function bytes2int32(arr){
	return arr.reduce((acc,b,i)=>acc|b<<(i*8));
}

function bytes2int32s(arr){
	let res=[];
	for(let i=0;i<arr.length;i+=4){
		res.push(bytes2int32(arr.slice(i,i+4)));
	}
	return res;
}

function int322bytes(x){
	let res=[];
	for(let i=0;i<4;i++){
		res.push(x&0xff);
		x>>>=8;
	}
	return res;
}

function int32s2bytes(arr){
	return arr.map(int322bytes).reduce((acc,bytes)=>acc.concat(bytes));
}

function bytes2hex(arr){
	return arr.map(x=>x.toString(16).padStart(2,"0")).join("");
}

function str2utf8(s){
	let res=[];
	let c=s.codePointAt(0);
	for(let i=0;c!==undefined;i++,c=s.codePointAt(i)){
		if(c<0x80){res.push(c);}
		else if(c<0x800){
			res.push(0b11000000|(c>>>6));
			res.push(0b10000000|(c&0b111111));
		}
		else if(c<0x10000){
			res.push(0b11100000|(c>>>12));
			res.push(0b10000000|((c>>>6)&0b111111));
			res.push(0b10000000|(c&0b111111));
		}
		else{
			res.push(0b11110000|(c>>>18));
			res.push(0b10000000|((c>>>12)&0b111111));
			res.push(0b10000000|((c>>>6)&0b111111));
			res.push(0b10000000|(c&0b111111));
		}
	}
	return res;
}

/*console.log(str2utf8("$").map(x=>x.toString(16)));
console.log(str2utf8("¢").map(x=>x.toString(16)));
console.log(str2utf8("€").map(x=>x.toString(16)));
console.log(str2utf8("𐍈").map(x=>x.toString(16)));*/