Expose ranged semantic tokens through LSP

Author: fwcd

server/src/main/kotlin/org/javacs/kt/KotlinLanguageServer.kt

@@ -82,7 +82,7 @@ class KotlinLanguageServer : LanguageServer, LanguageClientAware, Closeable {
         serverCapabilities.documentSymbolProvider = Either.forLeft(true)
         serverCapabilities.workspaceSymbolProvider = Either.forLeft(true)
         serverCapabilities.referencesProvider = Either.forLeft(true)
-        serverCapabilities.semanticTokensProvider = SemanticTokensWithRegistrationOptions(semanticTokensLegend, true)
+        serverCapabilities.semanticTokensProvider = SemanticTokensWithRegistrationOptions(semanticTokensLegend, true, true)
         serverCapabilities.codeActionProvider = Either.forLeft(true)
         serverCapabilities.documentFormattingProvider = Either.forLeft(true)
         serverCapabilities.documentRangeFormattingProvider = Either.forLeft(true)

server/src/main/kotlin/org/javacs/kt/KotlinTextDocumentService.kt

@@ -240,6 +240,20 @@ class KotlinTextDocumentService(
         }
     }
 
+    override fun semanticTokensRange(params: SemanticTokensRangeParams) = async.compute {
+        LOG.info("Ranged semantic tokens in {}", describeURI(params.textDocument.uri))
+
+        reportTime {
+            val uri = parseURI(params.textDocument.uri)
+            val file = sp.currentVersion(uri)
+
+            val tokens = semanticTokens(file, params.range)
+            LOG.info("Found {} tokens", tokens.size)
+
+            SemanticTokens(tokens)
+        }
+    }
+
     override fun resolveCodeLens(unresolved: CodeLens): CompletableFuture<CodeLens> {
         TODO("not implemented")
     }