sideEffects

emit

If the parser is successful, call the $receiver function with the output of the parser. The resulting parser behaves identical to the original one. This combinator is useful for expressing side effects during the parsing process. It can be hooked into existing event publishing libraries by using $receiver as an adapter for those. Other use cases are logging, caching, performing an action whenever a value is matched in a long running input stream, ...

function emit(Parser $parser, callable $receiver) : Parser