On 2008 Sep 3, at 14:34, Andrew Coppin wrote:
Brandon S. Allbery KF8NH wrote:
You can define a set of valid transformations, have the interpreter log each transformation, and verify that all are correct (that is, that both the transformation and the logged result are correct.
This assumes the interpreter can be resolved down to a sufficiently simple set of transformations; if not, you're right back at having the tester being the interpreter itself. Note that you don't check if the transformation plan for the program matches a specified list, just that all transformations are correct. (Just remember that "logic is an organized way of going wrong with confidence.")
The amusing (?) part is that the interpretter itself is essentially quite simple. I've implemented it several times before now. But what I'm trying to do it make it print out elaborately formatted execution traces so that a human user can observe how execution proceeds. This transforms an essentially simple algorithm into something quite nausiatingly complex, with many subtle bugs and issues.
This seems odd to me: I would expect to wrap a WriterT around it, log unformatted actions there, and dump it to a file at the end to be read by an analyzer tool which can optionally reformat the log to be human- readable. -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allbery@kf8nh.com system administrator [openafs,heimdal,too many hats] allbery@ece.cmu.edu electrical and computer engineering, carnegie mellon university KF8NH