Support parse(type, str) in @mutete and @transmute

[takuizum]

Hi all,

@mutate and @transmute cannot recognize a function's arguments correctly.
For example, the parse(type, str) function converts the string to another type, but @mutate recognizes the first argument, which is a target type, as the variable in the data frame.

The following code returns ERROR: ArgumentError: column name :Int64 not found in the data frame

df = DataFrame(A = ["1", "2"])
@mutate(df, B = parse(Int64, A))

[takuizum]

as_integer can parse string as integer.

[kdpsingh]

The original code doesn't work because Tidier looks for a column named Int64.

The following code uses interpolation to let Tidier know that Int64 is coming from the global environment and should work (though I haven't tested to confirm).

@mutate(df, B = parse(!!Int64, A))

However, I would like to fix this behavior so that keywords like Int64 and true/false don't require interpolation. I'll leave this issue open until we fix it.

[kdpsingh]

This is now fixed in #69. Here is the output from the fixed version:

julia> df = DataFrame(A = ["1", "2"])
2×1 DataFrame
 Row │ A      
     │ String 
─────┼────────
   1 │ 1
   2 │ 2

julia> @mutate(df, B = parse(Int64, A))
2×2 DataFrame
 Row │ A       B     
     │ String  Int64 
─────┼───────────────
   1 │ 1           1
   2 │ 2           2