function addUnderlyingListener( fullEventName, predicateEvent, compiledJsonPath ){
   
      var emitMatch = oboeBus(fullEventName).emit;
   
      predicateEvent.on( function (ascent) {

         var maybeMatchingMapping = compiledJsonPath(ascent);

         /* Possible values for maybeMatchingMapping are now:

          false: 
          we did not match 

          an object/array/string/number/null: 
          we matched and have the node that matched.
          Because nulls are valid json values this can be null.

          undefined:
          we matched but don't have the matching node yet.
          ie, we know there is an upcoming node that matches but we 
          can't say anything else about it. 
          */
         if (maybeMatchingMapping !== false) {

            emitMatchingNode(
               emitMatch, 
               nodeOf(maybeMatchingMapping), 
               ascent
            );
         }
      }, fullEventName);
     
      oboeBus('removeListener').on( function(removedEventName){

         // if the fully qualified match event listener is later removed, clean up 
         // by removing the underlying listener if it was the last using that pattern:
      
         if( removedEventName == fullEventName ) {
         
            if( !oboeBus(removedEventName).listeners(  )) {
               predicateEvent.un( fullEventName );
            }
         }
      });   
   }
function addUnderlyingListener( fullEventName, predicateEvent, compiledJsonPath ){
   
      var emitMatch = oboeBus(fullEventName).emit;
   
      predicateEvent.on( function (ascent) {

         var maybeMatchingMapping = compiledJsonPath(ascent);

         /* Possible values for maybeMatchingMapping are now:

          false: 
          we did not match 

          an object/array/string/number/null: 
          we matched and have the node that matched.
          Because nulls are valid json values this can be null.

          undefined:
          we matched but don't have the matching node yet.
          ie, we know there is an upcoming node that matches but we 
          can't say anything else about it. 
          */
         if (maybeMatchingMapping !== false) {

            emitMatchingNode(
               emitMatch, 
               nodeOf(maybeMatchingMapping), 
               ascent
            );
         }
      }, fullEventName);
     
      oboeBus('removeListener').on( function(removedEventName){

         // if the fully qualified match event listener is later removed, clean up 
         // by removing the underlying listener if it was the last using that pattern:
      
         if( removedEventName == fullEventName ) {
         
            if( !oboeBus(removedEventName).listeners(  )) {
               predicateEvent.un( fullEventName );
            }
         }
      });   
   }
function addUnderlyingListener ( fullEventName , predicateEvent , compiledJsonPath ) { var emitMatch = oboeBus ( fullEventName ) . emit ; predicateEvent . on ( function ( ascent ) { var maybeMatchingMapping = compiledJsonPath ( ascent ) ; /* Possible values for maybeMatchingMapping are now:

          false: 
          we did not match 

          an object/array/string/number/null: 
          we matched and have the node that matched.
          Because nulls are valid json values this can be null.

          undefined:
          we matched but don't have the matching node yet.
          ie, we know there is an upcoming node that matches but we 
          can't say anything else about it. 
          */ if ( maybeMatchingMapping !== false ) { emitMatchingNode ( emitMatch , nodeOf ( maybeMatchingMapping ) , ascent ) ; } } , fullEventName ) ; oboeBus ( 'removeListener' ) . on ( function ( removedEventName ) { // if the fully qualified match event listener is later removed, clean up  // by removing the underlying listener if it was the last using that pattern: if ( removedEventName == fullEventName ) { if ( ! oboeBus ( removedEventName ) . listeners ( ) ) { predicateEvent . un ( fullEventName ) ; } } } ) ; }
/*
Set up the catching of events such as NODE_CLOSED and NODE_OPENED and, if
matching the specified pattern, propagate to pattern-match events such as
oboeBus('node:!')



@param {Function} predicateEvent
either oboeBus(NODE_CLOSED) or oboeBus(NODE_OPENED).
@param {Function} compiledJsonPath
/ * Set up the catching of events such as NODE_CLOSED and NODE_OPENED and if matching the specified pattern propagate to pattern - match events such as oboeBus ( node : ! )
Add a listener to the underlying event bus.