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mongodb/db/minilex.h

116 lines
4.1 KiB
C++

// 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/>.
*/
namespace mongo {
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;
}
};
} // namespace mongo