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Re: More rabbit-holes with unset variables

On Fri, Nov 27, 2020 at 4:39 PM Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx> wrote:
> On Fri, Nov 27, 2020 at 2:10 PM Felipe Contreras
> <felipe.contreras@xxxxxxxxx> wrote:
> >
> > So we can interpret what you said as 'so the only useful "declared but
> > not set" variable is a string' without losing any meaning.
> That's not correct, but again I was hoping it wasn't necessary to
> spell all this out.
> All of the following create parameters representing strings, none of
> which are useful unless they either have a default or the "preserve
> when not set" behavior applies:

These are not contradictory unless you commit the fallacy of the converse.

"All animals that bark are mammals" doesn't mean "all mammals bark".


"All unset variables that are useful are strings" doesn't mean "all
strings are unset variables that are useful".

To be pedantic: param_is_useful_unset(p) -> param_type_is_string(p).
Not the other way around.

This is a bit tautological, because if the variable is unset, it can't
be anything else but a string: param_is_unset(p) ->


Felipe Contreras

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