Phase 5: add rename and find usages

AGENTS.md

@@ -59,20 +59,23 @@ class and still prints `OK`. `jaitest` therefore passes
 Last verified state (all green, `./jaigradle check` and `verifyPlugin` too):
 
 ```text
-dev.hgh.HarnessSmokeTest                    tests=2
-dev.hgh.jai.JaiFileTypeTest                 tests=4
-dev.hgh.jai.editor.JaiEditorSupportTest     tests=7
-dev.hgh.jai.editor.JaiFoldingBuilderTest     tests=3
-dev.hgh.jai.highlighting.*                  tests=8
-dev.hgh.jai.lexer.JaiCorpusLexerTest        tests=2   <- the Tier 0 gate
-dev.hgh.jai.lexer.JaiLexerTest              tests=13
-dev.hgh.jai.parser.JaiCorpusParserTest      tests=1   <- the Tier 3 gate
-dev.hgh.jai.parser.JaiParserGoldenTest      tests=5   <- Tier 2 golden trees
-dev.hgh.jai.parser.JaiParserLongTailTest    tests=1   <- focused parser regressions
-dev.hgh.jai.parser.DebugParseTest           tests=2   <- scratch harness, inert
-dev.hgh.jai.reference.JaiReferenceTest        tests=4
-dev.hgh.jai.structure.JaiStructureViewTest    tests=3
--> total 55, failures+errors 0
+dev.hgh.HarnessSmokeTest                       tests=2
+dev.hgh.jai.JaiFileTypeTest                    tests=4
+dev.hgh.jai.completion.JaiCompletionTest      tests=6
+dev.hgh.jai.editor.JaiEditorSupportTest       tests=7
+dev.hgh.jai.editor.JaiFoldingBuilderTest      tests=3
+dev.hgh.jai.findusages.JaiFindUsagesTest      tests=2
+dev.hgh.jai.highlighting.*                    tests=8
+dev.hgh.jai.lexer.JaiCorpusLexerTest           tests=2   <- the Tier 0 gate
+dev.hgh.jai.lexer.JaiLexerTest                 tests=13
+dev.hgh.jai.parser.JaiCorpusParserTest         tests=1   <- the Tier 3 gate
+dev.hgh.jai.parser.JaiParserGoldenTest         tests=5   <- Tier 2 golden trees
+dev.hgh.jai.parser.JaiParserLongTailTest       tests=1   <- focused parser regressions
+dev.hgh.jai.parser.DebugParseTest              tests=2   <- scratch harness, inert
+dev.hgh.jai.refactoring.JaiRenameTest          tests=3
+dev.hgh.jai.reference.JaiReferenceTest         tests=9
+dev.hgh.jai.structure.JaiStructureViewTest     tests=3
+-> total 71, failures+errors 0
 ```
 
 The corpus gates report what they actually did; check both lines are still there:
@@ -180,7 +183,9 @@ Tier 3: parsed 714 files, 714 clean (100.0%), 0 with errors, 0 PsiErrorElements
    compiler directives, `#import`/`#load` module paths is implemented in
    `dev.hgh.jai.completion.JaiCompletionContributor`. Identifier references now
    resolve procedures/types in the same file and transitively loaded/imported
-   files, with headless fixture coverage. Rename and find-usages remain.
+   files. Declaration names now support rename and find-usages through the
+   standard PSI contracts; module-qualified members, parameters, and fields
+   remain future symbol-resolution work.
 2. **Phases 6+** — formatter, inspections, compiler integration, and other
    optional work remain. `#asm` bodies are intentionally consumed opaquely, so
    nothing inside them has PSI yet.

CHANGELOG.md

@@ -20,6 +20,10 @@
 - Folding for blocks, nested comments, and multi-line here-strings.
 - Go-to-definition references for `#import` and `#load`, including project-relative
   files and the local Jai module layout (`Name.jai` or `Name/module.jai`).
+- Basic completion for Jai keywords, compiler directives, and module/file paths.
+- Go-to-definition for procedure and type symbols in the same file and through
+  loaded or imported Jai files.
+- Rename and find-usages support for declaration names and resolved references.
 
 ### Known gaps
 
@@ -29,3 +33,5 @@
   inner PSI or structure entries.
 - Import resolution uses the project/module roots and the local Jai installation;
   custom compiler `-import_dir` arguments are not discovered yet.
+- Module-qualified members, procedure parameters, and struct fields do not yet
+  have symbol resolution.

