nl_tokens: Executes a function as a promise for every item in a list .
pl_tokens: function ( visit , onFail , opts ) { var fail = onFail ? onFail : utils . ret ( false ) , config = opts || { compact : true } ; return function ( list ) { var p = Promise . resolve ( false ) , results = [ ] ; list . forEach ( function ( l , i ) { p = p . then ( visit . bind ( null , l ) ) . catch ( function ( err ) { return fail ( err , l ) ; } ) . then ( function ( result ) { results . push ( <mask> ) ; if ( config . onProgress ) config . onProgress ( list . length , i + 1 , l ) ; } ) ; } ) ; return p . then ( function ( ) { return config . compact ? results . filter ( Boolean ) : results ; } ) ; } ; }