Roslyn Query
A Visual Studio tool window that runs a C# predicate you write over every SyntaxNode,
SyntaxToken or IOperation in a scope you pick, and jumps to a double-clicked match.
View > Other Windows > Roslyn Query.
Using it
Pick a Target, pick a Scope, type a boolean expression, press Enter (or Run).
The signature line above the box tells you what is in scope:
| Target |
Predicate signature |
| SyntaxNode |
bool (SyntaxNode n, SemanticModel model, Document doc) |
| SyntaxToken |
bool (SyntaxToken t, SemanticModel model, Document doc) |
| IOperation |
bool (IOperation op, SemanticModel model, Document doc) |
System, System.Linq, System.Text.RegularExpressions, Microsoft.CodeAnalysis,
.CSharp, .CSharp.Syntax, .Operations and .Text are already imported.
Scopes: containing member, containing type, current document, current project, solution. The three
narrow ones are resolved from the caret in the last active code window.
Examples
n.IsKind(SyntaxKind.IfStatement)
n is InvocationExpressionSyntax i && i.ArgumentList.Arguments.Count > 4
n is MethodDeclarationSyntax m && m.Modifiers.Any(SyntaxKind.AsyncKeyword)
&& !m.Identifier.Text.EndsWith("Async")
t.IsKind(SyntaxKind.StringLiteralToken) && t.ValueText.Length > 200
op.Kind == OperationKind.Conversion && ((IConversionOperation)op).Conversion.IsBoxing
n is IdentifierNameSyntax id && model.GetSymbolInfo(id).Symbol is IMethodSymbol { IsStatic: true }
Keys
| Key |
Effect |
| Enter |
run the query (or commit the completion item, if the list is open) |
| Shift+Enter |
newline in the predicate |
| Ctrl+Space |
invoke completion |
| Up / Down |
move through the completion list, otherwise move the caret |
| Tab |
commit the completion item, otherwise leave the box |
| Esc |
dismiss the completion list |
| Double-click a result |
open the file and select the match |
The predicate box is a real editor view, not a TextBox, and it is not wired into VS's command
routing, so its keyboard map is implemented by the extension. Caret movement, selection, backspace
and delete (with the Ctrl word-wise variants), Ctrl+A/C/X/V and Ctrl+Z/Y all work; anything beyond
that is not bound.
Every run is explicit: Enter or the Run button. There is no run-as-you-type mode, on purpose. Each
distinct expression leaks a small assembly for the session (see below), and a debounced re-run turns
that into one leak per pause in your typing.
Cap stops the run once that many matches are found and marks the results as capped.
Generated includes .g.cs / .designer.cs / .generated.cs and source-generated documents.
Source-generated matches have no file on disk, so double-click reports that instead of navigating.
Building
Requires the Visual Studio SDK workload.
msbuild RoslynQuery/RoslynQuery.csproj -t:Rebuild -p:Configuration=Release -p:DeployExtension=false
The .vsix lands in RoslynQuery/bin/Release/net472/. F5 on the project launches the experimental
instance with the extension deployed.
Targets VS 2022 and VS 2026 from one artifact. See CLAUDE.roslyn-query.md
for the design, the rejected alternatives and the deferred work.
