Re: Data.Tree.Tree Show instance

2003-08-14 Thread Ross Paterson
On Mon, Aug 11, 2003 at 07:16:08PM +0200, Tomasz Zielonka wrote: I think it would be better to derive Show instance for Tree instead of providing a pretty printing one. Then it would be possible to have a complementing Read instance. The pretty printing function could be provided under a

Re: Data.Tree.Tree Show instance

2003-08-14 Thread Tomasz Zielonka
On Tue, Aug 12, 2003 at 12:30:27PM +0200, Johannes Waldmann wrote: On Mon, 11 Aug 2003, Tomasz Zielonka wrote: The Tree datatype in new Data.Tree module has a Show instance ... [...] On the other hand, it is my opinion that for a clean program design, you should normally define your own

Re: Data.Tree.Tree Show instance

2003-08-14 Thread Johannes Waldmann
On Mon, 11 Aug 2003, Tomasz Zielonka wrote: The Tree datatype in new Data.Tree module has a Show instance ... I agree that Read/Show should normally come as a pair. It is debatable whether a library should contain a Show instance that makes it rather impossible to write the corresponding Read

Data.Tree.Tree Show instance

2003-08-14 Thread Tomasz Zielonka
Hi! The Tree datatype in new Data.Tree module has a Show instance that works like shown below: Prelude Data.Tree print (Node 'a' [Node 'b' [], Node 'c' []]) - 'a' -+- 'b' | `- 'c' I use a similar module for Trees in conjunction with WASH for generating web pages. WASH