public void scan()
{
skipWhite();
if (Char.IsLetter(io.getNextChar()))
{
load_ident_or_keyword();
}
else if (Char.IsDigit(io.getNextChar()))
{
load_digits();
}
else if (is_op(io.getNextChar()))
{
load_op();
}
else if (is_bracket(io.getNextChar()))
{
load_bracket();
}
else if (io.EOF())
{
load_eof();
}
else
{
value = new StringBuilder(Io.MAXSTR);
value.Append(io.getNextChar());
token_id = TOK_UNKNOWN;
io.ReadChar();
}
skipWhite();
}
void stmt(VarList curtree, String ilabel, String olabel)
{
Var e = new Var();
currenttree = curtree;
if (io.EOF())
{
io.Abort("PL0142: expected statement but end of file encountered");
}
if ((tok.getId() != Tok.TOK_PROC) && (tok.getId() != Tok.TOK_PROCEDURE))
{
if (last_label != null)
{
emit.Label("L@@" + last_label);
last_label = null;
}
}
switch (tok.getId())
{
case Tok.TOK_RETURN:
ret_stmt(ilabel, olabel);
null_stmt();
break;
case Tok.TOK_IDENT:
ident_stmt(curtree);
break;
case Tok.TOK_CALL:
call_stmt(curtree);
null_stmt();
break;
case Tok.TOK_DO:
do_stmt(curtree);
null_stmt();
break;
case Tok.TOK_GO:
case Tok.TOK_GOTO:
goto_stmt(curtree);
null_stmt();
break;
case Tok.TOK_PROCEDURE:
case Tok.TOK_PROC:
proc_decl(curtree, last_label);
null_stmt();
break;
case Tok.TOK_IF:
if_stmt(curtree, ilabel, olabel);
break;
case Tok.TOK_DCL:
case Tok.TOK_DECLARE:
io.Abort("PL0143: wild declaration found");
break;
case Tok.TOK_UNKNOWN:
io.Abort("PL0144: unknown construction");
break;
case Tok.TOK_END:
case Tok.TOK_ELSE:
case Tok.TOK_THEN:
break;
default:
io.Abort("PL0145: wild symbol found");
break;
}
}