17 Feb
2015
17 Feb
'15
1:55 p.m.
View pattern support right pre-7.10 is fairly limited in that you have to write a chunk of code that can be interpreted as both a pattern and an expression, or limit yourself to just using the syntax for matching. Afterwards, this opens up a bit, and we get the new syntax for complex bidirectional pattern synonyms, as I recall, so you could make a view pattern for `:<` or something that does this, but we don't have a standard class for it. -Edward On Tue, Feb 17, 2015 at 1:44 PM, Henning Thielemann < lemming@henning-thielemann.de> wrote:
On Tue, 17 Feb 2015, Edward Kmett wrote:
The existing IsList machinery gets you the [], [x], and [x,y] cases, but
not (x:xs).
What about the view patterns?