SyntaxExtensions

Extension methods for working with syntax nodes.

C# Signature

internal static class SyntaxExtensions

Examples

The following example finds a field declaration from a syntax node and resolves attribute symbols.

C#

using System;
using System.Linq;
using Hertzole.SourceGen;
using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp.Syntax;

public static class SyntaxInspector
{
    public static void Inspect(SyntaxNode node, SemanticModel semanticModel)
    {
        // Finds the field declaration that contains the node or one of its ancestors.
        if (node.TryGetFieldDeclaration(out FieldDeclarationSyntax? field))
        {
            Console.WriteLine(field);
        }

        foreach (AttributeSyntax attribute in node.DescendantNodes().OfType<AttributeSyntax>())
        {
            // Resolves the attribute syntax to its type symbol.
            INamedTypeSymbol? attributeSymbol = attribute.GetAttributeSymbol(semanticModel);
            Console.WriteLine(attributeSymbol);
        }
    }
}

Methods

GetAttributeSymbol(AttributeSyntax, SemanticModel, CancellationToken)

Gets the INamedTypeSymbol for the specified attribute syntax.

C# Signature

public static INamedTypeSymbol? GetAttributeSymbol(this AttributeSyntax syntax, SemanticModel semanticModel, CancellationToken cancellationToken = default);

syntax

The attribute syntax node.

semanticModel

The semantic model for the syntax tree.

cancellationToken

A cancellation token.

Returns

The INamedTypeSymbol for the attribute, or null if not found.

TryGetFieldDeclaration(SyntaxNode, out FieldDeclarationSyntax?, CancellationToken)

Attempts to find a FieldDeclarationSyntax from the specified node or its ancestors.

C# Signature

public static bool TryGetFieldDeclaration(this SyntaxNode node, out FieldDeclarationSyntax? fieldDeclaration, CancellationToken cancellationToken = default);

node

The syntax node to search from.

fieldDeclaration

When this method returns, contains the field declaration if found; otherwise, null.

cancellationToken

A cancellation token.

Returns

true if a field declaration was found; otherwise false.