Пример #1
0
 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();
 }
Пример #2
0
        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;
            }
        }