Re: [Patch] definitions in when, unless, do as well as in cond- and case-clauses

[Maxime Devos <maximedevos@telenet.be>]

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Linus Björnstam schreef op do 17-06-2021 om 14:57 [+0200]:
> Guile already does definitions in expression context in
> the bodies of lambda and let-variants. I think this is
> not a big problem since any valid r6rs code is still valid guile.

‘Guile already does definitions in expression context in [...]’:
good point.

> The discussion is in my opinion whether guile's r6rs modules should
> enforce this behaviour. That might be a good thing, even though we
> will provide 2 cons and case forms to do that.

Pro: if your code works when using r6rs modules (in Guile), then it should
work on any r6rs-conforming implementation.

Con: (@ (guile) cond) != (@ (rnrs base) cond), which can be surprising.

Con: ‘I know this usage isn't universally portable, but I'll cross that
bridge when needed. All the Scheme I care about do have this extension.
If a Scheme doesn't have this extension, I'll just patch that Scheme
(free software for the win!)’

Greetings,
Maxime.

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