public void UnaryOperatorPrecedence_HigherThanBinaryOperatorPrecedence(
[ValueSource(nameof(UnaryOperators))] TokenKind unaryOp,
[ValueSource(nameof(BinaryOperators))] TokenKind binaryOp)
{
// Arrange
var unaryPrecedence = unaryOp.UnaryOperatorPrecedence();
var binaryPrecedence = binaryOp.BinaryOperatorPrecedence();
// Act
var highter = unaryPrecedence > binaryPrecedence;
// Assert
Assert.That(highter, Is.True);
}
public void Parse_WithBinaryUnaryPair_HonorsPrecedences(
[ValueSource(nameof(UnaryOperators))] TokenKind unaryOp,
[ValueSource(nameof(BinaryOperators))] TokenKind binaryOp)
{
// Arrange
var unaryPrecedence = unaryOp.UnaryOperatorPrecedence();
var binaryPrecedence = binaryOp.BinaryOperatorPrecedence();
var unaryText = unaryOp.GetText();
var binaryText = binaryOp.GetText();
var text = $"{unaryText} a {binaryText} b";
// Act
var expression = ParseExpression(text);
// Assert
if (unaryPrecedence >= binaryPrecedence)
{
// Expected:
// binary
// / \
// unary b
// |
// a
using var e = expression.Enumerate();
e.AssertBinaryExpression(binaryOp);
e.AssertUnaryExpression(unaryOp);
e.AssertNameExpression("a");
e.AssertNameExpression("b");
}
else
{
// Expected:
// unary
// |
// binary
// / \
// a b
using var e = expression.Enumerate();
e.AssertUnaryExpression(unaryOp);
e.AssertBinaryExpression(binaryOp);
e.AssertNameExpression("a");
e.AssertNameExpression("b");
}
}
public static bool IsUnaryOperator(this TokenKind kind) => kind.UnaryOperatorPrecedence() > 0;
