Uhm... you never closed that "will this value be .... thing and I'm expecting a "dary" answer like in few emails but my whole point is consuming an API in different scenarios: held or synchronous.
You can always create an API that always returns a Promise, that's nothing new for the language, but can you decide if it's he case to absolutely return a promise 'cause any other value would cause trouble within that generator or async function? On Thu, Dec 3, 2015 at 4:15 PM, John Lenz <[email protected]> wrote: > I don't think being executed in a generator or async function is a good > signal that a promise should be returned (something needs to "await" the > promise). The async function is really a chain of synchronous code split > at various points, during the synchronous parts the code would still need > to be synchronous and returning a promise would be wrong. The real data > you need is "will this value be consumed by an 'await' expression or be > used to resolve a Promise and, in the general case, that is not something > that can't be answered at the time your example function is executing. > > On Thu, Dec 3, 2015 at 4:15 AM, Andrea Giammarchi < > [email protected]> wrote: > >> Hi there, >> just writing down some thoughts about being able to understand if a >> method/function has been executed within a generator/async and is being >> yielded/awaited. >> >> Rationale: API that would like to behave synchronously in some case, >> returning Promises in other cases. >> >> Example: >> >> ```js >> function fileGetContent(fileName) { >> // random example >> if (held) { >> return fetch(fileName).then((r)=>r.text()); >> } else { >> var xhr = new XMLHttpRequest; >> xhr.open('GET', fileName, false); >> xhr.send(null); >> return xhr.responseText; >> } >> } >> ``` >> >> Above example will virtually return always the same type and it could >> work inside a generator or an async function as long as it's being held. >> >> Does any of this make sense? Is it worth exploring this pattern? >> >> Thanks for any sort of thought. >> >> Best Regards >> >> >> >> >> >> _______________________________________________ >> es-discuss mailing list >> [email protected] >> https://mail.mozilla.org/listinfo/es-discuss >> >> >
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