>) { par = new SystemParallel(); par.setOperand1(sys1); } <OR> 
	  <LBRACKET> ( s = Identifier() { par.addAction(s); } ( <COMMA> s = Identifier() { par.addAction(s); } )* ) <RBRACKET>
	  <OR> sys2 = SystemHideRename() { par.setOperand2(sys2); }
	)?
	{
		if (par==null) {
			return sys1;
		}
		else {
			par.setPosition(begin, getToken(0));
			return par;
		}
	}
}

// System definition component (hiding and renaming)

SystemDefn SystemHideRename() :
{
	SystemDefn sys = null;
	SystemHide hide = null;
	SystemRename rename = null;
	String s1 = null, s2 = null;
	Token begin;
}
{
	{ begin = getToken(1); }
	( sys = SystemAtomic() (
	// Hiding
	(
		{ hide = new SystemHide(sys); }
		<DIVIDE> <LBRACE> ( s1 = Identifier() { hide.addAction(s1); } ( <COMMA> s1 = Identifier() { hide.addAction(s1); } )* ) <RBRACE>
		{ sys = hide; }
	)
	// Renaming
	| (
		{ rename = new SystemRename(sys); }
		<LBRACE> s1 = Identifier() <RENAME> s2 = Identifier() { rename.addRename(s1, s2); }
		( <COMMA> s1 = Identifier() <RENAME> s2 = Identifier() { rename.addRename(s1, s2); } )* <RBRACE>
		{ sys = rename; }
	)
	)* )
	{ sys.setPosition(begin, getToken(0)); return sys; }
}

// System definition component (bottom level)

SystemDefn SystemAtomic() :
{
	String name = null;
	SystemDefn sys = null;
	Token begin;
}
{
	{ begin = getToken(1); }
	// Module name
	(( name = Identifier() { sys = new SystemModule(name); } )
	// Parentheses
	|( <LPARENTH> sys = SystemDefn() <RPARENTH> { sys = new SystemBrackets(sys); } ))
	{ sys.setPosition(begin, getToken(0)); return sys; }
}

//-----------------------------------------------------------------------------------
// Expressions.
// This includes PRISM properties (if the "prop" parameter is true)
// and (within this) path formulas (if the "pathprop" parameter is true).
// Which allows us to use the same productions for the grammars for
// all three cases (they are very similar).
//-----------------------------------------------------------------------------------

// Expression

Expression Expression(boolean prop, boolean pathprop) :
{
	Expression ret;
}
{
	ret = ExpressionTemporalBinary(prop, pathprop)
	{ return ret; }
}

// Expression: temporal operators, binary (U, W, R) and unary (X, F, G)

// Note: the potential occurrence of two successive (unseparated) expressions
// (e.g. "a" and "b" in "F<=a b") is a grammar flaw because the function and
// minus operators can cause ambiguities, for example:
// "F<=a(b)+c(d)" = "F<=a" "(b)+c(d)" = "F<=a(b)+c" "(d)" ?
// "F<=-a-b-c" = "F<=-a" "-b-c" = "F<=-a-b" "-c" ?
// In many cases, these could be distinguished by type checking but
// that does not really help since this is done post-parsing.
// To prevent (very common) cases such as "F<=t (b)", "F<=t (b)&(c)", etc.
// being mis-parsed ("t(b)" would always be taken over "t"), we catch this case
// separately (see TimeBound() production below for details).
// This means that more complex time-bounds, especially those that
// start/end with an identifier should be parenthesised, e.g. "F<=(t1+t2)".

// In fact, JavaCC also warns about lookahead for this function.
// This is because (like unary minus), R can appear on the left of a unary
// operator (reward R operator) or in the middle of a binary operator (release).

