ft: add debug and info logging

src/interpret.rs

@@ -7,8 +7,11 @@ pub fn interpret(code: &str) -> Vec<u8> {
     let mut loop_stack = Vec::new();
     let mut out = Vec::new();
 
+    log::info!("Program size: {}", code.len());
+
     let code_bytes = code.as_bytes();
     while pc < code.len() {
+        log::debug!("Next instruction: {}", code_bytes[pc] as char);
         match code_bytes[pc] as char {
             '>' => head += 1,
             '<' => head -= 1,
@@ -23,6 +26,7 @@ pub fn interpret(code: &str) -> Vec<u8> {
                 if io::stdin().read_exact(&mut input_buf).is_ok() {
                     memory[head] = input_buf[0];
                 }
+                log::debug!("Read user input: {}", input_buf[0]);
             }
             '[' => {
                 // loop start
@@ -46,6 +50,7 @@ pub fn interpret(code: &str) -> Vec<u8> {
                     }
                 } else {
                     // save pc to jump back to
+                    log::info!("Pushing location {} onto loop stack", pc);
                     loop_stack.push(pc);
                 }
             }
@@ -60,10 +65,12 @@ pub fn interpret(code: &str) -> Vec<u8> {
                     }
                 } else {
                     // loop done, continue normally
-                    loop_stack.pop();
+                    let location = loop_stack.pop();
+                    log::info!("Done with loop at location {}", location.unwrap());
                 }
             }
-            _ => panic!("Invalid instruction"),
+            // ignore unknown characters (e.g. weird line endings)
+            _ => {}
         }
         pc += 1;
     }

src/main.rs

@@ -4,6 +4,8 @@ use std::{env, fs, process};
 mod interpret;
 
 fn main() {
+    env_logger::init();
+
     let args: Vec<_> = env::args().collect();
     if args.len() != 2 {
         eprintln!("Usage: {} <filename>", args[0]);
@@ -15,5 +17,6 @@ fn main() {
         panic!("Error reading file {}: {}", filename, err);
     });
 
+    println!("Running file {} with program {}", filename, code);
     interpret(&code);
 }