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[Axiom-developer] RE: [Aldor-l] RE: Axiom domains and Aldor return types
From: |
Page, Bill |
Subject: |
[Axiom-developer] RE: [Aldor-l] RE: Axiom domains and Aldor return types |
Date: |
Wed, 12 Jan 2005 15:04:53 -0500 |
On Wednesday, January 12, 2005 11:03 AM Ralf Hemmecke wrote:
> ...
> I am, however, very much against the Any type. It is like
> building a strongly typed language and than trying to forget
> about types.
>
Well that is more or less what I naively thought as well but
from the ANY.spad file I read that:
)abbrev domain ANY Any
++ Author: Robert S. Sutor
++ Basic Functions: any, domainOf, objectOf, dom, obj,
++ showTypeInOutput
++ Related Constructors: AnyFunctions1
++ Description:
++ \spadtype{Any} implements a type that packages up objects and
++ their types in objects of \spadtype{Any}. Roughly speaking
++ that means that if \spad{s : S} then when converted to
++ \spadtype{Any}, the new object will include both the original
++ object and its type. This is a way of converting arbitrary
++ objects into a single type **without losing any** of the
++ original information. Any object can be converted to one of
++ \spadtype{Any}.
and in the related file ANY1.spad
)abbrev package ANY1 AnyFunctions1
++ Basic Functions: coerce, retractIfCan, retractable?, retract
++ Description:
++ \spadtype{AnyFunctions1} implements several utility functions
++ for working with \spadtype{Any}. These functions are used to
++ go back and forth between objects of \spadtype{Any} and objects
++ of other types.
So the situation is not quiet so simple. Apparently Any does not
mean Any in the sense of throwing away essential information.
Regards,
Bill Page.
- [Axiom-developer] RE: [Aldor-l] RE: Axiom domains and Aldor return types,
Page, Bill <=