Rustハンズオン@エウレカ社 (#34)

* feat: handson > cat

* feat: handson > grep

rust-handson/rsgrep/.gitignore

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+### https://raw.github.com/github/gitignore/3bb7b4b767f3f8df07e362dfa03c8bd425f16d32/Rust.gitignore
+
+# Generated by Cargo
+# will have compiled files and executables
+debug/
+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
+
+# MSVC Windows builds of rustc generate these, which store debugging information
+*.pdb
+
+

rust-handson/rsgrep/Cargo.toml

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+[package]
+name = "rsgrep"
+version = "0.1.0"
+authors = ["Shingo Yamazaki <[email protected]>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+rayon = "1.5.1"
+structopt = "0.3.22"

rust-handson/rsgrep/src/main.rs

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+use rayon::prelude::*;
+use std::{env::args, fs::read_to_string};
+use structopt::StructOpt;
+
+#[derive(StructOpt)]
+#[structopt(name = "rsgrep")]
+struct GrepArgs {
+    #[structopt(name = "PATTERN")]
+    pattern: String,
+    #[structopt(name = "FILE")]
+    path: Vec<String>,
+}
+
+fn grep(state: &GrepArgs, content: String, file_name: &str) {
+    for line in content.lines() {
+        if line.contains(state.pattern.as_str()) {
+            println!("{}: {}", file_name, line);
+        }
+    }
+}
+
+fn run(state: GrepArgs) {
+    state
+        .path
+        .par_iter()
+        .for_each(|file| match read_to_string(file) {
+            Ok(content) => grep(&state, content, file),
+            Err(reason) => println!("{}", reason),
+        });
+}
+
+fn main() {
+    run(GrepArgs::from_args());
+}