Suport history movment in the repl 🤓

Cargo.toml

@@ -39,6 +39,7 @@ log = "0.4.17"
 pretty_env_logger = "0.4.0"
 colored = "2.0.0"
 # no-panic = "0.1.16"
+console = "0.15.2"
 
 [dev-dependencies]
 pretty_assertions = "1.3.0"

src/bf_interpreter/cell.rs

@@ -0,0 +1,135 @@
+use crate::arguments::Feature;
+use crate::bf_interpreter::error::{InterpreterError, InterpreterErrorKind};
+
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub enum Cell {
+    Byte(u8),
+    Utf8(u32),
+}
+
+impl Cell {
+    pub fn set_value_utf8(&mut self, ch: char) {
+        match self {
+            Cell::Byte(_) => {}
+            Cell::Utf8(p) => {
+                *p = ch as u32;
+            }
+        }
+    }
+
+    pub fn set_value(&mut self, ch: char) {
+        match self {
+            Cell::Byte(p) => {
+                *p = ch as u8;
+            }
+            Cell::Utf8(_) => {}
+        }
+    }
+}
+
+impl Cell {
+    pub fn default_cell(future: &Vec<Feature>) -> Self {
+        if future.contains(&Feature::AllowUtf8) {
+            Cell::Utf8(0)
+        } else {
+            Cell::Byte(0)
+        }
+    }
+
+    pub fn new(value: u32, future: &Vec<Feature>) -> Self {
+        if future.contains(&Feature::AllowUtf8) {
+            Cell::Utf8(value)
+        } else {
+            Cell::Byte(value as u8)
+        }
+    }
+
+    pub fn get_value(&self) -> u8 {
+        match self {
+            Self::Byte(value) => *value,
+            Self::Utf8(value) => *value as u8,
+        }
+    }
+
+    pub fn get_value_utf8(&self) -> u32 {
+        match self {
+            Self::Byte(value) => *value as u32,
+            Self::Utf8(value) => *value,
+        }
+    }
+
+    pub fn increment(&mut self, no_reverse_value: bool) -> Result<(), InterpreterError> {
+        if self.get_value_utf8() == self.max_value() && no_reverse_value {
+            return Err(InterpreterErrorKind::ValueOutOfBounds.to_error())
+        }
+        match self {
+            Self::Byte(value) => {
+                if *value == 255 {
+                    *value = 0;
+                } else {
+                    *value += 1;
+                }
+            }
+            Self::Utf8(value) => {
+                if *value == 1114111 {
+                    *value = 0;
+                } else {
+                    *value += 1;
+                }
+            }
+        }
+        Ok(())
+    }
+
+    pub fn decrement(&mut self, no_reverse_value: bool) -> Result<(), InterpreterError> {
+        if self.get_value_utf8() == 0 && no_reverse_value {
+            return Err(InterpreterErrorKind::ValueOutOfBounds.to_error())
+        }
+        match self {
+            Self::Byte(value) => {
+                if *value == 0 {
+                    *value = 255;
+                } else {
+                    *value -= 1;
+                }
+            }
+            Self::Utf8(value) => {
+                if *value == 0 {
+                    *value = 1114111;
+                } else {
+                    *value -= 1;
+                }
+            }
+        }
+        Ok(())
+    }
+
+    pub fn max_value(&self) -> u32 {
+        match self {
+            Self::Byte(_) => u8::MAX as u32,
+            Self::Utf8(_) => u32::MAX,
+        }
+    }
+
+    pub fn to_char(&self) -> Result<char, InterpreterError> {
+        let c = match self {
+            Self::Byte(value) => Some(*value as char),
+            Self::Utf8(value) => char::from_u32(*value)
+        };
+
+        if let Some(c) = c {
+            Ok(c)
+        } else {
+            Err(InterpreterErrorKind::InvalidUtf8.to_error())
+        }
+    }
+}
+
+impl std::fmt::Display for Cell {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::Byte(value) => write!(f, "{}", value),
+            Self::Utf8(value) => write!(f, "{}", value),
+        }
+    }
+}

