断言
- (断言规格 x)
spec-checking assert expression. Returns x if x is valid? according to spec, else throws an ex-info with explain-data plus ::failure of :assertion-failed. Can be disabled at either compile time or runtime: If *compile-asserts* is false at compile time, compiles to x. Defaults to value of 'clojure.spec.compile-asserts' system property, or true if not set. If (check-asserts?) is false at runtime, always returns x. Defaults to value of 'clojure.spec.check-asserts' system property, or false if not set. You can toggle check-asserts? with (check-asserts bool).
© Rich Hickey. 保留所有权利。 Eclipse 公共许可证 1.0
1 Example
; Notice that if you try to execute assert it will always return the given value: (require ['clojure.spec.alpha :as 's]) (s/assert even? 1) => 1 ; This is because asserts are turned off by default: (s/check-asserts?) => false ; To enable asserts, run this (s/check-asserts true) => true ; Now your asserts will properly fail (s/assert even? 3) ; ExceptionInfo Spec assertion failed... ```