restrict shorter printing of wheres to gensym names

Author: vtjnash

base/show.jl

@@ -583,6 +583,8 @@ function make_typealias(@nospecialize(x::Type))
     end
 end
 
+isgensym(s::Symbol) = '#' in string(s)
+
 function show_can_elide(p::TypeVar, wheres::Vector, elide::Int, env::SimpleVector, skip::Int)
     elide == 0 && return false
     wheres[elide] === p || return false
@@ -612,9 +614,9 @@ function show_typeparams(io::IO, env::SimpleVector, orig::SimpleVector, wheres::
             if i == n && egal_var(p, orig[i]) && show_can_elide(p, wheres, elide, env, i)
                 n -= 1
                 elide -= 1
-            elseif p.lb === Union{} && show_can_elide(p, wheres, elide, env, i)
+            elseif p.lb === Union{} && isgensym(p.name) && show_can_elide(p, wheres, elide, env, i)
                 elide -= 1
-            elseif p.ub === Any && show_can_elide(p, wheres, elide, env, i)
+            elseif p.ub === Any && isgensym(p.name) && show_can_elide(p, wheres, elide, env, i)
                 elide -= 1
             end
         end
@@ -624,10 +626,10 @@ function show_typeparams(io::IO, env::SimpleVector, orig::SimpleVector, wheres::
         for i = 1:n
             p = env[i]
             if p isa TypeVar
-                if p.lb === Union{} && something(findfirst(w -> w === p, wheres), 0) > elide
+                if p.lb === Union{} && something(findfirst(@nospecialize(w) -> w === p, wheres), 0) > elide
                     print(io, "<:")
                     show(io, p.ub)
-                elseif p.ub === Any && something(findfirst(w -> w === p, wheres), 0) > elide
+                elseif p.ub === Any && something(findfirst(@nospecialize(w) -> w === p, wheres), 0) > elide
                     print(io, ">:")
                     show(io, p.lb)
                 else