src/bf_interpreter/interpreter.rs

@@ -1,24 +1,31 @@
 use crate::arguments;
 use crate::bf_interpreter::error::{InterpreterError, InterpreterErrorKind};
-use std::io::{Read, Write};
+use std::io::{Write};
 use std::{char, usize, vec};
+use crate::bf_interpreter::cell::Cell;
 
 pub struct Interpreter {
-    pub cells: Vec<u8>,
+    pub cells: Vec<Cell>,
     pub pointer: usize,
     pub bf_commands: Vec<BfCommand>,
     brackets: Vec<BfCommand>,
     pub features: Vec<arguments::Feature>,
+    term: console::Term,
 }
 
 impl Interpreter {
-    pub fn new(array_size: usize, features: Vec<arguments::Feature>) -> Self {
+    pub fn new(
+        array_size: usize,
+        features: Vec<arguments::Feature>,
+        term: &console::Term,
+    ) -> Self {
         Self {
-            cells: vec![0; array_size],
+            cells: vec![Cell::default_cell(&features); array_size],
             pointer: 0,
             bf_commands: vec![],
             brackets: Vec::new(),
             features,
+            term: term.clone(),
         }
     }
 
@@ -34,7 +41,7 @@ impl Interpreter {
     // +[>++<-]
     fn iterate(&mut self, code: &Vec<BfCommand>) -> Result<(), InterpreterError> {
         trace!("Iterate: {:?}", code);
-        while self.cells[self.pointer] != 0 {
+        while self.cells[self.pointer].get_value_utf8() != 0 {
             self.run_brainfuck_code(code)?;
         }
         Ok(())
@@ -85,29 +92,15 @@ impl Interpreter {
 
     fn increment_value(&mut self) -> Result<(), InterpreterError> {
         trace!("Increment value");
-        if self.cells[self.pointer] == 255 {
+        self.cells[self.pointer].increment(
-            if !self.features.contains(&arguments::Feature::NoReverseValue) {
+            !self.features.contains(&arguments::Feature::NoReverseValue))?;
-                self.cells[self.pointer] = 0;
-            } else {
-                return Err(InterpreterErrorKind::ValueOutOfBounds.to_error());
-            }
-        } else {
-            self.cells[self.pointer] += 1;
-        }
         Ok(())
     }
 
     fn decrement_value(&mut self) -> Result<(), InterpreterError> {
         trace!("Decrement value");
-        if self.cells[self.pointer] == 0 {
+        self.cells[self.pointer].decrement(
-            if !self.features.contains(&arguments::Feature::NoReverseValue) {
+            !self.features.contains(&arguments::Feature::NoReverseValue))?;
-                self.cells[self.pointer] = 255;
-            } else {
-                return Err(InterpreterErrorKind::ValueOutOfBounds.to_error());
-            }
-        } else {
-            self.cells[self.pointer] -= 1;
-        }
         Ok(())
     }
 
@@ -115,13 +108,13 @@ impl Interpreter {
         trace!("Output value");
 
         if self.features.contains(&arguments::Feature::AllowUtf8) {
-            let c = char::from_u32(self.cells[self.pointer] as u32);
+            let c = char::from_u32(self.cells[self.pointer].get_value_utf8());
             match c {
                 Some(c) => print!("{}", c),
                 None => return Err(InterpreterErrorKind::InvalidUtf8.to_error()),
             }
         } else {
-            print!("{}", self.cells[self.pointer] as char);
+            print!("{}", self.cells[self.pointer].get_value() as char);
         }
         match std::io::stdout().flush() {
             Ok(_) => Ok(()),
@@ -131,18 +124,25 @@ impl Interpreter {
 
