string-byte-slice/build/src/width.js

Like `string.slice()` but bytewise

import{LAST_ASCII_CODEPOINT,LAST_TWO_BYTES_CODEPOINT}from"./codepoints.js";







export const estimateCharWidth=(input)=>{
let asciiOnly=true;
let longCharsCount=0;

for(let index=0;index<SAMPLE_SIZE;index+=1){
const codepoint=getCodepoint(input,index);

if(codepoint<=LAST_ASCII_CODEPOINT){
continue
}

if(asciiOnly){
asciiOnly=false
}

if(codepoint>LAST_TWO_BYTES_CODEPOINT){
longCharsCount+=1
}
}

return{asciiOnly,longCharsPercentage:longCharsCount/SAMPLE_SIZE}
};


const getCodepoint=(input,index)=>{
const sampleSize=SAMPLE_SIZE-1;
const percentage=1-(sampleSize-index)/sampleSize;
const charIndex=Math.round(percentage*(input.length-1));

return input.charCodeAt(charIndex)
};




const SAMPLE_SIZE=50;