Add boolean dtype

[Uditgulati]

Issue: #10

VALUE <-> bool conversion reference: https://ruby.fandom.com/wiki/C_API/Boolean_values

[prasunanand]

what does adding bool dtypes return ?

Can you add tests ?

[Uditgulati]

@prasunanand I've not added bool dtype to addition function as I think that adding won't return bool. Or if we treat 'true' + 'true' as 'true' or maybe 'false' (I'm not sure if either one is correct or not).

I've added tests for bool dtype initialisation, get_dimension, get_elements. Let me know if more tests are to be added.

[Uditgulati]

Numpy gives answer as True if any of the operands in True. https://pastebin.com/0uZ928eX

[prasunanand]

Check how Ruby treats boolean add .

[Uditgulati]

Ruby does not support boolean addition. https://pastebin.com/ke0KRcWY

[Uditgulati]

@prasunanand Should I implement boolean add then?

[prasunanand]

Yeah

[prasunanand]

Also add test for nm + true

[Uditgulati]

I'm sorry, but what is nm + true?

[prasunanand]

nm = NMatrix.new([2,2], [true, false, true, true])
nm + true

[Uditgulati]

Got it. Thanks for clarifying.

[Uditgulati]

@prasunanand I've made changes and now nm_bool + bool works. I've added tests for it too.

Also, I've noticed that subtract operation doesn't give right answer when some constant is subtracted from matrix, like

n = NMatrix.new [2,2], [1,2,3,4]
m = n - 1

gives m = [2,3,4,5].

I'm still going through code to see how subtraction is implemented. Please have a look and let me know if this is a bug or not.