Expression ExpressionTemporalBinary(boolean prop, boolean pathprop) :
{
	Expression ret, expr;
	ExpressionTemporal exprTemp;
	TimeBound tb = null;
	Token begin = null;
}
{
	{ begin = getToken(1); } ret = ExpressionTemporalUnary(prop, pathprop)
	[
		// This production is only allowed in expressions if the "pathprop" parameter is true
		{ if (!pathprop) throw generateParseException(); }
		{ exprTemp = new ExpressionTemporal(); exprTemp.setOperand1(ret); }
		( <U> { exprTemp.setOperator(ExpressionTemporal.P_U); }
		| <W> { exprTemp.setOperator(ExpressionTemporal.P_W); }
		| <R> { exprTemp.setOperator(ExpressionTemporal.P_R); } )
		( tb = TimeBound() { exprTemp.setLowerBound(tb.lBound); exprTemp.setUpperBound(tb.uBound); } )?
		expr = ExpressionTemporalUnary(prop, pathprop)
		{ exprTemp.setOperand2(expr); exprTemp.setPosition(begin, getToken(0)); ret = exprTemp; }
	]
	{ return ret; }
}

Expression ExpressionTemporalUnary(boolean prop, boolean pathprop) :
{
	Expression ret, expr;
	ExpressionTemporal exprTemp;
	TimeBound tb = null;
	Token begin = null;
}
{
	(
		// This production is only allowed in expressions if the "pathprop" parameter is true
		{ if (!pathprop) throw generateParseException(); }
		{ begin = getToken(1); exprTemp = new ExpressionTemporal(); }
		( <X> { exprTemp.setOperator(ExpressionTemporal.P_X); }
		| <F> { exprTemp.setOperator(ExpressionTemporal.P_F); }
		| <G> { exprTemp.setOperator(ExpressionTemporal.P_G); } )
		( tb = TimeBound() { exprTemp.setLowerBound(tb.lBound); exprTemp.setUpperBound(tb.uBound); } )?
		expr = ExpressionTemporalUnary(prop, pathprop)
		{ exprTemp.setOperand2(expr); exprTemp.setPosition(begin, getToken(0)); ret = exprTemp; }
	|
		ret = ExpressionITE(prop, pathprop)
	)
	{ return ret; }
}

// Time bound for temporal operators
// (see ExpressionTemporal production for lookahead explanation)

TimeBound TimeBound() :
{
	TimeBound tb = new TimeBound();
}
{
	( <LE> ( LOOKAHEAD(IdentifierExpression() <LPARENTH>) tb.uBound = IdentifierExpression() | tb.uBound = Expression(false, false) )
	| <GE> ( LOOKAHEAD(IdentifierExpression() <LPARENTH>) tb.lBound = IdentifierExpression() | tb.lBound = Expression(false, false) )
	| <LBRACKET> tb.lBound = Expression(false, false) <COMMA> tb.uBound = Expression(false, false) <RBRACKET> )
	{ return tb; }
}

// Expression: if-then-else, i.e. "cond ? then : else"

Expression ExpressionITE(boolean prop, boolean pathprop) :
{
	Expression ret, left, right;
	Token begin = null;
}
{
	{ begin = getToken(1); } ret = ExpressionImplies(prop, pathprop) 
	[
		<QMARK> left = ExpressionImplies(prop, pathprop) <COLON> right = ExpressionITE(prop, pathprop)
		{ ret = new ExpressionITE(ret, left, right); ret.setPosition(begin, getToken(0)); }
	]
	{ return ret; }
}

// Expression: implies

Expression ExpressionImplies(boolean prop, boolean pathprop) :
{
	Expression ret, expr;
	Token begin = null;
}
{
	{ begin = getToken(1); } ret = ExpressionOr(prop, pathprop)
	( <IMPLIES> expr = ExpressionOr(prop, pathprop) { ret = new ExpressionBinaryOp(ExpressionBinaryOp.IMPLIES, ret, expr); ret.setPosition(begin, getToken(0)); } )*
	{ return ret; }
}

// Expression: or

Expression ExpressionOr(boolean prop, boolean pathprop) :
{
	Expression ret, expr;
	Token begin = null;
}
{
	{ begin = getToken(1); } ret = ExpressionAnd(prop, pathprop)
	( <OR> expr = ExpressionAnd(prop, pathprop) { ret = new ExpressionBinaryOp(ExpressionBinaryOp.OR, ret, expr); ret.setPosition(begin, getToken(0)); } )*
	{ return ret; }
}

// Expression: and

Expression ExpressionAnd(boolean prop, boolean pathprop) :
{
	Expression ret, expr;
	Token begin = null;
}
{
	{ begin = getToken(1); } ret = ExpressionNot(prop, pathprop)
	( <AND> expr = ExpressionNot(prop, pathprop) { ret = new ExpressionBinaryOp(ExpressionBinaryOp.AND, ret, expr); ret.setPosition(begin, getToken(0)); } )*
	{ return ret; }
}

