Egison Pattern Source

The egison-pattern-src provides a standalone syntax definition for patterns in Egison programming language. This package enables you to embed Egison's patterns in your parser (pretty-printer) by supplying expression and name parsers (printers) externally.

Syntax

The following is a simplified syntax of pattern expressions where x, v, op and e are respectively names, variable names, user-defined infix operators and expressions in host language.

p ::= _                     (wildcard pattern)
    | $v                    (pattern variable)
    | #e                    (value pattern)
    | ?e                    (predicate pattern)
    | p & p                 (and pattern)
    | p | p                 (or pattern)
    | !p                    (not pattern)
    | p op p                (user-defined infix pattern)
    | x                     (constructor pattern without argument)
    | (x p_1 p_2 ... p_n)   (constructor pattern with arguments)

License

egison-pattern-src is distributed as open source software under the terms of the 3 clause BSD License. See LICENSE for details.