[Haskell-cafe] what are the points in pointsfree?
Donald Bruce Stewart
dons at cse.unsw.edu.au
Thu Dec 14 19:41:25 EST 2006
> i'm not naive enough to think they are the composition function, and
> i've gathered it has something to do with free terms, but beyond that
> i'm not sure. unless it also has something to do with fix points?
The wiki knows all! :)
1 But pointfree has more points!
A common misconception is that the 'points' of pointfree style are the (.)
operator (function composition, as an ASCII symbol), which uses the same
identifier as the decimal point. This is wrong. The term originated in
topology, a branch of mathematics which works with spaces composed of points,
and functions between those spaces. So a 'points-free' definition of a function
is one which does not explicitly mention the points (values) of the space on
which the function acts. In Haskell, our 'space' is some type, and 'points' are
More information about the Haskell-Cafe