     fn input_value(&mut self) -> Result<(), InterpreterError> {
         trace!("Input value");
-        let mut input = [0; 1];
+        match self.term.read_char() {
-        match std::io::stdin().read_exact(&mut input) {
+            Ok(ch) => {
-            Ok(_) => {
+                if self.features.contains(&arguments::Feature::AllowUtf8) {
-                self.cells[self.pointer] = input[0];
+                    self.cells[self.pointer].set_value_utf8(ch);
-                Ok(())
+                } else {
+                    self.cells[self.pointer].set_value(ch);
+                }
+                print!("{}", ch);
+                match std::io::stdout().flush() {
+                    Ok(_) => Ok(()),
+                    Err(e) => Err(InterpreterErrorKind::FlushError(e).to_error()),
+                }
             }
             Err(e) => Err(InterpreterErrorKind::IoError(e).to_error()),
         }
     }
 
     pub fn reset(&mut self) {
-        self.cells = vec![0; self.cells.len()];
+        self.cells = vec![Cell::default_cell(&self.features); self.cells.len()];
         self.pointer = 0;
         self.brackets = Vec::new();
         self.bf_commands = Vec::new();
@@ -217,7 +217,8 @@ mod tests {
 
     #[test]
     fn print_h_combine_repl() {
-        let mut interpreter = Interpreter::new(30000, vec![]);
+        let mut interpreter = Interpreter::new(30000, vec![], 
+                                               &console::Term::stdout());
 
         assert_eq!(
             interpreter.run(String::from(">+++++++++[<++++ ++++>-]<.")),
@@ -229,7 +230,8 @@ mod tests {
 
     #[test]
     fn print_h_repl() {
-        let mut interpreter = Interpreter::new(30000, vec![]);
+        let mut interpreter = Interpreter::new(30000, vec![], 
+                                               &console::Term::stdout());
 
         assert_eq!(interpreter.run(String::from(">+++++++++")), Ok(0));
         assert_eq!(interpreter.run(String::from("[<++++ ++++>-]<.")), Ok(0));
@@ -239,17 +241,19 @@ mod tests {
 
     #[test]
     fn nested_loop_level_1_combine() {
-        let mut interpreter = Interpreter::new(5, vec![]);
+        let mut interpreter = Interpreter::new(5, vec![], 
+                                               &console::Term::stdout());
 
         assert_eq!(interpreter.run(String::from("++[>++[>+<-]<-]")), Ok(0));
-        assert_eq!(interpreter.cells[2], 4);
+        assert_eq!(interpreter.cells[2], Cell::new(4, &vec![]));
 
         println!();
     }
 
     #[test]
     fn execute_hello_world_from_file() {
-        let mut interpreter = Interpreter::new(30000, vec![]);
+        let mut interpreter = Interpreter::new(30000, vec![], 
+                                               &console::Term::stdout());
 
         println!();
 
@@ -263,7 +267,8 @@ mod tests {
 
     #[test]
     fn execute_print_hi_from_file() {
-        let mut interpreter = Interpreter::new(30000, vec![]);
+        let mut interpreter = Interpreter::new(30000, vec![], 
+                                               &console::Term::stdout());
 
         println!();
 
@@ -277,7 +282,8 @@ mod tests {
 
     #[test]
     fn execute_print_hi_yooo_from_file() {
-        let mut interpreter = Interpreter::new(30000, vec![]);
+        let mut interpreter = Interpreter::new(30000, vec![], 
+                                               &console::Term::stdout());
 
         println!();
 
@@ -291,7 +297,8 @@ mod tests {
 
     #[test]
     fn execute_print_my_first_name_from_formatted_file() {
-        let mut interpreter = Interpreter::new(30000, vec![]);
+        let mut interpreter = Interpreter::new(30000, vec![], 
+                                               &console::Term::stdout());
 
         println!();
 
@@ -305,7 +312,8 @@ mod tests {
 
     #[test]
     fn execute_print_my_first_name_from_file() {
-        let mut interpreter = Interpreter::new(30000, vec![]);
+        let mut interpreter = Interpreter::new(30000, vec![], 
+                                               &console::Term::stdout());
 
         println!();
 
