Does Factor have anything akin to the generators in the ICON language?
Generators are useful for recursive-descent searches. They aren't necessary;
it is possible to write these kinds of programs without generators (I did
one such program in IBM370 assembly-language). When you do without
generators, you have both the code that generates the datums, and the code
that tests the datums, and the recursive call (in the event of failure of
the test), all together in one big complicated function. With generators,
you can factor the code into separate functions that can be tested in
isolation. As factoring is what Factor is all about, I would hope for
generators, but I couldn't find anything in the documentation. If they are
there, can anybody point me toward them?
Generators are not something that I can write myself, as they require the
function to store its internal state ("suspend" itself, in ICON terminology)
somewhere --- then, the next time that it is called, it reanimates itself
from this suspended state rather than start from the beginning again. To
code this, I would have to know more about the internal workings of Factor
functions than I do. I might be able to write something like this in Forth
using CATCH and THROW, but I'm not sure about that without having tried it.
BTW, I have read about Python's generators, and they seem comparable to
ICON's, but haven't tried them out. Do any other languages have generators?
I have read that Prolog has something similar, but I don't know the first
thing about Prolog. Both ICON and Prolog seem to have largely disappeared; I
never hear anything about them anymore.
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