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Re: Meaning of <=> in the context of procedures
From: |
Linus Björnstam |
Subject: |
Re: Meaning of <=> in the context of procedures |
Date: |
Wed, 02 Jun 2021 18:21:39 +0200 |
User-agent: |
Cyrus-JMAP/3.5.0-alpha0-519-g27a961944e-fm-20210531.001-g27a96194 |
To reply to myself: it is an exported identifier that is used in a
define-json-mapping. It is good form for macros to export all its auxiliary
syntax.
--
Linus Björnstam
On Wed, 2 Jun 2021, at 18:12, Linus Björnstam wrote:
> It is a trick to allow using the symbol '<=> as an identifier instead
> of quoting it. Nothing special. Guile-json probably uses it somehow.
>
> If it is used as auxiliary syntax in a macro, it is probably exported
> so guile can warn that it is being shadowed instead of (or rather: in
> addition to) producing bad error messages.
>
> --
> Linus Björnstam
>
> On Wed, 2 Jun 2021, at 16:06, Mortimer Cladwell wrote:
> > Hi,
> > What does <=> mean/do?
> > It can be found in guile-json in the (json record) module, line 33:
> >
> > 33 #:export (<=> define-json-mapping define-json-type))
> >
> > Not mentioned in the entire Guile manual. Happens to be defined on line 36
> > of the module:
> >
> > 36 (define <=> '<=>)
> >
> > I didn't find that very helpful :)
> > Thanks
> > Mortimer
> >
>
>