writable counter 一个可写的流，计算它接收数据的次数

可写计数器创建可写的流，它只计算数据传递给它们的次数。安装npm install --save writable-counter用法var streamArray = require ( "stream-array" ) ; var WritableCounter = require ( 'writable-counter' ) ; var data = [ "foo" , "bar" , "fizz" , "baz" ] ; var counter = WritableCounter ( ) ; streamArray ( data ) . pipe ( counter ) . on ( 'finish' , function ( ) { console . log ( counter . count ) ; // logs 4 to the consol