public void Simplify_AddingLeftNestedIdentifiersSwapped_ReturnsOperatorNode()
{
Environment environment = new Environment();
environment.AddSymbol("x");
environment.AddSymbol("y");
SyntaxNode root = GetExpression("y + x + x", environment);
root = LeftNestedAlgebraicSimplifier.Simplify((OperatorNode)root, environment);
Assert.AreEqual("2 * x + y", root.ToString());
}
public void AddSymbol_AlreadyDefinedSymbol_ThrowsException()
{
Environment environment = new Environment();
environment.AddSymbol("x");
DefinedSymbolException exception = Assert.Throws <DefinedSymbolException>(() => {
environment.AddSymbol("x");
});
Assert.AreEqual("Symbol x has already been defined", exception.Message);
}
public void Simplify_AddingTwoDifferentVariables_ReturnsOperatorNode()
{
Environment environment = new Environment();
environment.AddSymbol("x");
environment.AddSymbol("y");
SyntaxNode node = GetExpression("x + y", environment);
node = AlgebraicIdentitySimplifier.Simplify((OperatorNode)node, environment);
Assert.AreEqual("x + y", node.ToString());
}
public void Analyze_RecognizeShorthandMultiplicationInsideIdentifer_ReturnsOperatorNode()
{
SyntaxNode root = new IdentifierNode("xy");
Environment environment = new Environment();
environment.AddSymbol("x");
environment.AddSymbol("y");
root = SemanticAnalyzer.Analyze(root, environment);
Assert.AreEqual("x * y", root.ToString());
}
public void ToString_DisplaysFunctionMultipleArguments_ReturnsString()
{
Environment environment = new Environment();
environment.AddSymbol("x");
environment.AddSymbol("y");
Expression expression = new Expression(Parser.ParseExpression("1/2x+2y", environment), environment);
Function f = new Function("f", new HashSet <string> {
"x", "y"
}, expression);
Assert.AreEqual(f.ToString(), "f(x, y) = 1 * 2 ^ -1 * x + 2 * y");
}
public void HasVariable_SymbolDoesNotExists_ReturnsFalse()
{
Environment environment = new Environment();
environment.AddSymbol("x");
Assert.True(environment.HasVariable("x"));
}
public void Simplify_Subtract0_X()
{
Environment environment = new Environment();
environment.AddSymbol("x");
ConstantSimplifier simplifier = new ConstantSimplifier(environment);
SyntaxNode node = Parser.ParseExpression("x - 0", environment);
Assert.AreEqual("x", simplifier.Simplify(node).ToString());
}
public void GetVariable_Symbol_ReturnsEnvironmentVariable()
{
Environment environment = new Environment();
environment.AddSymbol("x");
EnvironmentVariable variable = environment.Get("x");
Assert.AreEqual(EnvironmentVariableType.Symbol, variable.Type);
}
public void Analyze_AmbiguousVariable_ThrowsException()
{
IdentifierNode symbol = new IdentifierNode("xyz");
Environment environment = new Environment();
environment.AddSymbol("x");
environment.AddSymbol("y");
environment.AddSymbol("z");
environment.AddSymbol("xy");
environment.AddSymbol("yz");
AmbiguousIdentifierException exception = Assert.Throws <AmbiguousIdentifierException>(() =>
{
SemanticAnalyzer.Analyze(symbol, environment);
});
Assert.NotNull(exception);
Assert.AreEqual("Ambiguous identifier 'xyz' can be made from 'x, y, z', 'x, yz', 'xy, z'", exception.Message);
}
public void Simplify_MultiplyBy1ManyTimes_X()
{
Environment environment = new Environment();
environment.AddSymbol("x");
ConstantSimplifier simplifier = new ConstantSimplifier(environment);
SyntaxNode node = Parser.ParseExpression("x * 1 * 1 * 1", environment);
Assert.AreEqual("x", simplifier.Simplify(node).ToString());
}
public void Simplify_ComplexAlgebraExpression_SimplifiesDivision()
{
Environment environment = new Environment();
environment.AddSymbol("x");
ConstantSimplifier simplifier = new ConstantSimplifier(environment);
SyntaxNode node = Parser.ParseExpression("3 * x / 3 + 12", environment);
Assert.AreEqual("x + 12", simplifier.Simplify(node).ToString());
}
public void Simplify_ComplexAlgebraicAddition3_ReturnsExpression()
{
Environment environment = new Environment();
environment.AddSymbol("x");
SyntaxNode root = GetExpression("x + 3 * x", environment);
root = RightNestedAlgebraicSimplifier.Simplify((OperatorNode)root, environment);
Assert.AreEqual("4 * x", root.ToString());
}
public void Simplify_ExponentiationTwoOfTheSameVariables_ReturnsOperatorNode()
{
Environment environment = new Environment();