README.md

@@ -11,13 +11,20 @@ never from online material (see `AGENTS.md`).
   (`#import`, `#run`, …), notes (`@Cleanup`), numbers (hex / binary / hexfloat /
   `_` separators), strings, here-strings (`#string DONE … DONE`), nesting block
   comments, operators, `---`, `$`/`$$`, `it` / `it_index`
+- Grammar-Kit parser and PSI for the full local 714-file corpus
+- Structure view and folding for blocks, comments, and here-strings
 - Colour settings page (**Settings → Editor → Color Scheme → Jai**)
 - Comment / uncomment (`//` and nesting `/* */`)
 - Brace matching, including the Jai-only `.{` struct-literal and `.[`
   array-literal openers
+- Basic completion for keywords, directives, and local Jai module/file paths
+- Go-to-definition for procedures and types in the same file and through
+  `#import`/`#load`
+- Rename and find-usages for declaration names and their resolved references
 
-Not yet: parser and PSI, so no structure view, go-to-definition, completion,
-formatting, or inspections. See `docs/BUILD_PLAN.md` for the phase plan.
+Remaining code-insight gaps include module-qualified members, parameters, and
+struct fields. Formatting, inspections, and compiler integration are planned
+later. See `docs/BUILD_PLAN.md` for the phase plan.
 
 ## Install it locally
 

docs/BUILD_PLAN.md

@@ -169,7 +169,7 @@ Each phase has a machine-checkable gate. Do not advance without a green gate.
 | **2** | `SyntaxHighlighter`, color settings page, commenter, brace matcher | Tier 1 golden dumps; highlighter maps every token type |
 | **3** | `.bnf` grammar, generated parser + PSI, `ParserDefinition` | Tier 2 golden trees; Tier 3 corpus parse ≥ target — **done, 100.0% (714/714)** |
 | **4** | Structure view, folding, `#import`/`#load` reference resolution + go-to-definition | Tier 4 fixture tests — **done** |
-| **5** | Completion (keywords, directives, module names), rename, find-usages | Tier 4 fixture tests |
+| **5** | Completion (keywords, directives, module names), rename, find-usages | Tier 4 fixture tests — **done** (70-test suite) |
 | **6** | Formatter, code style settings | Formatter round-trip: formatting the corpus is idempotent |
 | **7** | Inspections (e.g. `#must` misuse), quick fixes, live templates | Tier 4 + `verifyPlugin` |
 | **8** | Optional: run-configuration to invoke the `jai` compiler, parse its error output | Integration test against `~/.local/jai/bin` |
@@ -196,8 +196,9 @@ corpus-scale invariant that needs no human judgment.
 
 ## 6. Open questions for you
 
-1. **Scope/ambition** — stop at solid syntax highlighting + navigation (Phases
-   0–4), or go all the way to formatter and inspections (0–7)?
+1. **Scope/ambition** — stop at the current syntax, navigation, and basic
+   refactoring support (Phases 0–5), or go all the way to formatter and
+   inspections (0–7)?
 2. **Compiler integration** (Phase 8) — worth it? It's the only phase needing
    the actual `jai` binary, and it's the least testable.
 3. **Target IDE** — IntelliJ IDEA only (current setting), or all JetBrains IDEs?
@@ -206,5 +207,6 @@ corpus-scale invariant that needs no human judgment.
    setup, works today), or install a system JDK via Homebrew? I'd default to the
    wrapper.
 
-My recommendation: approve Phases 0–4 now, decide on 5–8 once the parser gate is
-green and we can see how the grammar behaved against real code.
+Phases 0–5 are now implemented and verified headlessly. The remaining decision
+is whether to continue with the optional formatter, inspections, and compiler
+integration work in Phases 6–8.

src/main/gen/dev/hgh/jai/psi/impl/JaiDeclNameImpl.java

@@ -8,12 +8,12 @@ import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiElementVisitor;
 import com.intellij.psi.util.PsiTreeUtil;
 import static dev.hgh.jai.psi.JaiTypes.*;
-import com.intellij.extapi.psi.ASTWrapperPsiElement;
+import dev.hgh.jai.psi.mixin.JaiNamedElementMixin;
 import dev.hgh.jai.psi.*;
 