// Expression: not

Expression ExpressionNot(boolean prop, boolean pathprop) :
{
	Expression ret, expr;
	Token begin = null;
}
{
	(
		begin = <NOT> expr = ExpressionNot(prop, pathprop) { ret = new ExpressionUnaryOp(ExpressionUnaryOp.NOT, expr); ret.setPosition(begin, getToken(0)); }
	|
		ret = ExpressionEquality(prop, pathprop)
	)
	{ return ret; }
}

// Expression: equality operators: =, !=

Expression ExpressionEquality(boolean prop, boolean pathprop) :
{
	Expression ret, expr;
	int op;
	Token begin = null;
}
{
	{ begin = getToken(1); } ret = ExpressionRelop(prop, pathprop)
	( op = EqNeq() expr = ExpressionRelop(prop, pathprop) { ret = new ExpressionBinaryOp(op, ret, expr); ret.setPosition(begin, getToken(0)); } )*
	{ return ret; }
}

// Expression: relational operators: >, <, >=, <=

Expression ExpressionRelop(boolean prop, boolean pathprop) :
{
	Expression ret, expr;
	int op;
	Token begin = null;
}
{
	{ begin = getToken(1); } ret = ExpressionPlusMinus(prop, pathprop)
	( op = LtGt() expr = ExpressionPlusMinus(prop, pathprop) { ret = new ExpressionBinaryOp(op, ret, expr); ret.setPosition(begin, getToken(0)); } )*
	{ return ret; }
}

// Expression: plus/minus

// JavaCC warns about lookahead for this function. This is because in a few places
// (bounded temporal operators and semicolon-less properties files)
// (see the relevant productions for details)
// we allow two or more successive expressions resulting in potential ambiguities
// e.g. "-a-b" = "(-a)-b" = "-a" "-b"
// Ignoring the warning results in the largest match being taken.

Expression ExpressionPlusMinus(boolean prop, boolean pathprop) :
{
	Expression ret, expr;
	int op;
	Token begin = null;
}
{
	{ begin = getToken(1); } ret = ExpressionTimesDivide(prop, pathprop) 
	(
		( <PLUS> { op = ExpressionBinaryOp.PLUS; } | <MINUS> { op = ExpressionBinaryOp.MINUS; } )
		expr = ExpressionTimesDivide(prop, pathprop) { ret = new ExpressionBinaryOp(op, ret, expr); ret.setPosition(begin, getToken(0)); }
	)*
	{ return ret; }
}

// Expression: times/divide

Expression ExpressionTimesDivide(boolean prop, boolean pathprop) :
{
	Expression ret, expr;
	int op;
	Token begin = null;
}
{
	{ begin = getToken(1); } ret = ExpressionUnaryMinus(prop, pathprop)
	(
		( <TIMES> { op = ExpressionBinaryOp.TIMES; } | <DIVIDE> { op = ExpressionBinaryOp.DIVIDE; } )
		expr = ExpressionUnaryMinus(prop, pathprop) { ret = new ExpressionBinaryOp(op, ret, expr); ret.setPosition(begin, getToken(0)); }
	)*
	{ return ret; }
}

// Expression: unary minus

Expression ExpressionUnaryMinus(boolean prop, boolean pathprop) :
{
	Expression ret, expr;
	Token begin = null;
}
{
	(
		begin = <MINUS> expr = ExpressionUnaryMinus(prop, pathprop)
		{ ret = new ExpressionUnaryOp(ExpressionUnaryOp.MINUS, expr); ret.setPosition(begin, getToken(0)); }
	|
		ret = ExpressionBasic(prop, pathprop)
	)
	{ return ret; }
}

// Basic expression (top of operator precedence ordering)

Expression ExpressionBasic(boolean prop, boolean pathprop) :
{
	Expression ret;
}
{
	(
		ret = ExpressionLiteral(prop, pathprop)
	|
		ret = ExpressionFuncOrIdent(prop, pathprop)
	|
		ret = ExpressionFuncMinMax(prop, pathprop)
	|
		ret = ExpressionFuncOldStyle(prop, pathprop)
	|
		ret = ExpressionParenth(prop, pathprop)
	|
		// Remaining options are only applicable for properties
		ret = ExpressionProb(prop, pathprop)
	|
		ret = ExpressionSS(prop, pathprop)
	|
		ret = ExpressionReward(prop, pathprop)
	|
		ret = ExpressionLabel(prop, pathprop)
	)
	{ return ret; }
}

// Expression: function or identifier

// JavaCC warns about lookahead for this function. This is because in a few places
// (bounded temporal operators and semicolon-less properties files)
// (see the relevant productions for details)
// we allow two or more successive expressions resulting in potential ambiguities
// e.g. "a(b)" = "a" "(b)"
// Ignoring the warning results in the largest match being taken.

