More Rustiness

Author: ararslan

.gitignore

@@ -1,2 +1,2 @@
 # Binaries
-bin/qqq
+bin/

rust/main.rs

@@ -1,4 +1,4 @@
-use std::io::{stdin, stdout, Read, Write};
+use std::io::{Read, Write};
 
 fn parse_instructions(code: String) -> Vec<char> {
     let mut instructions = Vec::new();
@@ -52,11 +52,11 @@ fn evaluate(instructions: Vec<char>) {
                 tape[mem_ptr] -= 0x01;
             },
             '?' => {
-                let input: Option<u8> = io::stdin().bytes()
-                                                   .next()
-                                                   .map(|b| b as u8)
-                                                   .expect("No input received");
-                tape[mem_ptr] = input.unwrap();
+                let input: Option<u8> = std::io::stdin().bytes()
+                                                        .next()
+                                                        .and_then(|r| r.ok())
+                                                        .map(|b| b as u8);
+                tape[mem_ptr] = input.unwrap_or(0x00);
             },
             '!' => {
                 // print as char if printable ASCII, otherwise print raw
@@ -65,32 +65,47 @@ fn evaluate(instructions: Vec<char>) {
                 } else {
                     print!("{}", tape[mem_ptr])
                 }
-                io::stdout().flush().unwrap();
+                std::io::stdout().flush().unwrap();
             },
             '[' => {
                 if tape[mem_ptr] == 0x00 {
-                    // advance to matching close bracket
-                    while instructions[ins_ptr] != ']' {
-                        ins_ptr += 1
+                    let mut balance = 1;
+                    // find the corresponding closing bracket, move the ip to it
+                    loop {
+                        ins_ptr += 1;
+                        if instructions[ins_ptr] == '[' {
+                            balance += 1
+                        } else if instructions[ins_ptr] == ']' {
+                            balance -= 1
+                        }
+                        if balance == 0 { break }
                     }
                 }
-                continue
             },
             ']' => {
                 if tape[mem_ptr] == 0x00 {
-                    // move back to just before the matching open bracket
-                    while instructions[ins_ptr] != '[' {
-                        ins_ptr -= 1
+                    let mut balance = 1;
+                    // find the corresponding opening bracket, move the ip just before it
+                    loop {
+                        if instructions[ins_ptr] == '[' {
+                            balance += 1
+                        } else if instructions[ins_ptr] == ']' {
+                            balance -= 1
+                        }
+                        ins_ptr -= 1;
+                        if balance == 0 { break }
                     }
-                    ins_ptr -= 1
                 }
-                continue
             }
+            _ => unreachable!(),
         }
         ins_ptr += 1
     }
 }
 
 fn main() {
-    // TODO
+    // Just a test, doesn't seem to be working just yet
+    let code = "\"?'\"........'\",;;....\";.;.;.;..;...\"-'\";,\";;;.;.;.'\"-'\"--\";;;;.;....;!;,,,!.......!!'\",;.;.--'\";...!---!--!;;;;....'\",-....;'\"-,!;;!...!;!,,,,,,,,!-----!".to_string();
+    let instr = parse_instructions(code);
+    evaluate(instr);
 }