v4 Bytecode

Why hard

• control-flow introduces jump targets and patching
• wrong jump target can pass many tests and still fail edge cases

for lowering

• init
• cond before each iteration
• body
• post
• jump back to condition point
• exit label + scope cleanup

break / continue

• both initially emit placeholder jumps
• patch against current loop context
• loop context stack handles nesting

Short-circuit

• && jumps on falsey before evaluating RHS
• || jumps on truthy before evaluating RHS
• falsey rule remains false / nil

Contract checks

• every jump resolved
• every expression leaves expected stack value
• loop scopes are correctly entered/exited
• nested loops patch independently

Practical checks

• break skips post and body
• continue goes to post/next-iteration path
• omitted loop clauses remain deterministic