/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id$
 */

/*
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 * @author Morten Jorgensen
 *
 */

package org.apache.xalan.xsltc.compiler;

import java_cup.runtime.Symbol;
%%
%cup
%unicode
%class XPathLexer
%yyeof

%{
        int last;

        void initialize() {
            last = -1;
        }

        static boolean isWhitespace(int c) {
            return (c == ' ' || c == '\t' || c == '\r' || c == '\n'  || c == '\f');
        }

        /**
         * If symbol is not followed by '::' or '(', then treat it as a
         * name instead of an axis or function (Jira-1912).
         */ 
        Symbol disambiguateAxisOrFunction(int ss) throws Exception {
            // Peek in the input buffer without changing the internal state
            int index = yy_buffer_index;

            // Skip whitespace
            while (index < yy_buffer_read && isWhitespace(yy_buffer[index])) {
                index++;
            }

            // If end of buffer, can't disambiguate :(
            if (index >= yy_buffer_read) {
                // Can't disambiguate, so return as symbol
                return new Symbol(ss);
            }

            // Return symbol if next token is '::' or '('
            return (yy_buffer[index] == ':' && yy_buffer[index+1] == ':' ||
                    yy_buffer[index] == '(') ?
                    newSymbol(ss) : newSymbol(sym.QNAME, yytext());
        }

        /**
         * If symbol is first token or if it follows any of the operators
         * listed in http://www.w3.org/TR/xpath#exprlex then treat as a 
         * name instead of a keyword (Jira-1912).
         */ 
        Symbol disambiguateOperator(int ss) throws Exception {
            switch (last) {
            case -1:    // first token
            case sym.ATSIGN:
            case sym.DCOLON:
            case sym.LPAREN:
            case sym.LBRACK:
            case sym.COMMA:
            case sym.AND:
            case sym.OR:
            case sym.MOD:
            case sym.DIV:
            case sym.MULT:
            case sym.SLASH:
            case sym.DSLASH:
            case sym.VBAR:
            case sym.PLUS:
            case sym.MINUS:
            case sym.EQ:
            case sym.NE:
            case sym.LT:
            case sym.LE:
            case sym.GT:
            case sym.GE:
                return newSymbol(sym.QNAME, yytext());
            }
            return newSymbol(ss);
        }

        /**
         * If symbol is first token or if it follows any of the operators
         * listed in http://www.w3.org/TR/xpath#exprlex then treat as a
         * wildcard instead of a multiplication operator
         */
        Symbol disambiguateStar() throws Exception {
            switch (last) {
            case -1:    // first token
            case sym.ATSIGN:
            case sym.DCOLON:
            case sym.LPAREN:
            case sym.LBRACK:
            case sym.COMMA:
            case sym.AND:
            case sym.OR:
            case sym.MOD:
            case sym.DIV:
            case sym.MULT:
            case sym.SLASH:
            case sym.DSLASH:
            case sym.VBAR:
            case sym.PLUS:
            case sym.MINUS:
            case sym.EQ:
            case sym.NE:
            case sym.LT:
            case sym.LE:
            case sym.GT:
            case sym.GE:
                return newSymbol(sym.STAR);
            }
            return newSymbol(sym.MULT);
        }

        Symbol newSymbol(int ss) {
            last = ss;
            return new Symbol(ss);
        }

        Symbol newSymbol(int ss, String value) {
            last = ss;
            return new Symbol(ss, value);
        }

        Symbol newSymbol(int ss, Long value) {
            last = ss;
            return new Symbol(ss, value);
        }

        Symbol newSymbol(int ss, Double value) {
            last = ss;
            return new Symbol(ss, value);
        }
%}

