The Many Faces of Statically Typed JavaScript
When it comes to programming languages, there’s no one-size-fits-all solution. Different languages cater to different needs, and in the world of JavaScript, statically typed languages like TypeScript and PureScript offer a unique set of benefits.
The Rationale Behind Statically Typed Languages
All programming languages have types, even dynamically typed ones like JavaScript. The difference lies in when these types are checked. In dynamically typed languages, type checking occurs at runtime, which can lead to unexpected errors. Statically typed languages, on the other hand, check types at compile time, providing a shorter feedback loop and more confidence in the code.
TypeScript vs. PureScript
TypeScript, created by Microsoft in 2012, focuses on adding type annotations to existing JavaScript. Its syntax is familiar to C-family language users, and it’s designed to work seamlessly with JavaScript. TypeScript’s popularity has grown significantly, with many big-name projects like Angular and Vue.js adopting it.
PureScript, created by Phil Freeman in 2013, takes a different approach. As a purely functional language inspired by Haskell, it provides features like immutability, pattern matching, and type classes. Its syntax may seem strange at first, but it’s designed to improve code correctness and developer productivity.
Dissecting the Output
When we compile TypeScript and PureScript code, we get JavaScript output. However, the two languages approach compilation differently. TypeScript’s output resembles the input code, while PureScript’s output is more abstract, with features like effectful computations and immutable data structures.
Expressing Types
In TypeScript, type information is intertwined with values and keywords. We can provide explicit types or let the compiler infer them. In PureScript, type information is placed above the identifier, and the language has a stronger focus on correctness.
A Language Made for Composition
PureScript’s design makes it an ideal language for composition. Its do notation allows for effectful computations to be composed together, and its type system enables us to encode what we want to do and how we want to do it. This leads to more predictable and maintainable code.
In Conclusion
TypeScript and PureScript offer different approaches to statically typed JavaScript. While TypeScript is more focused on tooling and flexibility, PureScript prioritizes correctness and composition. Ultimately, the choice between these languages depends on your team’s needs and priorities. By understanding what each language provides, you can make an informed decision about which one is right for your project.