environment.AddSymbol("x");
SyntaxNode node = GetExpression("x ^ x", environment);
node = AlgebraicIdentitySimplifier.Simplify((OperatorNode)node, environment);
Assert.AreEqual("x ^ x", node.ToString());
}
public void Simplify_NestedAddition_ReturnsOperatorNode()
{
Environment environment = new Environment();
environment.AddSymbol("j");
SyntaxNode root = GetExpression("6 * j + 9 * j", environment);
root = NestedAlgebraicSimplifier.Simplify((OperatorNode)root, environment);
Assert.AreEqual("15 * j", root.ToString());
}
public void Simplify_AddingLeftNestedReverseTerm_ReturnsOperatorNode()
{
Environment environment = new Environment();
environment.AddSymbol("x");
SyntaxNode root = GetExpression("x * 2 + x", environment);
root = LeftNestedAlgebraicSimplifier.Simplify((OperatorNode)root, environment);
Assert.AreEqual("3 * x", root.ToString());
}
public void Analyze_VariableSymbol_ReturnsIdentifierNode()
{
SyntaxNode node = new IdentifierNode("x");
Environment environment = new Environment();
environment.AddSymbol("x");
node = SemanticAnalyzer.Analyze(node, environment);
Assert.AreEqual("x", node.ToString());
}
public void Analyze_RecognizeShorthandMultiplicationInsideIdentifierWithPredefinedSymbols_ReturnsIdentifierNode()
{
SyntaxNode root = new IdentifierNode("xe");
Environment environment = new Environment();
environment.AddSymbol("x");
root = SemanticAnalyzer.Analyze(root, environment);
Assert.AreEqual("x * e", root.ToString());
}
public void Analyze_Parentheses_ReturnsParenthesesNode()
{
Environment environment = new Environment();
environment.AddSymbol("x");
SyntaxNode root = new ParenthesesNode(new IdentifierNode("x"));
root = SemanticAnalyzer.Analyze(root, environment);
Assert.AreEqual("(x)", root.ToString());
}
public void Derive_x_Returns1()
{
Environment environment = new Environment();
environment.AddSymbol("x");
SyntaxNode node = Parser.ParseExpression("x", environment);
Expression expression = new Expression(node, environment);
Derivative derivative = new Derivative(expression, "x");
Assert.AreEqual(derivative.Derive().ToString(), "1");
}
public void Simplify_NestedAlgebraicOperator_ReturnsOperatorNode()
{
Environment environment = new Environment();
environment.AddSymbol("x");
SyntaxNode node = GetExpression("3 * x + 2 * x", environment);
node = OperatorSimplification.Simplify((OperatorNode)node, environment);
Assert.NotNull(node);
Assert.AreEqual("5 * x", node.ToString());
}
public void ParseExpression_KeywordExpression_ReturnsString()
{
Environment environment = new Environment();
environment.AddSymbol("x");
TestExpression(
"ln(x^2 + x - 3)",
"ln(x ^ 2 + x + -3)",
environment
);
}
public void Simplify_OperatorChildrenAreBothTheSameIdentifier_ReturnsOperatorNode()
{
Environment environment = new Environment();
environment.AddSymbol("x");
SyntaxNode node = GetExpression("x + x", environment);
node = OperatorSimplification.Simplify((OperatorNode)node, environment);
Assert.NotNull(node);
Assert.AreEqual("2 * x", node.ToString());
}
public void ToString_DisplaysFunction_ReturnsCachedString()
{
Environment environment = new Environment();
environment.AddSymbol("x");
Expression expression = new Expression(Parser.ParseExpression("1/2x+2", environment), environment);
Function f = new Function("f", new HashSet <string> {
"x"
}, expression);
Assert.AreEqual(f.ToString(), "f(x) = 1 * 2 ^ -1 * x + 2");
Assert.AreEqual(f.ToString(), "f(x) = 1 * 2 ^ -1 * x + 2");
}
public void Simplify_OperatorWithNumberAndFunction_ReturnsOperatorNode()
{
Environment environment = new Environment();
environment.AddSymbol("x");
environment.AddFunction("f", GetExpression("x", environment));
SyntaxNode node = GetExpression("2 + f(x)", environment);
node = OperatorSimplification.Simplify((OperatorNode)node, environment);
Assert.NotNull(node);
Assert.AreEqual("2 + f(x)", node.ToString());
}
public void Analyze_AmbigiousSymbolDistribution_ReturnsOperatorNode()
{
IdentifierNode left = new IdentifierNode("x");
SyntaxNode right = new NumberNode(1);
SyntaxNode root = new FunctionOrDistributionNode(left, right);
Environment environment = new Environment();
environment.AddSymbol("x");
root = SemanticAnalyzer.Analyze(root, environment);
Assert.AreEqual("x * 1", root.ToString());
}
