add peek comment

.idea/Chip8Emulator.iml

@@ -2,7 +2,8 @@
 <module type="EMPTY_MODULE" version="4">
   <component name="NewModuleRootManager">
     <content url="file://$MODULE_DIR$">
-      <sourceFolder url="file://$MODULE_DIR$/emulator/src" isTestSource="false" />
+      <sourceFolder url="file://$MODULE_DIR$/chip8_core/src" isTestSource="false" />
+      <sourceFolder url="file://$MODULE_DIR$/chip8_tui/src" isTestSource="false" />
       <excludeFolder url="file://$MODULE_DIR$/target" />
     </content>
     <orderEntry type="inheritedJdk" />

Cargo.lock

@@ -111,11 +111,23 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "chip8_tui"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "clap",
+ "crossterm",
+ "emulator",
+ "env_logger",
+ "ratatui",
+]
+
 [[package]]
 name = "clap"
-version = "4.5.23"
+version = "4.5.26"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3135e7ec2ef7b10c6ed8950f0f792ed96ee093fa088608f1c76e569722700c84"
+checksum = "a8eb5e908ef3a6efbe1ed62520fb7287959888c88485abe072543190ecc66783"
 dependencies = [
  "clap_builder",
  "clap_derive",
@@ -123,9 +135,9 @@ dependencies = [
 
 [[package]]
 name = "clap_builder"
-version = "4.5.23"
+version = "4.5.26"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "30582fc632330df2bd26877bde0c1f4470d57c582bbc070376afcd04d8cb4838"
+checksum = "96b01801b5fc6a0a232407abc821660c9c6d25a1cafc0d4f85f29fb8d9afc121"
 dependencies = [
  "anstream",
  "anstyle",
@@ -135,9 +147,9 @@ dependencies = [
 
 [[package]]
 name = "clap_derive"
-version = "4.5.18"
+version = "4.5.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4ac6a0c7b1a9e9a5186361f67dfa1b88213572f427fb9ab038efb2bd8c582dab"
+checksum = "54b755194d6389280185988721fffba69495eed5ee9feeee9a599b53db80318c"
 dependencies = [
  "heck",
  "proc-macro2",
@@ -248,13 +260,9 @@ name = "emulator"
 version = "0.1.0"
 dependencies = [
  "anyhow",
- "clap",
- "crossterm",
- "env_logger",
  "log",
  "pretty_assertions",
  "rand",
- "ratatui",
 ]
 
 [[package]]

Cargo.toml

@@ -2,5 +2,6 @@
 resolver = "2"
 
 members = [
-    "emulator",
+    "chip8_tui",
+    "chip8_core",
 ]

README.md

@@ -50,7 +50,7 @@ The project is written in Rust and it's organized in the following modules:
 │   └── ibm-logo.ch8 # IBM Logo Test ROM
 ├── src
 │   ├── display.rs # The screen / display module.
-│   ├── emulator.rs # The emulator logic which emulates the CPU.
+│   ├── chip8_core.rs # The chip8_core logic which emulates the CPU.
 │   ├── input.rs # The input logic.
 │   ├── instruction.rs # The instruction decoding logic.
 │   ├── main.rs # The main file. This is the entrypoint.

chip8_core/Cargo.toml

@@ -6,18 +6,10 @@ edition = "2021"
 [lints.rust]
 dead_code = "allow"
 
-[profile.release]
-lto = true
-codegen-units = 1
-
 [dependencies]
 log = "0.4.22"
-env_logger = "0.11.5"
 anyhow = "1.0.93"
-ratatui = "0.29.0"
-crossterm = "0.28.1"
 rand = "0.8.5"
-clap = { version = "4.5.23", features = ["derive"] }
 
 [dev-dependencies]
 pretty_assertions = "1.4.1"

chip8_core/src/display.rs

@@ -0,0 +1,13 @@
+/// Represents the display's width in pixels.
+pub const DISPLAY_WIDTH: usize = 64;
+
+/// Represents the display's height pixels.
+pub const DISPLAY_HEIGHT: usize = 32;
+
+/// Display trait
+pub trait Display {
+    /// Re-draws the display.
+    fn clear(&mut self);
+    /// Renders the display data on screen.
+    fn render(&mut self, display_data: &[bool; DISPLAY_WIDTH * DISPLAY_HEIGHT]);
+}

chip8_core/src/emulator.rs

@@ -42,7 +42,7 @@ where
     S: SoundModule,
     I: InputModule,
 {
-    /// Memory represents the emulator's memory.
+    /// Memory represents the chip8_core's memory.
     memory: [u8; MEMORY_SIZE],
     /// Registers holds the general purpose registers.
     registers: [u8; NUMBER_OF_REGISTERS],
@@ -63,7 +63,7 @@ where
     sound_module: S,
     /// The module responsible for receiving user input.
     input_module: I,
-    /// The stack of the emulator.
+    /// The stack of the chip8_core.
     stack: Stack<u16>,
     /// Holds the display data, each bit corresponds to a pixel.
     display_data: [bool; DISPLAY_WIDTH * DISPLAY_HEIGHT],
@@ -467,7 +467,7 @@ where
         ]))
     }
 
