Turn bool into a numeric type?

[mark-koch]

Should we turn bool into a numeric type to match Python's behaviour? This means all of the following equalities would hold:

True == 1
False == 0
True + True == 2
True - False == 1
2 * False == 0
...

See #263 for a PR that implements this.

Personally, I'd be in favour to increase consistency with Python. It also allows some nice patterns like

results = [measure(q) for q in qs]
parity = sum(results) % 2

What do you think? @croyzor @qartik @ss2165

[qartik]

If we are considering guppy as a strongly typed language, I think bool should not be implicitly treated as a numeric type. We could certainly provide casting/conversion functions for explicit coercion, if they don't exist already.

Originally posted by @qartik in #225 (comment)

Type-theoretically speaking, I wouldn't want to allow the equalities in the OP.

The pattern shown is very easy and way more explicit with a coercion function:

- results = [measure(q) for q in qs]
+ results = [int(measure(q)) for q in qs]
  parity = sum(results) % 2