Revert "Fix major unit operation issues in extension"

This reverts commit f1dee4e.

Author: ChrisRackauckas

ext/ModelingToolkitUnitfulExt.jl

@@ -40,40 +40,8 @@ function MT.equivalent(x::Unitful.Unitlike, y::Unitful.Unitlike)
 end
 
 # Mixed equivalence checks
-function MT.equivalent(x::Unitful.Unitlike, y)
-    if y isa MT.DQ.AbstractQuantity
-        # Handle dimensionless case
-        if Unitful.dimension(x) == Unitful.NoDims && MT.DQ.is_unitless(y)
-            return true
-        end
-        # For mixed unit systems, we can't reliably compare
-        # This would require a full dimensional analysis system
-        return false
-    else
-        try
-            return isequal(1 * x, y)
-        catch
-            return false
-        end
-    end
-end
-
-function MT.equivalent(x, y::Unitful.Unitlike)
-    if x isa MT.DQ.AbstractQuantity
-        # Handle dimensionless case
-        if Unitful.dimension(y) == Unitful.NoDims && MT.DQ.is_unitless(x)
-            return true
-        end
-        # For mixed unit systems, we can't reliably compare
-        return false
-    else
-        try
-            return isequal(x, 1 * y)
-        catch
-            return false
-        end
-    end
-end
+MT.equivalent(x::Unitful.Unitlike, y) = isequal(1 * x, y)
+MT.equivalent(x, y::Unitful.Unitlike) = isequal(x, 1 * y)
 
 # The safe_get_unit function stays in the main package and already handles DQ.DimensionError
 # We just need to make sure it can handle Unitful.DimensionError too

src/systems/unit_check.jl

@@ -81,32 +81,7 @@ function get_unit(op, args) # Fallback
         result = op(unit_args...)
         # For operations that return a unit directly, return it
         return screen_unit(result)
-    catch e
-        # If we get an ambiguous method error mixing DQ and Unitful, 
-        # try to handle common cases
-        if e isa MethodError && length(unit_args) >= 2
-            # Check if we have mixed DQ and Unitful units
-            unit_types = _get_unittype.(unit_args)
-            if Val(:DynamicQuantities) in unit_types && Val(:Unitful) in unit_types
-                # For multiplication/division operations involving unitless and Unitful
-                if op === (*) 
-                    # If first argument is unitless (like -1), result should have the unit of the second
-                    if unit_args[1] == unitless && length(unit_args) == 2
-                        return screen_unit(unit_args[2])
-                    elseif length(unit_args) == 2 && unit_args[2] == unitless
-                        return screen_unit(unit_args[1])
-                    end
-                elseif op === (/) && unit_args[1] == unitless
-                    # 1 / unitful_unit should give unitful_unit^-1
-                    try
-                        return screen_unit(inv(unit_args[2]))
-                    catch
-                        # Fall through to original error handling
-                    end
-                end
-            end
-        end
-        
+    catch
         try
             # Try with oneunit for numeric operations
             result = oneunit(op(unit_args...))
@@ -178,11 +153,8 @@ function get_unit(x::Symbolic)
     elseif ispow(x)
         pargs = arguments(x)
         base, expon = get_unit.(pargs)
-        # Check that exponent is dimensionless (works for both DQ and Unitful)
-        if !equivalent(expon, unitless)
-            throw(ValidationError("Power exponent must be dimensionless, got $expon"))
-        end
-        if equivalent(base, unitless)
+        @assert oneunit(expon) == unitless
+        if base == unitless
             unitless
         else
             pargs[2] isa Number ? base^pargs[2] : (1 * base)^pargs[2]

test/units.jl

@@ -19,9 +19,9 @@ D = Differential(t)
 @test ModelingToolkit.get_unit(t) == u"ms"
 @test ModelingToolkit.get_unit(E) == u"kJ"
 @test ModelingToolkit.get_unit(τ) == u"ms"
-@test ModelingToolkit.equivalent(ModelingToolkit.get_unit(γ), unitless)
-@test ModelingToolkit.equivalent(ModelingToolkit.get_unit(0.5), unitless)
-@test ModelingToolkit.equivalent(ModelingToolkit.get_unit(ModelingToolkit.SciMLBase.NullParameters()), unitless)
+@test ModelingToolkit.get_unit(γ) == unitless
+@test ModelingToolkit.get_unit(0.5) == unitless
+@test ModelingToolkit.get_unit(ModelingToolkit.SciMLBase.NullParameters()) == unitless
 
 # Prohibited unit types
 @parameters β [unit = u"°"] α [unit = u"°C"] γ [unit = 1u"s"]
@@ -34,14 +34,14 @@ D = Differential(t)
 @test ModelingToolkit.equivalent(ModelingToolkit.get_unit(D(E)), u"MW")
 @test ModelingToolkit.equivalent(ModelingToolkit.get_unit(E / τ), u"MW")
 @test ModelingToolkit.get_unit(2 * P) == u"MW"
-@test ModelingToolkit.equivalent(ModelingToolkit.get_unit(t / τ), unitless)
+@test ModelingToolkit.get_unit(t / τ) == unitless
 @test ModelingToolkit.equivalent(ModelingToolkit.get_unit(P - E / τ), u"MW")
 @test ModelingToolkit.equivalent(ModelingToolkit.get_unit(D(D(E))), u"MW/ms")
 @test ModelingToolkit.get_unit(ifelse(t > t, P, E / τ)) == u"MW"
-@test ModelingToolkit.equivalent(ModelingToolkit.get_unit(1.0^(t / τ)), unitless)
-@test ModelingToolkit.equivalent(ModelingToolkit.get_unit(exp(t / τ)), unitless)
-@test ModelingToolkit.equivalent(ModelingToolkit.get_unit(sin(t / τ)), unitless)
-@test ModelingToolkit.equivalent(ModelingToolkit.get_unit(sin(1 * u"rad")), unitless)
+@test ModelingToolkit.get_unit(1.0^(t / τ)) == unitless
+@test ModelingToolkit.get_unit(exp(t / τ)) == unitless
+@test ModelingToolkit.get_unit(sin(t / τ)) == unitless
+@test ModelingToolkit.get_unit(sin(1 * u"rad")) == unitless
 @test ModelingToolkit.get_unit(t^2) == u"ms^2"
 
 eqs = [D(E) ~ P - E / τ
@@ -225,7 +225,7 @@ end
 @test ModelingToolkit.getdefault(sys.a) ≈ [0.01, 0.03]
 
 @variables x(t)
-@test ModelingToolkit.equivalent(ModelingToolkit.get_unit(sin(x)), unitless)
+@test ModelingToolkit.get_unit(sin(x)) == unitless
 
 @mtkmodel ExpressionParametersTest begin
     @parameters begin