Parse 0 and 1 as Bool if asked for explicitly

[kescobo]

On julia master, CSV#master:

shell> cat test.csv
a,b
1.0,0
2.0,1
julia> CSV.File("test.csv", types=[Float64, Bool])
┌ Warning: thread = 1 warning: error parsing Bool around row = 2, col = 2: "0
│ ", error=INVALID: SENTINEL | NEWLINE | INVALID_DELIMITER 
└ @ CSV ~/.julia/packages/CSV/WixoJ/src/file.jl:630
┌ Warning: thread = 1 warning: error parsing Bool around row = 3, col = 2: "1", error=INVALID: SENTINEL | EOF | INVALID_DELIMITER 
└ @ CSV ~/.julia/packages/CSV/WixoJ/src/file.jl:630
2-element CSV.File{false}:
 CSV.Row: (a = 1.0, b = missing)
 CSV.Row: (a = 2.0, b = missing)

julia> versioninfo()
Julia Version 1.6.0-DEV.1342
Commit 6312bfec43 (2020-10-27 14:55 UTC)
Platform Info:
  OS: Linux (x86_64-linux-gnu)

Given that

julia> Bool(1)
true

julia> Bool(0)
false

It seems like this should work.

---

This is perhaps a separate issue (or just me misreading the docstring), but I thought perhaps typemap would work in this case, even though it's not generalizable (since a file might have legit Int and Bool columns), but I got this:

julia> CSV.File("test.csv", typemap=Dict(Int=>Bool))
2-element CSV.File{false}:
 CSV.Row: (a = 1.0, b = "0")
 CSV.Row: (a = 2.0, b = "1")

[quinnj]

You can do this like CSV.File(file; truestrings=["1"], falsestrings=["0"])

[kescobo]

Seems to also require specifying the column type:

shell> cat test.csv
a,b
1,0
2,1

julia> f1 = CSV.File("test.csv"; truestrings=["1"], falsestrings=["0"])
2-element CSV.File{false}:
 CSV.Row: (a = 1, b = 0)
 CSV.Row: (a = 2, b = 1)

julia> first(f1).b |> typeof
Int64

julia> f2 = CSV.File("test.csv"; types=[Int,Bool], truestrings=["1"], falsestrings=["0"])
2-element CSV.File{false}:
 CSV.Row: (a = 1, b = false)
 CSV.Row: (a = 2, b = true)

Which I guess is good, since it prevents the 1 in the first column from being parsed as true, but is there a reason that this can't be a default for Bool columns (if the column is explicitly declared Bool, I don't think a column with only 0 and 1 should be parsed as boolean implicitly)?

[quinnj]

Yeah, it seems like just adding "0" and "1" to the default truestrings/falsestrings would solve this; mind making a PR?