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REPL Development

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

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How to use this skill

Bring this guide into your coding agent with a prompt tailored to the tool you use.

  1. Open your project in Codex.
  2. Copy the prompt below and paste it into your agent.
  3. Review the proposed files and risks before you approve installation.
Prompt to paste
I want to install this Agent Skill for this project in Codex.

Source SKILL.md: https://github.com/a5c-ai/babysitter/blob/HEAD/library/specializations/programming-languages/skills/repl-development/SKILL.md

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First, summarize what it does, its dependencies, license status if identifiable, and any risks. Show the exact files you propose to add under .agents/skills/repl-development/. Do not write files or run scripts until I approve.

After I approve, install the complete skill folder, including required referenced files, into that project location. Verify it is discoverable, then tell me its actual invocation name and how to use it. Do not claim it is installed until you have verified it.

Copying this prompt does not install or run the skill. Review third-party files before use. Codex skill guide

REPL Development Skill

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

  1. Line Editing: Use established readline libraries for robust line editing
  2. Multi-line: Detect incomplete expressions for multi-line input
  3. Completion: Implement context-aware tab completion
  4. History: Persist history across sessions
  5. 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" }
    }
  }
}