// public compiler/runtime sketch
lex(source) -> token_stream
parse(tokens) -> syntax_tree
resolve(ast) -> resolved_tree
typecheck(tree) -> typed_module
lower(module) -> typed_ir
verify(typed_ir)
emit(typed_ir) -> bytecode
execute(bytecode, step_budget) -> result
invariant: malformed IR fails; undeclared effects fail; execution is bounded