diff --git a/util.js b/util.js
new file mode 100644
--- /dev/null
+++ b/util.js
@@ -0,0 +1,29 @@
+export function str2utf8(s){
+	let res=[];
+	let c=s.codePointAt(0);
+	for(let i=0;c!==undefined;i++,c=s.codePointAt(i)){
+		console.log(c);
+		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)));