1 files changed, 48 insertions(+), 45 deletions(-)

M src/main.rs

@@ 11,68 11,71 @@ fn eval(op: &Operator, n1: i64, n2: i64) -> i64 {
         Operator('-') => n1 - n2,
         Operator('*') => n1 * n2,
         Operator('/') => n1 / n2,
-        _ =>  { panic!("Bad op: {:?}", op); }
+        _ => {
+            panic!("Bad op: {:?}", op);
+        }
     }
 }
 
 peg::parser!(
-    grammar calc_parser() for str {
-        rule number() -> i64
-        = n:$(['0'..='9']+) {
-            ? n.parse().or(Err("bad num"))
-        }
+grammar calc_parser() for str {
+    rule number() -> i64
+    = n:$(['0'..='9']+) {
+        ? n.parse().or(Err("bad num"))
+    }
 
-        rule whitespace() = quiet!{[' ']*}
+    rule whitespace() = quiet!{[' ']*}
 
-        rule operator() -> Operator
-        = op:$(['*' | '/' | '+' | '-']) { Operator(op.chars().nth(0).unwrap()) }
+    rule operator() -> Operator
+    = op:$(['*' | '/' | '+' | '-']) { Operator(op.chars().next().unwrap()) }
 
-        rule paren() -> i64 
-        = "(" whitespace() n:calculate() whitespace() ")" { n }
+    rule paren() -> i64
+    = "(" whitespace() n:calculate() whitespace() ")" { n }
 
-        rule factor() -> i64 
-        =
-        n:number() { n }
-        /
-        n:paren() { n }
+    rule factor() -> i64
+    =
+    n:number() { n }
+    /
+    n:paren() { n }
 
-        rule term() -> i64
-        = 
-        n1:factor() whitespace() op:operator() whitespace() n2:factor() {
-            eval(&op, n1, n2)
-        }
-        /
-        n:factor() { n }
+    rule term() -> i64
+    =
+    n1:factor() whitespace() op:operator() whitespace() n2:factor() {
+        eval(&op, n1, n2)
+    }
+    /
+    n:factor() { n }
 
-        pub rule calculate() -> i64
-        =
-        n1:term() whitespace() op:operator() whitespace() n2:term() {
-            eval(&op, n1, n2)
-        }
-        / 
-        n:term() { n }
+    pub rule calculate() -> i64
+    =
+    n1:term() whitespace() op:operator() whitespace() n2:term() {
+        eval(&op, n1, n2)
     }
-    );
+    /
+    n:term() { n }
+}
+);
 
 fn main() {
- loop {
-    println!("Enter an expression, or 'END' to quit: ");
-    let mut input = String::new(); 
-    io::stdin().read_line(&mut input)
-    .expect("Error reading input!");
+    loop {
+        println!("Enter an expression, or 'END' to quit: ");
+        let mut input = String::new();
+        io::stdin()
+            .read_line(&mut input)
+            .expect("Error reading input!");
 
-    let input = input.as_str().trim();
+        let input = input.as_str().trim();
 
-    if input == "END" {
-        break;
-    }
+        if input == "END" {
+            break;
+        }
 
-    let answer = calc_parser::calculate(input);
-    match answer {
-        Ok(v) => println!("Answer: {:?}", v),
-        Err(e) => println!("Calculation error: {:?}", e),
+        let answer = calc_parser::calculate(input);
+        match answer {
+            Ok(v) => println!("Answer: {:?}", v),
+            Err(e) => println!("Calculation error: {:?}", e),
+        }
     }
- } 
 }
 
 #[test]