flathead | A toy JavaScript interpreter written in C | Interpreter library

An optimized solution is:

Based on your code, you can populate the item of inside on bottom of

Try this

I resolved this by setting the mode on Router to 'history'.

Router:

Is then this a valid for-loop?

Yes, absolutely.

If so, are there any performance reasons not to use this?

No, this is a very efficient way of iterating over enum values - likely to be more efficient than calling Enum.GetValues which needs to allocate an array, for example.

The disadvantages are:

• You need to know the "lowest" value of your enum (so adding a new lower value would involve changing every loop like this)
• You need to know the "highest" value of your enum (so adding a new lower value would involve changing every loop like this)
• If your enum has "gaps" (e.g. values 0, 1, 3, 4, 5 - but no 2) your loop won't skip over those gaps
• If your enum goes right up to the highest value of the underlying type (e.g. 255 for a byte-based enum) the loop will never terminate

You could use constants to mitigate the first two points; the third point would only be relevant with explicitly-valued enums; the last point would be pretty rare. You could write unit tests to check for all of them.