The first time I saw variable and return types on the right side after a colon was in ActionScript. This was beautiful.
function repeatString(string:String,
numTimes:uint):String
{
var output:String = "";
for(var i:uint = 0; i < numTimes; i++)
{
output += string;
}
return output;
}
Now a lot of very nice modern programming languages use this convention: TypeScript, Scala, Kotlin, Rust, Swift.