Open Technologicat opened 3 years ago
Supporting all of the generator API is a large project, so maybe just implement the very basics, showing how it could be done.
With the new get_cc
function in 0.15.1, and the multi-phase compiler in mcpyrate
, we can write a lot cleaner demo than what was possible before.
So, let's include such a short demo in 0.15.2.
Example moved into unpythonic.syntax.tests.test_conts_multishot
.
Now we just need to update the documentation, particularly the section on continuations in doc/macros.md
.
get_cc
and the pattern k = call_cc[get_cc()]
. Material exists in the docstring of get_cc
.unpythonic.syntax.tests.test_conts_multishot
, which demonstrates this and packages it into a @multishot
decorator macro, which can be used lexically inside a with continuations
block.Now the demo includes also a MultishotIterator
that shows how to make a @multishot
multi-shot generator conform to the most often used parts of Python's generator API.
As of v0.15.0, there is a toy implementation of multi-shot generators (i.e. re-resumable generators) buried within the automated tests, see unpythonic.syntax.tests.test_conts_gen.
Playing around with the idea, multi-shot generators seem a much nicer API to use continuations with than the low-level
call_cc[]
.Thus, we could extract it into a proper
mcpyrate
macro, and add it to the public macro API.We should caution in the docs that it'll only work inside a
with continuations
block, since doing things like this in Python requires a CPS conversion. Or maybe make this another, alternative multi-shot-continuations API, and internally compile into awith continuations
.This requires first fleshing out some details. Ideally, a multi-shot generator should look similar to a classical Python generator, with only the difference that a multi-shot generator can resume again from an earlier
yield
(arbitrarily many times).