Re: Dynamic programming in Forth

From	Alex <alex@rivadpm.com>
Newsgroups	comp.lang.forth
Subject	Re: Dynamic programming in Forth
Date	2017-02-14 16:34 +0000
Organization	A noiseless patient Spider
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On 2/14/2017 15:44, minforth@arcor.de wrote:
> the additional charm that one can take advantage of Forth's
> stack-cleaning CATCH/THROW mechanism

Which is exacty how I feel about CATCH and THROW. They are, to me, not a 
means of indicating errors or exceptions, but a means of providing a 
type of checkpoint with backtracking.

There are limitations; there's no guarantee that your newly 
depth-restored stack will have usable contents for example, or that some 
other global-ish variable or event hasn't hosed your environment. And 
restoring the input source is a hard trick, given that a THROW might 
happen a very long way indeed from the original CATCH.

But given these known limitations, they're still a very useful pair of 
words.

-- 
Alex

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Re: Dynamic programming in Forth lehs <skydda.barnen@gmail.com> - 2017-02-14 03:53 -0800
  Re: Dynamic programming in Forth "David N. Williams" <williams@umich.edu> - 2017-02-14 08:19 -0500
    Re: Dynamic programming in Forth lehs <skydda.barnen@gmail.com> - 2017-02-14 06:03 -0800
      Re: Dynamic programming in Forth minforth@arcor.de - 2017-02-14 07:44 -0800
        Re: Dynamic programming in Forth Alex <alex@rivadpm.com> - 2017-02-14 16:34 +0000

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