deprecate behavior of map on dicts. part of #5794 (#23648)

Author: JeffBezanson

NEWS.md

@@ -428,6 +428,9 @@ Deprecated or removed
 
   * The `Range` abstract type has been renamed to `AbstractRange` ([#23570]).
 
+  * `map` on dictionaries previously operated on `key=>value` pairs. This behavior is deprecated,
+    and in the future `map` will operate only on values ([#5794]).
+
 Command-line option changes
 ---------------------------
 

base/abstractarray.jl

@@ -1936,7 +1936,7 @@ function map!(f::F, dest::AbstractArray, A::AbstractArray) where F
 end
 
 # map on collections
-map(f, A::Union{AbstractArray,AbstractSet,Associative}) = collect_similar(A, Generator(f,A))
+map(f, A::Union{AbstractArray,AbstractSet}) = collect_similar(A, Generator(f,A))
 
 # default to returning an Array for `map` on general iterators
 """

base/deprecated.jl

@@ -1763,6 +1763,9 @@ import .Iterators.enumerate
 
 @deprecate_binding Range AbstractRange
 
+# issue #5794
+@deprecate map(f, d::T) where {T<:Associative}  T( f(p) for p in pairs(d) )
+
 # END 0.7 deprecations
 
 # BEGIN 1.0 deprecations

test/dict.jl

@@ -429,9 +429,8 @@ d = Dict('a'=>1, 'b'=>1, 'c'=> 3)
 
 # generators, similar
 d = Dict(:a=>"a")
-@test @inferred(map(identity, d)) == d
-@test @inferred(map(p->p.first=>p.second[1], d)) == Dict(:a=>'a')
-@test_throws ArgumentError map(p->p.second, d)
+# TODO: restore when 0.7 deprecation is removed
+#@test @inferred(map(identity, d)) == d
 
 # Issue 12451
 @test_throws ArgumentError Dict(0)