Add fancy cmd-line parsing

Cargo.lock

@@ -2,6 +2,26 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "ansi_term"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ee49baf6cb617b853aa8d93bf420db2383fab46d314482ca2803b40d5fde979b"
+dependencies = [
+ "winapi",
+]
+
+[[package]]
+name = "atty"
+version = "0.2.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d9b39be18770d11421cdb1b9947a45dd3f37e93092cbf377614828a319d5fee8"
+dependencies = [
+ "hermit-abi",
+ "libc",
+ "winapi",
+]
+
 [[package]]
 name = "bitflags"
 version = "1.2.1"
@@ -30,10 +50,26 @@ checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 name = "chip8-rs"
 version = "0.1.0"
 dependencies = [
+ "clap",
  "rand",
  "sdl2",
 ]
 
+[[package]]
+name = "clap"
+version = "2.33.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "37e58ac78573c40708d45522f0d80fa2f01cc4f9b4e2bf749807255454312002"
+dependencies = [
+ "ansi_term",
+ "atty",
+ "bitflags",
+ "strsim",
+ "textwrap",
+ "unicode-width",
+ "vec_map",
+]
+
 [[package]]
 name = "getrandom"
 version = "0.2.2"
@@ -45,6 +81,15 @@ dependencies = [
  "wasi",
 ]
 
+[[package]]
+name = "hermit-abi"
+version = "0.1.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "322f4de77956e22ed0e5032c359a0f1273f1f7f0d79bfa3b8ffbc730d7fbcc5c"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "lazy_static"
 version = "1.4.0"
@@ -127,6 +172,33 @@ dependencies = [
  "version-compare",
 ]
 
+[[package]]
+name = "strsim"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8ea5119cdb4c55b55d432abb513a0429384878c15dde60cc77b1c99de1a95a6a"
+
+[[package]]
+name = "textwrap"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d326610f408c7a4eb6f51c37c330e496b08506c9457c9d34287ecc38809fb060"
+dependencies = [
+ "unicode-width",
+]
+
+[[package]]
+name = "unicode-width"
+version = "0.1.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9337591893a19b88d8d87f2cec1e73fad5cdfd10e5a6f349f498ad6ea2ffb1e3"
+
+[[package]]
+name = "vec_map"
+version = "0.8.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f1bddf1187be692e79c5ffeab891132dfb0f236ed36a43c7ed39f1165ee20191"
+
 [[package]]
 name = "version-compare"
 version = "0.0.10"
@@ -138,3 +210,25 @@ name = "wasi"
 version = "0.10.2+wasi-snapshot-preview1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fd6fbd9a79829dd1ad0cc20627bf1ed606756a7f77edff7b66b7064f9cb327c6"
+
+[[package]]
+name = "winapi"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5c839a674fcd7a98952e593242ea400abe93992746761e38641405d28b00f419"
+dependencies = [
+ "winapi-i686-pc-windows-gnu",
+ "winapi-x86_64-pc-windows-gnu",
+]
+
+[[package]]
+name = "winapi-i686-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
+
+[[package]]
+name = "winapi-x86_64-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"

Cargo.toml

@@ -8,6 +8,7 @@ edition = "2018"
 
 [dependencies]
 rand = "0.8.3"
+clap = "2.33.3"
 
 [dependencies.sdl2]
 version = "0.34.5"

src/main.rs

@@ -1,7 +1,4 @@
-extern crate rand;
-extern crate sdl2;
-
-use std::env;
+use clap::{App, Arg};
 
 mod cartridge;
 mod display;
@@ -18,20 +15,32 @@ const SCREEN_WIDTH: usize = 64;
 const SCREEN_HEIGHT: usize = 32;
 const SCREEN_SCALE: usize = 20;
 
-fn main() {
-    let game_file = env::args().nth(1);
-    match game_file {
-        Some(_) => println!("Found a cartridge file! Trying to load..."),
-        None => {
-            println!("No cartridge file found! Exiting!");
-            return;
-        }
-    };
+#[derive(Debug)]
+enum ChipError {
+    CartridgeNotFound,
+}
+
+fn main() -> Result<(), ChipError> {
+    let app = App::new("chip8-rs")
+        .version("0.1.0")
+        .author("Marco Thomas <mail@marco-thomas.net>")
+        .about("A small chip8 emulator, written in Rust")
+        .arg(
+            Arg::with_name("cartridge")
+                .short("c")
+                .takes_value(true)
+                .help("A cartridge binary file"),
+        )
+        .get_matches();
+
+    let game_file = app
+        .value_of("cartridge")
+        .ok_or(ChipError::CartridgeNotFound)?;
 
     let mut processor = Processor::new();
 
-    // load cartridge file
-    let cartridge = Cartridge::new(&game_file.unwrap());
+    let cartridge = Cartridge::new(&game_file);
 
     processor.start(&cartridge.rom);
+    Ok(())
 }