From 003e092786221abaef21e197a810f40b1cc9b57f Mon Sep 17 00:00:00 2001
From: Jordan Gong <jordan.gong@protonmail.com>
Date: Tue, 8 Sep 2020 20:47:03 +0800
Subject: Improve minigrep with iterators

---
 minigrep-improved/.gitignore  | 18 ++++++++
 minigrep-improved/Cargo.toml  |  9 ++++
 minigrep-improved/poem.txt    |  9 ++++
 minigrep-improved/src/lib.rs  | 96 +++++++++++++++++++++++++++++++++++++++++++
 minigrep-improved/src/main.rs | 16 ++++++++
 5 files changed, 148 insertions(+)
 create mode 100644 minigrep-improved/.gitignore
 create mode 100644 minigrep-improved/Cargo.toml
 create mode 100644 minigrep-improved/poem.txt
 create mode 100644 minigrep-improved/src/lib.rs
 create mode 100644 minigrep-improved/src/main.rs

(limited to 'minigrep-improved')

diff --git a/minigrep-improved/.gitignore b/minigrep-improved/.gitignore
new file mode 100644
index 0000000..e629269
--- /dev/null
+++ b/minigrep-improved/.gitignore
@@ -0,0 +1,18 @@
+
+# Created by https://www.toptal.com/developers/gitignore/api/rust
+# Edit at https://www.toptal.com/developers/gitignore?templates=rust
+
+### Rust ###
+# Generated by Cargo
+# will have compiled files and executables
+/target/
+
+# Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
+# More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html
+Cargo.lock
+
+# These are backup files generated by rustfmt
+**/*.rs.bk
+
+# End of https://www.toptal.com/developers/gitignore/api/rust
+
diff --git a/minigrep-improved/Cargo.toml b/minigrep-improved/Cargo.toml
new file mode 100644
index 0000000..3fc4cdf
--- /dev/null
+++ b/minigrep-improved/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "minigrep"
+version = "0.1.0"
+authors = ["Jordan Gong <jordan.gong@protonmail.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/minigrep-improved/poem.txt b/minigrep-improved/poem.txt
new file mode 100644
index 0000000..208e35a
--- /dev/null
+++ b/minigrep-improved/poem.txt
@@ -0,0 +1,9 @@
+I’m nobody! Who are you?
+Are you nobody, too?
+Then there’s a pair of us - don’t tell!
+They’d banish us, you know.
+
+How dreary to be somebody!
+How public, like a frog
+To tell your name the livelong day
+To an admiring bog!
diff --git a/minigrep-improved/src/lib.rs b/minigrep-improved/src/lib.rs
new file mode 100644
index 0000000..b849ed1
--- /dev/null
+++ b/minigrep-improved/src/lib.rs
@@ -0,0 +1,96 @@
+use std::env;
+use std::error::Error;
+use std::fs;
+
+pub struct Config {
+    pub query: String,
+    pub filename: String,
+    pub case_sensitive: bool,
+}
+
+impl Config {
+    pub fn new(mut args: env::Args) -> Result<Config, &'static str> {
+        args.next();
+
+        let query = match args.next() {
+            Some(arg) => arg,
+            None => return Err("Didn't get a query string"),
+        };
+
+        let filename = match args.next() {
+            Some(arg) => arg,
+            None => return Err("Didn't get a file name"),
+        };
+
+        let case_sensitive = env::var("CASE_INSENSITIVE").is_err();
+
+        Ok(Config {
+            query,
+            filename,
+            case_sensitive,
+        })
+    }
+}
+
+pub fn run(config: Config) -> Result<(), Box<dyn Error>> {
+    let contents = fs::read_to_string(config.filename)?;
+
+    let results = if config.case_sensitive {
+        search(&config.query, &contents)
+    } else {
+        search_case_insensitive(&config.query, &contents)
+    };
+
+    for line in results {
+        println!("{}", line);
+    }
+
+    Ok(())
+}
+
+pub fn search<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
+    contents
+        .lines()
+        .filter(|line| line.contains(query))
+        .collect()
+}
+
+pub fn search_case_insensitive<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
+    let query = query.to_lowercase();
+
+    contents
+        .lines()
+        .filter(|line| line.to_lowercase().contains(&query))
+        .collect()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn case_sensitive() {
+        let query = "duct";
+        let contents = "\
+Rust:
+safe, fast, productive.
+Pick three.";
+
+        assert_eq!(vec!["safe, fast, productive."], search(query, contents));
+    }
+
+    #[test]
+    fn case_insensitive() {
+        let query = "rUsT";
+        let contents = "\
+Rust:
+safe, fast, productive.
+Pick three.
+Trust me.";
+
+        assert_eq!(
+            vec!["Rust:", "Trust me."],
+            search_case_insensitive(query, contents)
+        );
+    }
+}
diff --git a/minigrep-improved/src/main.rs b/minigrep-improved/src/main.rs
new file mode 100644
index 0000000..6c53f91
--- /dev/null
+++ b/minigrep-improved/src/main.rs
@@ -0,0 +1,16 @@
+use std::env;
+use std::process;
+use minigrep::Config;
+
+fn main() {
+    let config = Config::new(env::args()).unwrap_or_else(|err| {
+        eprintln!("Problem parsing arguments: {}", err);
+        process::exit(1);
+    });
+
+    if let Err(e) = minigrep::run(config) {
+        eprintln!("Application error: {}", e);
+
+        process::exit(1);
+    }
+}
-- 
cgit v1.2.3