Re: spend a lot of time with alex generated module
Malcolm Wallace <[email protected]> Wed, 16 Aug 2006 17:07:58 +0100
| Newsgroups | gmane.comp.lang.haskell.hat |
|---|---|
| Organization | Dept of Computer Science, University of York |
| Message-ID | <[email protected]> |
kgu <[email protected]> wrote: > hat-trans spends a lot of time (really a lot of time) in generate > module from a module generated by alex. The original module has 330 > lines of code and module generated by hat-trans has 40700 !!. It is well-known that giving a machine-generated input to any compiler-like tool is the best way to show up its weaknesses! I suppose the output from Alex is very different from the kind of code that a human would write. Since Alex creates essentially a table-driven lexical analyser, it is possible that a large static description of the tables is where hat-trans is spending lots of time. Also, if the Alex-generated code is deeply nested, hat-trans may spend too much time trying to pretty-print its output within 80 columns, when really the formatting will not fit nicely into such a small width. Just some ideas. If you want to send a copy of the original Alex specification, we may be able to investigate further. Regards, Malcolm