@@ -319,7 +327,8 @@ mod tests {
 
     #[test]
     fn execute_print_my_first_name_and_last_name_from_formatted_file() {
-        let mut interpreter = Interpreter::new(30000, vec![]);
+        let mut interpreter = Interpreter::new(30000, vec![], 
+                                               &console::Term::stdout());
 
         println!();
 
@@ -333,7 +342,8 @@ mod tests {
 
     #[test]
     fn execute_print_my_first_name_and_last_name_from_file() {
-        let mut interpreter = Interpreter::new(30000, vec![]);
+        let mut interpreter = Interpreter::new(30000, vec![], 
+                                               &console::Term::stdout());
 
         println!();
 
@@ -347,21 +357,22 @@ mod tests {
 
     #[test]
     fn reset() {
-        let mut interpreter = Interpreter::new(30000, vec![]);
+        let mut interpreter = Interpreter::new(30000, vec![], 
+                                               &console::Term::stdout());
 
         assert_eq!(interpreter.run(String::from(">++++")), Ok(0));
 
         assert_eq!(interpreter.pointer, 1);
-        assert_eq!(interpreter.cells[0], 0);
+        assert_eq!(interpreter.cells[0], Cell::new(0, &vec![]));
-        assert_eq!(interpreter.cells[1], 4);
+        assert_eq!(interpreter.cells[1], Cell::new(4, &vec![]));
         // assert_eq!(interpreter.commands, vec!['>', '+', '+', '+', '+']);
 
         // reset
         interpreter.reset();
 
         assert_eq!(interpreter.pointer, 0);
-        assert_eq!(interpreter.cells[0], 0);
+        assert_eq!(interpreter.cells[0], Cell::new(0, &vec![]));
-        assert_eq!(interpreter.cells[1], 0);
+        assert_eq!(interpreter.cells[1], Cell::new(0, &vec![]));
         assert_eq!(interpreter.bf_commands, Vec::<BfCommand>::new());
     }
 }

src/bf_interpreter/mod.rs

@@ -1,2 +1,3 @@
 pub mod error;
 pub mod interpreter;
+pub mod cell;

src/main.rs

@@ -19,9 +19,13 @@ fn main() {
     let args = Args::parse();
     info!("Parsed command line arguments: {:?}", args);
 
+    let term = console::Term::stdout();
+
     info!("Initializing interpreter");
     let mut interpreter =
-        Interpreter::new(args.array_size, args.features.unwrap_or_else(|| vec![]));
+        Interpreter::new(args.array_size,
+                         args.features.unwrap_or_else(|| vec![]),
+        &term);
 
     match args.source {
         Some(source) => {
@@ -56,6 +60,6 @@ fn main() {
                 }
             }
         }
-        None => repl::start(interpreter),
+        None => repl::start(interpreter, term),
     }
 }

src/repl.rs

@@ -1,9 +1,11 @@
 use crate::bf_interpreter::interpreter::Interpreter;
 use colored::Colorize;
 use std::io::Write;
+use console::{Term, Key};
 
 struct Repl {
     pub interpreter: Interpreter,
+    term: console::Term,
     history: Vec<String>,
     loop_body: String,
     loop_depth: usize,
@@ -14,9 +16,10 @@ const HISTORY_FILE: &str = "bf-interpreter-history.bfr";
 const COMMAND_PREFIX: &str = "!";
 
 impl Repl {
-    pub fn new(interpreter: Interpreter) -> Repl {
+    pub fn new(interpreter: Interpreter, term: Term) -> Repl {
         Repl {
             interpreter,
+            term,
             history: Vec::new(),
             loop_body: String::new(),
             loop_depth: 0,
@@ -26,33 +29,85 @@ impl Repl {
     // #[no_panic]
     pub fn run(mut self) -> Result<(), std::io::Error> {
         loop {
-            print!(
+            self.print_prompt();
-                "{}",
-                if self.loop_depth != 0 {
-                    "........ ".yellow()
-                } else {
-                    PROMPT.to_string().truecolor(54, 76, 76)
-                }
-            );
 
             std::io::stdout().flush()?;
 
