From 8628adc10d6ed2384f47e842f1bec2ecba079d93 Mon Sep 17 00:00:00 2001
From: Lars Wirzenius <liw@liw.fi>
Date: Sat, 21 Jul 2018 13:45:10 +0300
Subject: Change: use a type alias for WordCounts

---
 src/main.rs | 66 +++++++++++++++++++++++++------------------------------------
 1 file changed, 27 insertions(+), 39 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 2162453..aef750d 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -2,7 +2,6 @@ use std::env;
 use std::fs::File;
 use std::io;
 use std::io::BufRead;
-use std::ops;
 use std::collections::HashMap;
 
 
@@ -12,7 +11,7 @@ fn main() -> io::Result<()> {
         let mut f = File::open(&filename)?;
         let mut reader = io::BufReader::new(f);
         let counts = count_words(&mut reader)?;
-        counts.print(10)
+        print(&counts, 10)
     }
     Ok(())
 }
@@ -22,7 +21,7 @@ fn count_words(reader: &mut io::BufReader<File>) -> io::Result<WordCounts> {
     let mut counts = WordCounts::new();
     for line in reader.lines() {
         let line = line?;
-        counts += count_words_in_line(&line);
+        add_counts(&mut counts, &count_words_in_line(&line));
     }
     Ok(counts)
 }
@@ -36,60 +35,49 @@ fn count_words_in_line(line: &str) -> WordCounts {
             word.push(c);
         } else {
             if !word.is_empty() {
-                counts.count(word.clone());
+                count(&mut counts, word.clone());
                 word.clear();
             }
         }
     }
     if !word.is_empty() {
-        counts.count(word.clone());
+        count(&mut counts, word.clone());
     }
     counts
 }
 
 
-struct WordCounts {
-    counts: HashMap<String, u32>,
-}
+type WordCounts = HashMap<String, u32>;
 
 
-impl WordCounts {
-    fn new() -> Self {
-        WordCounts {
-            counts: HashMap::new(),
-        }
-    }
+fn count(counts: &mut WordCounts, word: String) {
+    add(counts, word, 1);
+}
 
-    fn count(&mut self, word: String) {
-        self.add(word, 1);
-    }
 
-    fn add(&mut self, word: String, count: u32) {
-        let counter = self.counts.entry(word).or_insert(0);
-        *counter += count;
-    }
-
-    fn print(&self, max: usize) {
-        let mut top = Vec::new();
-        for (word, count) in self.counts.iter() {
-            top.push((count, word));
-            if top.len() > max {
-                top.sort();
-                top.reverse();
-                top.truncate(max);
-            }
-        }
-        for (count, word) in top.iter() {
-            println!("{} {}", count, word);
-        }
+fn add_counts(counts: &mut WordCounts, other: &WordCounts) {
+    for (word, count) in other.iter() {
+        add(counts, word.to_string(), *count);
     }
 }
 
 
-impl ops::AddAssign for WordCounts {
-    fn add_assign(&mut self, other: WordCounts) {
-        for (word, count) in other.counts.iter() {
-            self.add(word.to_string(), *count);
+fn add(counts: &mut WordCounts, word: String, count: u32) {
+    let counter = counts.entry(word).or_insert(0);
+    *counter += count;
+}
+
+fn print(counts: &WordCounts, max: usize) {
+    let mut top = Vec::new();
+    for (word, count) in counts.iter() {
+        top.push((count, word));
+        if top.len() > max {
+            top.sort();
+            top.reverse();
+            top.truncate(max);
         }
     }
+    for (count, word) in top.iter() {
+        println!("{} {}", count, word);
+    }
 }
-- 
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