Expression ExpressionFuncOrIdent(boolean prop, boolean pathprop) :
{
	String s = null;
	Expression ret = null;
	Token begin = null;
}
{
	// If there is no "(...)", this is an identifier
	s = Identifier() { ret = new ExpressionIdent(s); begin = getToken(0); }
	// If there is, it's a function
	( <LPARENTH> { ret = new ExpressionFunc(s); } ExpressionFuncArgs(prop, pathprop, (ExpressionFunc)ret) <RPARENTH> )?
	{ ret.setPosition(begin, getToken(0)); return ret; }
}

// Expression: min/max function (treated differently because min/max are keywords)

Expression ExpressionFuncMinMax(boolean prop, boolean pathprop) :
{
	String s = null;
	ExpressionFunc func = null;
	Token begin = null;
}
{
	( begin = <MIN> { s = "min"; } | begin = <MAX> { s = "max"; } ) 
	{ func = new ExpressionFunc(s); } <LPARENTH>  ExpressionFuncArgs(prop, pathprop, func) <RPARENTH>
	{ func.setPosition(begin, getToken(0)); return func; }
}

// Expression: old-style function, i.e. "func(name, ...)"

Expression ExpressionFuncOldStyle(boolean prop, boolean pathprop) :
{
	String s = null;
	ExpressionFunc func = null;
	Token begin = null;
}
{
	begin = <FUNC> <LPARENTH> ( <MIN> { s = "min"; } | <MAX> { s = "max"; } | s = Identifier() )
	<COMMA> { func = new ExpressionFunc(s); func.setOldStyle(true); } ExpressionFuncArgs(prop, pathprop, func) <RPARENTH>
	{ func.setPosition(begin, getToken(0)); return func; }
}

// Arguments for a function in an expression

void ExpressionFuncArgs(boolean prop, boolean pathprop, ExpressionFunc func) :
{
	Expression expr;
}
{
	expr = Expression(prop, pathprop) { func.addOperand(expr); } ( <COMMA> expr = Expression(prop, pathprop) { func.addOperand(expr); })*
}

// Expression: literal

Expression ExpressionLiteral(boolean prop, boolean pathprop) :
{
	Expression ret = null;
}
{
	(
	<REG_INT> {
		try {
			int i = Integer.parseInt(getToken(0).image);
			ret = new ExpressionLiteral(Expression.INT, new Integer(i));
		} catch (NumberFormatException e) {
			// Need to catch this because some matches for regexp REG_INT
			// are not valid integers (e.g. too big).
			throw generateParseException();
		}}
	|
	<REG_DOUBLE> {
		try {
			double d = Double.parseDouble(getToken(0).image);
			ret = new ExpressionLiteral(Expression.DOUBLE, new Double(d), getToken(0).image);
		} catch (NumberFormatException e) {
			// Need to catch this because some matches for regexp REG_DOUBLE
			// may not be valid doubles.
			throw generateParseException();
		}}
	|
	<TRUE> { ret = new ExpressionLiteral(Expression.BOOLEAN, new Boolean(true)); }
	|
	<FALSE> { ret = new ExpressionLiteral(Expression.BOOLEAN, new Boolean(false)); }
	)
	{ ret.setPosition(getToken(0)); return ret; }
}

// Expression: parentheses

Expression ExpressionParenth(boolean prop, boolean pathprop) : 
{
	Expression expr, ret;
	Token begin = null;
}
{
	begin = <LPARENTH> expr = Expression(prop, pathprop) <RPARENTH>
	{ ret = new ExpressionUnaryOp(ExpressionUnaryOp.PARENTH, expr); ret.setPosition(begin, getToken(0)); return ret;}
}