-            let mut user_input = String::new();
+            match self.read_input() {
+                Ok(input) => {
+                    let user_input = input.trim().to_string(); // Remove trailing newline
 
-            match std::io::stdin().read_line(&mut user_input) {
+                    if !user_input.is_empty() && user_input.len() > 0 {
-                Ok(_) => {}
+                        self.history.push(user_input.clone()); // Save input to history
+                        self.process(user_input); // Process the input
+                    }
+                }
                 Err(e) => {
-                    error!("Failed to read input: {}", e);
+                    eprintln!("Error: {}", e);
-                    std::process::exit(1);
                 }
             }
-            user_input = user_input.trim().to_string(); // Remove trailing newline
+        }
+    }
 
-            if !user_input.is_empty() && user_input.len() > 0 {
+    fn print_prompt(&self) {
-                self.history.push(user_input.clone()); // Save input to history
+        print!(
-                self.process(user_input); // Process the input
+            "{}",
+            if self.loop_depth != 0 {
+                "........ ".yellow()
+            } else {
+                PROMPT.to_string().truecolor(54, 76, 76)
+            }
+        );
+    }
+
+    fn read_input(&mut self) -> Result<String, std::io::Error> {
+        let mut input = String::new();
+        let mut rev_index = 0;
+
+        loop {
+            let key = self.term.read_key()?; // Read key from terminal
+
+            match key {
+                Key::ArrowUp => {
+                    if !self.history.is_empty() && rev_index < self.history.len() {
+                        let last = self.history.get(self.history.len() - 1 - rev_index)
+                            .unwrap();
+                        rev_index += 1;
+                        self.term.clear_line()?;
+                        self.print_prompt();
+                        self.term.write_str(last)?;
+                        input = last.clone();
+                    }
+                }
+                Key::ArrowDown => {
+                    if !self.history.is_empty() && rev_index > 0 {
+                        let first = self.history.get(self.history.len() - rev_index)
+                            .unwrap();
+                        rev_index -= 1;
+                        self.term.clear_line()?;
+                        self.print_prompt();
+                        self.term.write_str(first)?;
+                        input = first.clone();
+                    }
+                }
+                Key::Char(c) => {
+                    self.term.write_str(&c.to_string())?;
+                    input.push(c);
+                }
+                Key::Backspace => {
+                    self.term.clear_line()?;
+                    self.term.write_str(&input[0..input.len() - 1])?;
+                    self.term.move_cursor_left(1)?;
+                    input.pop();
+                }
+                Key::Enter => {
+                    self.term.write_str("\n")?;
+                    break;
+                }
+                _ => {}
             }
         }
+        Ok(input)
     }
 
     pub fn process(&mut self, mut user_input: String) {
@@ -140,7 +195,7 @@ impl Repl {
                         println!(
                             "Current pointer value: {} = \'{}\' (char)",
                             self.interpreter.cells[self.interpreter.pointer],
-                            self.interpreter.cells[self.interpreter.pointer] as char
+                            self.interpreter.cells[self.interpreter.pointer].to_char().unwrap_or_else(|_| '?')
                         );
                     }
                     "history" | "h" => {
@@ -233,7 +288,7 @@ impl Repl {
                             user_input,
                             (COMMAND_PREFIX.to_string() + "help").green()
                         )
-                        .red()
+                            .red()
                     ),
                 }
             }
@@ -245,7 +300,7 @@ impl Repl {
 /// Run the REPL
 /// # Arguments
 /// * `interpreter` - The interpreter to use
-pub fn start(interpreter: Interpreter) {
+pub fn start(interpreter: Interpreter, term: Term) {
     info!("Entering REPL mode");
     println!(
         "{}\n\
@@ -263,7 +318,7 @@ pub fn start(interpreter: Interpreter) {
         (COMMAND_PREFIX.to_string() + "help").bold().green(),
     );
 
-    match Repl::new(interpreter).run() {
+    match Repl::new(interpreter, term).run() {
         Ok(_) => {
             info!("Successfully ran REPL");
         }
@@ -278,12 +333,14 @@ pub fn start(interpreter: Interpreter) {
 mod tests {
     use super::*;
     use pretty_assertions::assert_eq;
+    use crate::bf_interpreter::cell::Cell;
 
