Add echo commandlet

Author: Your Name

src/cmdlets/development/js.ts

@@ -80,6 +80,7 @@ import {
 } from '../trace/trace.js';
 import { MacroCmdLet } from '../misc/macro.js';
 import { ReplaceCmdLet } from '../breakpoints/replace.js';
+import { EchoCmdLet } from '../misc/echo.js';
 
 export class JsCmdLet extends CmdLetBase {
   name = 'js';
@@ -121,6 +122,7 @@ js path - load commandlet JS script
       CoverageBpCmdLet: CoverageBpCmdLet,
       DivCmdLet: DivCmdLet,
       DumpCmdLet: DumpCmdLet,
+      EchoCmdLet: EchoCmdLet,
       EqCmdLet: EqCmdLet,
       ExitCmdLet: ExitCmdLet,
       FalseCmdLet: FalseCmdLet,

src/cmdlets/misc/echo.ts

@@ -0,0 +1,43 @@
+import { CmdLetBase } from '../../commands/cmdlet.js';
+import { Output } from '../../io/output.js';
+import { Token } from '../../io/token.js';
+import { Var } from '../../vars/var.js';
+
+export class EchoCmdLet extends CmdLetBase {
+  name = 'echo';
+  category = 'misc';
+  help = 'toggle echo mode';
+
+  public static echo: boolean = true;
+
+  private static readonly USAGE: string = `Usage: echo
+echo on - enable echo (default)
+
+echo off - disable echo`;
+
+  public runSync(tokens: Token[]): Var {
+    const vars = this.transformOptional(tokens, [], [this.parseSwitch]);
+    if (vars === null) return this.usage();
+    const [, [state]] = vars as [[], [boolean | null]];
+    if (state === null) {
+      Output.writeln(
+        `echo is [${EchoCmdLet.echo ? Output.green('on') : Output.red('off')}]`,
+      );
+      return Var.ZERO;
+    }
+    EchoCmdLet.echo = state;
+    return Var.ZERO;
+  }
+
+  protected parseSwitch(token: Token): boolean | null {
+    const literal = token.getLiteral();
+    if (literal === 'on') return true;
+    if (literal === 'off') return false;
+    return null;
+  }
+
+  public usage(): Var {
+    Output.writeln(EchoCmdLet.USAGE);
+    return Var.ZERO;
+  }
+}

src/commands/cmdlets.ts

@@ -67,6 +67,7 @@ import {
 } from '../cmdlets/trace/trace.js';
 import { MacroCmdLet } from '../cmdlets/misc/macro.js';
 import { ReplaceCmdLet } from '../cmdlets/breakpoints/replace.js';
+import { EchoCmdLet } from '../cmdlets/misc/echo.js';
 
 export class CmdLets {
   private static byName: Map<string, CmdLet> = new Map<string, CmdLet>();
@@ -85,6 +86,7 @@ export class CmdLets {
     this.registerCmdletType(DivCmdLet);
     this.registerCmdletType(DumpCmdLet);
     this.registerCmdletType(DumpStringCmdLet);
+    this.registerCmdletType(EchoCmdLet);
     this.registerCmdletType(EndianCmdLet);
     this.registerCmdletType(EqCmdLet);
     this.registerCmdletType(ExitCmdLet);

src/commands/command.ts

@@ -6,35 +6,54 @@ import { Token } from '../io/token.js';
 import { CmdLet } from './cmdlet.js';
 import { Macro, Macros } from '../macros/macros.js';
 import { MacroCmdLet } from '../cmdlets/misc/macro.js';
+import { EchoCmdLet } from '../cmdlets/misc/echo.js';
 
 export class Command {
   private static readonly MACRO_PREFIX: string = '!';
   public static async run(tokens: Token[]): Promise<Var> {
-    const cmdlet = this.getCmdlet(tokens);
-    if (cmdlet !== null) {
-      return cmdlet.run(tokens.slice(1));
+    let suppressed = false;
+    if (!EchoCmdLet.echo && !Output.isSuppressed()) {
+      Output.suppress(true);
+      suppressed = true;
     }
+    try {
+      const cmdlet = this.getCmdlet(tokens);
+      if (cmdlet !== null) {
+        return cmdlet.run(tokens.slice(1));
+      }
 
-    const macro = this.getMacro(tokens);
-    if (macro !== null) {
-      return MacroCmdLet.runSync(macro, tokens.slice(1));
-    }
+      const macro = this.getMacro(tokens);
+      if (macro !== null) {
+        return MacroCmdLet.runSync(macro, tokens.slice(1));
+      }
 
-    return this.runFunction(tokens);
+      return this.runFunction(tokens);
+    } finally {
+      if (suppressed) Output.suppress(false);
+    }
   }
 
   public static runSync(tokens: Token[]): Var {
-    const cmdlet = this.getCmdlet(tokens);
-    if (cmdlet !== null) {
-      return cmdlet.runSync(tokens.slice(1));
+    let suppressed = false;
+    if (!EchoCmdLet.echo && !Output.isSuppressed()) {
+      Output.suppress(true);
+      suppressed = true;
     }
+    try {
+      const cmdlet = this.getCmdlet(tokens);
+      if (cmdlet !== null) {
+        return cmdlet.runSync(tokens.slice(1));
+      }
 
-    const macro = this.getMacro(tokens);
-    if (macro !== null) {
-      return MacroCmdLet.runSync(macro, tokens.slice(1));
-    }
+      const macro = this.getMacro(tokens);
+      if (macro !== null) {
+        return MacroCmdLet.runSync(macro, tokens.slice(1));
+      }
 
-    return this.runFunction(tokens);
+      return this.runFunction(tokens);
+    } finally {
+      if (suppressed) Output.suppress(false);
+    }
   }
 
   private static getCmdlet(tokens: Token[]): CmdLet | null {

src/io/input.ts

@@ -2,6 +2,7 @@ import { Output } from './output.js';
 import { History } from '../terminal/history.js';
 import { Vars } from '../vars/vars.js';
 import { CharCode, Vt } from './char.js';
+import { EchoCmdLet } from '../cmdlets/misc/echo.js';
 
 enum InputState {
   Default,
@@ -12,6 +13,7 @@ enum InputState {
 export class Input {
   public static readonly PROMPT: string = '-> ';
   public static readonly FILTERED_PROMPT: string = '~> ';
+  public static readonly NO_ECHO_PROMPT: string = '#> ';
   private static readonly EDIT_PROMPT: string = '. ';
 
   private static readonly QUIT_CHAR: string = 'q';
@@ -121,7 +123,9 @@ export class Input {
   public static prompt() {
     Output.clearLine();
     if (this.interceptLine === null) {
-      if (Output.isFiltered()) {
+      if (!EchoCmdLet.echo) {
+        Output.write(Output.bold(this.NO_ECHO_PROMPT));
+      } else if (Output.isFiltered()) {
         Output.write(Output.bold(this.FILTERED_PROMPT));
       } else {
         Output.write(Output.bold(this.PROMPT));

src/io/output.ts

@@ -182,4 +182,8 @@ export class Output {
   public static suppress(suppressed: boolean) {
     this.suppressed = suppressed;
   }
+
+  public static isSuppressed(): boolean {
+    return this.suppressed;
+  }
 }