Apply hash consing to Pow

Author: Blablablanca

src/types.jl

@@ -101,6 +101,7 @@ function ConstructionBase.setproperties(obj::BasicSymbolic{T}, patch::NamedTuple
         Add => Add(T, nt_new.coeff, nt_new.dict; nt_new...)
         Mul => Mul(T, nt_new.coeff, nt_new.dict; nt_new...)
         Div => Div{T}(nt_new.num, nt_new.den, nt_new.simplified; nt_new...)
+        Pow => Pow{T}(nt_new.base, nt_new.exp; nt_new...)
         _ => Unityper.rt_constructor(obj){T}(;nt_new...)
     end
 end
@@ -520,7 +521,8 @@ end
 function Pow{T}(a, b; metadata=NO_METADATA) where {T}
     _iszero(b) && return 1
     _isone(b) && return a
-    Pow{T}(; base=a, exp=b, arguments=[], metadata)
+    s = Pow{T}(; base=a, exp=b, arguments=[], metadata)
+    BasicSymbolic(s)
 end
 
 function Pow(a, b; metadata=NO_METADATA)

test/hash_consing.jl

@@ -1,5 +1,5 @@
 using SymbolicUtils, Test
-using SymbolicUtils: Term, Add, Mul, Div
+using SymbolicUtils: Term, Add, Mul, Div, Pow
 
 struct Ctx1 end
 struct Ctx2 end
@@ -85,3 +85,17 @@ end
     vm1 = setmetadata(v1,Ctx1, "meta_1")
     @test vm1 !== v1
 end
+
+@testset "Pow" begin
+    p1 = a^b
+    p2 = a^b
+    @test p1 === p2
+    p3 = a^(2^-b)
+    p4 = a^(2^-b)
+    @test p3 === p4
+    p5 = Pow{Float64}(a,b)
+    @test p1 !== p5
+
+    pm1 = setmetadata(p1,Ctx1, "meta_1")
+    @test pm1 !== p1
+end