4 Dec
2007
4 Dec
'07
7:41 p.m.
Hi, Lately I have been using pattern guards more than usual and I find that occasionally I need to nest them (i.e., I have alternatives with a common prefix). This seems to happen when I need to do some preliminary checking, followed by some decision making. Here is an example: server text | Just xs <- parse text , | "field1" `elem` xs = ... do one thing ... | "field2" `elem` xs = ... do something else ... server _ = ... invalid request ... As far as I can see this should be a fairly simple change to the pattern bindings extension. Would anyone else find this a useful feature, and if so what syntax should we use? -Iavor