> ## 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.

# Swift

> Semantic diffing for Swift

## Swift extractor

The Swift extractor maps tree-sitter Swift CST nodes to canonical concepts. Class, protocol, and function names come from the standard `name` field; property names come from the binding pattern.

### Detected concepts

| tree-sitter node type | Canonical concept |
| - | - |
| `class_declaration` | Class |
| `protocol_declaration` | Interface |
| `function_declaration` | Function |
| `property_declaration` | Variable |
| `import_declaration` | Import |
| `typealias_declaration` | TypeDef |
| `enum_entry` | Enum |
| `call_expression` | CallExpression |
| `assignment` | Assignment |
| `lambda_literal` | Closure |
| `line_string_literal` | string\_literal |
| `integer_literal` | integer\_literal |

### Example

Renaming a function:

```swift theme={null}
// old.swift
class Counter { func total(n: Int) -> Int { return n + 1 } }
```

```swift theme={null}
// new.swift
class Counter { func sum(n: Int) -> Int { return n + 1 } }
```

Running `differens old.swift new.swift`:

```
~ renamed function `total` to `sum` in class `Counter`
```

### Known limitations

* Property observers (`didSet`, `willSet`) are bodies; their edits report as body changes on the property.
* Computed property getters and setters are not labeled as accessor kinds; they diff as blocks inside the property.