-    /// Loads the ROM found at the rom path in the emulator's RAM memory.
+    /// Loads the ROM found at the rom path in the chip8_core's RAM memory.
     fn load_rom<T>(&mut self, mut rom: T) -> Result<(), anyhow::Error>
     where
         T: Read,

chip8_core/src/input.rs

@@ -0,0 +1,16 @@
+/// InputModule retrieves the keys from the hardware or software input control module.
+pub trait InputModule {
+    /// Returns the key value of the corresponding pressed key.
+    /// None if no key is pressed.
+    fn get_key_pressed(&mut self) -> Option<u16>;
+}
+
+/// NoInput always returns none when queried for input.
+#[derive(Clone)]
+pub struct NoInput;
+
+impl InputModule for NoInput {
+    fn get_key_pressed(&mut self) -> Option<u16> {
+        None
+    }
+}

chip8_core/src/lib.rs

@@ -0,0 +1,6 @@
+pub mod display;
+pub mod emulator;
+pub mod input;
+pub mod instruction;
+pub mod sound;
+pub mod stack;

chip8_core/src/sound.rs

@@ -0,0 +1,5 @@
+/// SoundModule represents a module which can produce sound.
+pub trait SoundModule {
+    /// beep makes a beep sound.
+    fn beep(&mut self);
+}

chip8_core/src/stack.rs

@@ -23,7 +23,7 @@ impl<T: Debug> Stack<T> {
         self.storage.pop()
     }
 
-    //
+    /// Returns the top element from the stack without removing it.
     pub fn peek(&self) -> Option<&T> {
         self.storage.last()
     }

chip8_tui/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "chip8_tui"
+version = "0.1.0"
+edition = "2021"
+
+[profile.release]
+lto = true
+codegen-units = 1
+
+[dependencies]
+emulator = { path = "../chip8_core" }
+clap = { version = "4.5.26", features = ["derive"] }
+anyhow = "1.0.95"
+env_logger = "0.11.6"
+ratatui = "0.29.0"
+crossterm = "0.28.1"

chip8_tui/src/display.rs

@@ -3,23 +3,12 @@ use ratatui::style::{Style, Stylize};
 use ratatui::widgets::{Block, Borders};
 use ratatui::DefaultTerminal;
 
-/// Represents the display's width in pixels.
-pub const DISPLAY_WIDTH: usize = 64;
+use emulator::display::{Display, DISPLAY_HEIGHT, DISPLAY_WIDTH};
 
-/// Represents the display's height pixels.
-pub const DISPLAY_HEIGHT: usize = 32;
-
-/// Display trait
-pub trait Display {
-    /// Re-draws the display.
-    fn clear(&mut self);
-    /// Renders the display data on screen.
-    fn render(&mut self, display_data: &[bool; DISPLAY_WIDTH * DISPLAY_HEIGHT]);
-}
-
-/// Simple terminal display for the Chip8's emulator.
+/// Simple terminal display for the Chip8's chip8_core.
 pub struct TerminalDisplay {}
 
+#[allow(dead_code)]
 impl TerminalDisplay {
     pub fn new() -> TerminalDisplay {
         TerminalDisplay {}

chip8_tui/src/input.rs

@@ -1,24 +1,8 @@
 use crossterm::event::{poll, read, Event, KeyCode};
 use crossterm::terminal::{disable_raw_mode, enable_raw_mode};
+use emulator::input::InputModule;
 use std::time::Duration;
 
-/// InputModule retrieves the keys from the hardware or software input control module.
-pub trait InputModule {
-    /// Returns the key value of the corresponding pressed key.
-    /// None if no key is pressed.
-    fn get_key_pressed(&mut self) -> Option<u16>;
-}
-
-/// NoInput always returns none when queried for input.
-#[derive(Clone)]
-pub struct NoInput;
-
-impl InputModule for NoInput {
-    fn get_key_pressed(&mut self) -> Option<u16> {
-        None
-    }
-}
-
 /// CrossTermInput implements input events via the crossterm crate.
 #[derive(Clone)]
 pub struct CrossTermInput {

chip8_tui/src/main.rs

@@ -1,21 +1,18 @@
+mod display;
+mod input;
+mod sound;
+
 use crate::display::RatatuiDisplay;
-use crate::emulator::Emulator;
 use crate::input::CrossTermInput;
 use crate::sound::TerminalSound;
 use clap::Parser;
+use emulator::emulator::Emulator;
 use std::fs::File;
 
-mod display;
-mod emulator;
-mod input;
-mod instruction;
-mod sound;
-mod stack;
-
 #[derive(Parser, Debug)]
 #[command(
     version = "1.0",
-    about = "A Chip8 emulator.",
+    about = "A Chip8 chip8_core.",
     long_about = "A program which emulates the Chip8 system."
 )]
 struct CliArgs {

chip8_tui/src/sound.rs

@@ -1,8 +1,4 @@
-/// SoundModule represents a module which can produce sound.
-pub trait SoundModule {
-    /// beep makes a beep sound.
-    fn beep(&mut self);
-}
+use emulator::sound::SoundModule;
 
 /// TerminalSound is a simple module that makes terminal beep sound.
 pub struct TerminalSound;