关于[Announcing TypeScript 4.0 Beta]的摘要:
Today we’re excited to release the beta of the next major milestone in the TypeScript programming language: TypeScript 4.0. This beta takes us on our first step into TypeScript 4.0, and while it brings a new major version, don’t fret – there are no substantially larger breaking changes than usual. Our philosophy in evolving TypeScript has always been to provide an upgrade path that minimizes disruptive breaking changes while still giving ourselves some flexibility to flag suspicious code as errors when appropriate. For this reason, we’re continuing with a similar versioning model to that of past releases, so 4.0 is just the natural continuation from TypeScript 3.9.