# type-check

> JavaScript library

**Wikidata**: [Q116951032](https://www.wikidata.org/wiki/Q116951032)  
**Source**: https://4ort.xyz/entity/type-check

## Summary
type-check is a cross-platform JavaScript library designed to function as a type checker. It is classified as free software and is distributed under the Expat license, also known as the MIT License. The library is available as an npm package and depends on the software library prelude-ls.

## Key Facts
*   **Classification:** It is an instance of a JavaScript library, a type checker, and free software.
*   **License:** The library is distributed under the **Expat license**, which is explicitly stated as the MIT License.
*   **Latest Version:** The most recent stable version is **0.4.0**, released on **April 3, 2020**.
*   **Platform:** It is cross-platform software, capable of operating on multiple computing platforms.
*   **Dependencies:** The library depends on **prelude-ls**.
*   **Source Repository:** The source code is hosted on GitHub at `github.com/gkz/type-check`.
*   **Distribution:** It is distributed as an npm package named `type-check`.
*   **Initial Release:** Version 0.1.0 was released on **September 29, 2013**.

## FAQs
### Q: What is the current stable version of type-check?
A: The current stable version is 0.4.0, which was released on April 3, 2020. It is available via the npm registry.

### Q: Under what license is type-check distributed?
A: type-check is distributed under the Expat license, which is legally stated as the MIT License. This allows users to freely run, study, change, and distribute the software.

### Q: What are the technical requirements to use type-check?
A: type-check is a cross-platform JavaScript library. It requires the software dependency `prelude-ls` to function correctly.

## Why It Matters
type-check plays a specific role in the JavaScript ecosystem by providing utilities for verifying data types. As a "type checker," it addresses the dynamic nature of JavaScript, allowing developers to enforce strict type constraints at runtime or within their development workflow. This capability is essential for improving code reliability and preventing type-related errors that are common in loosely typed languages.

Its significance is further underscored by its longevity and maintenance; the library has seen updates spanning from 2013 to 2020. As free software distributed under the permissive MIT (Expat) license, it is accessible for both open-source and commercial proprietary projects. Its integration into the npm ecosystem and reliance on `prelude-ls` positions it within a specific stack of functional programming tools available for JavaScript developers.

## Notable For
*   **Specialized Functionality:** Acts as a dedicated type checker within the JavaScript environment, a distinct category from general utility libraries.
*   **Permissive Licensing:** Distributed under the MIT License (Expat), facilitating broad adoption and modification.
*   **Cross-Platform Compatibility:** Designed to operate across various computing platforms without restriction.
*   **Active Maintenance History:** Demonstrates a history of updates over nearly a decade, with versions ranging from 2013 to 2020.
*   **Ecosystem Integration:** Natively distributed via npm and integrated with the `prelude-ls` library.

## Body

### Licensing and Status
type-check is classified as **free software**. It is distributed under the terms of the **Expat license**, which the project documentation explicitly equates to the **MIT License**. This licensing ensures that users have the freedom to run, study, change, and distribute the software and its modified versions. Despite being free software, the project retains a copyrighted status. The primary language for the project's website and documentation is English.

### Technical Specifications
The library is written in **JavaScript** (Wikidata ID: Q2005). It is designed to be **cross-platform**, meaning it is capable of being implemented and operating on multiple computing platforms. The software has a dependency on **prelude-ls**, which must be present for it to function. The official source code is maintained in a repository located at `github.com/gkz/type-check`.

### Version History
The development of type-check has been tracked through several stable releases on the npm registry. Key releases include:

*   **Version 0.1.0:** Released on September 29, 2013.
*   **Version 0.2.0:** Released on October 2, 2013.
*   **Version 0.3.0:** Released on October 29, 2013.
*   **Version 0.3.1:** Released on April 8, 2014.
*   **Version 0.3.2:** Released on December 29, 2015.
*   **Version 0.4.0:** Released on April 3, 2020. This version is marked as the preferred stable version. It has a distribution size of 21,167 bytes.

### Distribution
type-check is distributed as an **npm package** under the name `type-check`. Tarballs for specific versions are available through the npm registry (e.g., `registry.npmjs.org/type-check/-/type-check-0.4.0.tgz`). The project is categorized as a JavaScript library and a type checker.

## References

1. [Source](https://github.com/gkz/type-check/blob/master/LICENSE)
2. [npmjs](https://registry.npmjs.com/type-check)