Update

Author: odow

src/Utilities/functions.jl

@@ -1071,6 +1071,10 @@ function canonicalize!(
     return f
 end
 
+function canonical(f::MOI.ScalarNonlinearFunction)::MOI.ScalarNonlinearFunction
+    return MOI.Nonlinear.SymbolicAD.simplify(f)
+end
+
 function canonicalize!(f::MOI.ScalarNonlinearFunction)
     for (i, arg) in enumerate(f.args)
         if !is_canonical(arg)
@@ -1080,6 +1084,11 @@ function canonicalize!(f::MOI.ScalarNonlinearFunction)
     return f
 end
 
+function canonical(f::MOI.VectorNonlinearFunction)
+    rows = MOI.Nonlinear.SymbolicAD.simplify.(f.rows)
+    return MOI.VectorNonlinearFunction(rows)
+end
+
 function canonicalize!(f::MOI.VectorNonlinearFunction)
     for (i, fi) in enumerate(f.rows)
         f.rows[i] = canonicalize!(fi)

test/Nonlinear/SymbolicAD.jl

@@ -64,6 +64,7 @@ function test_simplify_ScalarNonlinearFunction()
     f = MOI.ScalarNonlinearFunction(:log, Any[x])
     g = MOI.ScalarNonlinearFunction(:sin, Any[f])
     @test SymbolicAD.simplify(g) ≈ g
+    @test MOI.Utilities.canonical(g) ≈ g
     return
 end
 
@@ -252,6 +253,7 @@ function test_simplify_VectorNonlinearFunction()
     f = MOI.VectorNonlinearFunction(wrap.([y; x_plus]))
     g = MOI.VectorNonlinearFunction([y; x_plus])
     @test SymbolicAD.simplify(f) ≈ g
+    @test isapprox(MOI.Utilities.canonical(f), g)
     return
 end