// minilex.h
// mini js lexical analyzer.  idea is to be dumb and fast.

/**
*    Copyright (C) 2008 10gen Inc.
*
*    This program is free software: you can redistribute it and/or  modify
*    it under the terms of the GNU Affero General Public License, version 3,
*    as published by the Free Software Foundation.
*
*    This program 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 Affero General Public License for more details.
*
*    You should have received a copy of the GNU Affero General Public License
*    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

struct MiniLex {
    strhashmap reserved;
    bool ic[256]; // ic=Identifier Character
    bool starter[256];

    // dm: very dumb about comments and escaped quotes -- but we are faster then at least,
    // albeit returning too much (which is ok for jsbobj current usage).
    void grabVariables(char *code /*modified and must stay in scope*/, strhashmap& vars) {
        char *p = code;
        char last = 0;
        while ( *p ) {
            if ( starter[*p] ) {
                char *q = p+1;
                while ( *q && ic[*q] ) q++;
                const char *identifier = p;
                bool done = *q == 0;
                *q = 0;
                if ( !reserved.count(identifier) ) {
                    // we try to be smart about 'obj' but have to be careful as obj.obj
                    // can happen; this is so that nFields is right for simplistic where cases
                    // so we can stop scanning in jsobj when we find the field of interest.
                    if ( strcmp(identifier,"obj")==0 && p>code && p[-1] != '.' )
                        ;
                    else
                        vars[identifier] = 1;
                }
                if ( done )
                    break;
                p = q + 1;
                continue;
            }

            if ( *p == '\'' ) {
                p++;
                while ( *p && *p != '\'' ) p++;
            }
            else if ( *p == '"' ) {
                p++;
                while ( *p && *p != '"' ) p++;
            }
            p++;
        }
    }

    MiniLex() {
        strhashmap atest;
        atest["foo"] = 3;
        assert( atest.count("bar") == 0 );
        assert( atest.count("foo") == 1 );
        assert( atest["foo"] == 3 );

        for ( int i = 0; i < 256; i++ ) {
            ic[i] = starter[i] = false;
        }
        for ( int i = 'a'; i <= 'z'; i++ )
            ic[i] = starter[i] = true;
        for ( int i = 'A'; i <= 'Z'; i++ )
            ic[i] = starter[i] = true;
        for ( int i = '0'; i <= '9'; i++ )
            ic[i] = true;
        for ( int i = 128; i < 256; i++ )
            ic[i] = starter[i] = true;
        ic['$'] = starter['$'] = true;
        ic['_'] = starter['_'] = true;

        reserved["break"] = true;
        reserved["case"] = true;
        reserved["catch"] = true;
        reserved["continue"] = true;
        reserved["default"] = true;
        reserved["delete"] = true;
        reserved["do"] = true;
        reserved["else"] = true;
        reserved["finally"] = true;
        reserved["for"] = true;
        reserved["function"] = true;
        reserved["if"] = true;
        reserved["in"] = true;
        reserved["instanceof"] = true;
        reserved["new"] = true;
        reserved["return"] = true;
        reserved["switch"] = true;
        reserved["this"] = true;
        reserved["throw"] = true;
        reserved["try"] = true;
        reserved["typeof"] = true;
        reserved["var"] = true;
        reserved["void"] = true;
        reserved["while"] = true;
        reserved["with "] = true;
    }
};