[antlr-interest] Inefficiency in lexer

[ttest]

Hi,

while looking thru my generated lexer code I came across the following
switch statement which is unnecessarily inefficient.

switch ( LA(1)) {
case '\n':  case '\r':  case ' ':  case '0':
case '1':  case '2':  case '3':  case '4':
case '5':  case '6':  case '7':  case '8':
case '9':  case 'A':  case 'B':  case 'C':
case 'D':  case 'E':  case 'F':  case 'G':
case 'H':  case 'I':  case 'J':  case 'K':
case 'L':  case 'M':  case 'N':  case 'O':
case 'P':  case 'Q':  case 'R':  case 'S':
case 'T':  case 'U':  case 'V':  case 'W':
case 'X':  case 'Y':  case 'Z':  case 'a':
case 'b':  case 'c':  case 'd':  case 'e':
case 'f':  case 'g':  case 'h':  case 'i':
case 'j':  case 'k':  case 'l':  case 'm':
case 'n':  case 'o':  case 'p':  case 'q':
case 'r':  case 's':  case 't':  case 'u':
case 'v':  case 'w':  case 'x':  case 'y':
case 'z':
{
	mText(true);
	theRetToken=_returnToken;
	break;
}

A better alternative which could also be easily generated from character
classes using .. i. e. 'a'..'z' would be the following.

char c = LA(1);
if( c=='\n' || c=='\r' || c==' '
	|| (c>='0' && c<='9')
	|| (c>='A' && c<='Z')
	|| (c>='a' && c<='z')
	)
{
	mText(true);
	theRetToken=_returnToken;
	break;
}

Greets,

Christian