Refactor common parts

Author: jishnub

src/fillbroadcast.jl

@@ -118,33 +118,36 @@ _isfill(f::Number) = true
 _isfill(f::Ref) = true
 _isfill(::Any) = false
 
-_broadcast_maybecopy(bc::Broadcast.Broadcasted{<:AbstractFillStyle}) = copy(bc)
-_broadcast_maybecopy(bc::Broadcast.Broadcasted) = Broadcast.broadcasted(bc.f, map(_broadcast_maybecopy, bc.args)...)
-_broadcast_maybecopy(x) = x
+function _copy_fill(bc)
+    v = _getindex_value(bc)
+    if _iszeros(bc)
+        return Zeros(typeof(v), axes(bc))
+    elseif _isones(bc)
+        return Ones(typeof(v), axes(bc))
+    end
+    return Fill(v, axes(bc))
+end
+
+# recursively copy the purely fill components
+function _preprocess_fill(bc::Broadcast.Broadcasted{<:AbstractFillStyle})
+    _isfill(bc) ? _copy_fill(bc) : Broadcast.broadcasted(bc.f, map(_preprocess_fill, bc.args)...)
+end
+_preprocess_fill(bc::Broadcast.Broadcasted) = Broadcast.broadcasted(bc.f, map(_preprocess_fill, bc.args)...)
+_preprocess_fill(x) = x
 
 function _fallback_copy(bc)
-    # treat the fill components
-    bc2 = Base.broadcasted(bc.f, map(_broadcast_maybecopy, bc.args)...)
+    # copy the purely fill components
+    bc2 = Base.broadcasted(bc.f, map(_preprocess_fill, bc.args)...)
     # fallback style
     S = Broadcast.Broadcasted{Broadcast.DefaultArrayStyle{ndims(bc)}}
     copy(convert(S, bc2))
 end
 
 function Base.copy(bc::Broadcast.Broadcasted{<:AbstractFillStyle})
-    if _iszeros(bc)
-        return Zeros(typeof(_getindex_value(bc)), axes(bc))
-    elseif _isones(bc)
-        return Ones(typeof(_getindex_value(bc)), axes(bc))
-    elseif _isfill(bc)
-        return Fill(_getindex_value(bc), axes(bc))
-    else
-        _fallback_copy(bc)
-    end
+    _isfill(bc) ? _copy_fill(bc) : _fallback_copy(bc)
 end
 # make the zero-dimensional case consistent with Base
-function Base.copy(bc::Broadcast.Broadcasted{<:AbstractFillStyle{0}})
-    _fallback_copy(bc)
-end
+Base.copy(bc::Broadcast.Broadcasted{<:AbstractFillStyle{0}}) = _fallback_copy(bc)
 
 # some cases that preserve 0d
 function broadcast_preserving_0d(f, As...)