Mariano's questions

Context. I try to eliminate the tildes (spelling accents) and tildes, to compare 2 words. I did the function:

let sinDiacriticos = (function(){
    let de = 'ÁÃÀÄÂÉËÈÊÍÏÌÎÓÖÒÔÚÜÙÛÑÇáãàäâéëèêíïìîóöòôúüùûñç',
         a = 'AAAAAEEEEIIIIOOOOUUUUNCaaaaaeeeeiiiioooouuuunc',
        re = new RegExp('['+de+']' , 'ug');

    return texto =>
        texto.replace(
            re, 
            match => a.charAt(de.indexOf(match))
        );
})();


let prue = 'Épico año de mal agüero, sólo Óscar y Ángel ganarán ésta. -Ímpetú Úrsula. ¡Ñañdú corre rápido por ahí!';
console.log(sinDiacriticos(prue));
    // ->   Epico ano de mal aguero, solo Oscar y Angel ganaran esta. -Impetu Ursula. ¡Nandu corre rapido por ahi!

Question 2. Bearing in mind that in Spanish la ñis a different letter from n, can diacritics be eliminated except if it is a ñ?
_{^{* Question asked by blonfu in comments}}

Question: How can I verify that the format of a Peruvian RUC is valid?

What is the RUC? The Single Taxpayer Registry ( RUC ) is the computer registry where taxpayers from all over Peru are registered. It is the tax code for individuals and companies issued by SUNAT ( National Superintendence of Customs and Tax Administration ), with records since 1993 and regulated since 2004 ^[1] .

It is a unique key, of a permanent nature and mandatory use, for all natural or legal persons (national or foreign) ^[2] . SUNAT maintains the taxpayer registry, associating the RUC with personal data ^[3] .

Each taxpayer is identified with an 11-digit number. The first 2 digits identify the type of person, the next 8 are the DNI or the number assigned to the company, and the last one is a verification digit ^{[4] [5]} .

What I tried: I used the same code that SUNAT uses on its website to validate a RUC. However, it accepts incorrect RUCs and would appear to have redundant calculations.

//Validación de SUNAT
function valruc(valor){
  valor = trim(valor)
  if ( esnumero( valor ) ) {
    if ( valor.length == 8 ){
      suma = 0
      for (i=0; i<valor.length-1;i++){
        digito = valor.charAt(i) - '0';
        if ( i==0 ) suma += (digito*2)
        else suma += (digito*(valor.length-i))
      }
      resto = suma % 11;
      if ( resto == 1) resto = 11;
      if ( resto + ( valor.charAt( valor.length-1 ) - '0' ) == 11 ){
        return true
      }
    } else if ( valor.length == 11 ){
      suma = 0
      x = 6
      for (i=0; i<valor.length-1;i++){
        if ( i == 4 ) x = 8
        digito = valor.charAt(i) - '0';
        x--
        if ( i==0 ) suma += (digito*x)
        else suma += (digito*x)
      }
      resto = suma % 11;
      resto = 11 - resto
      
      if ( resto >= 10) resto = resto - 10;
      if ( resto == valor.charAt( valor.length-1 ) - '0' ){
        return true
      }      
    }
  }
  return false
}
function trim(cadena){
  cadena2 = "";
  len = cadena.length;
  for ( var i=0; i <= len ; i++ )
    if (cadena.charAt(i) != " "){
      cadena2+=cadena.charAt(i);
    }
  return cadena2;
}
function esnumero(campo){
  return (!(isNaN( campo )));
}



//Prueba
var ruc    = '12345678903',
    valido = valruc(ruc);

console.log('El RUC', ruc,
            'es', (valido?'válido':'inválido'),
            'para SUNAT.');

Objective: I am interested in validating the format of a RUC entered by a user, which can accept characters such as hyphens or other punctuation marks between the digits. I would use it as a preliminary stage before submitting a form.
Additionally, if there was a way to check if the RUC exists and is active, it would be even better.

I'm testing in JavaScript, but it can be in any popular language. The important thing is the algorithm.

Tests: I found the following list of manufacturing companies in companies.regioncallao.gob.pe (? PDF) that can be used as test data.

F̲u̲e̲n̲t̲e̲s̲:
① _{^{Legislative Decree No. 943 - http://www.elperuano.com.pe/NormasElperuano/2015/06/16/1251160-1.html}}
② _{^{SUNAT - Single Taxpayer Registry - http://www.sunat. gob.pe/legislacion/ruc/}}
③ _{^{RUC law regulation (?PDF) - http://mariano.freevar.com/ruc/REGLAMENTO%20DE%20LA%20LEY%20DEL%20RUC.pdf}}
④ _{^{What is the SUNAT ? What is the RUC? - http://conexiontributaria.blogspot.com.ar/2011/10/que-es-la-sunat-que-es-el-ruc-que_9779.html}}
⑤ _{^{Accounting forum - other RUC digits - http://www .perucontable.com/modules/newbb/viewtopic.php?post_id=57226}}

Question: How can I verify that the format of a Mexican SSN is valid?

