Add linked editing ranges for variables within definition regions

Author: AJenbo

README.md

@@ -20,7 +20,7 @@ PHPantom focuses on deep type intelligence. Here's how it compares:
 | Common LSP features<sup>1</sup>      | ✅       | ✅           | ✅         | ✅          | ✅          |
 | Workspace symbols                    | 🚧       | ✅           | ✅         | ✅          | ✅          |
 | Semantic tokens                      | ✅       | ❌           | ✅         | ❌          | ✅          |
-| Linked editing                       | ❌       | ❌           | ✅         | ❌          | ✅          |
+| Linked editing                       | ✅       | ❌           | ✅         | ❌          | ✅          |
 | Extras<sup>2</sup>                   | ✅       | 💰           | 🚧         | 🚧          | ✅          |
 | **Diagnostics**                      |          |              |            |             |             |
 | PHPStan integration                  | ✅       | ❌           | ❌         | 🚧          | 🚧          |

docs/CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- **Linked editing ranges.** Place the cursor on a variable and all occurrences within its definition region (from one assignment to the next) enter linked editing mode. Typing a new name updates every occurrence simultaneously without affecting reassigned uses of the same variable name. Ranges exclude the leading `$` sigil so that typing before a variable (e.g. wrapping it in a function call) does not propagate to other occurrences.
 - **Invalid class-like kind diagnostics.** Flags class-like names used in positions where their kind is guaranteed to fail at runtime: `new` on abstract classes, interfaces, traits, or enums; `extends` on a final class, interface, or trait; `implements` with a non-interface; trait `use` with a non-trait; `instanceof` with a trait (always false); `catch` with a non-Throwable type or trait; and traits in native type-hint positions. Severity follows PHP semantics: unconditional fatal errors are Error, runtime-conditional failures are Warning.
 - **Nested array shape inference from multi-level key assignments.** Assignments like `$b['a']['b'] = 'x'` now produce a nested array shape type (`array{a: array{b: string}}`), enabling array key completion and hover for arrays built incrementally with nested keys. Previously only single-level key assignments were tracked.
 

docs/todo.md

@@ -21,19 +21,10 @@ within the same impact tier.
 
 # Scheduled Sprints
 
-## Sprint 4 — Refactoring toolkit & type inference
-
-| #    | Item                                                                                                                                                            | Impact     | Effort |
-| ---- | --------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------- | ------ |
-
-
-|      | **Release 0.7.0**                                                                                                                                               |            |        |
-
 ## Sprint 5 — Polish for office adoption
 
 | #   | Item                                                                                                                         | Impact      | Effort |
 | --- | ---------------------------------------------------------------------------------------------------------------------------- | ----------- | ------ |
-| F10 | [Linked editing ranges](todo/lsp-features.md#f10-linked-editing-ranges)                                                      | Medium      | Low    |
 | A36 | [Import all missing classes](todo/actions.md#a36-import-all-missing-classes) (bulk import)                                    | Medium      | Low    |
 | F6  | [Machine-readable CLI output formats](todo/lsp-features.md#f6-machine-readable-cli-output-formats) (`--format github\|json`) | Medium      | Low    |
 | D4  | [Unused variable diagnostic](todo/diagnostics.md#d4-unused-variable-diagnostic)                                              | Medium      | Medium |

docs/todo/lsp-features.md

@@ -443,66 +443,6 @@ PHPantom should eventually support both directions:
 
