Show of parameterized methods

[mauro3]

Below example shows that the method display does not make it clear whether the function parameter T features in the Array parameter or not.

julia> f{T}(::Array, x::T) = 1
f (generic function with 1 method)

julia> f{T}(::Array{T}, x::T) = 1
f (generic function with 2 methods)

julia> methods(f)
#2 methods for generic function "f":
f{T}(::Array{T,N},x::T) at none:1
f{T}(::Array{T,N},x::T) at none:1

for instance in methods(call) it looks like a lot of them are parametrized on the first argument but are not.

Maybe display like this instead:

ulia> methods(f)
#2 methods for generic function "f":
f{T}(::Array{_,_},x::T) at none:1
f{T}(::Array{T,N},x::T) at none:1

[JeffBezanson]

Here's a simple patch that I like for handling this; see if you like it:

diff --git a/base/methodshow.jl b/base/methodshow.jl
index e101dee..541a379 100644
--- a/base/methodshow.jl
+++ b/base/methodshow.jl
@@ -19,6 +19,9 @@ function argtype_decl(n, t) # -> (argname, argtype)
             return s, string(t.parameters[1], "...")
         end
     end
+    if isa(t,DataType) && t === t.name.primary
+        return s, string(t.name)
+    end
     return s, string(t)
 end

[mauro3]

Yes, I think that is better but not perfect. Here the output now:

julia> f{T,N}(a::Array, b::Array{T}, c::Array{T,N}) = 1
f (generic function with 1 method)

julia> methods(f)
# 1 method for generic function "f":
f{T,N}(a::Array,b::Array{T,N},c::Array{T,N}) at none:1

So the second Array prints N even though it shouldn't.

I put together PR #10861 which should address this:

f{T,N}(a::Array    , b::Array{T},  c::Array{T,N},d::T,e::Int32,f::Vector,    g::Vector{T}, h::Array{Vector,1}) = 1

f{T,N}(a::Array{*,*},b::Array{T,*},c::Array{T,N},d::T,e::Int32,f::Array{*,1},g::Array{T,1},h::Array{Array{*,1},1})

What do you think? An option would be to just print a space instead of the *, or anything. Not printing something for missing parameters would only work if we print the typealiases instead of the actual types.