/********************************************************
* next_token -- read the next token in an input stream *
* *
* Parameters *
* in_file -- file to read *
* *
* Returns *
* next token *
********************************************************/
TOKEN_TYPE token::next_token(input_file& in_file)
{
if (need_to_read_one)
in_file.read_char();
need_to_read_one = 0;
if (in_comment)
return (read_comment(in_file));
while (char_type.is(in_file.cur_char, char_type::C_WHITE)) {
in_file.read_char();
}
if (in_file.cur_char == EOF)
return (T_EOF);
switch (char_type.type(in_file.cur_char)) {
case char_type::C_NEWLINE:
in_file.read_char();
return (T_NEWLINE);
case char_type::C_ALPHA:
while (char_type.is(in_file.cur_char,
char_type::C_ALPHA_NUMERIC))
in_file.read_char();
return (T_ID);
case char_type::C_DIGIT:
in_file.read_char();
if ((in_file.cur_char == 'X') || (in_file.cur_char == 'x')) {
in_file.read_char();
while (char_type.is(in_file.cur_char,
char_type::C_HEX_DIGIT)) {
in_file.read_char();
}
return (T_NUMBER);
}
while (char_type.is(in_file.cur_char, char_type::C_DIGIT))
in_file.read_char();
return (T_NUMBER);
case char_type::C_SLASH:
// Check for /* characters
if (in_file.next_char == '*') {
return (read_comment(in_file));
}
// Now check for double slash comments
if (in_file.next_char == '/') {
while (true) {
// Comment starting with // and ending with EOF is legal
if (in_file.cur_char == EOF)
return (T_COMMENT);
if (in_file.cur_char == '\n')
return (T_COMMENT);
in_file.read_char();
}
}
// Fall through
case char_type::C_OPERATOR:
in_file.read_char();
return (T_OPERATOR);
case char_type::C_L_PAREN:
in_file.read_char();
return (T_L_PAREN);
case char_type::C_R_PAREN:
in_file.read_char();
return (T_R_PAREN);
case char_type::C_L_CURLY:
in_file.read_char();
return (T_L_CURLY);
case char_type::C_R_CURLY:
in_file.read_char();
return (T_R_CURLY);
case char_type::C_DOUBLE:
while (true) {
in_file.read_char();
// Check for end of string
if (in_file.cur_char == '"')
break;
// Escape character, then skip the next character
if (in_file.cur_char == '\\')
in_file.read_char();
}
in_file.read_char();
return (T_STRING);
case char_type::C_SINGLE:
while (true) {
in_file.read_char();
// Check for end of character
if (in_file.cur_char == '\'')
break;
// Escape character, then skip the next character
if (in_file.cur_char == '\\')
in_file.read_char();
}
in_file.read_char();
return (T_STRING);
default:
assert("Internal error: Very strange character" != 0);
}
assert("Internal error: We should never get here" != 0);
return (T_EOF); // Should never get here either
}
/*************************************************
* read_token -- read token in input stream
* argument
* in_file -- input file
* return
* next token
*************************************************/
TOKEN_TYPE token::next_token(input_file& in_file) {
if (need_to_read_one) {
in_file.read_char();
}
need_to_read_one = 0;
if (in_comment) {
return (read_comment(in_file));
}
while (char_type.is(in_file.cur_char, char_type::C_WHITE)) {
in_file.read_char();
}
if (in_file.cur_char == EOF) {
return T_EOF;
}
switch (char_type.type(in_file.cur_char)) {
case char_type::C_NEWLINE:
in_file.read_char();
return T_NEWLINE;
case char_type::C_ALPHA:
while (char_type.is(in_file.cur_char, char_type::C_ALPHA_NUMERIC)) {
in_file.read_char();
}
return T_ID;
case char_type::C_DIGIT:
in_file.read_char();
if ((in_file.cur_char == 'X') || (in_file.cur_char == 'x')) {
in_file.read_char();
while (char_type.is(in_file.cur_char, char_type::C_HEX_DIGIT)) {
in_file.read_char();
}
return T_NUMBER;
}
while (char_type.is(in_file.cur_char, char_type::C_DIGIT)) {
in_file.read_char();
}
return T_NUMBER;
case char_type::C_SLASH:
// check '/*' comment
if (in_file.next_char == '*') {
return (read_comment(in_file));
}
// check '//' comment
if (in_file.next_char == '/') {
while (true) {
if (in_file.cur_char == EOF) {
return T_COMMENT;
}
if (in_file.cur_char == '\n') {
return T_COMMENT;
}
in_file.read_char();
}
}
// fall through
case char_type::C_OPERATOR:
in_file.read_char();
return T_OPERATOR;
case char_type::C_L_PAREN:
in_file.read_char();
return T_L_PAREN;
case char_type::C_R_PAREN:
in_file.read_char();
return T_R_PAREN;
case char_type::C_L_CURLY:
in_file.read_char();
return T_L_CURLY;
case char_type::C_R_CURLY:
in_file.read_char();
return T_R_CURLY;
case char_type::C_DOUBLE:
while (true) {
in_file.read_char();
if (in_file.cur_char == '"') {
break;
}
if (in_file.cur_char == '\\') {
in_file.read_char();
}
}
in_file.read_char();
return T_STRING;
case char_type::C_SINGLE:
while (true) {
in_file.read_char();
if (in_file.cur_char == '\'') {
break;
}
if (in_file.cur_char == '\\') {
in_file.read_char();
}
}
in_file.read_char();
return T_STRING;
default:
assert("Internal error: Very strange character" != 0);
}
assert("Internal error: We should never get here" != 0);
return T_EOF;
}