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

%yylexthrow{
Exception
%yylexthrow}

Letter={BaseChar}|{Ideographic}

BaseChar=[\u0041-\u005A\u0061-\u007A\u00C0-\u00D6\u00D8-\u00F6\u00F8-\u00FF\u0100-\u0131\u0134-\u013E\u0141-\u0148\u014A-\u017E\u0180-\u01C3\u01CD-\u01F0\u01F4-\u01F5\u01FA-\u0217\u0250-\u02A8\u02BB-\u02C1\u0386\u0388-\u038A\u038C\u038E-\u03A1\u03A3-\u03CE\u03D0-\u03D6\u03DA\u03DC\u03DE\u03E0\u03E2-\u03F3\u0401-\u040C\u040E-\u044F\u0451-\u045C\u045E-\u0481\u0490-\u04C4\u04C7-\u04C8\u04CB-\u04CC\u04D0-\u04EB\u04EE-\u04F5\u04F8-\u04F9\u0531-\u0556\u0559\u0561-\u0586\u05D0-\u05EA\u05F0-\u05F2\u0621-\u063A\u0641-\u064A\u0671-\u06B7\u06BA-\u06BE\u06C0-\u06CE\u06D0-\u06D3\u06D5\u06E5-\u06E6\u0905-\u0939\u093D\u0958-\u0961\u0985-\u098C\u098F-\u0990\u0993-\u09A8\u09AA-\u09B0\u09B2\u09B6-\u09B9\u09DC-\u09DD\u09DF-\u09E1\u09F0-\u09F1\u0A05-\u0A0A\u0A0F-\u0A10\u0A13-\u0A28\u0A2A-\u0A30\u0A32-\u0A33\u0A35-\u0A36\u0A38-\u0A39\u0A59-\u0A5C\u0A5E\u0A72-\u0A74\u0A85-\u0A8B\u0A8D\u0A8F-\u0A91\u0A93-\u0AA8\u0AAA-\u0AB0\u0AB2-\u0AB3\u0AB5-\u0AB9\u0ABD\u0AE0\u0B05-\u0B0C\u0B0F-\u0B10\u0B13-\u0B28\u0B2A-\u0B30\u0B32-\u0B33\u0B36-\u0B39\u0B3D\u0B5C-\u0B5D\u0B5F-\u0B61\u0B85-\u0B8A\u0B8E-\u0B90\u0B92-\u0B95\u0B99-\u0B9A\u0B9C\u0B9E-\u0B9F\u0BA3-\u0BA4\u0BA8-\u0BAA\u0BAE-\u0BB5\u0BB7-\u0BB9\u0C05-\u0C0C\u0C0E-\u0C10\u0C12-\u0C28\u0C2A-\u0C33\u0C35-\u0C39\u0C60-\u0C61\u0C85-\u0C8C\u0C8E-\u0C90\u0C92-\u0CA8\u0CAA-\u0CB3\u0CB5-\u0CB9\u0CDE\u0CE0-\u0CE1\u0D05-\u0D0C\u0D0E-\u0D10\u0D12-\u0D28\u0D2A-\u0D39\u0D60-\u0D61\u0E01-\u0E2E\u0E30\u0E32-\u0E33\u0E40-\u0E45\u0E81-\u0E82\u0E84\u0E87-\u0E88\u0E8A\u0E8D\u0E94-\u0E97\u0E99-\u0E9F\u0EA1-\u0EA3\u0EA5\u0EA7\u0EAA-\u0EAB\u0EAD-\u0EAE\u0EB0\u0EB2-\u0EB3\u0EBD\u0EC0-\u0EC4\u0F40-\u0F47\u0F49-\u0F69\u10A0-\u10C5\u10D0-\u10F6\u1100\u1102-\u1103\u1105-\u1107\u1109\u110B-\u110C\u110E-\u1112\u113C\u113E\u1140\u114C\u114E\u1150\u1154-\u1155\u1159\u115F-\u1161\u1163\u1165\u1167\u1169\u116D-\u116E\u1172-\u1173\u1175\u119E\u11A8\u11AB\u11AE-\u11AF\u11B7-\u11B8\u11BA\u11BC-\u11C2\u11EB\u11F0\u11F9\u1E00-\u1E9B\u1EA0-\u1EF9\u1F00-\u1F15\u1F18-\u1F1D\u1F20-\u1F45\u1F48-\u1F4D\u1F50-\u1F57\u1F59\u1F5B\u1F5D\u1F5F-\u1F7D\u1F80-\u1FB4\u1FB6-\u1FBC\u1FBE\u1FC2-\u1FC4\u1FC6-\u1FCC\u1FD0-\u1FD3\u1FD6-\u1FDB\u1FE0-\u1FEC\u1FF2-\u1FF4\u1FF6-\u1FFC\u2126\u212A-\u212B\u212E\u2180-\u2182\u3041-\u3094\u30A1-\u30FA\u3105-\u312C\uAC00-\uD7A3]