     #[test]
     fn nested_loop_level_1() {
-        let interpreter = Interpreter::new(4, vec![]);
+        let mut term = Term::stdout();
+        let interpreter = Interpreter::new(4, vec![], &mut term);
 
-        let mut repl = Repl::new(interpreter);
+        let mut repl = Repl::new(interpreter, term);
 
         repl.process("++".to_string());
         repl.process("[>++".to_string());
@@ -292,16 +349,17 @@ mod tests {
 
         let cells = &repl.interpreter.cells;
 
-        assert_eq!(cells[0], 0);
+        assert_eq!(cells[0], Cell::default_cell(&vec![]));
-        assert_eq!(cells[1], 0);
+        assert_eq!(cells[1], Cell::default_cell(&vec![]));
-        assert_eq!(cells[2], 4);
+        assert_eq!(cells[2], Cell::new(4, &vec![]));
     }
 
     #[test]
     fn nested_loop_level_2() {
-        let interpreter = Interpreter::new(4, vec![]);
+        let mut term = console::Term::stdout();
+        let interpreter = Interpreter::new(4, vec![], &mut term);
 
-        let mut repl = Repl::new(interpreter);
+        let mut repl = Repl::new(interpreter, term);
 
         repl.process("++".to_string());
         repl.process("[>++".to_string());
@@ -313,16 +371,17 @@ mod tests {
 
         let cells = &repl.interpreter.cells;
 
-        assert_eq!(cells[0], 0);
+        assert_eq!(cells[0], Cell::default_cell(&vec![]));
-        assert_eq!(cells[1], 0);
+        assert_eq!(cells[1], Cell::default_cell(&vec![]));
-        assert_eq!(cells[2], 4);
+        assert_eq!(cells[2], Cell::new(4, &vec![]));
     }
 
     #[test]
     fn print_my_first_name() {
-        let interpreter = Interpreter::new(10, vec![]);
+        let mut term = console::Term::stdout();
+        let interpreter = Interpreter::new(10, vec![], &mut term);
 
-        let mut repl = Repl::new(interpreter);
+        let mut repl = Repl::new(interpreter, term);
 
         let code = "++++ ++++ 8
         [
@@ -384,9 +443,10 @@ mod tests {
 
     #[test]
     fn print_my_first_name_in_one_command() {
-        let interpreter = Interpreter::new(10, vec![]);
+        let mut term = console::Term::stdout();
+        let interpreter = Interpreter::new(10, vec![], &mut term);
 
-        let mut repl = Repl::new(interpreter);
+        let mut repl = Repl::new(interpreter, term);
 
         let code = "++++++++[>++++[>++<-]>>>>>>++[<<<->>>-]<<<<<<<-]>>+.<<++++[>+++
         [>+++<-]>++<<-]>>+.<<+++[>+++[>-<-]>-<<-]>>-.<<++++++[>>+++<<-]>>."
@@ -397,9 +457,10 @@ mod tests {
 
     #[test]
     fn print_hello_world() {
-        let interpreter = Interpreter::new(10, vec![]);
+        let mut term = console::Term::stdout();
+        let interpreter = Interpreter::new(10, vec![], &mut term);
 
-        let mut repl = Repl::new(interpreter);
+        let mut repl = Repl::new(interpreter, term);
 
         let _ = "[ This program prints \"Hello World!\" and a newline to the screen, its
                 length is 106 active command characters. [It is not the shortest.]
@@ -438,8 +499,8 @@ mod tests {
                 >>+.                    Add 1 to Cell #5 gives us an exclamation point
                 >++.                    And finally a newline from Cell #6
             "
-        .to_string()
+            .to_string()
-        .split("\n")
+            .split("\n")
-        .for_each(|s| repl.process(s.to_string()));
+            .for_each(|s| repl.process(s.to_string()));
     }
 }