What is the NSS? The Social Security Number (NSS) is the worker's social identity. It is issued by the IMSS and is made up of 11 digits.

Context: I want to validate that a SSN could be valid. I'm not interested in seeing if it actually exists. I am currently validating that they are 11 digits:

/^\d{11}$/

but now I'm interested to see if it can be more strictly validated.

Question: How can I verify that the format of a Mexican RFC is valid?

What is the RFC? The Federal Taxpayer Registry (RFC) is a unique key that every natural or legal person in Mexico requires to carry out any lawful economic activity. It is the tax code for individuals and companies issued by the SAT .

The RFC is generated from the letters of the name and surname (individuals), or from the initials or the first letters of the name and the date of creation (companies). The generation and validation rules are described in the Algorithm to generate the RFC with homoclave for natural and legal persons.odt ? .

Context: I want to validate that an RFC could be valid. I'm not interested in seeing if it actually exists. I implemented a very generic validation that allows the last 3 digits to be optional:

/^[A-ZÑ&]{3,4}\d{6}(?:[A-Z\d]{3})?$/

but now I am interested in more strictly validating the complete RFC, seeing that the check digit is correct (the last character).

Question: How can I verify that the format of a Mexican CURP is valid?

What is CURP? The Unique Population Registry Key (CURP) is a unique 18-character alphanumeric identity code used to officially identify both Mexican residents and citizens, issued by RENAPO .

It is formed from the letters of the names and surnames, the date and the state of birth, and the sex. Also, character 17 is to avoid duplicates, and the last character is a digit that is used as an error detector-corrector. The syntax is detailed in the Normative Instructions for the Assignment of the Unique Population Registry Key ? .

Context: I'm only interested in validating that a key could be valid. I am not interested at this point to see if that CURP exists or not.

So far, I'm just checking that it's 18 alphanumeric characters with the regex:

/^[A-Z\d]{18}$/

but I am also interested in considering that the characters are valid, and that the check digit matches.

I am trying to alphabetize a variable of type array in the following way:

Code

$palabras = array(
    'así',
    'alfabeto',
    'alfabético',
    'año',
);

sort($palabras);
var_export($palabras);

Result

array (
  0 => 'alfabeto',
  1 => 'alfabético',
  2 => 'así',
  3 => 'año',
)

But as you can see, it doesn't work correctly with the accents and the "ñ", which should be sorted as if the accents weren't there, and with "n" < "ñ" < "o".

How can I do to sort them alphabetically without using external libraries?

I was used to putting in the first line of all XMLs:

<?xml version="1.0" encoding="ISO-8859-1"?>

I had been doing it almost without thinking, but then I realized that the accented letters in Spanish looked bad. For example, in Chrome:

From there, I solved it using:

<?xml version="1.0" encoding="utf-8"?>

However, Wikipedia defines ISO-8859-1 as:

ISO 8859-1 is an ISO standard that defines the encoding of the Latin alphabet , including diacritics (such as accented letters, ñ, ç), and special letters (such as ß, Ø), necessary for...

and lists all the Spanish characters.

Ask

Why does it look bad in Chrome, and what encodingshould I use to include Spanish text?

Ask

How to validate an e-mail that accepts all Latin characters?

• By Latin characters I mean accented letters, ñ, ç, and all those used by languages ​​like Spanish, Portuguese, Italian... Latin.

Context

• The goal is to display an icon next to the text as the user types their email address.
• I am not interested in accepting all valid cases. It was a design decision to cover only the most frequent emails. That is, letters (including accents and the like) and the symbols ._%+-.
• I can use code from other sources, as long as they are popular (eg jQuery).

Code

document.getElementById('email').addEventListener('input', function() {
    campo = event.target;
    valido = document.getElementById('emailOK');
        
    emailRegex = /^[-\w.%+]{1,64}@(?:[A-Z0-9-]{1,63}\.){1,125}[A-Z]{2,63}$/i;
    //Se muestra un texto a modo de ejemplo, luego va a ser un icono
    if (emailRegex.test(campo.value)) {
      valido.innerText = "válido";
    } else {
      valido.innerText = "incorrecto";
    }
});

<p>
    Email:
    <input id="email">
    <span id="emailOK"></span>
</p>

cases

I am using the regex

/^[-\w.%+]{1,64}@(?:[A-Z0-9-]{1,63}\.){1,125}[A-Z]{2,63}$/i

Which works perfect in cases like

[email protected]
[email protected]

But it fails with accents and other Latin letters

germá[email protected]
yo@mi-compañía.com
estaçã[email protected]