6 files changed, 26 insertions, 28 deletions

diff --git a/editors/code/package-lock.json b/editors/code/package-lock.json
index 0288a468e..6901363fc 100644
--- a/editors/code/package-lock.json
+++ b/editors/code/package-lock.json
@@ -112,12 +112,6 @@
                 "@types/node": "*"
             }
         },
-        "@types/throttle-debounce": {
-            "version": "2.1.0",
-            "resolved": "https://registry.npmjs.org/@types/throttle-debounce/-/throttle-debounce-2.1.0.tgz",
-            "integrity": "sha512-5eQEtSCoESnh2FsiLTxE121IiE60hnMqcb435fShf4bpLRjEu1Eoekht23y6zXS9Ts3l+Szu3TARnTsA0GkOkQ==",
-            "dev": true
-        },
         "@types/vscode": {
             "version": "1.42.0",
             "resolved": "https://registry.npmjs.org/@types/vscode/-/vscode-1.42.0.tgz",
@@ -1517,11 +1511,6 @@
             "integrity": "sha1-f17oI66AUgfACvLfSoTsP8+lcLQ=",
             "dev": true
         },
-        "throttle-debounce": {
-            "version": "2.1.0",
-            "resolved": "https://registry.npmjs.org/throttle-debounce/-/throttle-debounce-2.1.0.tgz",
-            "integrity": "sha512-AOvyNahXQuU7NN+VVvOOX+uW6FPaWdAOdRP5HfwYxAfCzXTFKRMoIMk+n+po318+ktcChx+F1Dd91G3YHeMKyg=="
-        },
         "through": {
             "version": "2.3.8",
             "resolved": "https://registry.npmjs.org/through/-/through-2.3.8.tgz",
diff --git a/editors/code/package.json b/editors/code/package.json
index dff535fcd..2a89987e8 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -18,6 +18,7 @@
     "engines": {
         "vscode": "^1.42.0"
     },
+    "enableProposedApi": true,
     "scripts": {
         "vscode:prepublish": "tsc && rollup -c",
         "package": "vsce package -o rust-analyzer.vsix",
@@ -27,7 +28,6 @@
     "dependencies": {
         "jsonc-parser": "^2.1.0",
         "node-fetch": "^2.6.0",
-        "throttle-debounce": "^2.1.0",
         "vscode-languageclient": "^6.1.1"
     },
     "devDependencies": {
@@ -35,7 +35,6 @@
         "@rollup/plugin-node-resolve": "^7.1.1",
         "@types/node": "^12.12.27",
         "@types/node-fetch": "^2.5.4",
-        "@types/throttle-debounce": "^2.1.0",
         "@types/vscode": "^1.42.0",
         "@typescript-eslint/eslint-plugin": "^2.20.0",
         "@typescript-eslint/parser": "^2.20.0",
@@ -169,6 +168,11 @@
             "type": "object",
             "title": "Rust Analyzer",
             "properties": {
+                "rust-analyzer.highlighting.semanticTokens": {
+                    "type": "boolean",
+                    "default": false,
+                    "description": "Use proposed semantic tokens API for syntax highlighting"
+                },
                 "rust-analyzer.highlightingOn": {
                     "type": "boolean",
                     "default": false,
diff --git a/editors/code/src/client.ts b/editors/code/src/client.ts
index aaf2ef40e..44bd04c21 100644
--- a/editors/code/src/client.ts
+++ b/editors/code/src/client.ts
@@ -3,6 +3,7 @@ import * as vscode from 'vscode';
 
 import { Config } from './config';
 import { CallHierarchyFeature } from 'vscode-languageclient/lib/callHierarchy.proposed';
+import { SemanticTokensFeature } from 'vscode-languageclient/lib/semanticTokens.proposed';
 