-public class JaiDeclNameImpl extends ASTWrapperPsiElement implements JaiDeclName {
+public class JaiDeclNameImpl extends JaiNamedElementMixin implements JaiDeclName {
 
-  public JaiDeclNameImpl(@NotNull ASTNode node) {
+  public JaiDeclNameImpl(ASTNode node) {
     super(node);
   }
 

src/main/grammar/Jai.bnf

@@ -227,6 +227,7 @@ private declModifier_ ::= <<dirWithBlock>> directiveFlag_* block
 private usingModifier_ ::= 'using' [directiveFlag_ [<<exprNoAssign>>]]
 declNames ::= declName (['='] ',' declName ['='])* ['=']
 declName ::= ['`'] (IDENT | keywordAsName_)
+           { mixin="dev.hgh.jai.psi.mixin.JaiNamedElementMixin" }
 private declTail_ ::= ':' [<<exprNoAssign>>] procModifier* [',' assignTargets_] [('=' | ':') initializerList_]
                     | ':=' initializerList_
                     | '::' initializerList_

src/main/kotlin/dev/hgh/jai/findusages/JaiFindUsagesProvider.kt

@@ -0,0 +1,41 @@
+package dev.hgh.jai.findusages
+
+import com.intellij.lang.cacheBuilder.DefaultWordsScanner
+import com.intellij.lang.cacheBuilder.WordsScanner
+import com.intellij.lang.findUsages.FindUsagesProvider
+import com.intellij.psi.PsiElement
+import com.intellij.psi.PsiNameIdentifierOwner
+import com.intellij.psi.PsiNamedElement
+import com.intellij.psi.tree.TokenSet
+import dev.hgh.jai.lexer.JaiLexer
+import dev.hgh.jai.lexer.JaiTokenTypes
+import dev.hgh.jai.psi.JaiRefExpr
+
+/** Supplies word indexing and descriptions for Jai declaration usages. */
+class JaiFindUsagesProvider : FindUsagesProvider {
+    override fun getWordsScanner(): WordsScanner =
+        DefaultWordsScanner(
+            JaiLexer(),
+            TokenSet.create(JaiTokenTypes.IDENT),
+            JaiTokenTypes.COMMENTS,
+            JaiTokenTypes.STRINGS,
+        )
+
+    override fun canFindUsagesFor(psiElement: PsiElement): Boolean = psiElement is PsiNameIdentifierOwner || psiElement is JaiRefExpr
+
+    override fun getHelpId(psiElement: PsiElement): String? = null
+
+    override fun getType(element: PsiElement): String =
+        if (element is PsiNameIdentifierOwner || element is JaiRefExpr) {
+            "Jai declaration"
+        } else {
+            ""
+        }
+
+    override fun getDescriptiveName(element: PsiElement): String = (element as? PsiNamedElement)?.name ?: element.text
+
+    override fun getNodeText(
+        element: PsiElement,
+        useFullName: Boolean,
+    ): String = element.text
+}

src/main/kotlin/dev/hgh/jai/psi/JaiPsiElementFactory.kt

@@ -0,0 +1,23 @@
+package dev.hgh.jai.psi
+
+import com.intellij.openapi.project.Project
+import com.intellij.psi.PsiElement
+import com.intellij.psi.PsiFileFactory
+import com.intellij.psi.util.PsiTreeUtil
+import dev.hgh.jai.JaiLanguage
+import dev.hgh.jai.lexer.JaiTokenTypes
+
+/** Creates small Jai PSI fragments for AST replacements used by rename refactoring. */
+object JaiPsiElementFactory {
+    fun createIdentifier(
+        project: Project,
+        name: String,
+    ): PsiElement {
+        val file = PsiFileFactory.getInstance(project).createFileFromText("rename.jai", JaiLanguage, "$name :: 0;")
+        val declarationName =
+            PsiTreeUtil.findChildOfType(file, JaiDeclName::class.java)
+                ?: error("Could not parse a Jai declaration name for '$name'")
+        return declarationName.node.findChildByType(JaiTokenTypes.IDENT)?.psi
+            ?: error("Jai name '$name' is not an identifier")
+    }
+}

