On 13.05.2011 15:55, Hans-Peter Diettrich wrote:
Traditional Pascal added compiler directives, hidden inside comments. It's only a matter of performance, whether these directives should be handled immediately at detection of a comment, or after a comment has been fully recognized (skipped) by the scanner. Conditional compilation also can be implemented outside the scanner, with optional feedback instructing the scanner to *not* apply special processing to tokens which are skipped by conditional directives. Include directives require more support in the scanner, which then must be capable of switching between multiple input streams. Macros can be implemented in the same way, but it will be more efficient to Record and Replay token streams instead of character streams. This recorder also can be implemented outside the scanner, an according filter will either return a previously recorded token, or else it asks the scanner for the next token.
There is already a token recorder/replayer: the one that is used for generics.
Regards, Sven _______________________________________________ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-devel