Ideographic=[\u4E00-\u9FA5\u3007\u3021-\u3029] 

CombiningChar=[\u0300-\u0345\u0360-\u0361\u0483-\u0486\u0591-\u05A1\u05A3-\u05B9\u05BB-\u05BD\u05BF\u05C1-\u05C2\u05C4\u064B-\u0652\u0670\u06D6-\u06DC\u06DD-\u06DF\u06E0-\u06E4\u06E7-\u06E8\u06EA-\u06ED\u0901-\u0903\u093C\u093E-\u094C\u094D\u0951-\u0954\u0962-\u0963\u0981-\u0983\u09BC\u09BE\u09BF\u09C0-\u09C4\u09C7-\u09C8\u09CB-\u09CD\u09D7\u09E2-\u09E3\u0A02\u0A3C\u0A3E\u0A3F\u0A40-\u0A42\u0A47-\u0A48\u0A4B-\u0A4D\u0A70-\u0A71\u0A81-\u0A83\u0ABC\u0ABE-\u0AC5\u0AC7-\u0AC9\u0ACB-\u0ACD\u0B01-\u0B03\u0B3C\u0B3E-\u0B43\u0B47-\u0B48\u0B4B-\u0B4D\u0B56-\u0B57\u0B82-\u0B83\u0BBE-\u0BC2\u0BC6-\u0BC8\u0BCA-\u0BCD\u0BD7\u0C01-\u0C03\u0C3E-\u0C44\u0C46-\u0C48\u0C4A-\u0C4D\u0C55-\u0C56\u0C82-\u0C83\u0CBE-\u0CC4\u0CC6-\u0CC8\u0CCA-\u0CCD\u0CD5-\u0CD6\u0D02-\u0D03\u0D3E-\u0D43\u0D46-\u0D48\u0D4A-\u0D4D\u0D57\u0E31\u0E34-\u0E3A\u0E47-\u0E4E\u0EB1\u0EB4-\u0EB9\u0EBB-\u0EBC\u0EC8-\u0ECD\u0F18-\u0F19\u0F35\u0F37\u0F39\u0F3E\u0F3F\u0F71-\u0F84\u0F86-\u0F8B\u0F90-\u0F95\u0F97\u0F99-\u0FAD\u0FB1-\u0FB7\u0FB9\u20D0-\u20DC\u20E1\u302A-\u302F\u3099\u309A] 

Digit=[\u0030-\u0039\u0660-\u0669\u06F0-\u06F9\u0966-\u096F\u09E6-\u09EF\u0A66-\u0A6F\u0AE6-\u0AEF\u0B66-\u0B6F\u0BE7-\u0BEF\u0C66-\u0C6F\u0CE6-\u0CEF\u0D66-\u0D6F\u0E50-\u0E59\u0ED0-\u0ED9\u0F20-\u0F29] 

Extender=[\u00B7\u02D0\u02D1\u0387\u0640\u0E46\u0EC6\u3005\u3031-\u3035\u309D-\u309E\u30FC-\u30FE] 

NCName=({Letter}|"_"|{NCNameStartChar})({NCNameChar})*

NCNameChar={Letter}|{Digit}|"."|"-"|"_"|{CombiningChar}|{Extender}|{NCNameStartChar}| \u00B7 | [\u0300-\u036F] | [\u203F-\u2040] | [\u0130-\u0136]

NCNameStartChar=[\u0041-\u005A\u0061-\u007A\u00C0-\u00D6\u00D8-\u00F6\u00F8-\u02FF\u0370-\u037D\u037F-\u1FFF\u200C-\u200D\u2070-\u218F\u2C00-\u2FEF\u3001-\uD7FF\uF900-\uFDCF\uFDF0-\uFFFD] | \u005F |({HighSurrogate}{LowSurrogate})

HighSurrogate=[\uD800-\uDBFF]

LowSurrogate=[\uDC00-\uDFFF]

