/**
* Extract a Pascal special symbol token from the source.
*
* @throws Exception if an error occurred.
*/
protected void extract() throws Exception {
char currentChar = currentChar();
text = Character.toString(currentChar);
type = null;
switch (currentChar) {
// The following symbols are groups that contain multi-character symbols
// !, !=
// &, &=, &&
// ^, ^=
// *, */, *=
// -, --, -=
// +, ++, +=
// =, ==
// |, |=, ||
// /, /=, //, /*
// <, <<=, <<, <=
// >, >>=, >=, >>
// The following symbols are single-character
// :
// ;
// ?
// @
// %
// ~
// .
// ,
// '
// "
// (
// )
// [
// ]
// {
// }
// Single-character special symbols.
case ':':
case ';':
case '?':
case '@':
case '%':
case '~':
case '.':
case ',':
case '\'':
case '"':
case '(':
case ')':
case '[':
case ']':
case '{':
case '}':
{
nextChar(); // consume character
break;
}
// ! or !=
case '!':
{
currentChar = nextChar(); // consume ':';
if (currentChar == '=') {
text += currentChar;
nextChar(); // consume '='
}
break;
}
// & or &= or &&
case '&':
{
currentChar = nextChar(); // consume '<';
if (currentChar == '=') {
text += currentChar;
nextChar(); // consume '='
} else if (currentChar == '&') {
text += currentChar;
nextChar(); // consume '>'
}
break;
}
// ^ or ^=
case '^':
{
currentChar = nextChar(); // consume '>';
if (currentChar == '=') {
text += currentChar;
nextChar(); // consume '='
}
break;
}
// * or */ or *=
case '*':
{
currentChar = nextChar(); // consume '.';
if (currentChar == '/') {
text += currentChar;
nextChar(); // consume '.'
} else if (currentChar == '=') {
text += currentChar;
nextChar();
}
break;
}
// - or -- or -=
case '-':
{
currentChar = nextChar(); // consume '.';
if (currentChar == '-') {
text += currentChar;
nextChar(); // consume '.'
} else if (currentChar == '=') {
text += currentChar;
nextChar();
}
break;
}
// + or ++ or +=
case '+':
{
currentChar = nextChar(); // consume '.';
if (currentChar == '+') {
text += currentChar;
nextChar(); // consume '.'
} else if (currentChar == '=') {
text += currentChar;
nextChar();
}
break;
}
// = or ==
case '=':
{
currentChar = nextChar(); // consume '.';
if (currentChar == '=') {
text += currentChar;
nextChar(); // consume '.'
}
break;
}
// | or |= or ||
case '|':
{
currentChar = nextChar(); // consume '.';
if (currentChar == '=') {
text += currentChar;
nextChar(); // consume '.'
} else if (currentChar == '|') {
text += currentChar;
nextChar();
}
break;
}
// / or /= or // or /*
case '/':
{
currentChar = nextChar(); // consume '.';
if (currentChar == '=') {
text += currentChar;
nextChar(); // consume '.'
} else if (currentChar == '/') {
text += currentChar;
nextChar();
} else if (currentChar == '*') {
text += currentChar;
nextChar();
}
break;
}
// < or <<= or << or <=
case '<':
{
currentChar = nextChar(); // consume '.';
if (currentChar == '<') {
text += currentChar;
nextChar(); // consume '.'
if (currentChar == '=') {
text += currentChar;
nextChar();
}
} else if (currentChar == '=') {
text += currentChar;
nextChar();
}
break;
}
// > or >>= or >= or >>
case '>':
{
currentChar = nextChar(); // consume '.';
if (currentChar == '>') {
text += currentChar;
nextChar(); // consume '.'
if (currentChar == '=') {
text += currentChar;
nextChar();
}
} else if (currentChar == '=') {
text += currentChar;
nextChar();
}
break;
}
default:
{
nextChar(); // consume bad character
type = ERROR;
value = INVALID_CHARACTER;
}
}
// Set the type if it wasn't an error.
if (type == null) {
type = SPECIAL_SYMBOLS.get(text);
}
}
