/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
/** The actual routine to return one Symbol. This is normally called from
* next_token(), but for debugging purposes can be called indirectly from
* debug_next_token().
*/
protected static Symbol real_next_token()
{
int sym_num;
for (;;)
{
/* look for white space */
if (next_char == ' ' || next_char == '\t' || next_char == '\n' ||
next_char == '\f' || next_char == '\r')
{
/* advance past it and try the next character */
advance();
continue;
}
/* look for a single character symbol */
sym_num = find_single_char(next_char);
if (sym_num != -1)
{
/* found one -- advance past it and return a Symbol for it */
advance();
return(new Symbol(sym_num));
}
/* look for : or ::= */
if (next_char == ':')
{
/* if we don't have a second ':' return COLON */
if (next_char2 != ':')
{
advance();
return(new Symbol(sym.COLON));
}
/* move forward and look for the '=' */
advance();
if (next_char2 == '=')
{
advance(); advance();
return(new Symbol(sym.COLON_COLON_EQUALS));
}
else
{
/* return just the colon (already consumed) */
return(new Symbol(sym.COLON));
}
}
/* find a "%prec" string and return it. otherwise, a '%' was found,
* which has no right being in the specification otherwise */
if (next_char == '%')
{
advance();
if ((next_char == 'p') && (next_char2 == 'r') && (next_char3 == 'e') &&
(next_char4 == 'c'))
{
advance();
advance();
advance();
advance();
return(new Symbol(sym.PERCENT_PREC));
}
else
{
emit_error("Found extraneous percent sign");
}
}
/* look for a comment */
if (next_char == '/' && (next_char2 == '*' || next_char2 == '/'))
{
/* swallow then continue the scan */
swallow_comment();
continue;
}
/* look for start of code string */
if (next_char == '{' && next_char2 == ':')
{
return(do_code_string());
}
/* look for an id or keyword */
if (id_start_char(next_char))
{
return(do_id());
}
if (next_char == '#' && current_position == 1 && (next_char2 == 'u') && (next_char3 == 's') &&
(next_char4 == 'e'))
{ //https://github.com/TypeCobolTeam/TypeCobol/issues/1000
//#use directive must appears as the first character in the line.
//Read the whole line after the #use directive and trim it as being the file path to be included.
string useLine = System.Console.In.ReadLine();
current_line += 1;
lexer.InitLookaheads();
return(LexerContext.HandleUseDirective(useLine?.Trim()));
}
/* look for EOF */
if (next_char == EOF_CHAR)
{
return(new Symbol(sym.EOF));
}
/* if we get here, we have an unrecognized character */
emit_warn("Unrecognized character '" +
next_char + "'(" + next_char +
") -- ignored");
/* advance past it */
advance();
}
}