First attempt at a dumb brainfuck interpreter

.gitignore

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+/target

Cargo.lock

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+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "bfin"
+version = "0.1.0"

Cargo.toml

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+[package]
+name = "bfin"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

input/cat.bf

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+,[.,]

input/hello-world.bf

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++++++++++++[>++++++>+++++++++>++++++++>++++>+++>+<<<<<<-]>+++
++++.>++.+++++++..+++.>>.>-.<<-.<.+++.------.--------.>>>+.>-.

input/loop.bf

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+,[->+<]>++.

input/math.bf

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+,++.

rust-toolchain.toml

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+[toolchain]
+channel = "nightly"

src/main.rs

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+use std::{
+    collections::{HashMap, VecDeque},
+    fs,
+    io::{self, Write},
+    path::PathBuf,
+};
+
+const PROGRAM: &str = "hello-world.bf";
+
+fn main() {
+    let program: Vec<u8> = load_program();
+
+    let mut tape: Vec<u8> = vec![0];
+    let mut cell_index: usize = 0;
+
+    let mut ip: usize = 0;
+    let mut user_input: Vec<u8> = vec![];
+
+    let mut table: HashMap<usize, usize> = HashMap::new();
+    let mut stack: VecDeque<usize> = VecDeque::new();
+    for (ip, instruction) in program.iter().enumerate() {
+        if *instruction == b'[' {
+            stack.push_back(ip);
+        } else if *instruction == b']' {
+            let begin_index = stack.pop_front().unwrap();
+            table.insert(begin_index, ip);
+            table.insert(ip, begin_index);
+        }
+    }
+
+    while ip < program.len() {
+        let Some(instruction) = program.get(ip) else {
+            break;
+        };
+
+        match instruction {
+            b'+' => tape[cell_index] = tape[cell_index].wrapping_add(1),
+            b'-' => tape[cell_index] = tape[cell_index].wrapping_sub(1),
+            b'>' => {
+                cell_index = cell_index.wrapping_add(1);
+                if tape.len() <= cell_index {
+                    tape.push(0);
+                }
+            }
+            b'<' => cell_index = cell_index.wrapping_sub(1),
+            b'.' => print!("{}", tape[cell_index] as char),
+            b',' => {
+                if user_input.is_empty() {
+                    user_input = input();
+                }
+                tape[cell_index] = user_input.remove(0);
+            }
+            b'[' => {
+                if tape[cell_index] == 0 {
+                    ip = *table.get(&ip).unwrap();
+                }
+            }
+            b']' => {
+                if tape[cell_index] != 0 {
+                    ip = *table.get(&ip).unwrap();
+                }
+            }
+            _ => {}
+        }
+
+        ip += 1;
+    }
+
+    println!();
+}
+
+fn input() -> Vec<u8> {
+    let mut input = String::new();
+
+    print!("Input: ");
+    let _ = io::stdout().flush();
+    let _ = io::stdin().read_line(&mut input);
+
+    input.as_bytes().to_vec()
+}
+
+fn load_program() -> Vec<u8> {
+    let path: PathBuf = [".", "input", PROGRAM].iter().collect();
+    let input = fs::read_to_string(path).unwrap();
+    input.as_bytes().to_vec()
+}