Re: [racket-users] Names for flat-contract-with-explanation contracts

[Robby Findler]

Probably it would be good to make rename-contract and
flat-named-contract cooperate better with
flat-contract-with-explanation, but for now I've just added a #:name
argument, whose value defaults to the name of the procedure that's
passed in.

Robby

On Tue, Apr 11, 2017 at 12:06 PM, Philip McGrath
 wrote:
> Is it possible to give a name to a contract created with
> contract-with-explanation?
>
> To illustrate, this example:
>>
>> #lang racket
>> (define has-explanation/c
>>   (flat-contract-with-explanation
>>(λ (val)
>>  (λ (blame)
>>(raise-blame-error blame val
>>   '(expected:
>> "nothing would pass this"
>> given: "~e")
>>   val)
>> (define/contract sample-violation
>>   has-explanation/c
>>   42)
>
> prints this error message:
>>
>> sample-violation: broke its own contract
>>   promised: nothing would pass this
>>   produced: 42
>>   in: anonymous-flat-contract
>>   contract from: (definition sample-violation)
>>   blaming: (definition sample-violation)
>>(assuming the contract is correct)
>
> which is wonderful, except for the "anonymous-flat-contract" part.
>
> If I try to give it a name with rename-contract, it loses the custom error
> reporting: e.g. this example:
>>
>> (define/contract sample-violation/renamed
>>   (rename-contract has-explanation/c
>>'renamed:has-explanation/c)
>>   42)
>
> prints this:
>>
>> sample-violation/renamed: broke its own contract
>>   promised: renamed:has-explanation/c
>>   produced: 42
>>   in: renamed:has-explanation/c
>>   contract from:
>>   (definition sample-violation/renamed)
>>   blaming: (definition sample-violation/renamed)
>>(assuming the contract is correct)
>
>
> The same thing happens with flat-named-contract: e,g, this
>>
>> (define/contract sample-violation/flat-named
>>   (flat-named-contract 'flat-named:has-explanation/c
>>has-explanation/c)
>>   42)
>
> prints this:
>>
>> sample-violation/flat-named: broke its own contract
>>   promised: flat-named:has-explanation/c
>>   produced: 42
>>   in: flat-named:has-explanation/c
>>   contract from:
>>   (definition sample-violation/flat-named)
>>   blaming: (definition sample-violation/flat-named)
>>(assuming the contract is correct)
>
>
>
>
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[racket-users] Names for flat-contract-with-explanation contracts

[Philip McGrath]

Is it possible to give a name to a contract created with
contract-with-explanation?

To illustrate, this example:

> #lang racket
> (define has-explanation/c
>   (flat-contract-with-explanation
>(λ (val)
>  (λ (blame)
>(raise-blame-error blame val
>   '(expected:
> "nothing would pass this"
> given: "~e")
>   val)
> (define/contract sample-violation
>   has-explanation/c
>   42)

prints this error message:

> sample-violation: broke its own contract
>   promised: nothing would pass this
>   produced: 42
>   in: anonymous-flat-contract
>   contract from: (definition sample-violation)
>   blaming: (definition sample-violation)
>(assuming the contract is correct)

which is wonderful, except for the "anonymous-flat-contract" part.

If I try to give it a name with rename-contract, it loses the custom error
reporting: e.g. this example:

> (define/contract sample-violation/renamed
>   (rename-contract has-explanation/c
>'renamed:has-explanation/c)
>   42)

prints this:

> sample-violation/renamed: broke its own contract
>   promised: renamed:has-explanation/c
>   produced: 42
>   in: renamed:has-explanation/c
>   contract from:
>   (definition sample-violation/renamed)
>   blaming: (definition sample-violation/renamed)
>(assuming the contract is correct)


The same thing happens with flat-named-contract: e,g, this

> (define/contract sample-violation/flat-named
>   (flat-named-contract 'flat-named:has-explanation/c
>has-explanation/c)
>   42)

prints this:

> sample-violation/flat-named: broke its own contract
>   promised: flat-named:has-explanation/c
>   produced: 42
>   in: flat-named:has-explanation/c
>   contract from:
>   (definition sample-violation/flat-named)
>   blaming: (definition sample-violation/flat-named)
>(assuming the contract is correct)

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