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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