 export async function createClient(config: Config, serverPath: string): Promise<lc.LanguageClient> {
     // '.' Is the fallback if no folder is open
@@ -26,7 +27,7 @@ export async function createClient(config: Config, serverPath: string): Promise<
     const clientOptions: lc.LanguageClientOptions = {
         documentSelector: [{ scheme: 'file', language: 'rust' }],
         initializationOptions: {
-            publishDecorations: true,
+            publishDecorations: !config.highlightingSemanticTokens,
             lruCapacity: config.lruCapacity,
             maxInlayHintLength: config.maxInlayHintLength,
             cargoWatchEnable: cargoWatchOpts.enable,
@@ -83,5 +84,10 @@ export async function createClient(config: Config, serverPath: string): Promise<
     // Here we want to just enable CallHierarchyFeature since it is available on stable.
     // Note that while the CallHierarchyFeature is stable the LSP protocol is not.
     res.registerFeature(new CallHierarchyFeature(res));
+
+    if (config.highlightingSemanticTokens) {
+        res.registerFeature(new SemanticTokensFeature(res));
+    }
+
     return res;
 }
diff --git a/editors/code/src/config.ts b/editors/code/src/config.ts
index 47e8cd45d..bf915102c 100644
--- a/editors/code/src/config.ts
+++ b/editors/code/src/config.ts
@@ -22,6 +22,7 @@ export class Config {
     private static readonly requiresReloadOpts = [
         "cargoFeatures",
         "cargo-watch",
+        "highlighting.semanticTokens"
     ]
         .map(opt => `${Config.rootSection}.${opt}`);
 
@@ -143,6 +144,7 @@ export class Config {
     // We don't do runtime config validation here for simplicity. More on stackoverflow:
     // https://stackoverflow.com/questions/60135780/what-is-the-best-way-to-type-check-the-configuration-for-vscode-extension
 
+    get highlightingSemanticTokens() { return this.cfg.get("highlighting.semanticTokens") as boolean; }
     get highlightingOn() { return this.cfg.get("highlightingOn") as boolean; }
     get rainbowHighlightingOn() { return this.cfg.get("rainbowHighlightingOn") as boolean; }
     get lruCapacity() { return this.cfg.get("lruCapacity") as null | number; }
diff --git a/editors/code/src/installation/download_artifact.ts b/editors/code/src/installation/download_artifact.ts
index 356723aba..8ed99bf0a 100644
--- a/editors/code/src/installation/download_artifact.ts
+++ b/editors/code/src/installation/download_artifact.ts
@@ -5,7 +5,6 @@ import { strict as assert } from "assert";
 
 import { ArtifactReleaseInfo } from "./interfaces";
 import { downloadFile } from "./download_file";
-import { throttle } from "throttle-debounce";
 
 /**
  * Downloads artifact from given `downloadUrl`.
@@ -38,19 +37,15 @@ export async function downloadArtifact(
         async (progress, _cancellationToken) => {
             let lastPrecentage = 0;
             const filePermissions = 0o755; // (rwx, r_x, r_x)
-            await downloadFile(downloadUrl, installationPath, filePermissions, throttle(
-                200,
-                /* noTrailing: */ true,
-                (readBytes, totalBytes) => {
-                    const newPercentage = (readBytes / totalBytes) * 100;
-                    progress.report({
-                        message: newPercentage.toFixed(0) + "%",
-                        increment: newPercentage - lastPrecentage
-                    });
+            await downloadFile(downloadUrl, installationPath, filePermissions, (readBytes, totalBytes) => {
+                const newPercentage = (readBytes / totalBytes) * 100;
+                progress.report({
+                    message: newPercentage.toFixed(0) + "%",
+                    increment: newPercentage - lastPrecentage
+                });
 
-                    lastPrecentage = newPercentage;
-                })
-            );
+                lastPrecentage = newPercentage;
+            });
         }
     );
 }
diff --git a/editors/code/src/main.ts b/editors/code/src/main.ts
index 424ff1ac3..ecf53cf77 100644
--- a/editors/code/src/main.ts
+++ b/editors/code/src/main.ts
@@ -89,7 +89,9 @@ export async function activate(context: vscode.ExtensionContext) {
 
     activateStatusDisplay(ctx);
 
-    activateHighlighting(ctx);
+    if (!ctx.config.highlightingSemanticTokens) {
+        activateHighlighting(ctx);
+    }
     activateInlayHints(ctx);
 }