Migrate to PEG parser. Introduce boolean operators and constants.

src/CommunityToolkit.Maui.Core/Primitives/MathOperator.shared.cs

@@ -27,17 +27,14 @@ public sealed class MathOperator
 	/// </summary>
 	/// <param name="name">Name</param>
 	/// <param name="numericCount">Number of Numerals</param>
-	/// <param name="precedence">Math Operator Preference</param>
 	/// <param name="calculateFunc">Calculation Function</param>
 	public MathOperator(
 		string name,
 		int numericCount,
-		MathOperatorPrecedence precedence,
-		Func<double[], double> calculateFunc)
+		Func<object?[], object?> calculateFunc)
 	{
 		Name = name;
 		CalculateFunc = calculateFunc;
-		Precedence = precedence;
 		NumericCount = numericCount;
 	}
 
@@ -59,5 +56,5 @@ public MathOperator(
 	/// <summary>
 	/// Calculation Function
 	/// </summary>
-	public Func<double[], double> CalculateFunc { get; }
+	public Func<object?[], object?> CalculateFunc { get; }
 }

src/CommunityToolkit.Maui.UnitTests/Converters/MathExpressionConverterTests.cs

@@ -30,7 +30,30 @@ public void MathExpressionConverter_ReturnsCorrectResult(string expression, doub
 		var convertFromResult = mathExpressionConverter.ConvertFrom(x, expression);
 
 		Assert.True(Math.Abs((double)convertResult - expectedResult) < tolerance);
-		Assert.True(Math.Abs(convertFromResult - expectedResult) < tolerance);
+		Assert.True(Math.Abs((double)convertFromResult - expectedResult) < tolerance);
+	}
+
+	[Theory]
+	[InlineData("3 < x", 2d, false)]
+	[InlineData("x > 3", 2d, false)]
+	[InlineData("3 < x == x > 3", 2d, true)]
+	[InlineData("3 <= x != 3 >= x", 2d, true)]
+	[InlineData("x >= 1", 2d, true)]
+	[InlineData("x <= 3", 2d, true)]
+	[InlineData("x >= 1 && (x <= 3 || x >= 0)", 2d, true)]
+	[InlineData("true", 2d, true)]
+	[InlineData("false", 2d, false)]
+	[InlineData("-x > 2", 3d, false)]
+	[InlineData("!!! (---x > 2)", 3d, true)]
+	public void MathExpressionConverter_ReturnsCorrectBooleanResult(string expression, double x, bool expectedResult)
+	{
+		var mathExpressionConverter = new MathExpressionConverter();
+
+		var convertResult = ((ICommunityToolkitValueConverter)mathExpressionConverter).Convert(x, mathExpressionTargetType, expression, cultureInfo) ?? throw new NullReferenceException();
+		var convertFromResult = mathExpressionConverter.ConvertFrom(x, expression);
+
+		Assert.True((bool)convertResult == expectedResult);
+		Assert.True((bool)convertFromResult == expectedResult);
 	}
 
 	[Theory]
@@ -47,6 +70,22 @@ public void MathExpressionConverter_WithMultiplyVariable_ReturnsCorrectResult(st
 		Assert.True(Math.Abs((double)result - expectedResult) < tolerance);
 	}
 
+	[Theory]
+	[InlineData("x == x1", new object?[] { 2d, 2d }, true)]
+	[InlineData("x == x1", new object?[] { 2d, null }, false)]
+	[InlineData("x == x1", new object?[] { null, 2d}, false)]
+	[InlineData("x == x1", new object?[] { null, null }, true)]
+	[InlineData("(x ? x1 : x2) == null", new object?[] { true, null, 2d }, true)]
+	public void MathExpressionConverter_WithMultiplyVariable_ReturnsCorrectBooleanResult(string expression, object[] variables, bool expectedResult)
+	{
+		var mathExpressionConverter = new MultiMathExpressionConverter();
+
+		object? result = mathExpressionConverter.Convert(variables, mathExpressionTargetType, expression);
+
+		Assert.True(result is not null);
+		Assert.Equal(expectedResult, result);
+	}
+
 	[Theory]
 	[InlineData("1 + 3 + 5 + (3 - 2))")]
 	[InlineData("1 + 2) + (9")]
@@ -74,7 +113,7 @@ public void MultiMathExpressionConverterInvalidParameterThrowsArgumentException(
 	public void MultiMathExpressionConverterInvalidValuesReturnsNull()
 	{
 		var mathExpressionConverter = new MultiMathExpressionConverter();
-		var result = mathExpressionConverter.Convert([0d, null], mathExpressionTargetType, "x", cultureInfo);
+		var result = mathExpressionConverter.Convert([0d, null], mathExpressionTargetType, "x + x1", cultureInfo);
 		result.Should().BeNull();
 	}
 
@@ -85,9 +124,9 @@ public void MathExpressionConverterNullInputTest()
 		Assert.Throws<ArgumentNullException>(() => ((ICommunityToolkitValueConverter)new MathExpressionConverter()).Convert(0.0, null, "x", null));
 		Assert.Throws<ArgumentNullException>(() => ((ICommunityToolkitValueConverter)new MathExpressionConverter()).ConvertBack(0.0, null, null, null));
 #pragma warning restore CS8625 // Cannot convert null literal to non-nullable reference type.
-		Assert.Throws<ArgumentNullException>(() => ((ICommunityToolkitValueConverter)new MathExpressionConverter()).Convert(null, typeof(bool), "x", null));
+		//Assert.Throws<ArgumentNullException>(() => ((ICommunityToolkitValueConverter)new MathExpressionConverter()).Convert(null, typeof(bool), "x", null));
 		Assert.Throws<ArgumentNullException>(() => ((ICommunityToolkitValueConverter)new MathExpressionConverter()).Convert(null, typeof(bool), null, null));
-		Assert.Throws<ArgumentNullException>(() => ((ICommunityToolkitValueConverter)new MathExpressionConverter()).ConvertBack(null, typeof(bool), null, null));
+		//Assert.Throws<ArgumentNullException>(() => ((ICommunityToolkitValueConverter)new MathExpressionConverter()).ConvertBack(null, typeof(bool), null, null));
 	}
 
 	[Fact]