anchor.diff:  
   === Error handling
   
  -One of the advantages of using promise abstraction is that it natively has a notion
  -of error, so you don't need reinvent it. If some of the computations of the composed
  -promise chain/pipeline raises an exception, that one is automatically propagated to
  -the last promise making the effect of short-circuiting.
  +One of the advantages of using the promise abstraction is that it natively has a notion
  +of errors, so you don't need reinvent it. If some computation inside the composed
  +promise chain/pipeline raises an exception, the pipeline short-circuits and propogates
  +the exception to the last promise in the chain.
   
   Let see an example:
   
  
positive.code: ;; => 85
  ----
  
  The `let` macro behaves identical to the `let` with the exception
  that it always return a promise.
  
  If an error occurs at any step the entire composition will be
  short-circuited, returning exceptionally resolved promise.
  
  Under the hood, the previous `let` macro evalutes to something like
  
negative.code: 
  === Contributing
  
  Unlike Clojure and other Clojure contrib libs, this project does not have many restrictions for
  contributions. Just open a issue or pull request.
  
  
  