From: Ari Johnson
Subject: make-array :element-type
Date: Thu, 13 May 2004 03:33:09 +0000
Message-ID: <F%Boc.125022$Jy3.35873@fed1read03>

I see in the CLHS that :element-type actually enforces 
(upgraded-array-element-type type).  In CLISP, 
(upgraded-array-element-type x) => T for all X that I can come up with. 
  Is this a shortcoming of CLOS and/or arrays in CLISP?

• Re: make-array :element-type Barry Margolin
  • Re: make-array :element-type Ari Johnson
  • Re: make-array :element-type Paul F. Dietz

From: Barry Margolin
Subject: Re: make-array :element-type
Date: Thu, 13 May 2004 04:37:35 +0000
Message-ID: <barmar-58D494.00373513052004@comcast.dca.giganews.com>

In article <······················@fed1read03>,
 Ari Johnson <·····@hotmail.com> wrote:

> I see in the CLHS that :element-type actually enforces 
> (upgraded-array-element-type type).  In CLISP, 

This is a tautology, since UPGRADED-ARRAY-ELEMENT-TYPE is defined in 
terms of what MAKE-ARRAY does (or vice versa).

> (upgraded-array-element-type x) => T for all X that I can come up with. 
>   Is this a shortcoming of CLOS and/or arrays in CLISP?

CL requires that there be specialized array types for strings and bit 
strings, but everything else can be a general array.

-- 
Barry Margolin, ······@alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***

From: Ari Johnson
Subject: Re: make-array :element-type
Date: Thu, 13 May 2004 05:13:58 +0000
Message-ID: <auDoc.125909$Jy3.102616@fed1read03>

Barry Margolin wrote:

> In article <······················@fed1read03>,
>  Ari Johnson <·····@hotmail.com> wrote:
> 
> 
>>I see in the CLHS that :element-type actually enforces 
>>(upgraded-array-element-type type).  In CLISP, 
> 
> 
> This is a tautology, since UPGRADED-ARRAY-ELEMENT-TYPE is defined in 
> terms of what MAKE-ARRAY does (or vice versa).
> 
> 
>>(upgraded-array-element-type x) => T for all X that I can come up with. 
>>  Is this a shortcoming of CLOS and/or arrays in CLISP?
> 
> 
> CL requires that there be specialized array types for strings and bit 
> strings, but everything else can be a general array.

Thanks - I was reading more into it than is there.

From: Paul F. Dietz
Subject: Re: make-array :element-type
Date: Thu, 13 May 2004 10:06:41 +0000
Message-ID: <xKWdnXp37Zfy1T7dRVn-hg@dls.net>

Barry Margolin wrote:

> CL requires that there be specialized array types for strings and bit 
> strings, but everything else can be a general array.

More precisely, it requires that u-a-e-t of BIT or CHARACTER be type
equivalent to those types (no requirement that the element type be
of a one dimensional array).  It also requires that any subtype
of BIT or CHARACTER have u-a-e-t of BIT or CHARACTER (respectively).

	Paul