Externalize logic into library crate

minigrep/src/lib.rs

@@ -0,0 +1,26 @@
+use std::error::Error;
+use std::fs;
+
+pub struct Config {
+    pub query: String,
+    pub file_path: String,
+}
+
+impl Config {
+    pub fn build(args: &[String]) -> Result<Config, &'static str> {
+        if args.len() < 3 {
+            return Err("not enough arguments");
+        }
+
+        let query = args[1].clone();
+        let file_path = args[2].clone();
+
+        Ok(Config { query, file_path })
+    }
+}
+
+pub fn run(config: Config) -> Result<(), Box<dyn Error>> {
+    let contents = fs::read_to_string(config.file_path)?;
+    println!("With text:\n{contents}");
+    Ok(())
+}

minigrep/src/main.rs

@@ -1,8 +1,8 @@
 use std::env;
-use std::error::Error;
-use std::fs;
 use std::process;
 
+use minigrep::Config;
+
 fn main() {
     let args: Vec<String> = env::args().collect();
 
@@ -14,32 +14,8 @@ fn main() {
     println!("Searching for {}", config.query);
     println!("In file {}", config.file_path);
 
-    if let Err(e) = run(config) {
+    if let Err(e) = minigrep::run(config) {
         println!("Application error: {e}");
         process::exit(1);
     }
 }
-
-fn run(config: Config) -> Result<(), Box<dyn Error>> {
-    let contents = fs::read_to_string(config.file_path)?;
-    println!("With text:\n{contents}");
-    Ok(())
-}
-
-struct Config {
-    query: String,
-    file_path: String,
-}
-
-impl Config {
-    fn build(args: &[String]) -> Result<Config, &'static str> {
-        if args.len() < 3 {
-            return Err("not enough arguments");
-        }
-
-        let query = args[1].clone();
-        let file_path = args[2].clone();
-    
-        Ok(Config { query, file_path })
-    }
-}