[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Chicken-users] match-let and hygiene incompatible?
From: |
felix winkelmann |
Subject: |
Re: [Chicken-users] match-let and hygiene incompatible? |
Date: |
Fri, 20 May 2005 08:16:41 +0200 |
On 5/20/05, Michele Simionato <address@hidden> wrote:
> On 5/20/05, felix winkelmann <address@hidden> wrote:
> > I usually recommend
> >
> > (require-extension match)
> >
> > instead of `(require 'match)', though.
>
> Is there any practical difference?
>
`require' works at run-time. But in compiled code you want to
have the macro definitions at compile-time.
`require-extension' knows about "special" extensions (like match)
and handles syntactic extensions of eggs (provided the setup
script adds the necessary properties at installation).
`require' is sometimes useful when you want to load extensions
lazily at runtime, or when you just need a "load-once" operation.
`require-for-syntax' is sometimes useful when you have situations
where a syntactic extension needs to load support code at compile-
time.
One should _always_ use `require-extension' (it also expands into
`(declare (uses ...))' forms for the builtin extensions like srfi-1, etc.),
since it usually just does "the right thing".
And finally: `use' is just an alias for `require-extension'.
cheers,
felix