Re: Another alternative (Re: format strings are the Right Thing)

Taylor Campbell <[email protected]> Tue, 30 Dec 2003 20:48:43 -0500
Newsgroups gmane.lisp.scheme.srfi.srfi-48
Message-ID <[email protected]>
On Dec 29, 2003, at 11:22 PM, Alex Shinn wrote:

[Order of reply is changed slightly.]

> I think the primary arguments are against using any kind of
> mini-language at all vs. just using normal function composition of
> write and display.

No.  It's against _badly_designed_ mini-languages, and _especially_ 
those
encoded in the totally wrong data structure: strings (which we still 
aren't
particularly solid on the definition & usage of, with regard to 
character sets,
Unicode, multi-byte stuff, et cetera).  Marc Feeley had another point, 
too:
that separating the directive and the argument to that directive is a 
bad idea.
You state that separating them is separating data from logic, but it is 
not:
the data is the _combination_ of directive and input; the logic is what 
uses
that data to produce the final output.

(Before you say something along the lines of 'this whole SRFI is about 
strings;
why on earth would you want to avoid them?' let me state that the 
formatting
_output_ is about strings (whether it be in Scheme's string structure, 
in some
future string structure in, for any n such that n > 5, RnRs, in output 
ports,
in streams, or anything), but the formatting routines themselves can be 
much
more structured; likewise, SREs' _input_ deals with processing of 
strings, but
the code to use & manipulate SREs is a lot more structured than as the 
obscure,
string-encoded format of POSIX regexps.)

> But SRE is still a mini-language.  Indeed, I've been suggesting
> possibilities of using arbitrary lists or more verbose format strings.

Verbose format strings aren't much better than format strings with 
single-
character directives: they still have all the above problems.

What do you mean by 'using arbitrary lists?'  I don't believe you've 
described
this alternative in great detail, or if you have, my scouring of the 
archive
has proven fruitless.