Re: Why is booleanp defined this way?

[Rusi]

On Saturday, April 18, 2015 at 7:48:56 AM UTC+5:30, Emanuel Berg wrote:
> Rusi  writes:
> 
> > Elisp does not have a proper boolean type; unlike
> > say symbols with symbolp, strings with stringp,
> > numberp -- some union of numeric types etc.
> > However programmers need boolean in their ontology
> > even if (and even more if) the language does not
> > support it.
> 
> I never used `booleanp' and I never experienced that
> the boolean built-in type was missing from my
> "ontology".

If you how to write (and grok) an 'if' you have boolean in your ontology.
That you dont know that you know is ok; most programmers dont get that their
'thinking language' is a superset of their programming language.

eg When we were students we learnt flowcharts (or flawcharts)
Most today's kids think thats irrelevant but then they think UML is relevant.
The Dijkstra school would tout logic
The FP school will tout lambda calculus (or dependent types)
Even the box-and-arrow diagrams of classic data structures books goes beyond the
language the book claims to be using