package edu.berkeley.cs.db.yfilterplus.queryparser.xpathparser;

import java_cup.runtime.*;
import edu.berkeley.cs.db.yfilterplus.queryparser.xpathparser.sym;

%%

%class Lexer

%unicode
%cup
%cupdebug
%ignorecase /* do we want this? */
%line
%column
//%final /* ? */

//%pack /* ? */

%eofval{
	return symbol(sym.EOF);
%eofval}


%{
	private Symbol symbol (int type) {
		return new Symbol(type, yyline, yycolumn);
	}	


	private Symbol symbol (int type, Object value) {
		return new Symbol(type, yyline, yycolumn, value);
	}

	private String errorString (String errorDescription) {	
		return ("line " + yyline + ", column " + yycolumn + " : " + errorDescription);
	}

	private StringBuffer string = new StringBuffer();
	
	static boolean debug = false;

	// input buffer for better error reporting
	protected StringBuffer inputBuffer = new StringBuffer();

	// return all tokens read so far
	public StringBuffer getInputBuffer () {
		return inputBuffer;
	}

	// set debug flag from the command line
	public void setDebug (boolean flag) {
		debug = flag;
	}
%}

letter = [a-zA-Z]

digit = [0-9]

number = [1-9][0-9]*

literal = 	([\"] [^\"]* [\"])

ncnamechar = {letter} | {digit} | "." | "-" | "_"

ncname = ({letter} | "_" ) {ncnamechar}* 

line_terminator = \r | \n | \r\n

/* from JFlex manual*/
white_space = line_terminator | [ \t\f]

/* ? */
%state STRING

%%

<YYINITIAL> {

	/* literals */
/*	\"			{string.setLength(0); yybegin(STRING); } */

	/* whitespace */
	{white_space}		{/* ignore */}

	{number}		{inputBuffer.append(yytext()); if (debug) System.err.println("lex: " + yytext()); return symbol(sym.NUMBER, yytext()); } 
	{literal}		{inputBuffer.append(yytext()); if (debug) System.err.println("lex: " + yytext()); return symbol(sym.LITERAL, yytext()); } 



	"."			{inputBuffer.append(yytext()); if (debug) System.err.println("lex:."); 	return symbol(sym.DOT); }
	"="			{inputBuffer.append(yytext()); if (debug) System.err.println("lex:="); 	return symbol(sym.EQUALS); }
	"!="			{inputBuffer.append(yytext()); if (debug) System.err.println("lex:!="); return symbol(sym.NOT_EQUALS); }
	"("			{inputBuffer.append(yytext()); if (debug) System.err.println("lex:("); 	return symbol(sym.L_PAREN); }
  	")"			{inputBuffer.append(yytext()); if (debug) System.err.println("lex:)"); 	return symbol(sym.R_PAREN); }
  	"["			{inputBuffer.append(yytext()); if (debug) System.err.println("lex:["); 	return symbol(sym.L_BRACKET); }
  	"]"			{inputBuffer.append(yytext()); if (debug) System.err.println("lex:]"); 	return symbol(sym.R_BRACKET); }
	">"			{inputBuffer.append(yytext()); if (debug) System.err.println("lex:>"); 	return symbol(sym.GREATER_THAN); }
	"<"			{inputBuffer.append(yytext()); if (debug) System.err.println("lex:<"); 	return symbol(sym.LESS_THAN); }
	">="			{inputBuffer.append(yytext()); if (debug) System.err.println("lex:>="); return symbol(sym.GREATER_THAN_EQUALS); }
	"<="			{inputBuffer.append(yytext()); if (debug) System.err.println("lex:<="); return symbol(sym.LESS_THAN_EQUALS); }
  	"//"			{inputBuffer.append(yytext()); if (debug) System.err.println("lex://"); return symbol(sym.DOUBLE_SLASH); }
  	"/"			{inputBuffer.append(yytext()); if (debug) System.err.println("lex:/"); 	return symbol(sym.SLASH); }
	"@"			{inputBuffer.append(yytext()); if (debug) System.err.println("lex:@");	return symbol(sym.AT); }
	"*"			{inputBuffer.append(yytext()); if (debug) System.err.println("lex:*"); 	return symbol(sym.STAR); }
	"_"			{inputBuffer.append(yytext()); if (debug) System.err.println("lex:_");	return symbol(sym.UNDERSCORE); }
	{ncname}		{inputBuffer.append(yytext()); if (debug) System.err.println("lex:" + yytext());return symbol(sym.NCNAME, yytext()); } 
/*	{letter}		{return symbol(sym.LETTER, yytext()); } */
/*	{ncnamechar}		{return symbol(sym.NCNAMECHAR, yytext()); }  */
	{line_terminator}	{/* ignore */}
}

/*
<STRING> {
  \"                             { yybegin(YYINITIAL); inputBuffer.append(yytext()); if (debug) System.err.println("lex: " + string.toString() );
                                   return symbol(sym.LITERAL, 
                                   string.toString()); }
  [^\n\r\"\\]+                   { string.append( yytext() );  }
  \\t                            { string.append('\t'); }
  \\n                            { string.append('\n'); }

  \\r                            { string.append('\r'); }
  \\\"                           { string.append('\"'); }
  \\                             { string.append('\\'); }
}
*/


/* error fallback */
/* .|\n                             { throw new Error("Illegal character <"+yytext()+">"); } */