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Re: Fluids vs parameters: which API is better?
From: |
Ludovic Courtès |
Subject: |
Re: Fluids vs parameters: which API is better? |
Date: |
Mon, 25 Jul 2011 11:24:31 +0200 |
User-agent: |
Gnus/5.110018 (No Gnus v0.18) Emacs/24.0.50 (gnu/linux) |
Hi BT,
BT Templeton <address@hidden> skribis:
> Andy Wingo <address@hidden> writes:
[...]
>> Here I disagree. From the perspective of semantics and security, it's
>> important to be able to make assertions as to the type of value returned
>> by a procedure -- that (current-input-port) returns a port. The same
>> goes for (current-language) and all the other dynamic parameters.
>> Parameters allow us to make guarantees like that.
>
> Why is it uniquely useful to be able to make these guarantees for
> dynamically-bound values? Static/soft typing would be more generally
> useful than parameters.
I agree it’s not specific to dynamically-bound values.
Andy mentioned that exporting, say, the fluid that underlies
‘current-output-port’ would be a problem because you could ‘fluid-set!’
it to anything, which would lead to an obscure wrong-type-arg error
sometime.
OTOH it could be argued that this is no different with mutable global
variables.
> Also, I'd prefer it if parameters used a type predicate or a type
> specifier object instead of a conversion procedure. ISTM that the
> current interface conflates type checking and coercion.
Well, Andy’s proposal is similar to SRFI-39 and I find it convenient
this way.
Thanks,
Ludo’.
- Re: How can I tell guile to shut up? ;), Andy Wingo, 2011/07/01
- Re: How can I tell guile to shut up? ;), Andy Wingo, 2011/07/01
- Re: How can I tell guile to shut up? ;), Ludovic Courtès, 2011/07/01
- Re: How can I tell guile to shut up? ;), Andy Wingo, 2011/07/01
- Re: How can I tell guile to shut up? ;), Ludovic Courtès, 2011/07/04
- Fluids vs parameters: which API is better?, Mark H Weaver, 2011/07/18
- Re: Fluids vs parameters: which API is better?, Andy Wingo, 2011/07/19
- Re: Fluids vs parameters: which API is better?, BT Templeton, 2011/07/24
- Re: Fluids vs parameters: which API is better?,
Ludovic Courtès <=
- Re: Fluids vs parameters: which API is better?, Andy Wingo, 2011/07/25