interactive brainfuck repl

bfi-rust/src/interpreter/mod.rs

@@ -1,13 +1,16 @@
+use crate::interpreter::optimized::PrintMode;
+use std::str::Chars;
+
 pub mod simple;
 pub mod parsed;
 pub mod optimized;
 
-const MEM_SIZE: usize = 0xFFFF;
+pub const MEM_SIZE: usize = 0xFFFF;
 
-type Memory = [u8; MEM_SIZE];
+pub type Memory = [u8; MEM_SIZE];
 
 #[derive(Debug, PartialOrd, PartialEq, Ord, Eq, Clone)]
-enum Statement {
+pub enum Statement {
     Inc,
     Dec,
     R,
@@ -20,11 +23,11 @@ enum Statement {
 
 const ALLOWED_CHARS: [char; 8] = ['>', '<', '+', '-', '.', ',', '[', ']'];
 
-fn minify(code: &str) -> String {
+pub fn minify(code: &str) -> String {
     code.chars().filter(|c| ALLOWED_CHARS.contains(c)).collect()
 }
 
-fn parse(chars: Vec<char>, direct_print: bool) -> Vec<Statement> {
+pub fn parse(chars: Chars, print_mode: PrintMode) -> Vec<Statement> {
     let mut loop_stack = vec![vec![]];
 
     for c in chars {
@@ -34,10 +37,9 @@ fn parse(chars: Vec<char>, direct_print: bool) -> Vec<Statement> {
             '>' => loop_stack.last_mut().unwrap().push(Statement::R),
             '<' => loop_stack.last_mut().unwrap().push(Statement::L),
             '.' => {
-                if direct_print {
-                    loop_stack.last_mut().unwrap().push(Statement::DOut)
-                } else {
-                    loop_stack.last_mut().unwrap().push(Statement::Out)
+                match print_mode {
+                    PrintMode::ToString => loop_stack.last_mut().unwrap().push(Statement::Out),
+                    PrintMode::DirectPrint => loop_stack.last_mut().unwrap().push(Statement::DOut)
                 }
             }
             ',' => loop_stack.last_mut().unwrap().push(Statement::In),

bfi-rust/src/interpreter/optimized/mod.rs

@@ -24,7 +24,7 @@ enum ExStatement {
     Loop(Vec<ExStatement>),
     SetNull,
     Repeat(Box<ExStatement>, usize),
-    ForLoop(usize, Box<ExStatement>),
+    _ForLoop(usize, Box<ExStatement>),
 }
 
 impl From<Statement> for ExStatement {
@@ -46,7 +46,7 @@ impl From<Statement> for ExStatement {
 
 #[derive(Debug)]
 pub struct BfErr {
-    msg: &'static str
+    msg: &'static str,
 }
 
 impl BfErr {
@@ -64,10 +64,15 @@ impl Display for BfErr {
 impl Error for BfErr {}
 
 
-pub fn run(pgm: &str, direct_print: bool) -> Result<String, BfErr> {
+pub enum PrintMode {
+    ToString,
+    DirectPrint,
+}
+
+pub fn run(pgm: &str, print_mode: PrintMode) -> Result<String, BfErr> {
     let pgm = minify(pgm);
     if pgm.is_empty() { return Err(BfErr::new("no program found")); };
-    let pgm = parse(pgm.chars().collect(), direct_print);
+    let pgm = parse(pgm.chars(), print_mode);
     let pgm = optimize(&pgm);
     let out = interpret(&pgm);
     Ok(out)
@@ -177,7 +182,7 @@ fn execute(statement: &ExStatement, mem: &mut Memory, pointer: &mut usize, out:
                 }
             }
         }
-        ExStatement::ForLoop(offset, statement) => {
+        ExStatement::_ForLoop(offset, statement) => {
             *pointer += offset;
             while mem[*pointer - offset] != 0 {
                 execute(statement, mem, pointer, out);

bfi-rust/src/interpreter/optimized/patterns.rs

@@ -7,12 +7,12 @@ use crate::interpreter::optimized::ExStatement;
 
