function testBrr()
{
$str = 'a+(b+(c+1))';
$brr = new Brr();
$substituted = $brr->sub($str);
$this->assertEqual($substituted, 'a+([0]b+([1]c+1)[1])[0]');
$substituted = str_replace('a', 'A', $substituted);
$substituted = str_replace('b', 'B', $substituted);
$substituted = str_replace('c', 'C', $substituted);
$substituted = $brr->subback($substituted);
$this->assertEqual($substituted, 'A+(B+(C+1))');
}
/**
* Parse a string into an expression
*/
function parse($str)
{
// replace backslashes with sqrt, eg \2 -> sqrt(2)
$ss = preg_replace(':\\\\([\\w\\.]+):', 'sqrt($1)', $str);
// this replaces \(stuff) with sqrt(stuff), eg \(a^2+b^2) -> sqrt(a^2+b^2)
$ss = preg_replace(':\\\\\\((.+)\\):', 'sqrt($1)', $ss);
// equations/inequalities containing unary '-' are parsed wrongly
// fix it by putting both part in brackets
$ss = preg_replace(':(.+?)(<=|>=|<|>|=)(.+):', '($1)$2($3)', $ss);
//echo $ss.'<br>';
$brr = new Brr();
$c = $brr->sub($ss);
//echo "parse $c\n";
$this->parse1($c, 0);
array_splice($this->brackets, 0);
array_splice($this->brackets_re, 0);
}
