Re: SRFI-64: test exception symbol

[Taylan Kammer]

On 30.04.2020 17:55, Vladimir Zhbanov wrote:
> On Thu, Apr 30, 2020 at 06:06:21PM +0300, Vladimir Zhbanov wrote:
> > Hi,
> >
> > In SRFI-64, is there a way to test what exception raised using
> > test-error() or anything else?  I know about looking into test
> > logs (if 'test-error' is used), though that's not what I need.  I
> > need a way to be sure a test raises the exception it should raise.

The test-error form takes two optional operands before the test 
expression.  It's defined as:

<start snip>

(test-error [[test-name] error-type] test-expr)

Evaluating test-expr is expected to signal an error. The kind of error 
is indicated by error-type.

If the error-type is left out, or it is #t, it means "some kind of 
unspecified error should be signaled". For example:

(test-error #t (vector-ref '#(1 2) 9))

This specification leaves it implementation-defined (or for a future 
specification) what form test-error may take, though all implementations 
must allow #t. Some implementations may support SRFI-35's conditions, 
but these are only standardized for SRFI-36's I/O conditions, which are 
seldom useful in test suites. An implementation may also allow 
implementation-specific "exception types". For example Java-based 
implementations may allow the names of Java exception classes:

;; Kawa-specific example
(test-error <java.lang.IndexOutOfBoundsException> (vector-ref '#(1 2) 9))

An implementation that cannot catch exceptions should skip test-error forms.

<end snip>

My SRFI-64 implementation allows the error-type operand to be a 
predicate (one-argument procedure that returns a Boolean) to allow 
maximum flexibility.  It's found here:

https://github.com/TaylanUB/scheme-srfis


- Taylan