Hi Claus, On Wed 24 Jul 2013 22:07, "Claus Reinke" <[email protected]> writes:
> 2 generators do not compose as freely as iteration functions, > because they are tied to special syntax and restricted contexts You place blame on generators here, but beside the laments about deep coroutines -- totally understandable, but Brendan is right that that they are pointless -- your examples apply just as well to iterators of all kinds. It just happens that generators are a convienient way to implement iterators. Your point sounds like "external iteration does not compose as freely as internal iteration" -- which is strictly not true! You can't implement zip, for example, with internal iteration, whereas you can with external iteration. > - if you compare the versions that use "for-of" with those (ending with > a "_") that use a user-defined abstraction "forofG", you'll see a lot > of syntax noise, even worse than with the old long-hand "function" - in > terms of making functional abstraction readable, this is going in the > wrong direction, opposite to arrow functions. I humbly suggest that these abstractions are simply in the wrong place. The defining characteristic of an external iterator is that the consumer is external to the producer. Trying to push the consumer inside is going to lead to contorted code, as you have seen. > - I haven't yet figured out how to end an outer generator early > from within a "yield*" nested one (as needed for "take_"), without > replacing "yield*" with a micro-interpreter. That might just be > my incomplete reading of the draft spec, though? "I haven't yet figured out how to end an outer function early from within a nested function call, without replacing the call site with a micro-interpreter." :) Cheers, Andy _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