doc/src/manual/types.md

@@ -1034,7 +1034,7 @@ consider the two types created by the following declarations:
 
 ```jldoctest
 julia> const T1 = Array{Array{T, 1} where T, 1}
-Vector{Vector} (alias for Array{Array{<:Any, 1}, 1})
+Vector{Vector} (alias for Array{Array{T, 1} where T, 1})
 
 julia> const T2 = Array{Array{T, 1}, 1} where T
 Array{Vector{T}, 1} where T

test/errorshow.jl

@@ -432,7 +432,7 @@ let err_str,
     @test startswith(sprint(show, which(FunctionLike(), Tuple{})),
                      "(::$(curmod_prefix)FunctionLike)() in $curmod_str at $sp:$(method_defs_lineno + 7)")
     @test startswith(sprint(show, which(StructWithUnionAllMethodDefs{<:Integer}, (Any,))),
-                     "($(curmod_prefix)StructWithUnionAllMethodDefs{<:Integer})(x)")
+                     "($(curmod_prefix)StructWithUnionAllMethodDefs{T} where T<:Integer)(x)")
     @test repr("text/plain", FunctionLike()) == "(::$(curmod_prefix)FunctionLike) (generic function with 1 method)"
     @test repr("text/plain", Core.arraysize) == "arraysize (built-in function)"
 

test/show.jl

@@ -1570,7 +1570,7 @@ end
 
 let x = TypeVar(:_), y = TypeVar(:_)
     @test repr(UnionAll(x, UnionAll(y, Pair{x,y}))) == "Pair"
-    @test repr(UnionAll(y, UnionAll(x, Pair{x,y}))) == "Pair{<:Any, _1} where _1"
+    @test repr(UnionAll(y, UnionAll(x, Pair{x,y}))) == "Pair{_2, _1} where {_1, _2}"
     @test repr(UnionAll(x, UnionAll(y, Pair{UnionAll(x,Ref{x}),y}))) == "Pair{Ref}"
     @test repr(UnionAll(y, UnionAll(x, Pair{UnionAll(y,Ref{x}),y}))) == "Pair{Ref{_2}, _1} where {_1, _2}"
 end
@@ -1584,9 +1584,9 @@ let x, y, x
 end
 
 let x = TypeVar(:_, Number), y = TypeVar(:_, Number)
-    @test repr(UnionAll(x, UnionAll(y, Pair{x,y}))) == "Pair{<:Number, <:Number}"
-    @test repr(UnionAll(y, UnionAll(x, Pair{x,y}))) == "Pair{<:Number, _1} where _1<:Number"
-    @test repr(UnionAll(x, UnionAll(y, Pair{UnionAll(x,Ref{x}),y}))) == "Pair{Ref{<:Number}, <:Number}"
+    @test repr(UnionAll(x, UnionAll(y, Pair{x,y}))) == "Pair{_1, _2} where {_1<:Number, _2<:Number}"
+    @test repr(UnionAll(y, UnionAll(x, Pair{x,y}))) == "Pair{_2, _1} where {_1<:Number, _2<:Number}"
+    @test repr(UnionAll(x, UnionAll(y, Pair{UnionAll(x,Ref{x}),y}))) == "Pair{Ref{_1} where _1<:Number, _1} where _1<:Number"
     @test repr(UnionAll(y, UnionAll(x, Pair{UnionAll(y,Ref{x}),y}))) == "Pair{Ref{_2}, _1} where {_1<:Number, _2<:Number}"
 end
 
@@ -1771,7 +1771,7 @@ end
     @test replstr([[1.0]=>1.0]) == "1-element Vector{Pair{Vector{Float64}, Float64}}:\n [1.0] => 1.0"
 
     # issue #28159
-    @test replstr([(a=1, b=2), (a=3,c=4)]) == "2-element Vector{NamedTuple{<:Any, Tuple{$Int, $Int}}}:\n (a = 1, b = 2)\n (a = 3, c = 4)"
+    @test replstr([(a=1, b=2), (a=3,c=4)]) == "2-element Vector{NamedTuple{names, Tuple{$Int, $Int}} where names}:\n (a = 1, b = 2)\n (a = 3, c = 4)"
 
     @test replstr(Vector[Any[1]]) == "1-element Vector{Vector}:\n Any[1]"
     @test replstr(AbstractDict{Integer,Integer}[Dict{Integer,Integer}(1=>2)]) ==
@@ -2166,8 +2166,8 @@ end
 @test string(Union{Nothing, AbstractVecOrMat}) == "Union{Nothing, AbstractVecOrMat}"
 @test string(Union{Nothing, AbstractVecOrMat{<:Integer}}) == "Union{Nothing, AbstractVecOrMat{<:Integer}}"
 @test string(M37012.BStruct{T, T} where T) == "$(curmod_prefix)M37012.B2{T, T} where T"
-@test string(M37012.BStruct{T, S} where {T<:Unsigned, S<:Signed}) == "$(curmod_prefix)M37012.B2{<:Signed, T} where T<:Unsigned"
-@test string(M37012.BStruct{T, S} where {T<:Signed, S<:T}) == "$(curmod_prefix)M37012.B2{<:T, T} where T<:Signed"
+@test string(M37012.BStruct{T, S} where {T<:Unsigned, S<:Signed}) == "$(curmod_prefix)M37012.B2{S, T} where {T<:Unsigned, S<:Signed}"
+@test string(M37012.BStruct{T, S} where {T<:Signed, S<:T}) == "$(curmod_prefix)M37012.B2{S, T} where {T<:Signed, S<:T}"
 @test string(Union{M37012.SimpleU, Nothing}) == "Union{Nothing, $(curmod_prefix)M37012.SimpleU}"
 @test string(Union{M37012.SimpleU, Nothing, T} where T) == "Union{Nothing, $(curmod_prefix)M37012.SimpleU, T} where T"
 @test string(Union{AbstractVector{T}, T} where T) == "Union{AbstractVector{T}, T} where T"