Implement is_sumtype (#90)

JuliaDynamics · Jul 6, 2024 · 88cc7c9 · 88cc7c9
1 parent 77cf02c
commit 88cc7c9
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Showing 3 changed files with 17 additions and 5 deletions.
diff --git a/docs/src/index.md b/docs/src/index.md
@@ -2,6 +2,7 @@
 
 ```@docs
 @sumtype
-DynamicSumTypes.variant
-DynamicSumTypes.allvariants
+variant
+allvariants
+is_sumtype
 ```
diff --git a/src/DynamicSumTypes.jl b/src/DynamicSumTypes.jl
@@ -1,7 +1,7 @@
 
 module DynamicSumTypes
 
-export @sumtype
+export @sumtype, variant, allvariants, is_sumtype
 
 unwrap(sumt) = getfield(sumt, :variants)
 
@@ -42,7 +42,7 @@ macro sumtype(typedef)
                 variants::Union{$(variants...)}
                 $type(v) = $(branchs(variants, :(return new(v)))...)
             end
-            function variant(sumt::$type)
+            function DynamicSumTypes.variant(sumt::$type)
                 v = DynamicSumTypes.unwrap(sumt)
                 $(branchs(variants, :(return v))...)
             end
@@ -66,7 +66,8 @@ macro sumtype(typedef)
                 v = DynamicSumTypes.unwrap(sumt)
                 print(string($type), "'.", string(v))                
             end
-            allvariants(sumt::Type{$type}) = tuple($(variants...))
+            DynamicSumTypes.allvariants(sumt::Type{$type}) = tuple($(variants...))
+            DynamicSumTypes.is_sumtype(sumt::Type{$type}) = true
             $type
     end)
 end 
@@ -129,4 +130,12 @@ julia> allvariants(AB)
 """
 function allvariants end
 
+"""
+    is_sumtype(T)
+
+Returns true if the type is a sum type otherwise
+returns false.
+"""
+is_sumtype(T::Type) = false
+
 end
diff --git a/test/sumtype_macro_tests.jl b/test/sumtype_macro_tests.jl
@@ -76,6 +76,8 @@ end
     @test g1.e === g2.e === 1
     @test hasproperty(g1, :e) == true
     @test hasproperty(g1, :w) == false
+    @test is_sumtype(typeof(g1)) == true
+    @test is_sumtype(G) == false
 
     f.a = (3, 3)
     @test f.a == (3, 3)