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futures

futures
Repository
1. Version history
2. License

A straightforward implementation of "futures" for concurrent evaluation of expressions. This extension provides syntax and data types for futures - concurrently evaluated expressions that memoize their result.

Usage

(import futures)

future

[syntax] (future EXPRESSION ...) -> future

Starts evaluation of EXPRESSION ... in a separate thread and returns a future object representing the computation.

future?

[procedure] (future? X) -> boolean

Is X is a future?

force/future

[procedure] (force/future X) -> * ...

If X is a future, then the current threads waits until the expression evaluated at the point of creating the future is complete. If an error occurred during that evaluation, or when the future executed to completion, then force will return the result(s) of the future expression.

If the argument is not a future, then the usual semantics of force apply.

future-complete?

[procedure] (future-complete? FUTURE) -> boolean

Has the FUTURE completed execution, successfully or not?

future-failed?

[procedure] (future-failed? FUTURE) -> boolean

Has an exception occurred during evaluation of the FUTURE?

future-condition

[procedure] (future-condition FUTURE) -> *

Returns the error-condition if an exception occurred during evaluation of the FUTURE, or #f if still executing, or executed without an error.

Requirements

test test-utils

Authors

Felix Kon Lovett

Repository

This egg is hosted on the CHICKEN Subversion repository:

https://anonymous@code.call-cc.org/svn/chicken-eggs/release/5/futures

If you want to check out the source code repository of this egg and you are not familiar with Subversion, see this page.

Version history

2.0.0: CHICKEN 5 release.
1.1: Thomas Chust added some missing functions
1.0: Initial release

License

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. Neither the name of the author nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.