fast-cartesian/build/src/main.js

Fast cartesian product

import{validateInputs}from"./validate.js";





































const fastCartesian=(
inputs)=>
{
validateInputs(inputs);
const result=[];

if(inputs.length===0){
return result
}

const loopFunc=getLoopFunc(inputs.length);
loopFunc(inputs,result);
return result
};

export default fastCartesian;










const getLoopFunc=(length)=>{
const cachedLoopFunc=cache[length];

if(cachedLoopFunc!==undefined){
return cachedLoopFunc
}

const loopFunc=mGetLoopFunc(length);

cache[length]=loopFunc;
return loopFunc
};

const cache={};










const mGetLoopFunc=(length)=>{
const indexes=Array.from({length},getIndex);
const start=indexes.
map((index)=>`for (const value${index} of arrays[${index}]) {`).
join("\n");
const middle=indexes.map((index)=>`value${index}`).join(", ");
const end="}\n".repeat(length);


return new Function(
"arrays",
"result",
`${start}\nresult.push([${middle}])\n${end}`
)
};

const getIndex=(value,index)=>String(index);