WITH macro

WITH, the 'Bastard Son Of Loop', is a general binding construct allowing simple, special variable, destructuring, multiple-value, flet, labels, and with-open-file bindings in the same form without multiple indendation levels. This Library was written by Michael Parker.

Here is his description from the WITH webpage:

WITH is a macro that provides a general, conversational binding construct much like loop does for iterative constructs. It allows the programmer to mix and match simple variable bindings, special variable bindings, destructuring-bind, multiple-value-bind, flet, labels, with-open-file without constantly opening up a new indendation level for each new type of binding. It also allows a more convenient syntax for type declarations that places the declaration nearer to the variable being bound. Unlike loop it doesn't try to be exhaustive, but it does try to cover the basics, and it does allow a convenient hook for extending the syntax.