Emphasizing lifetime-polymorphism can also make type inference untenable, a design choice that wouldn’t fit OCaml.

OCaml 语言能做些什么？

OCaml语言有什么先进的地方?

OCaml 类型系统的缺陷有哪些？

This project file is needed in the root directory of every source tree that you want to compile with Dune. In general, you’ll have a dune file in every subdirectory of the source tree but only one dune-project file at the root.

let increment x = x + 1

There are five essential components to learning a language: syntax, semantics, idioms, libraries, and tools.

Parametric polymorphism: Functions and data structures can be parameterized over types. This is crucial for being able to re-use code.

The language for writing React. Reason's creator also created ReactJS, whose first prototypes were written in SML, a distant cousin of OCaml. We've transcribed ReactML into ReactJS for wide adoption. A few years later, we're now iterating on the future of ReactJS through ReasonReact.

Many backing languages would satisfy the previous section's points; the points below, however, have been deal-breakers in our considerations.

The ability to render to native code. OCaml's native (assembly) startup time is in single digit milliseconds. We have big plans to use Reason on native one day; meanwhile, we're focusing on adoption through great JavaScript compatibility.

We've worked very hard to make Reason look like JS while preserving OCaml's great semantics & types.