[julia-users] fieldtype() for parameterised types

['Greg Plowman' via julia-users]

For a parameterised composite type, I want to distinguish between 
fields defined with parameters and generic fields.

An example is probably best:
 
type Foo{T,N}
    a::Array
    b::Array{T,N}
end

fieldtype(Foo,:a) returns Array{T,N}
fieldtype(Foo,:b) returns Array{T,N}



And if I use different parameters:

type Bar{S,M}
    a::Array
    b::Array{S,M}
end

fieldtype(Bar,:a) returns Array{T,N}
fieldtype(Bar,:b) returns Array{S,M}


So if I'm careful to use different parameters to the default for the 
field type (Array in this case), I could perhaps distinguish between 
parameterised/non-parameterised fields.

However, it would be nice if fieldtype returned no parameters for case 
where they are not specified for the field.
i.e. fieldtype(Foo,:a) returns Array

Are there any other suggestions?