Proposal static type constraints features

[YU HengChun]

Consider the significance of this proposal from another perspective:

1. It is a native ECMAScript
1. It can be regarded as an enhanced version of asm.js
1. It has always existed, but it has been neglected and has not been fully utilized.
1. The cost is much lighter than adding a new grammar
1. After the proposal is passed, it will seamlessly connect with WebAssembly


从另外的角度考虑这个提案的意义:

1. 它是原生的 ECMAScript
1. 这几乎就是 asm.js 的加强版啊
1. 本来就一直存在, 只是被忽略了, 未被充分利用
1. 成本上比添加新语法要轻量的多
1. 这个提案被通过后将和 WebAssembly 无缝对接