Merge branch 'master' of github.com-functora:functora/functora.github.io

Author: functora

rust/minigrep/src/lib.rs

@@ -1,23 +1,17 @@
-pub fn search<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
-    let mut results = Vec::new();
-    for line in contents.lines() {
-        if line.contains(query) {
-            results.push(line);
-        }
-    }
-    results
+pub fn search<'a>(query: &str, contents: &'a str) -> impl Iterator<Item = &'a str> {
+    contents.lines().filter(move |line| line.contains(query))
 }
 
-pub fn search_case_insensitive<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
+pub fn search_case_insensitive<'a>(
+    query: &str,
+    contents: &'a str,
+) -> impl Iterator<Item = &'a str> {
     let query = query.to_lowercase();
-    let mut results = Vec::new();
-    for line in contents.lines() {
-        if line.to_lowercase().contains(&query) {
-            results.push(line);
-        }
-    }
-    results
+    contents
+        .lines()
+        .filter(move |line| line.to_lowercase().contains(&query))
 }
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -30,7 +24,10 @@ Rust:
 safe, fast, productive.
 Pick three.
 Duct tape.";
-        assert_eq!(vec!["safe, fast, productive."], search(query, contents))
+        assert_eq!(
+            vec!["safe, fast, productive."],
+            search(query, contents).collect::<Vec<&str>>()
+        )
     }
 
     #[test]
@@ -43,7 +40,7 @@ Pick three.
 Trust me.";
         assert_eq!(
             vec!["Rust:", "Trust me."],
-            search_case_insensitive(query, contents)
+            search_case_insensitive(query, contents).collect::<Vec<&str>>()
         )
     }
 }

rust/minigrep/src/main.rs

@@ -5,8 +5,7 @@ use std::fs;
 use std::process;
 
 fn main() {
-    let args: Vec<String> = env::args().collect();
-    let config = Config::build(&args).unwrap_or_else(|e| {
+    let config = Config::build(env::args()).unwrap_or_else(|e| {
         eprintln!("Problem parsing args: {e}");
         process::exit(1);
     });
@@ -18,14 +17,12 @@ fn main() {
 
 fn run(config: Config) -> Result<(), Box<dyn Error>> {
     let contents = fs::read_to_string(config.file_path)?;
-    let results = if config.ignore_case {
-        search_case_insensitive(&config.query, &contents)
+    let print = |line| println!("{line}");
+    if config.ignore_case {
+        search_case_insensitive(&config.query, &contents).for_each(print);
     } else {
-        search(&config.query, &contents)
+        search(&config.query, &contents).for_each(print);
     };
-    for line in results {
-        println!("{line}")
-    }
     Ok(())
 }
 
@@ -36,12 +33,16 @@ struct Config {
 }
 
 impl Config {
-    fn build(args: &[String]) -> Result<Config, &'static str> {
-        if args.len() < 3 {
-            return Err("not enough args!");
-        }
-        let query = args[1].clone();
-        let file_path = args[2].clone();
+    fn build(mut args: impl Iterator<Item = String>) -> Result<Config, &'static str> {
+        args.next();
+        let query = match args.next() {
+            Some(arg) => arg,
+            None => return Err("Didn't get a query string"),
+        };
+        let file_path = match args.next() {
+            Some(arg) => arg,
+            None => return Err("Didn't get a file path"),
+        };
         let ignore_case = env::var("IGNORE_CASE").is_ok();
         Ok(Config {
             query,