From bc40f1153cb731a55338ab318f62e77aa3a3edac Mon Sep 17 00:00:00 2001
From: Anders Nilsson <anders.nilsson@control.lth.se>
Date: Mon, 30 Nov 2015 14:55:58 +0100
Subject: [PATCH] Some error handling included
---
city-pop/src/main.rs | 36 ++++++++++++++++++++++++------------
1 file changed, 24 insertions(+), 12 deletions(-)
diff --git a/city-pop/src/main.rs b/city-pop/src/main.rs
index 6c6dd25..7737fce 100644
--- a/city-pop/src/main.rs
+++ b/city-pop/src/main.rs
@@ -26,7 +26,7 @@ struct Row {
struct PopulationCount {
city: String,
- country: String
+ country: String,
// This is no longer an `Option` because values of this type are only
// constructed if they have a population count.
count: u64,
@@ -36,6 +36,26 @@ fn print_usage(program: &str, opts: Options) {
println!("{}", opts.usage(&format!("Usage: {} [options] <data-path> <city>",program)));
}
+fn search<P: AsRef<path::Path>>(file_path: P, city: &str) -> Vec<PopulationCount> {
+ let mut found = vec![];
+ let file = fs::File::open(file_path).unwrap();
+ let mut rdr = csv::Reader::from_reader(file);
+ for row in rdr.decode::<Row>() {
+ let row = row.unwrap();
+ match row.population {
+ None => { }
+ Some(count) => if row.city == city {
+ found.push(PopulationCount {
+ city: row.city,
+ country: row.country,
+ count: count,
+ });
+ },
+ }
+ }
+ found
+}
+
fn main() {
let args: Vec<String> = env::args().collect();
let program = args[0].clone();
@@ -56,16 +76,8 @@ fn main() {
let data_path = path::Path::new(&data_file);
let city = args[2].clone();
- let file = fs::File::open(data_path).unwrap();
- let mut rdr = csv::Reader::from_reader(file);
-
- for row in rdr.decode::<Row>() {
- let row = row.unwrap();
-
- if row.city == city {
- println!("{}, {}: {:?}",
- row.city, row.country,
- row.population.expect("population count"));
- }
+ for pop in search(&data_path, &city) {
+ println!("{}, {}: {:?}",pop.city, pop.country, pop.count);
}
+
}
--
GitLab