TypeConstructor errors confusing

[amckinlay]

julia> foo{T}(x::T) = None
foo (generic function with 1 method)

julia> foo{Int}
ERROR: type: instantiate_type: expected TypeConstructor, got Function

yet you can't seem to test whether a type is a type constructor

julia> type Foo{T}; x::T; end

julia> isa(Foo, TypeConstructor)
false

julia> Foo{Int}
Foo{Int64} (constructor with 2 methods)

[amckinlay]

Also,

julia> type Foo{T}; x::T; end

julia> typealias Baz{T} Foo{T}
Foo{T}

julia> typeof(Baz)
TypeConstructor

julia> typeof(Foo)
DataType

julia> Baz == Foo
true

julia> methods(Baz)
ERROR: no method methods(Type{Foo{T}})

julia> methods(Foo)
# 1 method for generic function "Foo":
Foo{T}(x::T)

julia> typealias Bar Foo{Int}
Foo{Int64} (constructor with 2 methods)

julia> typeof(Bar)
DataType

julia> methods(Bar)
# 2 methods for generic function "Foo":
Foo(x::Int64)
Foo(x)

1. Why does the type of a parametric type alias singleton not match the type of the parametric type singleton it represents, yet == says they're the same?
2. Why do you lose access to the parametric constructors when referencing a parametric type through a parametric type alias? You don't lose constructors when the type alias represents a concrete type.

[JeffBezanson]

These issues and more are to be resolved in the future. Until then I advise stepping back and looking at the bigger picture.

[JeffBezanson]

See existing issues such as #2552, #6721