[Python-Dev] [PEP 3148] futures - execute computations asynchronously (original) (raw)

Guido van Rossum guido at python.org
Fri Mar 5 21:55:46 CET 2010

On Fri, Mar 5, 2010 at 12:18 PM, <exarkun at twistedmatrix.com> wrote:

The "explicit" futures on the wikipedia page seems to cover what is commonly referred to as a future.  For example, Java's futures look like this.

The "implicit" futures are what is generally called a promise.  For example, E's promises look like this.

Fair enough, though the article confuses the matter by using the words more or less interchangeably.

Though the difference is mainly one of API, it turns out to make a significant difference in what you can accomplish.  Promises are much more amenable to the pipelining optimization, for example.  They're also much harder to implement in Python without core language changes.

That's why implicit futures (by any name) aren't on the table.

-- --Guido van Rossum (python.org/~guido)

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