Re: Comparison operators for strings /and/ numbers?

[Arne Babenhauserheide <arne_bab@web.de>]

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Hi Christopher,

You can use GOOPS to make them generic:

> (import (oop goops))
> (< "a" "b")
<unnamed port>:3:0: <unnamed port>:3:0: In procedure <: Wrong type argument in position 1: "a"

Entering a new prompt.  Type `,bt' for a backtrace or `,q' to continue.
[1]> (define-method (< (a <string>) (b <string>)) (string<? a b))
[1]> (< "a" "b")
$1 = #t

For some functions you might need to call (define-generic <function>)
before this (you’ll notice because define-method will signal an error).

Best wishes,
Arne

Christopher Howard <christopher.howard@qlfiles.net> writes:

> Hi, in another lisp I have been working with, it has <, >, and ==
> (structure equality) operators which can take string arguments, number
> arguments, or a mixture of both. But it seems in guile that there are
> separate comparison operators for strings and for numbers. This makes
> sense but is not very convenient for my present purpose. Is there some
> other guile operators or extension operators that will handle both? I
> could make some I'm sure, but I don't want to reinvent the wheel.

-- 
Unpolitisch sein
heißt politisch sein
ohne es zu merken

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