Introduction to Compiler Construction in a Java World

34 An Introduction to Compiler Construction in a Java World

The code corresponding to this logic would look something like the following:

if ( isLetter ( ch ) || ch == ’_’ || ch == ’$ ’) {

buffer = new String B u ffer ();

while ( isLet t e r ( ch ) || i s Digit ( ch ) ||

ch == ’_ ’ || ch == ’$ ’){

buffer . append ( ch );

nextCh ();

}

String identi f i e r = buffer . toString ();

if ( reserved . contai n s K ey ( identi f i e r )) {

return new T o kenInfo ( reserved . get ( i dentifier ),

line );

}

else {

return new T o kenInfo ( IDENTIFI ER , identifier ,

line );

}

}

This relies on a map (hash table), reserved, mapping reserved identifiers to their rep-

resentations: ...