Article View: comp.lang.functional
Article #88Re: ** LAZY LANGUAGES FASTER?? **
From: Karl-Filip Faxen
Date: Mon, 27 Jul 1992 13:07
Date: Mon, 27 Jul 1992 13:07
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In article <3737@svin02.info.win.tue.nl>, erik@wsinfo03.win.tue.nl (Erik Poll) writes: |> In lazy languages, an argument is evaluated once for every time that it |> is used. No, in a lazy implementation (and laziness is an implementation related concept - the corresponding semantic concept is nonstrictness (as Nikhil pointed out earlier)) an argument to a function is evaluated *at most once*. A lazy implementation is required to save the result of evaluation for later use. What *has* to be done for each use of the argument (in the absence of strictness analysis) is a check of whether the argument is or isn't already evaluated, ie if we should evaluate it or use the saved result of an earlier evaluation. Karl-Filip --------------------------------------------------------------------- Make the frequent case fast, and the fast case frequent!
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Newsgroups: comp.lang.functional Path: arc1-ca.pugleaf.net!sparky!uunet!mcsun!sunic!kth.se!dentex.tds.kth.se!kff From: kff@dentex.tds.kth.se (Karl-Filip Faxen) Subject: Re: ** LAZY LANGUAGES FASTER?? ** Message-ID: <1992Jul27.130709.13348@kth.se> Sender: usenet@kth.se (Usenet) Nntp-Posting-Host: dentex.tds.kth.se Reply-To: kff@dentex.tds.kth.se (Karl-Filip Faxen) Organization: Royal Institute of Technology, Stockholm, Sweden References: <1992Jul24.134857.23289@gdstech.grumman.com> <3737@svin02.info.win.tue.nl> Date: Mon, 27 Jul 1992 13:07:09 GMT Lines: 17