From 37d2bdac1af3301a484cf891d51db1b5e0df9b5b Mon Sep 17 00:00:00 2001
From: Ronaldo Ropelatto <ronaldo@mrsistemas.com.br>
Date: Wed, 30 Apr 2025 14:47:43 -0300
Subject: [PATCH] Fix unicode validation

---
 cpfcnpj.go |  3 +--
 rg.go      |  3 +--
 util.go    | 11 ++++++++---
 3 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/cpfcnpj.go b/cpfcnpj.go
index d4032af..287ef59 100644
--- a/cpfcnpj.go
+++ b/cpfcnpj.go
@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"regexp"
 	"strconv"
-	"unicode"
 )
 
 // "Cadastro" will be used internally to define both CPF and CNPJ.
@@ -85,7 +84,7 @@ func calcCadastroDigit(doc string, position int) string {
 func cleanCadastro(doc *string) {
 	buf := bytes.NewBufferString("")
 	for _, r := range *doc {
-		if unicode.IsDigit(r) || unicode.IsLetter(r) {
+		if isDigit(r) || ('A' <= r && r <= 'Z') {
 			buf.WriteRune(r)
 		}
 	}
diff --git a/rg.go b/rg.go
index 0bbb00b..49892ec 100644
--- a/rg.go
+++ b/rg.go
@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"errors"
 	"regexp"
-	"unicode"
 )
 
 var (
@@ -60,7 +59,7 @@ func calcRGDigit(doc string) int {
 func cleanRG(doc *string) {
 	buf := bytes.NewBufferString("")
 	for _, r := range *doc {
-		if unicode.IsDigit(r) || r == 'X' || r == 'x' {
+		if isDigit(r) || r == 'X' || r == 'x' {
 			buf.WriteRune(r)
 		}
 	}
diff --git a/util.go b/util.go
index de04e40..3cd25bc 100644
--- a/util.go
+++ b/util.go
@@ -2,13 +2,12 @@ package brdoc
 
 import (
 	"bytes"
-	"unicode"
 )
 
 // allDigit checks if every rune in a given string is a digit.
 func allDigit(doc string) bool {
 	for _, r := range doc {
-		if !unicode.IsDigit(r) {
+		if !isDigit(r) {
 			return false
 		}
 	}
@@ -25,7 +24,7 @@ func toInt(r rune) int {
 func cleanNonDigits(doc *string) {
 	buf := bytes.NewBufferString("")
 	for _, r := range *doc {
-		if unicode.IsDigit(r) {
+		if isDigit(r) {
 			buf.WriteRune(r)
 		}
 	}
@@ -57,3 +56,9 @@ func isFrom(uf UF, ufs []UF) bool {
 	}
 	return false
 }
+
+// isDigit is a simpler version of unicode.IsDigit: verifies whether a rune is
+// a single digit number.
+func isDigit(r rune) bool {
+	return '0' <= r && r <= '9'
+}