/* *************************************************************************************
* copyright: Copyright (c) 2021 Lowell D. Thomas, all rights reserved
* license: BSD-2-Clause (https://opensource.org/licenses/BSD-2-Clause)
* ********************************************************************************* */This is a demonstration using look-around operators to define word boundaries.
In this straight-forward grammar, parsing environment, it is a very artificial example.
It simply wants to know if the whole word cat is found at the 10th character.
However, in the context of a pattern matching engine (see apg-exp) it is very real use.
You can examine the trace of each of these examples to see how the left boundary is matched,
or not matched, using negative look-behind (!! or BKN) and the right boundary is determined
with negative look-ahead (! or NOT).
(function boundaries() {
let input = 'The black cat is in the window.';
const grammar = new (require('./boundaries-grammar'))();
const setup = require('./setup');
setup(input, grammar, 'boundaries-cat');
input = "Don't truncate this line.";
setup(input, grammar, 'boundaries-truncate');
input = "It's a Bobcat, not house cat..";
setup(input, grammar, 'boundaries-bobcat');
input = "You can't categorize it.";
setup(input, grammar, 'boundaries-catagorize');
})();