Optimization: label not needed

[allonhadaya]

Hey, I'm using this version:

--version
Closure Compiler (http://github.com/google/closure-compiler)
Version: v20160517
Built on: 2016/05/18 16:21

and my example program is:

label: for(var i = 0; i < 10; i++) {
  if (i == 1) {
    continue label;
  }
  console.log(i);
}

which compiles to:

var i=0;a:for(;10>i;i++){if(1==i)continue a;console.log(i)};

Notice that continue label was translated to continue a. Since the target of a bare continue statement would be the same as continue label in this case, a could be omitted.

I know it might be silly to save two bytes on a case that doesn't happen very often, but I figured I'd document the behaviour in case it's a new observation.

I think the idea could be generalized to, "labels can be omitted from continue statements when the label is equal to the current loop" AND "labels can be omitted from break statements when the label is equal to the current loop, switch, or label"... Something like that.

[MatrixFrog]

I think @concavelenz was looking at this kind of thing recently.

[concavelenz]

There are two optimizations possible here (eliminating the label and eliminating the continue) but the existing minimize exit points could should handle the second if the first is taken care of.