parse and use `@if true` properly

[gergelyattilakiss]

Constant conditions are not working well

[gergelyattilakiss]

booleans are fixed in https://github.com/codedthinking/Kezdi.jl/commit/0c5540534e0bf1b57f08bce9f7b08c8aa2183029

[gergelyattilakiss]

constant conditions are a bit more difficult, they are expressions, but in the bitmask they are evaluated as booleans that can not be row condition.

[gergelyattilakiss]

fixed in 0bf74c7d3e457fe74aec30aabbf0c7c49dbbb918 , used variables do not make a problem because @if only looks for variabels in the dataframe, and later if we add context with scalars(...), then in scalars too.

[korenmiklos]

Now I see the problem. If the condition returns a vector, we get a BitVector that can be used to index the dataframe.

If the condition is a scalar, it cannot be used for indexing.

What if we just add a vector of 0s? Automatic broadcasting should turn the scalar into a vector, and we are fine.

[korenmiklos]

BitVector(zeros(Bool, n)) .| bitmask

[gergelyattilakiss]

Will start working on it.

[korenmiklos]

No, that's the beauty. Broadcasting is automatic and false | x is equal to x. The only difference is that BitVector .| x will be Vector shaped.

[korenmiklos]

julia> BitVector(zeros(5)) .| false
5-element BitVector:
 0
 0
 0
 0
 0

julia> BitVector(zeros(5)) .| true
5-element BitVector:
 1
 1
 1
 1
 1

julia> BitVector(zeros(5)) .| [1, 0, 1, 1, 0]
5-element Vector{Int64}:
 1
 0
 1
 1
 0

[gergelyattilakiss]

Yepp, I started testing these in terminal and see how it goes.

[korenmiklos]

Make sure to put $bitmask in () to ensure operator precedence.

[gergelyattilakiss]

Do we prefer inline solution or should I put the indexing vector into a different variable?

[gergelyattilakiss]

It took me sometime to find the proper place for the broadcasting... but it seems to work fine now.

[korenmiklos]

I'd rather add this to build_bitmask

[korenmiklos]

Please move to build_bitmask. This will be easier to maintain and to merge with other code.

Also add at least 3 tests for this condition, like if true and if 2 + 2 == 4 and if 1 < 0