update doc

Dongss · Feb 7, 2018 · 9f6430f · 9f6430f
1 parent cab44f9
commit 9f6430f
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/README.md b/README.md
@@ -86,7 +86,7 @@ Get length of operations pending in queue (exclude the operation in processing)
 Push operation to queue
 
 * `op` value returned by `OpQueue.buildOperation(fn)`
-* `callback` returns of op, optional, (error, data) => {}
+* `callback` returns of op, optional, (error, data) => {} `error`: error op rejected, or null if op resolved, `data`: value op resolved.
 
 ### start()