Fix construction with no parameters (#108)

README.md

@@ -23,18 +23,17 @@ like so:
 ```julia
 julia> using DynamicSumTypes
 
-julia> abstract type AbstractAT end
+julia> abstract type AbstractS end
 
 julia> struct A{X}
            x::X
        end
 
 julia> mutable struct B
-           y::Float64
+           y::Int
        end
 
-julia> @sumtype AT(A{Int},B) <: AbstractAT
-AT
+julia> @sumtype S{X}(A{X},B) <: AbstractS
 ```
 
 ## Construction
@@ -43,21 +42,11 @@ Then constructing instances is just a matter of enclosing the type constructed i
 predefined sum type:
 
 ```julia
-julia> a = AT(A(1))
-AT(A{Int64}(1))
+julia> a = S(A(1))
+S{Int64}(A{Int64}(1))
 
-julia> b = AT(B(1.0))
-AT(B(1.0))
-```
-
-Or an alternative syntax can also be used:
-
-```julia
-julia> a = AT'.A(1)
-AT(A{Int64}(1))
-
-julia> b = AT'.B(1.0)
-AT(B(1.0))
+julia> b = S{Int}(B(1))
+S{Int64}(B(1))
 ```
 
 ## Access and Mutation
@@ -68,8 +57,8 @@ This works like if they were normal Julia types:
 julia> a.x
 1
 
-julia> b.y = 3.0
-3.0
+julia> b.y = 3
+3
 ```
 
 ## Dispatch
@@ -78,7 +67,7 @@ For this, you can simply access the variant
 inside the sum type and then dispatch on it:
 
 ```julia
-julia> f(x::AT) = f(variant(x))
+julia> f(x::S) = f(variant(x))
 
 julia> f(x::A) = 1
 

src/DynamicSumTypes.jl

@@ -54,11 +54,21 @@ macro sumtype(typedef)
         end
     end
 
+    constructors = [:(@inline $(namify(type))(v::Union{$(variants...)}) where {$(typeparams...)} = 
+                        $(branchs(variants, variants_with_P, :(return new{$(typeparams...)}(v)))...))]
+
+    if type isa Expr
+        push!(
+            constructors, 
+            :(@inline $type(v::Union{$(variants...)}) where {$(typeparams...)} = 
+                $(branchs(variants, variants_with_P, :(return new{$(typeparams...)}(v)))...))
+        )
+    end
+
     esc(quote
             struct $type <: $(abstract_type)
                 variants::Union{$(variants...)}
-                @inline $type(v::Union{$(variants...)}) where {$(typeparams...)} = 
-                    $(branchs(variants, variants_with_P, :(return new{$(typeparams...)}(v)))...)
+                $(constructors...)
             end
             @inline function $Base.getproperty(sumt::$typename, s::Symbol)
                 v = $DynamicSumTypes.unwrap(sumt)

test/sumtype_macro_tests.jl

@@ -144,7 +144,8 @@ struct None end
     @test allvariants(Simple) == allvariants(typeof(b)) == (SimpleA = SimpleA, SimpleB = SimpleB)
 
     option_none = Option{Int}(None())
-    option_some = Option{Int}(Some(1))
+    option_some = Option(Some(1))
+    option_some2 = Option{Int}(Some(1))
     @test variant(option_none) isa None
     @test variant(option_some) isa Some{Int}
     @test allvariants(Option) == (None = None, Some = Some)