Name regex variable after its usage

Author: yhabteab

internal/filter/lexer.go

@@ -10,9 +10,9 @@ import (
 	"text/scanner"
 )
 
-// regex contains a compiled regexp and is used by the Lexer to match filter identifiers.
-// Currently, it allows to match any character except these inside the curly braces.
-var regex = regexp.MustCompile("[^!&|~<>=()]")
+// identifiersMatcher contains a compiled regexp and is used by the Lexer to match filter identifiers.
+// Currently, it allows to match any character except a LogicalOp and CompOperator.
+var identifiersMatcher = regexp.MustCompile("[^!&|~<>=()]")
 
 // init just sets the global yyErrorVerbose variable to true.
 func init() {
@@ -146,7 +146,7 @@ func (l *Lexer) Error(s string) {
 // isIdentRune provides custom implementation of scanner.IsIdentRune.
 // This function determines whether a given character is allowed to be part of an identifier.
 func isIdentRune(ch rune, i int) bool {
-	return regex.MatchString(string(ch))
+	return identifiersMatcher.MatchString(string(ch))
 }
 
 // ScanError is used to capture all errors the Scanner encounters.