#491 - Add simplification rules for mass.

Author: sys27

xFunc.Maths/Analyzers/Simplifier.cs

@@ -200,6 +200,13 @@ public override IExpression Analyze(Add exp)
             (Temperature left, Temperature right)
                 => (left.Value + right.Value).AsExpression(),
 
+            (Number left, Mass right)
+                => (left.Value + right.Value).AsExpression(),
+            (Mass left, Number right)
+                => (left.Value + right.Value).AsExpression(),
+            (Mass left, Mass right)
+                => (left.Value + right.Value).AsExpression(),
+
             // x + x
             (Variable left, Variable right) when left.Name == right.Name
                 => new Mul(Number.Two, left),
@@ -314,6 +321,8 @@ public override IExpression Analyze(Div exp)
                 => (left.Value / right.Value).AsExpression(),
             (Temperature left, Number right)
                 => (left.Value / right.Value).AsExpression(),
+            (Mass left, Number right)
+                => (left.Value / right.Value).AsExpression(),
 
             // x / x
             (Variable left, Variable right) when left.Equals(right)
@@ -506,6 +515,11 @@ public override IExpression Analyze(Mul exp)
             (Temperature left, Number right)
                 => (left.Value * right.Value).AsExpression(),
 
+            (Number left, Mass right)
+                => (left.Value * right.Value).AsExpression(),
+            (Mass left, Number right)
+                => (left.Value * right.Value).AsExpression(),
+
             // x * -y
             (var left, UnaryMinus minus)
                 => new UnaryMinus(new Mul(left, minus.Argument)),
@@ -747,6 +761,13 @@ public override IExpression Analyze(Sub exp)
             (Temperature left, Temperature right)
                 => (left.Value - right.Value).AsExpression(),
 
+            (Number left, Mass right)
+                => (left.Value - right.Value).AsExpression(),
+            (Mass left, Number right)
+                => (left.Value - right.Value).AsExpression(),
+            (Mass left, Mass right)
+                => (left.Value - right.Value).AsExpression(),
+
             // x + x
             (Variable left, Variable right) when left.Name == right.Name
                 => Number.Zero,

xFunc.Tests/Analyzers/SimplifierTests/AddSimplifierTest.cs

@@ -149,6 +149,42 @@ public void AddTwoTemperatures()
         SimplifyTest(add, expected);
     }
 
+    [Fact(DisplayName = "10 + 10 g")]
+    public void AddNumberAndMass()
+    {
+        var add = new Add(
+            new Number(10),
+            MassValue.Gram(10).AsExpression()
+        );
+        var expected = MassValue.Gram(20).AsExpression();
+
+        SimplifyTest(add, expected);
+    }
+
+    [Fact(DisplayName = "10 g + 10")]
+    public void AddMassAndNumber()
+    {
+        var add = new Add(
+            MassValue.Gram(10).AsExpression(),
+            new Number(10)
+        );
+        var expected = MassValue.Gram(20).AsExpression();
+
+        SimplifyTest(add, expected);
+    }
+
+    [Fact(DisplayName = "10 g + 10 kg")]
+    public void AddTwoMasses()
+    {
+        var add = new Add(
+            MassValue.Kilogram(10).AsExpression(),
+            MassValue.Gram(10).AsExpression()
+        );
+        var expected = MassValue.Gram(10010).AsExpression();
+
+        SimplifyTest(add, expected);
+    }
+
     [Fact(DisplayName = "-x + 2")]
     public void AddFirstUnaryMinus()
     {

xFunc.Tests/Analyzers/SimplifierTests/DivSimplifierTest.cs

@@ -85,6 +85,18 @@ public void DivTemperatureByNumber()
         SimplifyTest(div, expected);
     }
 
+    [Fact(DisplayName = "90 g / 2")]
+    public void DivMassByNumber()
+    {
+        var div = new Div(
+            MassValue.Gram(90).AsExpression(),
+            new Number(2)
+        );
+        var expected = MassValue.Gram(45).AsExpression();
+
+        SimplifyTest(div, expected);
+    }
+
     [Fact(DisplayName = "(2 * x) / 4")]
     public void DivDiff_NumMulVar_DivNum()
     {

xFunc.Tests/Analyzers/SimplifierTests/MulSimplifierTest.cs

@@ -149,6 +149,30 @@ public void MulTemperatureByNumber()
         SimplifyTest(mul, expected);
     }
 
+    [Fact(DisplayName = "10 * 2 g")]
+    public void MulNumberByMass()
+    {
+        var mul = new Mul(
+            new Number(10),
+            MassValue.Gram(2).AsExpression()
+        );
+        var expected = MassValue.Gram(20).AsExpression();
+
+        SimplifyTest(mul, expected);
+    }
+
+    [Fact(DisplayName = "2 g * 10")]
+    public void MulMassByNumber()
+    {
+        var mul = new Mul(
+            MassValue.Gram(2).AsExpression(),
+            new Number(10)
+        );
+        var expected = MassValue.Gram(20).AsExpression();
+
+        SimplifyTest(mul, expected);
+    }
+
     [Fact(DisplayName = "2 * (2 * x)")]
     public void MulDiffNumMul_NumMulVar_()
     {

xFunc.Tests/Analyzers/SimplifierTests/SubSimplifierTest.cs

@@ -140,6 +140,42 @@ public void SubTemperatureFromTemperature()
         SimplifyTest(sub, expected);
     }
 
+    [Fact(DisplayName = "20 - 10 g")]
+    public void SubMassFromNumber()
+    {
+        var sub = new Sub(
+            new Number(20),
+            MassValue.Gram(10).AsExpression()
+        );
+        var expected = MassValue.Gram(10).AsExpression();
+
+        SimplifyTest(sub, expected);
+    }
+
+    [Fact(DisplayName = "20 g - 10")]
+    public void SubNumberFromMass()
+    {
+        var sub = new Sub(
+            MassValue.Gram(20).AsExpression(),
+            new Number(10)
+        );
+        var expected = MassValue.Gram(10).AsExpression();
+
+        SimplifyTest(sub, expected);
+    }
+
+    [Fact(DisplayName = "20 kg - 10 g")]
+    public void SubMassFromMass()
+    {
+        var sub = new Sub(
+            MassValue.Kilogram(20).AsExpression(),
+            MassValue.Gram(10).AsExpression()
+        );
+        var expected = MassValue.Kilogram(19.990).AsExpression();
+
+        SimplifyTest(sub, expected);
+    }
+
     [Fact(DisplayName = "2 - -x")]
     public void SubSecondUnaryMinus()
     {