Tweak new terminfo logical operator support

Author: lilyball

src/libextra/terminfo/parm.rs

@@ -68,7 +68,6 @@ pub fn expand(cap: &[u8], params: &mut [Param], sta: &mut [Param], dyn: &mut [Pa
 
     while i < cap.len() {
         cur = cap[i] as char;
-        debug!("current char: %c", cur);
         let mut old_state = state;
         match state {
             Nothing => {
@@ -134,43 +133,29 @@ pub fn expand(cap: &[u8], params: &mut [Param], sta: &mut [Param], dyn: &mut [Pa
                         (_, _) => return Err(~"non-numbers on stack with |")
                     },
                     'A' => match (stack.pop(), stack.pop()) {
-                        (Number(x), Number(y)) => {
-                            if x == 1 && y == 1 {
-                                stack.push(Number(1));
-                            } else {
-                                stack.push(Number(0));
-                            }
-                        },
-                        (_, _) => return Err(~"non-numbers on stack with logical and")
+                        (Number(0), Number(_)) => stack.push(Number(0)),
+                        (Number(_), Number(0)) => stack.push(Number(0)),
+                        (Number(_), Number(_)) => stack.push(Number(1)),
+                        _ => return Err(~"non-numbers on stack with logical and")
                     },
                     'O' => match (stack.pop(), stack.pop()) {
-                        (Number(x), Number(y)) => {
-                            if x == 1 && y == 1 {
-                                stack.push(Number(1));
-                            } else {
-                                stack.push(Number(0));
-                            }
-                        },
-                        (_, _) => return Err(~"non-numbers on stack with logical or")
+                        (Number(0), Number(0)) => stack.push(Number(0)),
+                        (Number(_), Number(_)) => stack.push(Number(1)),
+                        _ => return Err(~"non-numbers on stack with logical or")
                     },
                     '!' => match stack.pop() {
-                        Number(x) => {
-                            if x == 1 {
-                                stack.push(Number(0))
-                            } else {
-                                stack.push(Number(1))
-                            }
-                        },
+                        Number(0) => stack.push(Number(1)),
+                        Number(_) => stack.push(Number(0)),
                         _ => return Err(~"non-number on stack with logical not")
                     },
                     '~' => match stack.pop() {
                         Number(x) => stack.push(Number(!x)),
                         _         => return Err(~"non-number on stack with %~")
                     },
                     'i' => match (copy params[0], copy params[1]) {
-                        (Number(x), Number(y)) => {
-                            params[0] = Number(x + 1);
-                            params[1] = Number(y + 1);
+                        (Number(ref mut x), Number(ref mut y)) => {
+                            *x += 1;
+                            *y += 1;
                         },
                         (_, _) => return Err(~"first two params not numbers with %i")
                     },