QueryNormalizer: Fix support for brackets, number followed by variable, pi and sqrt function.

Author: janbarasek

src/QueryNormalizer.php

@@ -20,20 +20,23 @@ class QueryNormalizer
 		'(\d)\s+(\d)' => '$1$2',
 		'(\d)(\*{2,}|\˘)(\d)' => '$1^$3',
 		'(\d)\s*(\:|÷)\s*(\d)' => '$1/$3',
+		'(^|[^\d\,])(\d+)\,((?:\d{3}\s*)+)($|[^\d\,])' => '$1$2$3$4',
 		'(^|[^\d\,])(\d+)\,(\d+)($|[^\d\,])' => '$1$2.$3$4',
-		'(\d)\s+([a-z])' => '$1$2',
+		'(\d)\s+(\p{L})([^\p{L}]|$)' => '$1$2$3',
 		'\+\-' => '-',
 		'(\d+)\s*plus\s*(\d+)' => '$1+$2',
 		'(\d+)\s*(krát|krat)\s*(\d+)' => '$1*$3',
 		'\s*([\+\-\*\/\^])\s*' => '$1',
-		'(\d)([xyz])' => '$1*$2',
+		'(\d)(\p{L})([^\p{L}]|$)' => '$1*$2$3',
 		'(nekonecno|nekonečno|infty|infinity|[iI][nN][fF]|∞)' => 'INF',
-		'(π|[pP][iíI])' => 'PI',
+		'(π|(?:\\\\)?[pP][iíI])' => 'PI',
+		'\\\\frac{([^{}]+)}{([^{}]+)}' => '($1)/($2)',
+		'([^\p{L}]|^)\((-?[\d\.]+)\)' => '$1$2',
 		'\s*\=\s*' => '=',
 		'×' => '*',
 		'[–−]+' => '-',
 		'(\d)\(' => '$1*(',
-		'([√√]|odmocnina|odm|sqrt)(?:\s(?:ze|z))?\(?' => 'sqrt(',
+		'([√√]|odmocnina|odm|sqrt)(?:\s(?:ze|z))?\s*\(?' => 'sqrt(',
 		'\)\(' => ')*(',
 		'\|([^|]+)\|' => 'abs($1)',
 		'\s*(vs\.?)\s*' => ' $1 ',