[plt-scheme] SRFI-42

From: Jens Axel Søgaard (jensaxel at soegaard.net)
Date: Mon Aug 13 16:43:06 EDT 2007

Noel Welsh skrev:
> Any reason not to make this the PLT-distributed version?  Also,
> someone mentioned that the SRFI 42 distributed w/ PLT is out of date.

For most users (95%?) it would probably be a good idea
to use the new version, since it gives *much* better error messages.
All generators and comprehensions in srfi-42 are to my knowledge
fully compatible.

But - the mechanism for definining your own generators are slightly 
different than the original srfi, which means that we can't simply 
replace (lib "42.ss" "srfi") and expect old code to run unaltered. The 
good news is that it is straight forward to rewrite an old generator 
(see the examples in doc.txt).

One option is to include the new version as

   (lib "42-plt.ss" "srfi")

and the old one as

   (lib "42.ss" "srfi") .

That ensures that old code still runs, and people can still use the
new one.

Jens Axel Søgaard

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