MiniTPL

MiniTPL is a lightweight MoonBit template toolkit for configuration generation, document generation, and code snippet generation.

Besides basic variable replacement, it provides variable extraction, template static checks, and missing-variable diagnostics so templates can be validated early in CI or build workflows.

Features

• Basic {{name}} variable replacement with render.
• Trims whitespace around variable names, such as {{ name }}.
• Leniently renders missing variables as an empty string.
• Extracts template variables in source order with extract_vars.
• Statically checks templates with lint.
• Diagnoses empty variable names.
• Diagnoses unclosed placeholders.
• Diagnoses missing variables.
• Has no external dependencies.

Installation And Running

Make sure MoonBit is installed and available in your terminal:

moon version

Format, check, test, and build the project:

moon fmt
moon check
moon test
moon build

Run the example command:

moon run cmd/main

Expected output:

Hello MiniTPL! You are 5 years old.

Run the English example:

moon run examples/english

Expected output:

Hello MoonBit developer, welcome to MiniTPL.

Run the Chinese example:

moon run examples/chinese

Expected output:

你好，MoonBit 开发者！欢迎使用 MiniTPL。

CI

GitHub Actions runs project checks, tests, and builds on push and pull request. For local development, run moon fmt before committing MoonBit source changes.

Publishing

MiniTPL is published to mooncakes.io as:

joanna/minitpl@0.1.2

Package page:

https://mooncakes.io/docs/joanna/minitpl@0.1.2

API Example

let tpl : String = "Hello {{name}}!"
let keys : Array[String] = ["name"]
let vals : Array[String] = ["MiniTPL"]
let output : String = @src.render(tpl, keys, vals)
println(output)

Output:

Hello MiniTPL!

Extract variables from a template:

let vars : Array[String] = @src.extract_vars("Hello {{ name }}, {{age}}")

The result is ["name", "age"]. Variable names are trimmed, order is preserved, and repeated variables are kept.

Lint a template before rendering:

let diagnostics : Array[String] = @src.lint("Hello {{name}} {{tool}}", ["name"])

The result is ["missing variable: tool"].

Missing Variables

If a variable name does not exist in the provided keys, MiniTPL renders that variable as an empty string.

For example, Hello {{name}}! with no name value becomes Hello !.

Current Limitations

• Only simple {{name}} placeholder rendering is supported.
• MiniTPL does not aim for full Mustache compatibility.
• if, each, filters, and nested data are not supported yet.
• Missing variables render as an empty string by default.

Roadmap

• Improve the public API for passing template data.
• Add clearer error handling for malformed templates and mismatched data.
• Support escaping literal braces.
• Add more tests for edge cases.
• Expand examples and documentation.
• Add CI for automatic check, test, and build.

License

This project is licensed under the Apache License 2.0. See LICENSE for details.