Literally

Literally is a minimal Haskell library that converts type literals into values. It provides type-safe literal conversion functionality using Haskell's advanced type system.

Overview

The literally library allows you to convert compile-time type literals (numbers, strings, characters, etc.) into runtime values in a type-safe manner. This is accomplished through a single literal function that leverages type-level programming to ensure correctness at compile time.

Installation

Add literally to your project's dependencies:

# In your package.yaml
dependencies:
  - literally

Or in your .cabal file:

build-depends: literally

Usage

Import the module and use the literal function with type annotations:

{-# LANGUAGE RequiredTypeArguments #-}
import Literally

-- Convert numeric literals
number :: Integer
number = literal 42

naturalNum :: Natural  
naturalNum = literal 123

-- Convert string literals
greeting :: String
greeting = literal "hello"

-- Convert character literals
letter :: Char
letter = literal 'x'

-- Convert boolean literals
truth :: Bool
truth = literal 'True

falsehood :: Bool  
falsehood = literal 'False

-- Convert unit type
unit :: ()
unit = literal ()

-- Works with tuples too
pair :: (Integer, String)
pair = literal (42, "hello")

How It Works

The library uses the FromType type class:

• FromType: Defines how to convert from a type literal to a value, with an associated KnownType constraint