Support rekeying a KeyedArray (#63)

* Support various kinds of rekeying/renaming keys.

* Simplify revise rekey signatures and try to keep things tuple-ish.

* Dropped method to rekey and rename at the same time

* Bump patch release since we're pre-1.0

Author: rofinn

Project.toml

@@ -1,7 +1,7 @@
 name = "AxisKeys"
 uuid = "94b1ba4f-4ee9-5380-92f1-94cde586c3c5"
 license = "MIT"
-version = "0.2.9"
+version = "0.2.10"
 
 [deps]
 AbstractFFTs = "621f4979-c628-5d54-868e-fcf4e3e8185c"

src/AxisKeys.jl

@@ -6,7 +6,7 @@ export KeyedArray, axiskeys
 include("lookup.jl")
 
 include("names.jl")
-export named_axiskeys
+export named_axiskeys, rekey
 export NamedDimsArray, dimnames, rename  # Reexport key NamedDimsArrays things
 
 include("wrap.jl")

src/names.jl

@@ -173,3 +173,27 @@ function named_axiskeys(A::AbstractArray)
     NT = NamedTuple{dimnames(A)}
     NT(axiskeys(A))
 end
+
+
+"""
+    rekey(A, (1:10, [:a, :b]))
+    rekey(A, 2 => [:a, :b])
+    rekey(A, :y => [:a, :b])
+
+Rekey a KeyedArray via `Tuple`s or `Pair`s, `dim => newkey`. If `A` also has named
+dimensions then you can also pass `dimname => newkey`.
+"""
+rekey(A::Union{KeyedArray, NdaKa}, k2::Tuple) = KeyedArray(keyless(A), k2)
+function rekey(A::Union{KeyedArray, NdaKa}, k2::Pair{<:Integer, <:AbstractVector}...)
+    dims, vals = first.(k2), last.(k2)
+    new_key = ntuple(ndims(A)) do d
+        idx = findfirst(==(d), dims)
+        idx === nothing ? axiskeys(A, d) : vals[idx]
+    end
+    return rekey(A, new_key)
+end
+
+function rekey(A::Union{KaNda, NdaKa}, k2::Pair{Symbol, <:AbstractVector}...)
+    pairs = map(p -> NamedDims.dim(A, p[1]) => p[2], k2)
+    return rekey(A, pairs...)
+end

test/_basic.jl

@@ -170,6 +170,16 @@ end
 
         @test_throws Exception N(obs=55)  # ideally ArgumentError
         @test_throws Exception N(obs='z') # ideally BoundsError
+
+        new_obs = [:x, :y, :z]
+        new_iter = 1:4
+
+        # Rekey with Tuple
+        @test axiskeys(rekey(N, ([:x, :y, :z], 1:4))) == ([:x, :y, :z], 1:4)
+        # Rekey with dim => axiskey pair
+        @test axiskeys(rekey(N, 2 => 1:4)) == (['a', 'b', 'c'], 1:4)
+        # Rekey with dimname => axiskey pair
+        @test axiskeys(rekey(N, :iter => 1:4)) == (['a', 'b', 'c'], 1:4)
     end
 
     @testset "named_axiskeys" begin