It extends vi’s modal editing with built-in support for multiple cursors/selections and combines it with sam’s structural regular expression based command language.
A universal editor, it has decent Unicode support and should cope with arbitrary files, including large, binary or single-line ones.
Efficient syntax highlighting is provided using Parsing Expression Grammars, which can be conveniently expressed using Lua in the form of LPeg.
vis supports an interactive variant of the structural regular expression based command language introduced by sam.
vis uses selections as core editing primitives. A selection is a non-empty, directed range with two endpoints called cursor and anchor. A selection can be anchored in which case the anchor remains fixed while only the position of the cursor is adjusted. For non-anchored selections both endpoints are updated. A singleton selection covers one character on which both cursor and anchor reside. There always exists a primary selection which remains visible (i.e. changes to its position will adjust the viewport).