Add generator syntax as DimArray method (#852)

* Add DimArray generator method

* Test generator constructor

* Added documentation on new DimArray generator syntax

* Improved test and docs for new DimArray generator method

* Added more DimArray construction examples to docs

* Removed incorrect doc example of DimArray generator construction

* Simplified and corrected DimArray generator construction examples

* Improve docstring example on DimArray generator method

Co-authored-by: Rafael Schouten <[email protected]>

* Improve docstring description on DimArray generator syntax

Co-authored-by: Rafael Schouten <[email protected]>

* Remove unnecessary description in DimArray docstring

Co-authored-by: Rafael Schouten <[email protected]>

* Clarified docstring on DimArray generator method syntax

Co-authored-by: Rafael Schouten <[email protected]>

* Improved tests for DimArray generator constructor syntax

---------

Co-authored-by: Rafael Schouten <[email protected]>

docs/src/dimarrays.md

@@ -58,6 +58,14 @@ fill(7, X(5), Y(10))
 fill(7, X(5), Y(10); name=:fill, metadata=Dict())
 ```
 
+== generator construction
+
+```@ansi dimarray
+[x + y for x in X(1:5), y in Y(1:10)]
+DimArray(x + y for x in X(1:5), y in Y(1:10))
+DimArray(x + y for x in X(1:5), y in Y(1:10); name=:sum, metadata=Dict())
+```
+
 :::
 
 ## Constructing DimArray with arbitrary dimension names

src/array/array.jl

@@ -362,6 +362,7 @@ end
 
     DimArray(data, dims, refdims, name, metadata)
     DimArray(data, dims::Tuple; refdims=(), name=NoName(), metadata=NoMetadata())
+    DimArray(gen; kw...)
 
 The main concrete subtype of [`AbstractDimArray`](@ref).
 
@@ -372,6 +373,7 @@ moves dimensions to reference dimension `refdims` after reducing operations
 ## Arguments
 
 - `data`: An `AbstractArray`.
+- `gen`: A generator expression. Where source iterators are `Dimension`s the dim args or kw is not needed.
 - `dims`: A `Tuple` of `Dimension`
 - `name`: A string name for the array. Shows in plots and tables.
 - `refdims`: refence dimensions. Usually set programmatically to track past
@@ -384,6 +386,9 @@ and/or [`Selector`](@ref)s.
 Indexing `AbstractDimArray` with non-range `AbstractArray` has undefined effects
 on the `Dimension` index. Use forward-ordered arrays only"
 
+Note that the generator expression syntax requires usage of the semi-colon `;`
+to distinguish generator dimensions from keywords.
+
 Example:
 
 ```jldoctest; setup = :(using Random; Random.seed!(123))
@@ -415,6 +420,22 @@ julia> A[Near(DateTime(2001, 5, 4)), Between(20, 50)]
  40  0.637077
  50  0.692235
 ```
+
+Generator expression:
+
+```jldoctest
+julia> DimArray((x, y) for x in X(1:3), y in Y(1:2); name = :Value)
+╭───────────────────────────────────────────╮
+│ 3×2 DimArray{Tuple{Int64, Int64},2} Value │
+├───────────────────────────────────────────┴───── dims ┐
+  ↓ X Sampled{Int64} 1:3 ForwardOrdered Regular Points,
+  → Y Sampled{Int64} 1:2 ForwardOrdered Regular Points
+└───────────────────────────────────────────────────────┘
+ ↓ →  1        2
+ 1     (1, 1)   (1, 2)
+ 2     (2, 1)   (2, 2)
+ 3     (3, 1)   (3, 2)
+```
 """
 struct DimArray{T,N,D<:Tuple,R<:Tuple,A<:AbstractArray{T,N},Na,Me} <: AbstractDimArray{T,N,D,A}
     data::A
@@ -467,6 +488,8 @@ function DimArray(f::Function, dim::Dimension; name=Symbol(nameof(f), "(", name(
      DimArray(f.(val(dim)), (dim,); name)
 end
 
+DimArray(itr::Base.Generator; kwargs...) = rebuild(collect(itr); kwargs...)
+
 const DimVector = DimArray{T,1} where T
 const DimMatrix = DimArray{T,2} where T
 const DimVecOrMat = Union{DimVector,DimMatrix}

test/array.jl

@@ -473,7 +473,41 @@ end
 
 
 @testset "generator constructor" begin
-    [(x, y) for x in X(10:10:50), y in Y(0.0:0.1:1.0)]
+    Xs = X(10:10:50)
+    Ys = Y(0.0:0.1:1.0)
+    Zs = Z(100:10:500)
+    name = :Value
+
+    A = [(x, y) for x in Xs, y in Ys]
+    @test dims(A) == (Xs, Ys)
+    @test size(A) == (Xs, Ys) .|> length
+
+    A = DimArray(x for x in Xs)
+    @test dims(A) == (Xs,)
+    @test size(A) == (Xs,) .|> length
+
+    A = DimArray(x for x in Xs; name)
+    @test dims(A) == (Xs,)
+    @test size(A) == (Xs,) .|> length
+    @test A.name == name
+
+    A = DimArray((x, y) for x in Xs, y in Ys)
+    @test dims(A) == (Xs, Ys)
+    @test size(A) == (Xs, Ys) .|> length
+
+    A = DimArray((x, y) for x in Xs, y in Ys; name)
+    @test dims(A) == (Xs, Ys)
+    @test size(A) == (Xs, Ys) .|> length
+    @test A.name == name
+
+    A = DimArray((x, y, z) for x in Xs, y in Ys, z in Zs)
+    @test dims(A) == (Xs, Ys, Zs)
+    @test size(A) == (Xs, Ys, Zs) .|> length
+
+    A = DimArray((x, y, z) for x in Xs, y in Ys, z in Zs; name)
+    @test dims(A) == (Xs, Ys, Zs)
+    @test size(A) == (Xs, Ys, Zs) .|> length
+    @test A.name == name
 end
 
 @testset "ones, zeros, trues, falses constructors" begin