 ---
 
-## F10. Linked editing ranges
-
-**Impact: Medium · Effort: Low**
-
-Implement the `textDocument/linkedEditingRange` LSP request so that
-renaming one occurrence of a paired token simultaneously updates the
-other. The primary use case in PHP is matching opening and closing
-tags in HTML-embedded PHP, but the most immediately useful case for
-pure PHP is variable renaming within a scope.
-
-### Use cases
-
-1. **Variables within a scope.** Place the cursor on `$userName` and
-   every other occurrence of `$userName` in the same function or
-   method body enters linked editing mode. Typing a new name updates
-   all occurrences simultaneously without triggering a full rename
-   request. This is faster and more fluid than `textDocument/rename`
-   for local renames.
-
-2. **Matching PHP open/close tags.** When editing `<?php ... ?>` in
-   mixed HTML/PHP files, linked editing could pair the tags. Lower
-   priority since most PHP files use only an opening tag.
-
-### Implementation
-
-1. **Register the capability.** Advertise
-   `linkedEditingRangeProvider: true` in the server capabilities
-   during `initialize`.
-
-2. **Handle the request.** When the client sends
-   `textDocument/linkedEditingRange`, determine what the cursor is
-   on:
-   - **Variable name:** use the scope collector to find all
-     occurrences of that variable in the enclosing scope. Return
-     their ranges. Set `wordPattern` to `\$[a-zA-Z_\x80-\xff][a-zA-Z0-9_\x80-\xff]*`
-     so the editor knows to include the `$` prefix in the linked
-     edit region.
-   - If the cursor is not on a supported token, return `null`.
-
-3. **Leverage existing infrastructure.** The scope collector
-   (`scope_collector/mod.rs`) already tracks variable definition and
-   read sites with byte offsets. The document highlight handler
-   (`highlight/mod.rs`) already finds all occurrences of a variable
-   in a scope and returns their ranges. The linked editing handler
-   is essentially the same logic but returning a
-   `LinkedEditingRanges` response instead of `DocumentHighlight[]`.
-
-### Constraints
-
-- All returned ranges must be on the same line or the client may
-  reject them (some clients impose this restriction, though the spec
-  does not). In practice, variable occurrences span multiple lines,
-  and modern clients (VS Code, Zed) handle multi-line linked editing
-  correctly.
-- The response must not include ranges that overlap or that would
-  produce invalid syntax when edited together. Since all ranges are
-  the same variable name, this is naturally satisfied.
-
----
-
 ## F11. VS Code extension
 
 | Field      | Value                    |

example.php

@@ -19,10 +19,18 @@
 namespace Demo {
 
 use Attribute;
+use Bug10298\PropAttr;
+use Bug5607\Cl;
 use Closure;
 use Demo\ValidationException;
 use Demo\NotFoundException;
+use EloquentBuilder\OnlyUsers;
 use Exception;
+use Override;
+use PHPStan\DependencyInjection\GenerateFactory;
+use PHPStan\Reflection\ClassReflection;
+use ReadonlyPropertyAssignPhpDoc\C;
+use Stringable;
 use Demo\UserProfile as Profile;
 
 // ═══════════════════════════════════════════════════════════════════════════
@@ -3354,16 +3362,7 @@ private function acceptTrait(JsonSerializer $x): JsonSerializer
     }
 
     // These also produce diagnostics but would crash at class-load time,
-    // so they are shown as comments only:
-    //
-    //   class Bad1 extends ScaffoldingDrawable {}     // Error: interface in extends
-    //   class Bad2 implements Pen {}                   // Error: class in implements
-    //   class Bad3 { use ScaffoldingDrawable; }        // Error: interface in trait use
-    //   class Bad4 extends ScaffoldingAbstractShape {} // OK: abstract classes CAN be extended
-}
-
-
-// ═══════════════════════════════════════════════════════════════════════════
+    // so they are═══════════════════════════════════════════════════════════════════════════
 // ┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
 // ┃  SCAFFOLDING — Supporting definitions below this line.              ┃
 

src/definition/resolve.rs

@@ -128,7 +128,10 @@ impl Backend {
         let maps = self.symbol_maps.read();
         let map = maps.get(uri)?;
         let def = map.var_def_at(var_name, cursor_offset)?;
-        if matches!(def.kind, VarDefKind::Assignment) {
+        if matches!(
+            def.kind,
+            VarDefKind::Assignment | VarDefKind::CompoundAssignment
+        ) {
             Some(def.effective_from)
         } else {
             None

src/hover/mod.rs

@@ -507,6 +507,7 @@ impl Backend {
                     && !matches!(
                         def_kind,
                         VarDefKind::Assignment
+                            | VarDefKind::CompoundAssignment
                             | VarDefKind::Parameter
                             | VarDefKind::Foreach
                             | VarDefKind::Catch

src/lib.rs

@@ -114,6 +114,7 @@ mod highlight;
 mod hover;
 pub(crate) mod inheritance;
 mod inlay_hints;
+mod linked_editing;
 pub(crate) mod names;
 mod parser;
 pub(crate) mod phar;