lint: fix clippy and fmt issues

Signed-off-by: Amin Yahyaabadi <aminyahyaabadi74@gmail.com>

README.md

@@ -48,7 +48,7 @@ Among them, each task may produce output, and may also require the output of som
 
 ### Programmatically implement task definition
 
-Users need to program to implement the `Action` trait to define the specific logic of the task, and then build a series of `DefaultTask`. 
+Users need to program to implement the `Action` trait to define the specific logic of the task, and then build a series of `DefaultTask`.
 
 First, users need to define some specific task logic. There are two ways to define task logic:
 
@@ -70,7 +70,7 @@ Finally, don’t forget to initialize the logger, and then you can call the `sta
 You can refer to an example for the above complete steps: `examples/compute_dag.rs`
 
 
-Here is the `examples/impl_action.rs` example:
+Here is the `examples/compute_dag.rs` example:
 
 ```rust
 //! Only use Dag, execute a job. The graph is as follows:

examples/compute_dag.rs

@@ -11,8 +11,8 @@
 
 extern crate dagrs;
 
-use std::sync::Arc;
 use dagrs::{log, Complex, Dag, DefaultTask, EnvVar, Input, LogLevel, Output};
+use std::sync::Arc;
 
 struct Compute(usize);
 

examples/custom_parser_and_task.rs

@@ -89,16 +89,16 @@ impl ConfigParser {
     }
 
     fn parse_one(&self, item: String) -> MyTask {
-        let attr: Vec<&str> = item.split(",").collect();
+        let attr: Vec<&str> = item.split(',').collect();
 
         let pres_item = *attr.get(2).unwrap();
         let pres = if pres_item.eq("") {
             Vec::new()
         } else {
-            pres_item.split(" ").map(|pre| pre.to_string()).collect()
+            pres_item.split(' ').map(|pre| pre.to_string()).collect()
         };
 
-        let id = *attr.get(0).unwrap();
+        let id = *attr.first().unwrap();
         let name = attr.get(1).unwrap().to_string();
         let cmd = *attr.get(3).unwrap();
         MyTask::new(id, pres, name, CommandAction::new(cmd))

examples/dependencies.rs

@@ -54,13 +54,13 @@ fn main() {
             g ->
     );
     let mut x = 1;
-    for index in 0..4 {
-        tasks[index].set_action(Compute(x * 2));
+    for task in tasks.iter_mut().take(4) {
+        task.set_action(Compute(x * 2));
         x *= 2;
     }
 
-    for index in 4..7 {
-        tasks[index].set_closure(|input, env| {
+    for task in tasks.iter_mut().skip(4) {
+        task.set_closure(|input, env| {
             let base = env.get::<usize>("base").unwrap();
             let mut sum = 0;
             input

tests/dag_job_test.rs

@@ -1,6 +1,7 @@
+//! Some tests of the dag engine.
+
 use std::{collections::HashMap, sync::Arc};
 
-///! Some tests of the dag engine.
 use dagrs::{log, Complex, Dag, DagError, DefaultTask, EnvVar, Input, LogLevel, Output};
 
 #[test]