4 ms·

That is a masterpiece of Forth programming! I particularly enjoyed this section from the template renderer which made me think... Return stack manipulation - t

by nickcw 8y ago

That is a masterpiece of Forth programming! I particularly enjoyed this section from the template renderer which made me think... Return stack manipulation - that's playing with fire. And also - wow Forth is not much higher level than assembly, and gosh, I don't think I could have written that without writing some stack diagrams! 2dup s" $>" search if \ Check to see if there's a closing tag $>. 2 - \ Add the close tag to the search result. nip \ Save the end position of $>. dup >r - \ Reduce the string to <$ ... $>. evaluate \ Run user's code (maybe a bad idea?). r> \ Retrieve our saved end position of $>. r> r> \ Retrive the addr u from start of loop iter. rot \ Bring end $> to stack top. over >r \ Store the real string's length. - \ Subtract end $> from u to get the pos from top r> swap \ that we'd like to strip away. Restore saved u. /string \ Drop top of the string until the end of $>. 0 \ Keep looping. Thanks for the trip down memory lane!

james_s_tayler 8y ago
I like the (maybe a bad idea?) comment.
- GrumpyNl 8y ago
  Its the only distracting comment, the rest tels me what it does, this one tells me how he feels.
  - macintux 8y ago
    Documenting potential security issues with your code is rarely a bad idea.
RodgerTheGreat 8y ago
The rstack is just a temporary second stack with the caveat that you have to be a bit careful about cleaning it up after you're finished with it. (Unless you intend to do something fun and exotic like : goto r> drop >r ;) Usually I'm more tense about code that uses rot/-rot; a little harder to keep track of in my head.
panic 8y ago
The beauty of Forth is that you can write at as low or as high a level as you'd like. I think most Forth programmers would factor out some of these operations into their own words rather than writing such a low-level definition, but there's nothing preventing you from writing your web server like it's assembly code.

by nickcw 8y ago

james_s_tayler 8y ago

I like the (maybe a bad idea?) comment.

GrumpyNl 8y ago
Its the only distracting comment, the rest tels me what it does, this one tells me how he feels.
- macintux 8y ago
  Documenting potential security issues with your code is rarely a bad idea.

RodgerTheGreat 8y ago

The rstack is just a temporary second stack with the caveat that you have to be a bit careful about cleaning it up after you're finished with it. (Unless you intend to do something fun and exotic like : goto r> drop >r ;) Usually I'm more tense about code that uses rot/-rot; a little harder to keep track of in my head.

panic 8y ago

The beauty of Forth is that you can write at as low or as high a level as you'd like. I think most Forth programmers would factor out some of these operations into their own words rather than writing such a low-level definition, but there's nothing preventing you from writing your web server like it's assembly code.