 ///
 /// Replace this: `[>>x<<-]` or `[->>x<<]` with `WhileAdd(2, x)`
-fn for_loop(to_test: ExStatement) -> ExStatement {
+fn _for_loop(to_test: ExStatement) -> ExStatement {
     match to_test {
         ExStatement::Loop(v) => {
             match v[..] {
                 [ExStatement::R, ExStatement::Inc, ExStatement::L, ExStatement::Dec] => {
-                    ExStatement::ForLoop(1, Box::from(ExStatement::Inc))
+                    ExStatement::_ForLoop(1, Box::from(ExStatement::Inc))
                 }
                 _ => ExStatement::Loop(v)
             }
@@ -26,18 +26,18 @@ fn for_loop(to_test: ExStatement) -> ExStatement {
 
 #[cfg(test)]
 mod test {
-    use crate::interpreter::optimized::ExStatement::{Out, Loop, Inc, R, L, Dec, ForLoop};
-    use crate::interpreter::optimized::patterns::for_loop;
+    use crate::interpreter::optimized::ExStatement::{Out, Loop, Inc, R, L, Dec, _ForLoop};
+    use crate::interpreter::optimized::patterns::_for_loop;
 
     #[test]
     fn for_loop_false() {
         let statement = Loop(vec![Out, Inc]);
-        assert_eq!(statement.clone(), for_loop(statement));
+        assert_eq!(statement.clone(), _for_loop(statement));
     }
 
     #[test]
     fn for_loop_simplest() {
         let statement = Loop(vec![R, Inc, L, Dec]);
-        assert_eq!(ForLoop(1, Box::from(Inc)), for_loop(statement));
+        assert_eq!(_ForLoop(1, Box::from(Inc)), _for_loop(statement));
     }
 }

bfi-rust/src/interpreter/parsed.rs

@@ -8,13 +8,16 @@
 use std::io::{Read, stdin, Write};
 
 use crate::interpreter::{MEM_SIZE, Memory, minify, parse, Statement};
+use crate::interpreter::optimized::PrintMode;
+use crate::repl::BrainfuckState;
 
 pub fn run(pgm: &str) -> String {
     let pgm = minify(pgm);
-    let pgm = parse(pgm.chars().collect(), false);
+    let pgm = parse(pgm.chars(), PrintMode::ToString);
     interpret(&pgm)
 }
 
+
 fn interpret(pgm: &[Statement]) -> String {
     let mut out = String::new();
     let mut pointer: usize = 0;
@@ -27,6 +30,12 @@ fn interpret(pgm: &[Statement]) -> String {
     out
 }
 
+pub fn interpret_with_state(pgm: &[Statement], state: &mut BrainfuckState) {
+    for s in pgm {
+        execute(s, &mut state.memory, &mut state.pointer, &mut String::new())
+    }
+}
+
 fn execute(statement: &Statement, mem: &mut Memory, pointer: &mut usize, out: &mut String) {
     match statement {
         Statement::R => if *pointer == MEM_SIZE - 1 { *pointer = 0 } else { *pointer += 1 },

bfi-rust/src/main.rs

@@ -3,37 +3,35 @@ mod repl;
 
 use std::{env, fs};
 use std::time::SystemTime;
+use crate::repl::start_repl;
+use crate::interpreter::optimized::{PrintMode};
+use std::error::Error;
 
