diff --git a/extension/src/cli.ts b/extension/src/cli.ts
index 26d818c..365f18e 100644
--- a/extension/src/cli.ts
+++ b/extension/src/cli.ts
@@ -35,6 +35,7 @@ export interface CliOutput {
 export type CliResult =
   | { hasRun: true } & CliOutput
   | { hasRun: false, success: false } & CliNotOk
+//| { healthy: false, hasRun: false, success: false } & CliNotHealthy
 
 export type CliNamespace = string;
 
diff --git a/extension/src/diagnostics.ts b/extension/src/diagnostics.ts
index 5ed822e..8ad27a8 100644
--- a/extension/src/diagnostics.ts
+++ b/extension/src/diagnostics.ts
@@ -47,6 +47,14 @@ export class Diagnostics {
         cause: ("cause" in event.error) ? event.error.cause : event.error,
       });
     }
+    /*
+     * Pseudo-code for interface segregation:
+     * const ifmMessages: ifm.Message[] = ifm.parseCliStderr(event.stderr);
+     * const diagnostics: Diagnostic[] = ifmMessages.map((message) =>
+     *   toDiagnostic(message, event.document),
+     * );
+     * this.#diagnosticCollection.set(event.document.uri, diagnostics);
+     */
     const matchResult = grammar.match(event.stderr);
     if (matchResult.failed()) {
       throw new Error(matchResult.message);
diff --git a/extension/src/parser.ts b/extension/src/parser.ts
index 7bf4d95..2434c55 100644
--- a/extension/src/parser.ts
+++ b/extension/src/parser.ts
@@ -17,6 +17,22 @@ export class Parser {
   }
 
   async parseDocument(document: TextDocument) {
+    /*
+     * Pseudo-code for interface segregation:
+     * const config: ExecutableConfig = await this.#configFor(document);
+     * try {
+     *   const cliResult: ifm.CliResult = ifm.runSync(document.getText(), config);
+     *   if (!cliResult.success) {
+     *     log.error("exit status:", cliResult.status);
+     *     log.error("error:", cliResult.error);
+     *   }
+     * } catch (error) {
+     *   // …
+     * }
+     * this.#didParseDocumentEventEmitter.fire(
+     *   { document, ...cliResult });
+     */
+
     const cli: IfmCli = await this.#cliProvider.cliFor(document);
     if (!cli.ok) {
       this.#didParseDocumentEventEmitter.fire(