//-----------------------------------------------------------------------------------
// Property stuff
//-----------------------------------------------------------------------------------

// (Property) expression: probabilistic operator P

Expression ExpressionProb(boolean prop, boolean pathprop) :
{
	int r;
	String relOp = null;
	Expression prob = null;
	Expression expr;
	Filter filter = null;
	ExpressionProb ret = new ExpressionProb();
	Token begin = null;
}
{
	// This production is only allowed in expressions if the "prop" parameter is true
	{ if (!prop) throw generateParseException(); }
	// Various options for "P" keyword and attached symbols
	(( begin = <P> (( r = LtGt() prob = Expression(false, false) { relOp = ExpressionBinaryOp.opSymbols[r]; } )
	       |( <EQ> <QMARK> { relOp = "="; } )
	       |( <MIN> <EQ> <QMARK> { relOp = "min="; } )
	       |( <MAX> <EQ> <QMARK> { relOp = "max="; } )))
	// These two are dupes of above but allow space to be omitted
	|( begin = <PMIN> <EQ> <QMARK> { relOp = "min="; } )
	|( begin = <PMAX> <EQ> <QMARK> { relOp = "max="; } ))
	// Path formula, optional filter
	<LBRACKET> expr = Expression(prop, true) (filter = Filter())? <RBRACKET>
	{
		ret.setRelOp(relOp);
		ret.setProb(prob);
		ret.setExpression(expr);
		ret.setFilter(filter);
		ret.setPosition(begin, getToken(0));
		return ret;
	}
}

// Filter for a P/S/R operator

Filter Filter() :
{
	Filter filter;
	Expression expr;
	Token begin = null;
}
{
	begin = <LBRACE> expr = Expression(true, false) { filter = new Filter(expr); } <RBRACE>
	( <LBRACE>
		( <MIN> { filter.setMinRequested(true); }
		| <MAX> { filter.setMaxRequested(true); } )
	<RBRACE> )*
	{ filter.setPosition(begin, getToken(0)); return filter; }
}

// (Property) expression: steady-state operator S

Expression ExpressionSS(boolean prop, boolean pathprop) :
{
	int r;
	String relOp = null;
	Expression prob = null;
	Expression expr;
	Filter filter = null;
	ExpressionSS ret = new ExpressionSS();
	Token begin;
}
{
	// This production is only allowed in expressions if the "prop" parameter is true
	{ if (!prop) throw generateParseException(); }
	// Various options for "S" keyword and attached symbols
	begin = <S> (
		( r = LtGt() prob = Expression(false, false) { relOp = ExpressionBinaryOp.opSymbols[r]; } ) |
		( <EQ> <QMARK> { relOp = "="; } )
	)
	// Expression, optional filter
	<LBRACKET> expr = Expression(prop, pathprop) (filter = Filter())? <RBRACKET>
	{
		ret.setRelOp(relOp);
		ret.setProb(prob);
		ret.setExpression(expr);
		ret.setFilter(filter);
		ret.setPosition(begin, getToken(0));
		return ret;
	}
}

// (Property) expression: expected reward operator R

Expression ExpressionReward(boolean prop, boolean pathprop) :
{
	int r;
	Object index = null;
	String relOp = null;
	Expression rew = null;
	Expression expr;
	Filter filter = null;
	ExpressionReward ret = new ExpressionReward();
	Token begin;
}
{
	// This production is only allowed in expressions if the "prop" parameter is true
	{ if (!prop) throw generateParseException(); }
	// Various options for "R" keyword and attached symbols
	(( begin = <R> (index = RewardIndex())?
	(( r = LtGt() rew = Expression(false, false) { relOp = ExpressionBinaryOp.opSymbols[r]; } )
	   |( <EQ> <QMARK> { relOp = "="; } )
	   |( <MIN> <EQ> <QMARK> { relOp = "min="; } )
	   |( <MAX> <EQ> <QMARK> { relOp = "max="; } )))
	// These two are dupes of above but allow space to be omitted
	|( begin = <RMIN> <EQ> <QMARK> { relOp = "min="; } )
	|( begin = <RMAX> <EQ> <QMARK> { relOp = "max="; } ))
	// Path formula, optional filter
	<LBRACKET> expr = ExpressionRewardContents(prop, pathprop) (filter = Filter())? <RBRACKET>
	{
		ret.setRewardStructIndex(index);
		ret.setRelOp(relOp);
		ret.setReward(rew);
		ret.setExpression(expr);
		ret.setFilter(filter);
		ret.setPosition(begin, getToken(0));
		return ret;
	}
}

