public void Parser_UnaryExpression_HonorsPrecedences(SyntaxKind unaryKind, SyntaxKind binaryKind)
{
var unaryPrecedence = unaryKind.GetUnaryOperatorPrecedence();
var binaryPrecedence = binaryKind.GetBinaryOperatorPrecedence();
var unaryText = SyntaxFacts.GetText(unaryKind);
var binaryText = SyntaxFacts.GetText(binaryKind);
var text = $"{unaryText} a {binaryText} b";
var expression = SyntaxTree.Parse(text).Root;
if (unaryPrecedence >= binaryPrecedence)
{
// binary
// / \
// unary b
// |
// a
using (var e = new AssertingEnumerator(expression))
{
e.AssertNode(SyntaxKind.BinaryExpression);
e.AssertNode(SyntaxKind.UnaryExpression);
e.AssertToken(unaryKind, unaryText);
e.AssertNode(SyntaxKind.NameExpression);
e.AssertToken(SyntaxKind.IdentifierToken, "a");
e.AssertToken(binaryKind, binaryText);
e.AssertNode(SyntaxKind.NameExpression);
e.AssertToken(SyntaxKind.IdentifierToken, "b");
}
}
else
{
// unary
// |
// binary
// / \
// a b
using (var e = new AssertingEnumerator(expression))
{
e.AssertNode(SyntaxKind.UnaryExpression);
e.AssertToken(unaryKind, unaryText);
e.AssertNode(SyntaxKind.BinaryExpression);
e.AssertNode(SyntaxKind.NameExpression);
e.AssertToken(SyntaxKind.IdentifierToken, "a");
e.AssertToken(binaryKind, binaryText);
e.AssertNode(SyntaxKind.NameExpression);
e.AssertToken(SyntaxKind.IdentifierToken, "b");
}
}
}
public void HonorPrecedences_GivenUnaryExpression(SyntaxKind unaaryKind, SyntaxKind binaryKind)
{
var unaryPrecedence = unaaryKind.GetUnaryOperatorPrecedence();
var binaryPrecedence = binaryKind.GetBinaryOperatorPrecedence();
var unaryText = unaaryKind.GetText();
var binaryText = binaryKind.GetText();
var text = $"{unaryText} a {binaryText} b";
var expressionSyntax = ParseExpression(text);
if (unaryPrecedence >= binaryPrecedence)
{
// op2
// / \
// op1 b
// |
// a
using (var asserter = new AssertingEnumerator(expressionSyntax))
{
asserter.AssertNode(SyntaxKind.BinaryExpression);
asserter.AssertNode(SyntaxKind.UnaryExpression);
asserter.AssertToken(unaaryKind, unaryText);
asserter.AssertNode(SyntaxKind.NameExpression);
asserter.AssertToken(SyntaxKind.IdentifierToken, "a");
asserter.AssertToken(binaryKind, binaryText);
asserter.AssertNode(SyntaxKind.NameExpression);
asserter.AssertToken(SyntaxKind.IdentifierToken, "b");
}
}
else
{
// op2
// |
// op1
// / \
// a b
using (var asserter = new AssertingEnumerator(expressionSyntax))
{
asserter.AssertNode(SyntaxKind.UnaryExpression);
asserter.AssertNode(SyntaxKind.BinaryExpression);
asserter.AssertToken(unaaryKind, unaryText);
asserter.AssertNode(SyntaxKind.NameExpression);
asserter.AssertToken(SyntaxKind.IdentifierToken, "a");
asserter.AssertToken(binaryKind, binaryText);
asserter.AssertNode(SyntaxKind.NameExpression);
asserter.AssertToken(SyntaxKind.IdentifierToken, "b");
}
}
}
