Brandon S. Allbery KF8NH
allbery at ece.cmu.edu
Wed Oct 15 19:09:24 EDT 2008
On 2008 Oct 15, at 19:04, Brandon S. Allbery KF8NH wrote:
> On 2008 Oct 15, at 18:51, Matthew J. Williams wrote:
>> Yet, it does not quite explain how 'fix' does not result in
>> infinite recursion.
> Remember, Haskell is non-strict. When the computation reaches 0,
> the "then" branch of the conditional is evaluated and the "else" is
> unneeded and therefore ignored, so its re-invocation isn't seen.
Think about this, btw: you can create new control operations as
ordinary functions In strict languages you need to rely on special
syntax (such as Perl's IO syntax + \& prototype, or Ruby's special
block/proc syntax; in LISP/Scheme, you have to use a macro and/or
quoting); non-strict evaluation gives it to you for free.
brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allbery at kf8nh.com
system administrator [openafs,heimdal,too many hats] allbery at ece.cmu.edu
electrical and computer engineering, carnegie mellon university KF8NH
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