[Python-ideas] Python Numbers as Human Concept Decimal System

[Tim Peters]

[Tim]
>> That would be true if the standard explicitly forbade extensions (any
>> optional operation or behavior not specified by the standard).  But
>> there are no standards like that ;-)  To comply with a standard, there
>> just needs to be _some_ way to "spell" all the behaviors the standard
>> mandates.

[Mark H. Harris]
> The IEEE 854 1987  is just such a standard (Mike Cowlishaw's extension).
>
> The generalized  IEEE 754 2008  standard might not have as much wiggly
> room.

I have the 2008 version of the standard; it's thoroughly ordinary in
these respects.

As usual, it's not even "a language" that's normally said to be
compliant with the standard.  Instead:

    Conformance to this standard is a property of a specific
    implementation of a specific programming environment, rather
    than of a language specification.

Although:

    However a language standard could also be said to conform to this standard
    if it were constructed so that every conforming implementation of
that language
    also conformed automatically to this standard.

So far as languages go, there's very little a standard of this nature
_can_ say!  Languages vary enormously in syntax and conventions.
Indeed, for example, the standard "spells" multiplication as

    multiplication(x, y)

That doesn't mean a conforming implementation has to supply a
2-argument function named "multiplication".  It just means a
conforming implementation has to supply _some_ way to spell what the
standard defines via "multiplication(x, y)".

Etc.