Vectro: efficient, dense, high-fanout immutable vectors

This package provides the vectro module, a Haskell library for working with immutable vectors that provide an efficient mutation interface (no, really!).

The vector type is represented internally as a tree with high fanout, so its depth is bounded and accesses are very cheap. Updates are also cheap, as they only need to copy those parts of a tree whose structures need modifying.

Get involved!

Please report bugs via the bitbucket issue tracker.

Master Mercurial repository:

  • hg clone

There's also a git mirror:

  • git clone git://

(You can create and contribute changes using either Mercurial or git.)


This library is written and maintained by Bryan O'Sullivan,