Added functional and implemented iterators in minigrep.

2 files changed, 19 insertions, 38 deletions

diff --git a/minigrep/src/lib.rs b/minigrep/src/lib.rs
index bf7118f..bb8b4d7 100644
--- a/minigrep/src/lib.rs
+++ b/minigrep/src/lib.rs
@@ -10,26 +10,20 @@ pub struct Config {
 
 impl Config {
 
-    pub fn new(args: &[String]) -> Result<Config, &'static str> {
+    pub fn new(mut args: std::env::Args) -> Result<Config, &'static str> {
+        args.next();
 
-        if args.len() < 3 {
-            return Err("Not enough arguments.");
-        }
+        let query = match args.next() {
+            Some(arg) => arg,
+            None => return Err("Didn't get a query string"),
+        };
 
-        let query = args[1].clone();
-        let filename = args[2].clone();
-        let mut case_sensitive = env::var("CASE_INSENSITIVE").is_err();
-
-        // override environment variable if cli arg is present
-        if args.len() > 3 {
-            if args[3] == "-s" {
-                case_sensitive = true;
-            }
-            else if args[3] == "-i" {
-                case_sensitive = false;
-            }
-        }
+        let filename = match args.next() {
+            Some(arg) => arg,
+            None => return Err("Didn't get a filename"),
+        };
 
+        let case_sensitive = env::var("CASE_INSENSITIVE").is_err();
 
         Ok(Config { query, filename, case_sensitive })
     }
@@ -54,28 +48,16 @@ pub fn run(config: Config) -> Result<(), Box<dyn Error>> {
 }
 
 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
+    contents.lines()
+        .filter(|line| line.contains(query))
+        .collect()
 }
 
 fn search_case_insensitive<'a>(query: &str, contents: &'a str) -> Vec<&'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(|line| line.to_lowercase()
+                .contains(&query.to_lowercase()))
+        .collect()
 }
 
 #[cfg(test)]
diff --git a/minigrep/src/main.rs b/minigrep/src/main.rs
index 3cec101..c752da1 100644
--- a/minigrep/src/main.rs
+++ b/minigrep/src/main.rs
@@ -5,8 +5,7 @@ use minigrep;
 use minigrep::Config;
 
 fn main() {
-    let args: Vec<String> = env::args().collect();
-    let config = Config::new(&args).unwrap_or_else(|err| {
+    let config = Config::new(env::args()).unwrap_or_else(|err| {
         eprintln!("Problem parsing arguments: {}", err);
         process::exit(1);
     });