| Maintainer | diagrams-discuss@googlegroups.com |
|---|---|
| Safe Haskell | Safe-Inferred |
Data.Monoid.Cut
Description
The Cut monoid transformer introduces "cut points" such that
all values between any two cut points are thrown away. That is,
a b c | d e | f g h i | j k == a b c | j k
Documentation
A value of type Cut m is either a single m, or a pair of
m's separated by a divider. The divider represents a "cut
point".
Cut is similar to Data.Monoid.Split, but split keeps only the
rightmost divider and accumulates all values, whereas cut always
keeps the leftmost and rightmost divider, coalescing them into
one and throwing away all the information in between.
Split uses the asymmetric constructor :|, and Cut the
symmetric constructor :||:, to emphasize the inherent asymmetry
of Split and symmetry of Cut. Split keeps only the
rightmost split and combines everything on the left; Cut keeps
the outermost splits and throws away everything in between.
Instances
| Show m => Show (Cut m) | |
| (Semigroup m, Monoid m) => Monoid (Cut m) | |
| Semigroup m => Semigroup (Cut m) | If |