https://github.com/matklad/typed_key

A Rust library for strongly-typed string keys for configuration.
https://github.com/matklad/typed_key

rust type-safety

Last synced: over 1 year ago
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A Rust library for strongly-typed string keys for configuration.

• Host: GitHub
• URL: https://github.com/matklad/typed_key
• Owner: matklad
• License: apache-2.0
• Created: 2018-05-24T09:59:03.000Z (about 8 years ago)
• Default Branch: master
• Last Pushed: 2018-06-03T06:33:55.000Z (about 8 years ago)
• Last Synced: 2025-04-04T05:38:02.461Z (over 1 year ago)
• Topics: rust, type-safety
• Language: Rust
• Homepage: https://matklad.github.io/2018/05/24/typed-key-pattern.html
• Size: 33.2 KB
• Stars: 25
• Watchers: 2
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE-APACHE

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README

          
# typed_key

[![Build Status](https://travis-ci.org/matklad/typed_key.svg?branch=master)](https://travis-ci.org/matklad/typed_key)

[![Crates.io](https://img.shields.io/crates/v/typed_key.svg)](https://crates.io/crates/typed_key)

[![API reference](https://docs.rs/typed_key/badge.svg)](https://docs.rs/typed_key/)

Strongly-typed string keys for configuration.

A frequent task is to extract a typed value from an untyped `Map`.

Typically, this is done via string keys: `let port: u32 = map.get("port")?.parse()?`.

A slightly more type-safe approach is to associate certain types with corresponding

string constants:

```rust

#[macro_use]

extern crate typed_key;

use typed_key::Key;

// `PORT` is basically `"port"` string with associated `u32` type.

const PORT: Key = typed_key!("port");

```

This crate provides basic building block for such strongly-typed strings.

See [example] for a complete example of reading configuration, and the [blog post]

for a more long winded explanation of the pattern.

[example]: https://github.com/matklad/typed_key/blob/master/examples/serde.rs

[blog post]: https://matklad.github.io/2018/05/24/typed-key-pattern.html

Using string keys is totally fine for small isolated cases, but if this pattern

is pervasive, `typed_key` can provide the following benefits:

  * Documentation: all possible keys are declared in one place, specify

    their type explicitly, and can have documentation comments.

  * Type safety: because each key carries its type, it's impossible to read

    the value of wrong type. Unlike string keys, typed keys never need a turbofish

    operator.

  * Typo safety: you can't misspell a type key on the call site.

  * Navigation: with typed_keys, you can use "go to definition", "find usages", and

    refactor without fear.