string-byte-slice/build/src/char_code/main.js

Like `string.slice()` but bytewise

import{replaceInvalidSurrogate}from"../surrogate.js";

import{byteToChar}from"./direction.js";


export const charCodeSlice=(input,byteStart,byteEnd)=>{
const charStart=byteToChar(input,byteStart,false);
const charEnd=getByteEnd(input,byteEnd);
const inputA=
charStart===0&&charEnd===undefined?
input:
input.slice(charStart,charEnd);
return replaceInvalidSurrogate(inputA)
};

const getByteEnd=(input,byteEnd)=>{
if(byteEnd===undefined){
return byteEnd
}

const charEnd=byteToChar(input,byteEnd,true);
return charEnd===input.length?undefined:charEnd
};