%%

"*"                      { return disambiguateStar(); }
"/"                      { return newSymbol(sym.SLASH); } 
"+"                      { return newSymbol(sym.PLUS); }
"-"                      { return newSymbol(sym.MINUS); }
"div"                    { return disambiguateOperator(sym.DIV); }
"mod"                    { return disambiguateOperator(sym.MOD); }
"::"                     { return newSymbol(sym.DCOLON); }
","                      { return newSymbol(sym.COMMA); }
"@"                      { return newSymbol(sym.ATSIGN); }
".."                     { return newSymbol(sym.DDOT); }
"|"                      { return newSymbol(sym.VBAR); }
"$"                      { return newSymbol(sym.DOLLAR); }
"//"                     { return newSymbol(sym.DSLASH); }
"="                      { return newSymbol(sym.EQ); }
"!="                     { return newSymbol(sym.NE); }
"<"                      { return newSymbol(sym.LT); } 
">"                      { return newSymbol(sym.GT); }
"<="                     { return newSymbol(sym.LE); }
">="                     { return newSymbol(sym.GE); }
"id"                     { return disambiguateAxisOrFunction(sym.ID); }
"key"                    { return disambiguateAxisOrFunction(sym.KEY); }
"text()"                 { return newSymbol(sym.TEXT); }
"text"+[ \t\r\n\f]+"()"  { return newSymbol(sym.TEXT); }
"node()"                 { return newSymbol(sym.NODE); }
"node"+[ \t\r\n\f]+"()"  { return newSymbol(sym.NODE); }
"comment()"                 { return newSymbol(sym.COMMENT); }
"comment"+[ \t\r\n\f]+"()"  { return newSymbol(sym.COMMENT); }
"processing-instruction" { return disambiguateAxisOrFunction(sym.PIPARAM); }
"processing-instruction()"                { return newSymbol(sym.PI); }
"processing-instruction"+[ \t\r\n\f]+"()" { return newSymbol(sym.PI); }
"or"                     { return disambiguateOperator(sym.OR); }
"and"                    { return disambiguateOperator(sym.AND); }
"child"                  { return disambiguateAxisOrFunction(sym.CHILD); }
"attribute"              { return disambiguateAxisOrFunction(sym.ATTRIBUTE); }
"ancestor"               { return disambiguateAxisOrFunction(sym.ANCESTOR); }
"ancestor-or-self"       { return disambiguateAxisOrFunction(sym.ANCESTORORSELF); }
"descendant"             { return disambiguateAxisOrFunction(sym.DESCENDANT); }
"descendant-or-self"     { return disambiguateAxisOrFunction(sym.DESCENDANTORSELF); }
"following"              { return disambiguateAxisOrFunction(sym.FOLLOWING); }
"following-sibling"      { return disambiguateAxisOrFunction(sym.FOLLOWINGSIBLING); }
"namespace"              { return disambiguateAxisOrFunction(sym.NAMESPACE); }
"parent"                 { return disambiguateAxisOrFunction(sym.PARENT); }
"preceding"              { return disambiguateAxisOrFunction(sym.PRECEDING); }
"preceding-sibling"      { return disambiguateAxisOrFunction(sym.PRECEDINGSIBLING); }
"self"                   { return disambiguateAxisOrFunction(sym.SELF); }
"["                      { return newSymbol(sym.LBRACK); }
"]"                      { return newSymbol(sym.RBRACK); }
"("                      { return newSymbol(sym.LPAREN); }
")"                      { return newSymbol(sym.RPAREN); }
"<PATTERN>"              { initialize(); return new Symbol(sym.PATTERN); }
"<EXPRESSION>"           { initialize(); return new Symbol(sym.EXPRESSION); }
\"[^\"]*\"               { return newSymbol(sym.Literal,
			      yytext().substring(1, yytext().length() - 1)); }
\'[^\']*\'               { return newSymbol(sym.Literal,
			      yytext().substring(1, yytext().length() - 1)); }
{Digit}+               	 { return newSymbol(sym.INT, new Long(yytext())); }
{Digit}+("."{Digit}*)? 	 { return newSymbol(sym.REAL, new Double(yytext())); }
"."{Digit}+            	 { return newSymbol(sym.REAL, new Double(yytext())); }
"."                      { return newSymbol(sym.DOT); }
({NCName}":")?{NCName}   { return newSymbol(sym.QNAME, yytext()); }
({NCName}":")?"*"        { return newSymbol(sym.QNAME, yytext()); }
({NCName}":")?"@*"       { return newSymbol(sym.QNAME, yytext()); }
[ \t\r\n\f]              { /* ignore white space. */ }
.                        { throw new Exception(yytext()); }