[racket-dev] [plt] Push #21701: master branch updated

On Dec 10, 2010, at 11:38 AM, Robby Findler wrote:
> Both this and Sam's idea seem like good ways to improve the error
> message to me. Not sure if Casey or Sam (or Christos?) wants to try to
> their hand at the actual formatting or not. I will, if not.

A couple of things to note for anyone who attempts this (including me):

1) There are three test suites that I know of that depend in some way on being able to parse these error messages:

 a) collects/tests/racket/contract-test.rktl
 b) collects/tests/racket/contract-mzlib-test.rktl
 c) collects/tests/units/test-unit-contracts.rktl

Make sure you change all three appropriately after changing the error message.

2) There are _three_ parties in each blame struct:

  a) positive (the party that exported the value through the contract)
  b) negative (the party that imported the value through the contract)
  c) user     (the party that used the value)

The negative and user parties will be different if the contracted value is reexported from the negative party without a contract.  When the negative and user parties are the same, you don't need to list both, but please list all three if they differ.

Stevie