normalizar function
Implementation
String normalizar(String input) {
return input
.toLowerCase()
.replaceAll(RegExp(r'[áàâã]'), 'a')
.replaceAll(RegExp(r'[éèê]'), 'e')
.replaceAll(RegExp(r'[íìî]'), 'i')
.replaceAll(RegExp(r'[óòôõ]'), 'o')
.replaceAll(RegExp(r'[úùû]'), 'u')
.replaceAll(RegExp(r'[^a-z0-9\s:]'), ''); // remove símbolos extras
}