REPL Development

SkillDev tools

Expert skill for building interactive REPLs with rich editing and evaluation features

Instructions available. Your AI can read the instructions. Execution depends on the setup they require.

Account requirements not reviewed. Check the skill instructions before use; ahel provides instructions and does not run this skill.

Add ahel to your AI once: Claude, ChatGPT, Cursor, Claude Code or Codex. Then ask it to use this.

Then ask your AI: use the REPL Development skill

What this skill tells your AI

The instructions your AI receives, as published by a5c-ai/babysitter in library/specializations/programming-languages/skills/repl-development/SKILL.md and read by ahel’s review.

Overview

Expert skill for building interactive REPLs with rich editing and evaluation features.

Capabilities

Implement readline integration with history
Handle multi-line input detection
Implement tab completion for identifiers
Design incremental compilation for REPL
Handle top-level expression evaluation
Implement persistent REPL state
Design pretty-printing for values
Support special REPL commands (:help, :type, etc.)

Target Processes

repl-development.js
interpreter-implementation.js
lsp-server-implementation.js

Dependencies

rustyline
readline libraries
linenoise

Usage Guidelines

Line Editing: Use established readline libraries for robust line editing
Multi-line: Detect incomplete expressions for multi-line input
Completion: Implement context-aware tab completion
History: Persist history across sessions
Commands: Provide useful meta-commands (:help, :type, :quit, etc.)

Output Schema

{
  "type": "object",
  "properties": {
    "lineLibrary": {
      "type": "string",
      "enum": ["readline", "rustyline", "linenoise", "custom"]
    },
    "features": {
      "type": "array",
      "items": { "type": "string" }
    },
    "commands": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "name": { "type": "string" },
          "description": { "type": "string" }
        }
      }
    },
    "generatedFiles": {
      "type": "array",
      "items": { "type": "string" }
    }
  }
}

Signals

GitHub stars: 2k
Forks: 112
Last commit: Sep 2026

Advanced

Item type: skill
Key: repl-development
Source: github.com/a5c-ai/babysitter

github.com/a5c-ai/babysitter