grammar xtext.e.EDsl hidden(WHITESPACE)

import "http://www.eclipse.org/emf/2002/Ecore" as ecore
generate eDsl "http://www.e.xtext/EDsl"

// based on example at: http://blog.efftinge.de/2010/08/parsing-expressions-with-xtext.html
Model:
	expression=Multiply '.';

terminal WHITESPACE:
	(' ' | '\t' | '\r' | '\n')+;

terminal VARIABLE:
	'a'..'z' ('a'..'z' | 'A'..'Z' | '0'..'9' | '_')*;

terminal NUMBER:
	('0'..'9')+ ('.' ('0'..'9')+)?;

Multiply returns Expression:
	Add ({Expression.left=current} op='*' right=Add)*;

Add returns Expression:
	Root ({Expression.left=current} op='+' right=Root)*;

Root returns Expression:
	{Variable} name=VARIABLE
	| {Literal} value=NUMBER;

required (...)+ loop did not match anything at character '<EOF>' at offset: 4 for: 4.1+<<<HERE>>>3.

terminal NUMBER:
	'-'? ('0'..'9')+ ('.' ('0'..'9')+)? (('e' | 'E') ('-' | '+')? ('0'..'9')+)?;

terminal INT:
	'0'..'9';

NUMBER:
	'-'? INT+ ('.' INT+)? (('e' | 'E') ('-' | '+')? INT+)?;

grammar org.archstudio.prolog.xtext.Prolog hidden(WHITESPACE, SINGLE_LINE_COMMENT)

import "http://www.eclipse.org/emf/2002/Ecore" as ecore
generate prolog "http://www.archstudio.org/prolog/xtext/Prolog"

Model:
	(exps+=ExpressionInfinity '.')+;

terminal WHITESPACE:
	(' ' | '\t' | '\r' | '\n')+;

terminal SINGLE_LINE_COMMENT:
	'%' !('\n' | '\r')* ('\r'? '\n')?;

terminal STRING:
	'\''->'\'';

terminal NUMBER:
	'-'? ('0'..'9')+ ('.' ('0'..'9')+)? (('e' | 'E') ('-' | '+')? ('0'..'9')+)?;

terminal VARIABLE:
	('A'..'Z' | '_') ('A'..'Z' | 'a'..'z' | '0'..'9' | '_')*;

	// http://www.cse.unsw.edu.au/~billw/cs9414/notes/prolog/op.html
terminal OP1200XFX:
	'-->' | ':-';

terminal OP1200FX:
	':-' | '?-';

terminal OP1150FX:
	'dynamic' | 'discontiguous' | 'initialization' | 'module_transparent' | 'multifile' | 'thread_local' | 'volatile';

terminal OP1100XFY:
	';' | '|';

terminal OP1050XFY:
	'->' | '*->';

terminal OP1000XFY:
	',';

terminal OP954XFY:
	'\\';

terminal OP900FY:
	'\\+';

terminal OP900FX:
	'~';

terminal OP700XFX:
	'<' | '=' | '=..' | '=@=' | '=:=' | '=<' | '==' | '=\\=' | '>' | '>=' | '@<' | '@=<' | '@>' | '@>=' | '\\=' | '\\=='
	| 'is';

terminal OP600XFY:
	':';

terminal OP500YFX:
	'+' | '-' | '/\\' | '\\/' | 'xor';

terminal OP500FX:
	'+' | '-' | '?' | '\\';

terminal OP400YFX:
	'*' | '/' | '//' | 'rdiv' | '<<' | '>>' | 'mod' | 'rem';

terminal OP200XFX:
	'**';

terminal OP200XFY:
	'^';

terminal ATOM:
	'a'..'z' ('A'..'Z' | 'a'..'z' | '0'..'9' | '_')*;

ATOMS:
	'.' | '!' | ATOM | OP1200XFX | OP1200FX | OP1150FX | OP1100XFY | OP1050XFY | OP1000XFY | OP954XFY | OP900FY | OP900FX
	| OP700XFX | OP600XFY | OP500YFX | OP500FX | OP400YFX | OP200XFX | OP200XFY;

	// http://www.csupomona.edu/~jrfisher/www/prolog_tutorial/4.html
// xfx infix nonassociative 
// xfy infix right-associative 
// yfx infix left-associative 
// fx prefix nonassociative 
// fy prefix right-associative 
// xf postfix nonassociative 
// yf postfix left-associative
ExpressionInfinity returns Expression:
	Expression1200xfx;

Expression1200xfx returns Expression:
	Expression1200fx ({Expression.left=current} op=OP1200XFX right=Expression1200fx)?;

Expression1200fx returns UnaryExpression:
	(op=OP1200FX)? right=Expression1150fx;

Expression1150fx returns UnaryExpression:
	(op=OP1150FX)? right=Expression1100xfy;

Expression1100xfy returns Expression:
	Expression1050xfy ({Expression.left=current} op=OP1100XFY right=Expression1100xfy)?;

Expression1050xfy returns Expression:
	Expression1000xfy ({Expression.left=current} op=OP1050XFY right=Expression1050xfy)?;

Expression1000xfy returns Expression:
	Expression954xfy ({Expression.left=current} op=OP1000XFY right=Expression1000xfy)?;

Expression954xfy returns Expression:
	Expression900fy ({Expression.left=current} op=OP954XFY right=Expression954xfy)?;

	// TODO: Determine how to do right-associative UnaryExpressions, if necessary
Expression900fy returns UnaryExpression:
	(op=OP900FY)? right=Expression900fx;

Expression900fx returns UnaryExpression:
	(op=OP900FX)? right=Expression700xfx;

Expression700xfx returns Expression:
	Expression600xfy ({Expression.left=current} op=OP700XFX right=Expression600xfy)?;

Expression600xfy returns Expression:
	Expression500yfx ({Expression.left=current} op=OP600XFY right=Expression600xfy)?;

Expression500yfx returns Expression:
	Expression500fx ({Expression.left=current} op=OP500YFX right=Expression500fx)*;

Expression500fx returns UnaryExpression:
	(op=OP500FX)? right=Expression400yfx;

Expression400yfx returns Expression:
	Expression200xfx ({Expression.left=current} op=OP400YFX right=Expression200xfx)*;

Expression200xfx returns Expression:
	Expression200xfy ({Expression.left=current} op=OP200XFX right=Expression200xfy)?;

Expression200xfy returns Expression:
	Expression0 ({Expression.left=current} op=OP200XFY right=Expression200xfy)?;

Expression0 returns Expression:
	{AtomExpression} atom=ATOMS ('(' terms=ExpressionInfinity ')')?
	| {VariableExpression} name=VARIABLE
	| {StringExpression} value=STRING
	| {NumberExpression} value=NUMBER
	| {ListExpression} '[' (head=ExpressionInfinity ('|' tail=ExpressionInfinity)?)? ']'
	| '(' ExpressionInfinity ')';

terminal DIGIT:
	('0'..'9')+;

NUMBER:
	'-'? DIGIT ('.' DIGIT)?;

terminal NUMBER:
	'-'? ('0'..'9')+ ('.' ('0'..'9')+)? (('e' | 'E') ('-' | '+')? ('0'..'9')+)?;

terminal INT:
	('0'..'9')+;

terminal EXT_INT:
	INT ('e' | 'E') ('-' | '+')? INT;

NUMBER hidden():
	'-'? INT ('.' (EXT_INT | INT))?;