Add Culture property (default InvariantCulture) extend Number regex to support commas

Author: stephenquan

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

@@ -284,4 +284,33 @@ public void MathExpressionConverter_WithAlternateCulture_ReturnsCorrectNumericRe
 		Assert.True(result is not null);
 		Assert.Equal(expectedResult, result);
 	}
+
+	[Theory]
+	[InlineData("", "-12.34 + 56.78", 44.44)]
+	[InlineData("en-US", "-12.34 + 56.78", 44.44)]
+	[InlineData("fr-FR", "-12,34 + 56,78", 44.44)]
+	public void MathExpressionConverter_CultureInfoProperty_HandlesDoubleParsing(string cultureName, string expression, double expectedResult)
+	{
+		CultureInfo culture = !string.IsNullOrEmpty(cultureName) ? new CultureInfo(cultureName) : CultureInfo.InvariantCulture;
+		var mathExpressionConverter = new MultiMathExpressionConverter
+		{
+			Culture = culture
+		};
+		var result = mathExpressionConverter.Convert(new object?[] { }, mathExpressionTargetType, expression);
+		Assert.True(result is not null);
+		Assert.Equal(expectedResult, result);
+	}
+
+	[Theory]
+	[InlineData("ar-SA", "-12.34 + 56.78")]
+	[InlineData("ar-SA", "-12,34 + 56.78")]
+	public void MathExpressionConverter_ArabicCulture_ThrowsException(string cultureName, string expression)
+	{
+		CultureInfo culture = !string.IsNullOrEmpty(cultureName) ? new CultureInfo(cultureName) : CultureInfo.InvariantCulture;
+		var mathExpressionConverter = new MultiMathExpressionConverter
+		{
+			Culture = culture
+		};
+		Assert.Throws<FormatException>(() => mathExpressionConverter.Convert(new object?[] { }, mathExpressionTargetType, expression));
+	}
 }

src/CommunityToolkit.Maui/Converters/MathExpressionConverter/MathExpression.shared.cs

@@ -15,9 +15,11 @@ sealed record MathToken(MathTokenType Type, string Text, object? Value);
 
 sealed partial class MathExpression
 {
+	CultureInfo culture { get; init; } = CultureInfo.InvariantCulture;
+
 	readonly IReadOnlyList<MathOperator> operators;
 
-	internal MathExpression(in string expression, in IReadOnlyList<object?> arguments)
+	internal MathExpression(in string expression, in IReadOnlyList<object?> arguments, CultureInfo culture)
 	{
 		ArgumentException.ThrowIfNullOrEmpty(expression, "Expression can't be null or empty.");
 		ArgumentNullException.ThrowIfNull(arguments, "Arguments cannot be null.");
@@ -96,6 +98,7 @@ internal MathExpression(in string expression, in IReadOnlyList<object?> argument
 		}
 
 		this.operators = operators;
+		this.culture = culture;
 	}
 
 	static ReadOnlyDictionary<string, string> BinaryMappingDictionary { get; } = new Dictionary<string, string>
@@ -223,7 +226,7 @@ internal MathExpression(in string expression, in IReadOnlyList<object?> argument
 	[GeneratedRegex("""^(\-|\!)""")]
 	private static partial Regex EvaluateUnaryOperators();
 
-	[GeneratedRegex("""^(\-?\d+\.\d+|\-?\d+)""")]
+	[GeneratedRegex("""^(\-?\d+[\.,]\d+| \-?\d+)""")]
 	private static partial Regex EvaluateNumberPattern();
 
 	[GeneratedRegex("""^["]([^"]*)["]""")]
@@ -241,20 +244,20 @@ internal MathExpression(in string expression, in IReadOnlyList<object?> argument
 	[GeneratedRegex("""^\s*""")]
 	private static partial Regex EvaluateWhitespace();
 
-	static bool ConvertToBoolean(object? b) => b switch
+	bool ConvertToBoolean(object? b) => b switch
 	{
 		bool x => x,
 		null => false,
 		double doubleValue => doubleValue != 0 && !double.IsNaN(doubleValue),
 		string stringValue => !string.IsNullOrEmpty(stringValue),
-		_ => Convert.ToBoolean(b, CultureInfo.InvariantCulture)
+		_ => Convert.ToBoolean(b, culture)
 	};
 
-	static double ConvertToDouble(object? x) => Convert.ToDouble(x, CultureInfo.InvariantCulture);
+	double ConvertToDouble(object? x) => Convert.ToDouble(x, culture);
 
-	static int ConvertToInt32(object? x) => Convert.ToInt32(x, CultureInfo.InvariantCulture);
+	int ConvertToInt32(object? x) => Convert.ToInt32(x, culture);
 
-	static string? ConvertToString(object? x) => Convert.ToString(x, CultureInfo.InvariantCulture);
+	string? ConvertToString(object? x) => Convert.ToString(x, culture);
 
 	bool ParsePattern(Regex regex)
 	{
@@ -367,7 +370,7 @@ bool ParsePrimary()
 		if (ParsePattern(EvaluateNumberPattern()))
 		{
 			string _number = PatternMatch.Groups[1].Value;
-			RPN.Add(new MathToken(MathTokenType.Value, _number, double.Parse(_number, CultureInfo.InvariantCulture)));
+			RPN.Add(new MathToken(MathTokenType.Value, _number, double.Parse(_number, culture)));
 			return true;
 		}
 

src/CommunityToolkit.Maui/Converters/MathExpressionConverter/MathExpressionConverter.shared.cs

@@ -11,6 +11,11 @@ public partial class MathExpressionConverter : BaseConverterOneWay<object?, obje
 	/// <inheritdoc/>
 	public override object? DefaultConvertReturnValue { get; set; } = 0.0d;
 
+	/// <summary>
+	/// Get or set the culture to use in the converter.
+	/// </summary>
+	public CultureInfo Culture { get; set; } = CultureInfo.InvariantCulture;
+
 	/// <summary>
 	/// Calculate the incoming expression string with one variable.
 	/// </summary>
@@ -22,6 +27,6 @@ public partial class MathExpressionConverter : BaseConverterOneWay<object?, obje
 	{
 		ArgumentNullException.ThrowIfNull(parameter);
 
-		return new MathExpression(parameter, [inputValue]).CalculateResult();
+		return new MathExpression(parameter, [inputValue], Culture).CalculateResult();
 	}
 }

src/CommunityToolkit.Maui/Converters/MathExpressionConverter/MultiMathExpressionConverter.shared.cs

@@ -10,6 +10,11 @@ namespace CommunityToolkit.Maui.Converters;
 [AcceptEmptyServiceProvider]
 public class MultiMathExpressionConverter : MultiValueConverterExtension, ICommunityToolkitMultiValueConverter
 {
+	/// <summary>
+	/// Get or set the culture to use in the converter.
+	/// </summary>
+	public CultureInfo Culture { get; set; } = CultureInfo.InvariantCulture;
+
 	/// <summary>
 	/// Calculate the incoming expression string with variables.
 	/// </summary>
@@ -30,7 +35,7 @@ public class MultiMathExpressionConverter : MultiValueConverterExtension, ICommu
 
 		return values is null
 			? null
-			: new MathExpression(expression, values).CalculateResult();
+			: new MathExpression(expression, values, this.Culture).CalculateResult();
 	}
 
 	/// <summary>