diff options
| -rw-r--r-- | src/main.rs | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/src/main.rs b/src/main.rs index d93bc5f..75d5d2e 100644 --- a/src/main.rs +++ b/src/main.rs @@ -98,6 +98,23 @@ fn find_loops(commands: &mut Vec<Command>) -> Result<(), String> { Ok(()) } +fn optimize(program: &mut Vec<Command>) { + let mut remove_pair = |first: Command, second: Command| -> bool { + for i in 0 .. program.len() - 1 { + if (program[i] == first && program[i+1] == second) || + (program[i] == second && program[i+1] == first) { + program.remove(i+1); + program.remove(i); + return true; + } + } + false + }; + + while remove_pair(Command::INCPTR, Command::DECPTR) {} + while remove_pair(Command::INCVAL, Command::DECVAL) {} +} + fn preprocess(program: &str) -> String { let allowed_chars = ['>', '<', '+', '-', '.', ',', '[', ']']; program.chars().filter(|c| allowed_chars.contains(c)).collect() @@ -129,6 +146,7 @@ fn run() -> Result<(), String> { Err(e) => return Err(format!("Cannot open file: {}", e)), }; let mut commands = tokenize(&input); + optimize(&mut commands); find_loops(&mut commands)?; let mut program = Program{commands}; @@ -220,4 +238,19 @@ mod tests { let expected = vec!['4' as u8, '2' as u8]; assert_eq!(buf_out.get_ref(), &expected); } + + #[test] + fn test_optimize() { + let mut commands = vec![ + Command::INCPTR, Command::DECPTR, + Command::DECPTR, Command::INCPTR, + Command::INCVAL, Command::DECVAL, + Command::DECVAL, Command::INCVAL, + Command::INCPTR, Command::GETC, Command::DECPTR, + Command::INCVAL, Command::INCVAL, Command::DECPTR, Command::INCPTR, Command::DECVAL, Command::DECVAL, + Command::PUTC, Command::INCVAL, + ]; + optimize(&mut commands); + assert_eq!(commands, [Command::INCPTR, Command::GETC, Command::DECPTR, Command::PUTC, Command::INCVAL]); + } } |