One thing to note here: we need to allow scopes to return a value. While there are not so many places in P4 language where we can expect values to be returned from entire scopes, it would help to:

• Implement shortcut semantics of && / || (essentially, we can just transform them to something similar to C/C++ cond ? : true : false operator in order not to lower to explicit control flow earlier
• Simplify inlining (no need to to do some special logic for result copy out: just inline the whole outer scope and replace return with yield)
• Simplify loop iteration variable handling (just have loop header scope to yield new index value each time).
• ...