Merge pull request #21 from mrufsvold/add-prettyprint

basic pretty printing

src/DuckDispatch.jl

@@ -29,6 +29,7 @@ include("TypeUtils.jl")
 include("BehaviorDispatch.jl")
 include("MethodDispatch.jl")
 include("DuckTypeMacro.jl")
+include("PrettyPrinting.jl")
 
 @testitem "Test Basics" begin
  DuckDispatch.@duck_type struct Iterable{T}

src/PrettyPrinting.jl

@@ -0,0 +1,39 @@
+# function Base.show(io::IO, ::Type{Behavior{F, S}}) where {F, S}
+# print(io, "Behavior{", string(F.instance), ", ", tuple(static_fieldtypes(S)...), "}")
+# end
+
+function get_duck_type_name(::Type{D}) where {D<:DuckType}
+ (name, params) = if D isa UnionAll
+ (D.body.name.name, D.body.parameters)
+ else
+ (D.name.name, D.parameters)
+ end
+ if isempty(params)
+ return string(name)
+ end
+ return string(name) * "{" * (map(string, params)...) * "}"
+end
+
+function Base.show(io::IO, ::Type{D}) where {D<:DuckType}
+ duck_type_name = get_duck_type_name(D)
+ print(io, duck_type_name)
+ behaviors = DuckDispatch.all_behaviors_of(D)
+ print(io, "\n Behaviors:\n ")
+
+ number_to_show = min(3, length(behaviors)-1)
+ for b in Iterators.take(behaviors, number_to_show)
+ print(io, b)
+ print(io, ",","\n ")
+ end
+ print(io, behaviors[number_to_show+1])
+
+ length(behaviors) > number_to_show+1 && print(io, ",\n ... (Behaviors omitted. call `DuckDispatch.all_behaviors_of(duck_type)` to see all)")
+end
+
+function Base.show(io::IO, ::Type{Guise{D, T}}) where {D, T}
+ print(io, "Guise{", get_duck_type_name(D), ", ", T, "}")
+end
+
+function Base.show(io::IO, g::G) where {G<:Guise}
+ print(io, G, " wrapping:\n", g.data)
+end