src/main/kotlin/dev/hgh/jai/psi/mixin/JaiNamedElementMixin.kt

@@ -0,0 +1,28 @@
+package dev.hgh.jai.psi.mixin
+
+import com.intellij.extapi.psi.ASTWrapperPsiElement
+import com.intellij.lang.ASTNode
+import com.intellij.psi.PsiElement
+import com.intellij.psi.PsiNameIdentifierOwner
+import dev.hgh.jai.lexer.JaiTokenTypes
+import dev.hgh.jai.psi.JaiPsiElementFactory
+
+/** Gives declaration names the standard PSI naming contract used by rename/find-usages. */
+abstract class JaiNamedElementMixin(
+    node: ASTNode,
+) : ASTWrapperPsiElement(node),
+    PsiNameIdentifierOwner {
+    override fun getNameIdentifier(): PsiElement? = node.findChildByType(JaiTokenTypes.IDENT)?.psi
+
+    override fun getName(): String? = nameIdentifier?.text
+
+    override fun setName(name: String): PsiElement {
+        val identifier = nameIdentifier ?: return this
+        identifier.replace(JaiPsiElementFactory.createIdentifier(project, name))
+        return this
+    }
+
+    override fun getNavigationElement(): PsiElement = nameIdentifier ?: this
+
+    override fun getTextOffset(): Int = nameIdentifier?.textOffset ?: super.getTextOffset()
+}

src/main/kotlin/dev/hgh/jai/refactoring/JaiNamesValidator.kt

@@ -0,0 +1,26 @@
+package dev.hgh.jai.refactoring
+
+import com.intellij.lang.refactoring.NamesValidator
+import com.intellij.openapi.project.Project
+import dev.hgh.jai.lexer.JaiTokenTypes
+
+/** Applies Jai's ASCII identifier and keyword rules to rename input. */
+class JaiNamesValidator : NamesValidator {
+    override fun isKeyword(
+        name: String,
+        project: Project?,
+    ): Boolean = name in JaiTokenTypes.KEYWORD_MAP
+
+    override fun isIdentifier(
+        name: String,
+        project: Project?,
+    ): Boolean {
+        if (name.isEmpty() || isKeyword(name, project)) return false
+        if (!isIdentifierStart(name.first())) return false
+        return name.drop(1).all(::isIdentifierPart)
+    }
+
+    private fun isIdentifierStart(character: Char): Boolean = character in 'a'..'z' || character in 'A'..'Z' || character == '_'
+
+    private fun isIdentifierPart(character: Char): Boolean = isIdentifierStart(character) || character in '0'..'9'
+}

src/main/kotlin/dev/hgh/jai/refactoring/JaiRefactoringSupportProvider.kt

@@ -0,0 +1,14 @@
+package dev.hgh.jai.refactoring
+
+import com.intellij.lang.refactoring.RefactoringSupportProvider
+import com.intellij.psi.PsiElement
+import com.intellij.psi.PsiNameIdentifierOwner
+import dev.hgh.jai.JaiLanguage
+
+/** Enables standard and in-place rename for Jai declaration names. */
+class JaiRefactoringSupportProvider : RefactoringSupportProvider() {
+    override fun isMemberInplaceRenameAvailable(
+        elementToRename: PsiElement,
+        context: PsiElement?,
+    ): Boolean = elementToRename is PsiNameIdentifierOwner && elementToRename.language == JaiLanguage
+}

src/main/kotlin/dev/hgh/jai/reference/JaiReferenceContributor.kt

@@ -22,6 +22,7 @@ import dev.hgh.jai.psi.JaiDeclName
 import dev.hgh.jai.psi.JaiDeclaration
 import dev.hgh.jai.psi.JaiDirectiveExpr
 import dev.hgh.jai.psi.JaiLiteralExpr
+import dev.hgh.jai.psi.JaiPsiElementFactory
 import dev.hgh.jai.psi.JaiRefExpr
 
 /** Adds file references for directives and symbol references for Jai identifiers. */
@@ -106,6 +107,12 @@ private class JaiSymbolReference(
 ) : PsiReferenceBase<JaiRefExpr>(sourceElement, TextRange(0, sourceElement.textLength), true) {
     override fun resolve(): PsiElement? = JaiSymbolResolver.resolve(sourceElement)
 
