alt Hacker NewsInterpreters don't have to be slow.
Forth is usually interpreted and pretty fast. And, of course, we have very fast Javascript engines these days. Python speed is being worked on, but it's pretty slow, true.
Replies
ErroneousBosh • today at 9:37 AM
It's not really "interpreted", in the way that for example BASIC or Java is.
It's a list of jumps to functions.
anthk • today at 8:34 AM
Some Forths are dog slow such as PFE compared to GForth. Meanwhile others running in really slow platforms such as subleq (much faster in muxleq) run really fast for that the VM actually as (almost something slightly better than a 8086).
Classic Forth Dimensions article: Why Forth Isn't Slow
* https://www.forth.org/fd/FD-V06N5.pdf
Basically it is because Forth programs are fairly flat and don't go deep into subfunctions. So the interpreter overhead is not that great and the processor spends most of the time running the machine code that underlays the primitives that live at the bottom of the program.