// Reward struct index for R operator

Object RewardIndex() :
{
	Object index;
}
{
	// Lookahead here is to ensure that "id" is not misdetected as an ExpressionLabel
	( <LBRACE> ( LOOKAHEAD(<DQUOTE>) ( <DQUOTE> index = Identifier() <DQUOTE> ) | index = Expression(false, false) ) <RBRACE> )
	{ return index; }
}

// Contents of an R operator

Expression ExpressionRewardContents(boolean prop, boolean pathprop) :
{
	Expression expr = null;
	ExpressionTemporal ret = null;
	Token begin;
}
{
	( begin = <C> <LE> expr = Expression(false, false) { ret = new ExpressionTemporal(ExpressionTemporal.R_C, null, null); ret.setUpperBound(expr); }
	| begin = <I> <EQ> expr = Expression(false, false) { ret = new ExpressionTemporal(ExpressionTemporal.R_I, null, null); ret.setUpperBound(expr);  }
	| begin = <F> expr = Expression(prop, pathprop) { ret = new ExpressionTemporal(ExpressionTemporal.R_F, null, expr); }
	| begin = <S> { ret = new ExpressionTemporal(ExpressionTemporal.R_S, null, null); } )
	{ ret.setPosition(begin, getToken(0)); return ret; }
}

// (Property) expression: label (including "init")

Expression ExpressionLabel(boolean prop, boolean pathprop) :
{
	String s;
	ExpressionLabel ret = null;
	Token begin;
}
{
	// This production is only allowed in expressions if the "prop" parameter is true
	{ if (!prop) throw generateParseException(); }
	// Label can be arbitary string or the "init" keyword
	( begin = <DQUOTE> ( s=Identifier() | <INIT> { s = "init"; } ) <DQUOTE> )
	{ ret = new ExpressionLabel(s); ret.setPosition(begin, getToken(0)); return ret; }
}

//-----------------------------------------------------------------------------------
// Miscellaneous stuff
//-----------------------------------------------------------------------------------

// Identifier (returns String)

String Identifier() :
{
}
{
	<REG_IDENT> { return getToken(0).image; }
}

// Identifier (returns ExpressionIdent, storing position info)

ExpressionIdent IdentifierExpression() :
{
	String ident;
	ExpressionIdent ret;
}
{
	ident = Identifier()
	{ ret = new ExpressionIdent(ident); ret.setPosition(getToken(0)); return ret; }
}

// Primed identifier

ExpressionIdent IdentifierPrime() :
{
}
{
	<REG_IDENTPRIME>
	{
		// Remove prime, create new ident and return
		String s = getToken(0).image;
		s = s.substring(0, s.length()-1);
		ExpressionIdent expr = new ExpressionIdent(s);
		expr.setPosition(token);
		expr.setEndColumn(expr.getEndColumn() - 1);
		return expr;
	}
}

// Equality operators: =, !=

int EqNeq() :
{
}
{
	<EQ> {return ExpressionBinaryOp.EQ; } |
	<NE> {return ExpressionBinaryOp.NE; }
}

// Relational operators: >, <, >=, <=

int LtGt() :
{
}
{
	<GT> {return ExpressionBinaryOp.GT; } |
	<LT> {return ExpressionBinaryOp.LT; } |
	<GE>  {return ExpressionBinaryOp.GE; }|
	<LE> {return ExpressionBinaryOp.LE; }
}

// For loop

ForLoop ForLoop() :
{
	String s;
	Expression from = null, to = null, step = null;
	ForLoop fl = new ForLoop();
	Token begin;
}
{
	( { begin = getToken(1); } s=Identifier() <EQ> from = Expression(false, false) <COLON> to = Expression(false, false)
	( <COLON> step = Expression(false, false) )? <EOF> )
	{
		fl.setLHS(s);
		fl.setFrom(from);
		fl.setTo(to);
		if (step != null) fl.setStep(step);
		fl.setPosition(begin, getToken(0));
		return fl;
	}
}

//------------------------------------------------------------------------------