Dalap is an extremely flexible tree-walking / tree-transformation library for Clojure and Clojurescript. It is the foundation of dalap-html, an html templating/serialization library (similar to hiccup and enlive), and lein-dalap, a Clojure->Clojurescript code transformation tool.

The name is the acronym for Decide As Late As Possible, from lean programming.

The namespace dalap.walk provides Walker, which is a wrapper around a visitor function (a multimethod or a single function from a Protocol). It simplifies the recursive invocation of the visitor over a seq of objects (possibly nested) and makes it possible to:

a) decorate or replace the visitor for sub-regions of the tree and

b) maintain traversal state if needed.

The namespace dalap.rules implements a css-like selector+transformer rules system, which allows you to selectively transform portions of a tree. See lein-dalap for an example of this in action.

See the test suite or the packages dalap-html and lein-dalap for usage examples.

Copyright (C) 2012 Birdseye Software Inc.

Distributed under the MIT License.