 
 fn main() {
     let path = env::args().nth(1);
-    let path = match path {
-        Some(p) => p,
-        None => {
-            println!("Please specify a path");
-            return;
-        }
+
+    match path {
+        Some(p) => {
+            if let Err(why) = run_program(p) {
+                eprintln!("An error occurred in the program: {}", why)
+            }
+        },
+        None => start_repl()
     };
+}
+
+fn run_program(path: String) -> Result<(), Box<dyn Error>> {
     let program = match fs::read_to_string(path) {
         Ok(p) => p,
         Err(e) => {
             println!("Error reading file: {}", e);
-            return;
+            return Err(Box::from(e));
         }
     };
-
-    run(program);
-}
-
-fn run(program: String) {
-/*
-    let start1 = SystemTime::now();
-    let out = interpreter::o1::run(&*program);
-    let end1 = start1.elapsed().unwrap();*/
-    let start2 = SystemTime::now();
-    let out2 = interpreter::optimized::run(&*program, false).unwrap();
-    let end2 = start2.elapsed().unwrap();
-    //assert_eq!(out, out2);
-    //println!("{}\nFinished execution. Took o1: 18008ms (for hanoi), o2: {}ms", out2/*, end1.as_millis()*/, end2.as_millis());
-    println!("{}\nFinished execution. Took {}ms", out2/*, end1.as_millis()*/, end2.as_millis());
+    let start_time = SystemTime::now();
+    let out = interpreter::optimized::run(&*program, PrintMode::DirectPrint)?;
+    let duration = start_time.elapsed()?;
+    println!("{}\nFinished execution. Took {}ms", out, duration.as_millis());
+    Ok(())
 }

bfi-rust/src/repl/mod.rs

@@ -0,0 +1,111 @@
+use std::fmt::{Display, Formatter};
+use std::fmt;
+use std::io::{stdin, stdout, Write};
+use crate::interpreter::{minify, parse, parsed, Memory, MEM_SIZE};
+use crate::interpreter::optimized::PrintMode;
+
+pub struct BrainfuckState {
+    pub memory: Memory,
+    pub pointer: usize,
+}
+
+impl Display for BrainfuckState {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", display_state(self))
+    }
+}
+
+fn display_state(state: &BrainfuckState) -> String {
+    let start = if state.pointer < 5 {
+        0
+    } else if state.pointer > MEM_SIZE - 10 {
+        MEM_SIZE - 10
+    } else {
+        state.pointer - 5
+    };
+
+    format!("{}-\n|{}|\n{}-\n{}|\n{}|\n{}|\n{}-\n   {}^^^^",
+            "----------".repeat(10),
+            {
+                let mut out = String::new();
+                let end = start + 10;
+                for i in start..end {
+                    out.push_str(&*format!("   {: >5}  ", i));
+                }
+                out
+            },
+            "----------".repeat(10),
+            "|         ".repeat(10),
+            {
+                let mut out = String::new();
+                let end = start + 10;
+                for i in start..end {
+                    out.push_str(&*format!("|   {: >3}   ", state.memory[i]));
+                }
+                out
+            },
+            "|         ".repeat(10),
+            "----------".repeat(10),
+            "          ".repeat(state.pointer - start))
+}
+
+pub fn start_repl() {
+    println!("Brainfuck REPL");
+
+    let mut state = BrainfuckState {
+        memory: [0; MEM_SIZE],
+        pointer: 0,
+    };
+
+    println!("Enter Brainfuck programs and they will be executed immediatly.");
+    println!("State is kept.");
+    println!("{}", state);
+    loop {
+        print!(">> ");
+        stdout().flush().unwrap();
+        match read_line() {
+            Ok(s) => {
+                match &*s {
+                    ":q" => break,
+                    ":?" | "help" | "?" => print_help(),
+                    ":r" => {
+                        reset(&mut state);
+                        println!("{}", state);
+                    },
+                    _ => {
+                        print!("Output: ");
+                        println!();
+                        parse_input(s, &mut state);
+                        println!("{}", state);
+                    }
+                }
+            }
+            Err(why) => println!("Error reading input: {}\nPlease try again.", why)
+        }
+    }
+}
+
+fn reset(state: &mut BrainfuckState) {
+    state.pointer = 0;
+    state.memory = [0; MEM_SIZE];
+}
+
+fn print_help() {
+    println!("Brainfuck REPL help
+   :q => quit
+   :? => help
+   :r => reset state");
+}
+
+fn parse_input(pgm: String, state: &mut BrainfuckState) {
+    let pgm = minify(&*pgm);
+    let pgm = parse(pgm.chars(), PrintMode::DirectPrint);
+    parsed::interpret_with_state(&*pgm, state);
+}
+
+pub fn read_line() -> Result<String, std::io::Error> {
+    let mut buf = String::new();
+    stdin().read_line(&mut buf)?;
+    buf.pop();
+    Ok(buf)
+}