+    override fun handleElementRename(newElementName: String): PsiElement {
+        val identifier = sourceElement.node.findChildByType(JaiTokenTypes.IDENT)?.psi ?: return sourceElement
+        identifier.replace(JaiPsiElementFactory.createIdentifier(sourceElement.project, newElementName))
+        return sourceElement
+    }
+
     override fun getVariants(): Array<Any> = emptyArray()
 }
 

src/main/resources/META-INF/plugin.xml

@@ -41,6 +41,15 @@
         <completion.contributor
             language="Jai"
             implementationClass="dev.hgh.jai.completion.JaiCompletionContributor"/>
+        <lang.refactoringSupport
+            language="Jai"
+            implementationClass="dev.hgh.jai.refactoring.JaiRefactoringSupportProvider"/>
+        <lang.namesValidator
+            language="Jai"
+            implementationClass="dev.hgh.jai.refactoring.JaiNamesValidator"/>
+        <lang.findUsagesProvider
+            language="Jai"
+            implementationClass="dev.hgh.jai.findusages.JaiFindUsagesProvider"/>
     </extensions>
 
 </idea-plugin>

src/test/kotlin/dev/hgh/jai/findusages/JaiFindUsagesTest.kt

@@ -0,0 +1,37 @@
+package dev.hgh.jai.findusages
+
+import com.intellij.psi.search.searches.ReferencesSearch
+import com.intellij.psi.util.PsiTreeUtil
+import com.intellij.testFramework.fixtures.BasePlatformTestCase
+import dev.hgh.jai.psi.JaiDeclName
+
+class JaiFindUsagesTest : BasePlatformTestCase() {
+    fun testFindUsagesActionFindsProcedureReference() {
+        val usages = myFixture.testFindUsages("Declaration.jai", "Usage.jai")
+
+        assertEquals(1, usages.size)
+    }
+
+    fun testFindsProcedureReferencesFromDeclaration() {
+        val source =
+            myFixture.addFileToProject(
+                "find-usages.jai",
+                """
+                helper :: () {}
+                first :: () { helper(); }
+                second :: () { helper(); }
+                """.trimIndent(),
+            )
+        val declaration =
+            PsiTreeUtil
+                .findChildrenOfType(source, JaiDeclName::class.java)
+                .single { it.text == "helper" }
+
+        val usages = ReferencesSearch.search(declaration).findAll()
+
+        assertEquals(2, usages.size)
+        assertTrue(usages.all { it.element.text == "helper" })
+    }
+
+    override fun getTestDataPath(): String = "src/test/testData/findusages"
+}

src/test/kotlin/dev/hgh/jai/refactoring/JaiRenameTest.kt

@@ -0,0 +1,59 @@
+package dev.hgh.jai.refactoring
+
+import com.intellij.psi.PsiNameIdentifierOwner
+import com.intellij.testFramework.fixtures.BasePlatformTestCase
+
+class JaiRenameTest : BasePlatformTestCase() {
+    fun testDeclarationNamesParticipateInRename() {
+        myFixture.configureByText(
+            "rename.jai",
+            """
+            helper<caret> :: () {}
+            main :: () { helper(); }
+            """.trimIndent(),
+        )
+
+        val declaration = myFixture.elementAtCaret
+
+        assertTrue("declaration name should be a named PSI element", declaration is PsiNameIdentifierOwner)
+        assertEquals("helper", (declaration as PsiNameIdentifierOwner).name)
+    }
+
+    fun testRenameProcedureUpdatesSameFileReferences() {
+        myFixture.configureByText(
+            "rename.jai",
+            """
+            helper<caret> :: () {}
+            main :: () { helper(); }
+            """.trimIndent(),
+        )
+
+        myFixture.renameElementAtCaret("renamed")
+
+        myFixture.checkResult(
+            """
+            renamed :: () {}
+            main :: () { renamed(); }
+            """.trimIndent(),
+        )
+    }
+
+    fun testRenameTypeUpdatesTypeReferences() {
+        myFixture.configureByText(
+            "rename-type.jai",
+            """
+            Point<caret> :: struct { x: int; }
+            use_point :: (point: Point) -> int { return point.x; }
+            """.trimIndent(),
+        )
+
+        myFixture.renameElementAtCaret("Coordinate")
+
+        myFixture.checkResult(
+            """
+            Coordinate :: struct { x: int; }
+            use_point :: (point: Coordinate) -> int { return point.x; }
+            """.trimIndent(),
+        )
+    }
+}

src/test/testData/findusages/Declaration.jai

@@ -0,0 +1 @@
+helper<caret> :: () {}

src/test/testData/findusages/Usage.jai

@@ -0,0 +1,2 @@
+#load "Declaration.jai";
+main :: () { helper(); }