swift3运算符的优先级和结合性？

Question

现在已经使用precedencegroup ，语法怎么用呢，(associativity)，(precedence)具体怎么定义啊

infix operator ^{associativity left precedence 140 }怎么用 precedencegroup 改写啊

Answer 1

precedencegroup testPrecedence {    associativity: left    higherThan: AdditionPrecedence}infix operator ^ : testPrecedence