/// <summary>
/// Высчитывает ответ из текстового математического выражения
/// <para>Допустимые символы:</para>
/// <para>Цифры [0 - 9];</para>
/// <para>Знак точки для обозначения дробной части</para>
/// <para>Знаки арифметических операций: + - * / %</para>
/// <para>Круглые скобочки для обозначения приоритета одной операции над другой</para>
/// </summary>
/// <param name="input"></param>
/// <exception cref="Exception"></exception>
/// <returns></returns>
public decimal Evaluate(string input)
{
var unexpectedCharacter = InputValidationService.FindUnexpectedCharacters(input).FirstOrDefault();
if (unexpectedCharacter != null)
{
throw new Exception($"Unexpected character: \'{unexpectedCharacter.Character}\', position: \'{unexpectedCharacter.Index}\'");
}
var invalidBracket = InputValidationService.FindInvalidBracket(input).FirstOrDefault();
if (invalidBracket != null)
{
throw new Exception($"Invalid bracket: \'{invalidBracket.Character}\', position: \'{invalidBracket.Index}\'");
}
var normalizedInput = input.RemoveExcessSpacebar().RemoveExcessLeadingSign().AddSpacebars().AddBracers();
if (ExpressionUnit.TryParse(normalizedInput, out var expressionUnit))
{
return(expressionUnit.GetResult());
}
throw new Exception("Parsing Error");
}
public void TryParse_SecondValueIsValue_ExpressionAndValue()
{
var input = "(1 + 2) + 1";
var isSuccessfull = ExpressionUnit.TryParse(input, out var expressionUnit);
Assert.IsTrue(isSuccessfull);
Assert.AreEqual(typeof(ValueUnit), expressionUnit.SecondValue.GetType());
}
public void TryParse_PlusOperation_ValueAndValue()
{
var input = "1 + 2";
var isSuccessfull = ExpressionUnit.TryParse(input, out var expressionUnit);
Assert.IsTrue(isSuccessfull);
Assert.AreEqual(Operation.Plus, expressionUnit.Operation);
}
public void TryParse_PlusOperation_ExpressionAndExpression()
{
var input = "(1 + 5) + (2 - 1)";
var isSuccessfull = ExpressionUnit.TryParse(input, out var expressionUnit);
Assert.IsTrue(isSuccessfull);
Assert.AreEqual(Operation.Plus, expressionUnit.Operation);
}
public void TryParse_MultiplyOperation_ExpressionAndValue()
{
var input = "(1 - 0) * 2";
var isSuccessfull = ExpressionUnit.TryParse(input, out var expressionUnit);
Assert.IsTrue(isSuccessfull);
Assert.AreEqual(Operation.Multiply, expressionUnit.Operation);
}
public void TryParse_MinusOperation_ExpressionAndValue()
{
var input = "(1 * 8) - 2";
var isSuccessfull = ExpressionUnit.TryParse(input, out var expressionUnit);
Assert.IsTrue(isSuccessfull);
Assert.AreEqual(Operation.Minus, expressionUnit.Operation);
}
public void TryParse_DivRemainderOperation_ValueAndValue()
{
var input = "1 % 2";
var isSuccessfull = ExpressionUnit.TryParse(input, out var expressionUnit);
Assert.IsTrue(isSuccessfull);
Assert.AreEqual(Operation.DivRem, expressionUnit.Operation);
}
public void TryParse_DivRemainderOperation_ExpressionAndExpression()
{
var input = "(1 + 5) % (2 - 1)";
var isSuccessfull = ExpressionUnit.TryParse(input, out var expressionUnit);
Assert.IsTrue(isSuccessfull);
Assert.AreEqual(Operation.DivRem, expressionUnit.Operation);
}
public void TryParse_DivideOperation_ExpressionAndValue()
{
var input = "(1 + 1) / 2";
var isSuccessfull = ExpressionUnit.TryParse(input, out var expressionUnit);
Assert.IsTrue(isSuccessfull);
Assert.AreEqual(Operation.Div, expressionUnit.Operation);
}
public void TryParse_ExpressionBothValuesIsValueUnit_ValueAndValue_Negative()
{
var input = "-1 + -2";
var isSuccessfull = ExpressionUnit.TryParse(input, out var expressionUnit);
Assert.IsTrue(isSuccessfull);
Assert.AreEqual(typeof(ValueUnit), expressionUnit.FirstValue.GetType());
Assert.AreEqual(typeof(ValueUnit), expressionUnit.SecondValue.GetType());
}
public void TryParse_ExpressionBothValueIsExpression_ExpressionAndExpression()
{
var input = "(1 + 5) * (2 - 1)";
var isSuccessfull = ExpressionUnit.TryParse(input, out var expressionUnit);
Assert.IsTrue(isSuccessfull);
Assert.AreEqual(typeof(ExpressionUnit), expressionUnit.FirstValue.GetType());
Assert.AreEqual(typeof(ExpressionUnit), expressionUnit.SecondValue.GetType());
}
