17:22
<Jack Works>
Is the content I added implicitly given somewhere? Or is it a mistake? (CompileAtom is not explicitly defined for production Atom :: \ AtomEscape, but is defined for AtomEscape)
17:27
<nicolo-ribaudo>

https://tc39.es/ecma262/#sec-algorithm-conventions-syntax-directed-operations

Unless explicitly specified otherwise, all chain productions have an implicit definition for every operation that might be applied to that production's left-hand side nonterminal. The implicit definition simply reapplies the same operation with the same parameters, if any, to the chain production's sole right-hand side nonterminal and then returns the result.