Show inferred captures

package.json

@@ -6,7 +6,7 @@
         "type": "git",
         "url": "https://github.com/effekt-lang/effekt-vscode.git"
     },
-    "version": "0.1.5",
+    "version": "0.1.6",
     "publisher": "b-studios",
     "engines": {
         "vscode": "^1.30.0"
@@ -81,6 +81,11 @@
                     "default": true,
                     "description": "Display additional information when hovering over identifier."
                 },
+                "effekt.showCaptures": {
+                    "type": "boolean",
+                    "default": false,
+                    "description": "Show additional information about resources used by a function."
+                },
                 "effekt.showIR": {
                     "type": "string",
                     "default": "none",

src/extension.ts

@@ -1,7 +1,7 @@
 'use strict';
 
-import { ExtensionContext, workspace, window, Range, DecorationOptions } from 'vscode';
-import { LanguageClient, LanguageClientOptions, ServerOptions } from 'vscode-languageclient';
+import { ExtensionContext, workspace, window, Range, DecorationOptions, Location } from 'vscode';
+import { LanguageClient, LanguageClientOptions, ServerOptions, ExecuteCommandRequest } from 'vscode-languageclient';
 import { Monto } from './monto';
 import { platform } from 'os';
 
@@ -89,22 +89,67 @@ export function activate(context: ExtensionContext) {
 		dark: { backgroundColor: "rgba(255,255,255,0.05)" }
     })
 
+    // the decorations themselves don't have styles. Only the added before-elements.
+    const captureDecoration = window.createTextEditorDecorationType({})
 
     // based on https://github.com/microsoft/vscode-extension-samples/blob/master/decorator-sample/src/extension.ts
     let timeout: NodeJS.Timer;
     let editor = window.activeTextEditor
 
     function scheduleDecorations() {
 		if (timeout) { clearTimeout(timeout) }
-		timeout = setTimeout(decorate, 50);
+		timeout = setTimeout(updateHoles, 50);
+    }
+
+    function updateCaptures() {
+
+        if (!editor) { return; }
+
+        if (!config.get<boolean>("showCaptures")) { return; }
+
+        client.sendRequest(ExecuteCommandRequest.type, { command: "inferredCaptures", arguments: [{
+            uri: editor.document.uri.toString()
+        }]}).then(
+            (result : [{ location: Location, captureText: string }]) => {
+                if (!editor) { return; }
+
+                let captureAnnotations: DecorationOptions[] = []
+
+                console.log(result)
+
+                if (result == null) return;
+
+                result.forEach(response => {
+                    if (!editor) { return; }
+                    const loc = response.location
+                    if (loc.uri != editor.document.uri) return;
+
+                    captureAnnotations.push({
+                        range:  loc.range,
+                        renderOptions: {
+                            before: {
+                            contentText: response.captureText,
+                            backgroundColor: "rgba(170,210,255,0.3)",
+                            color: "rgba(50,50,50,0.5)",
+                            fontStyle: "italic",
+                            margin: "0 0.5em 0 0.5em"
+                            }
+                        }
+                    })
+                })
+
+                if (!editor) { return; }
+                return editor.setDecorations(captureDecoration, captureAnnotations)
+            }
+        );
     }
 
     const holeRegex = /<>|<{|}>/g
 
     /**
      * TODO clean this up -- ideally move it to the language server
      */
-    function decorate() {
+    function updateHoles() {
         if (!editor) { return; }
 
         const text = editor.document.getText()
@@ -137,6 +182,10 @@ export function activate(context: ExtensionContext) {
 		}
     }, null, context.subscriptions);
 
+    workspace.onDidSaveTextDocument(ev => {
+        setTimeout(updateCaptures, 50)
+    })
+
 	scheduleDecorations();
 
     context.subscriptions.push(client.start());