--- NEWS.~1.393.~ 2003-05-22 11:39:29.000000000 +1000 +++ NEWS 2003-05-31 15:12:07.000000000 +1000 @@ -278,27 +278,10 @@ version string without the final micro-version number. See "Changes to the distribution" above. -** Futures +** Futures: future, future-ref -Futures is a way of providing an alternative evaluation policy, very -similar in principle to "promises". Like promises, futures allow the -main process to continue instantly, but while promises postpone -evaluation ("lazy" evaluation) until the value is requested, futures -immediately starts evaluation in a parallel thread. - -Futures are good when you want to express that "I'll need the value of -this computation sometime soon" and want to allow processing to go on -in the background until that time arrives. - -** New syntax: future FORM - -Begin evaluation of FORM in a parallel thread and return the future -immediately. (Akin to 'delay'.) - -** New procedure: future-ref FUTURE - -Return the computed value of the future. Wait if the computation is -not finished. (Akin to 'force'.) +Futures are like promises, but begun immediately in a new thread. See +"Futures" in the reference manual. ** New syntax: parallel FORM ...