From 504971a163e7d436e25329bd27c92a8fd2845652 Mon Sep 17 00:00:00 2001
From: Andrew Johnson <andrewjohnson@Andrews-MacBook-Pro.local>
Date: Thu, 3 May 2018 12:23:14 -0600
Subject: [PATCH] update with TR edits (ongoing)

---
 Chapter03/src/lib.rs   | 43 +++++++++++++-----------------------------
 Chapter03/src/motor.rs | 20 ++++++++++++--------
 2 files changed, 25 insertions(+), 38 deletions(-)

diff --git a/Chapter03/src/lib.rs b/Chapter03/src/lib.rs
index a63197a..0779546 100644
--- a/Chapter03/src/lib.rs
+++ b/Chapter03/src/lib.rs
@@ -157,21 +157,12 @@ pub fn run_simulation()
    let mut floor_requests = Vec::new();
 
    //4. Parse input and store as building description and floor requests
-   match env::args().nth(1) {
+   let buffer = match env::args().nth(1) {
       Some(ref fp) if *fp == "-".to_string()  => {
          let mut buffer = String::new();
          io::stdin().read_to_string(&mut buffer)
                     .expect("read_to_string failed");
-        
-         for (li,l) in buffer.lines().enumerate() {
-            if li==0 {
-               esp.floor_count = l.parse::<u64>().unwrap();
-            } else if li==1 {
-               esp.floor_height = l.parse::<f64>().unwrap();
-            } else {
-               floor_requests.push(l.parse::<u64>().unwrap());
-            }
-         }
+         buffer
       },
       None => {
          let fp = "test1.txt";
@@ -180,16 +171,7 @@ pub fn run_simulation()
               .expect("File::open failed")
               .read_to_string(&mut buffer)
               .expect("read_to_string failed");
-
-         for (li,l) in buffer.lines().enumerate() {
-            if li==0 {
-               esp.floor_count = l.parse::<u64>().unwrap();
-            } else if li==1 {
-               esp.floor_height = l.parse::<f64>().unwrap();
-            } else {
-               floor_requests.push(l.parse::<u64>().unwrap());
-            }
-         }
+         buffer
       },
       Some(fp) => {
          let mut buffer = String::new();
@@ -197,16 +179,17 @@ pub fn run_simulation()
               .expect("File::open failed")
               .read_to_string(&mut buffer)
               .expect("read_to_string failed");
+         buffer
+      }
+   };
 
-         for (li,l) in buffer.lines().enumerate() {
-            if li==0 {
-               esp.floor_count = l.parse::<u64>().unwrap();
-            } else if li==1 {
-               esp.floor_height = l.parse::<f64>().unwrap();
-            } else {
-               floor_requests.push(l.parse::<u64>().unwrap());
-            }
-         }
+   for (li,l) in buffer.lines().enumerate() {
+      if li==0 {
+         esp.floor_count = l.parse::<u64>().unwrap();
+      } else if li==1 {
+         esp.floor_height = l.parse::<f64>().unwrap();
+      } else {
+         floor_requests.push(l.parse::<u64>().unwrap());
       }
    }
 
diff --git a/Chapter03/src/motor.rs b/Chapter03/src/motor.rs
index c7667a5..3520328 100644
--- a/Chapter03/src/motor.rs
+++ b/Chapter03/src/motor.rs
@@ -26,16 +26,19 @@ impl MotorController for SimpleMotorController
       //at an average velocity of v/2 before stopping
       let d = t * (est.velocity/2.0);
 
+      let dst_height = (dst as f64) * self.esp.floor_height;
+
       //l = distance to next floor
-      let l = (est.location - (dst as f64)*self.esp.floor_height).abs();
+      let l = (est.location - dst_height).abs();
 
       let target_acceleration = {
          //are we going up?
-         let going_up = est.location < (dst as f64)*self.esp.floor_height;
+         let going_up = est.location < dst_height;
 
          //Do not exceed maximum velocity
          if est.velocity.abs() >= 5.0 {
-            if going_up==(est.velocity>0.0) {
+            if (going_up && est.velocity>0.0)
+            || (!going_up && est.velocity<0.0) {
                0.0
             //decelerate if going in wrong direction
             } else if going_up {
@@ -45,7 +48,8 @@ impl MotorController for SimpleMotorController
             }
 
          //if within comfortable deceleration range and moving in right direction, decelerate
-         } else if l < d && going_up==(est.velocity>0.0) {
+         } else if l < d && ((going_up && est.velocity>0.0)
+                             || (!going_up && est.velocity<0.0)) {
             if going_up {
                -1.0
             } else {
@@ -73,6 +77,10 @@ impl MotorController for SimpleMotorController
    }
 }
 
+const MAX_JERK: f64 = 0.2;
+const MAX_ACCELERATION: f64 = 2.0;
+const MAX_VELOCITY: f64 = 5.0;
+
 pub struct SmoothMotorController
 {
    pub esp: ElevatorSpecification,
@@ -91,10 +99,6 @@ impl MotorController for SmoothMotorController
    {
       //5.3. Adjust motor control to process next floor request
 
-      let MAX_JERK = 0.2;
-      let MAX_ACCELERATION = 2.0;
-      let MAX_VELOCITY = 5.0;
-
       //it will take t seconds to reach max from max
       let t_accel = MAX_ACCELERATION / MAX_JERK;
       let t_veloc = MAX_VELOCITY / MAX_ACCELERATION;