> ## Documentation Index
> Fetch the complete documentation index at: https://differens.ossl.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# C#

> Semantic diffing for C#

## C# extractor

The C# extractor maps tree-sitter C# CST nodes to canonical concepts. Class, method, and namespace names come from the standard `name` field; variable names come from the declarator.

### Detected concepts

| tree-sitter node type | Canonical concept |
| - | - |
| `class_declaration` | Class |
| `namespace_declaration` | Namespace |
| `using_directive` | Import |
| `method_declaration` | Method |
| `variable_declaration` | Variable |
| `parameter_list` | Parameters |
| `invocation_expression` | CallExpression |
| `member_access_expression` | MemberAccess |
| `conditional_expression` | TernaryOp |
| `predefined_type` | TypeIdentifier |
| `string_literal` | string\_literal |
| `integer_literal` | integer\_literal |

### Example

Renaming a method:

```csharp theme={null}
// old.cs
class Counter { int Total(int n) { return n + 1; } }
```

```csharp theme={null}
// new.cs
class Counter { int Sum(int n) { return n + 1; } }
```

Running `differens old.cs new.cs`:

```
~ renamed method `Total` to `Sum` in class `Counter`
```

### Known limitations

* Partial classes across files are correlated per file; the cross-file correlator pairs moved members when the whole changeset is diffed at once.
* LINQ query syntax reports as call expressions, not query clauses.