I am attempting to retrieve the index of all instances of a pattern in a String vector with missing values.
E.g. How can I get a vector with the index of all instances containing the pattern "a" from:
x = ["ab", "ca", "bc", missing, "ad"]
The desired outcome would be equal to:
Vector([1, 2, 5])
3-element Vector{Int64}:
1
2
5
As these are the indexes in which the pattern appears.
>Solution :
A natural way to write it is:
julia> findall(v -> ismissing(v) ? false : contains(v, "a"), x)
3-element Vector{Int64}:
1
2
5
Alternatively you could write:
julia> using Missings
julia> findall(coalesce.(passmissing(contains).(x, "a"), false))
3-element Vector{Int64}:
1
2
5
which in this case is less readable, but in other contexts you might find passmissing and coalesce useful so I mention them.