rust-calc/src/main.rs

@@ -1,4 +1,7 @@
-use std::process;
+use std::{
+    ops::{AddAssign, DivAssign, MulAssign, SubAssign},
+    process,
+};
 
 #[derive(Debug)]
 enum Symbol {
@@ -7,6 +10,16 @@ enum Symbol {
     Multiply,
     Divide,
 }
+impl Symbol {
+    fn priority(&self) -> bool {
+        match self {
+            Symbol::Multiply => true,
+            Symbol::Divide => true,
+
+            _ => false,
+        }
+    }
+}
 
 struct TmpNum {
     s: String,
@@ -58,6 +71,81 @@ fn parse(pattern: String) -> (Vec<Symbol>, Vec<f32>) {
     (symbols, numbers)
 }
 
+fn calcul(symbols: Vec<Symbol>, numbers: Vec<f32>) -> f32 {
+    let mut counter = 0;
+    let mut n1 = *numbers.get(0).expect("expect at least the first value");
+    while counter < symbols.len() {
+        let s = symbols
+            .get(counter)
+            .expect("expect at least a symbol value");
+        let n2 = *numbers
+            .get(counter + 1)
+            .expect("expect at least a second value");
+
+        if s.priority() {
+            match s {
+                Symbol::Multiply => {
+                    n1.mul_assign(n2);
+                }
+                Symbol::Divide => {
+                    n1.div_assign(n2);
+                }
+                _ => {}
+            };
+        } else {
+            let next_s = symbols.get(counter + 1);
+            match next_s {
+                Some(ss) => {
+                    if ss.priority() {
+                        let mut counter_2 = counter + 1;
+                        let mut nn1 = *numbers
+                            .get(counter_2)
+                            .expect("during the priority, we expect at least the first value");
+                        while counter_2 < symbols.len() {
+                            let nn2 = *numbers
+                                .get(counter_2)
+                                .expect("during the priority, we expect at least the second value");
+
+                            if ss.priority() {
+                                match ss {
+                                    Symbol::Multiply => {
+                                        nn1.mul_assign(nn2);
+                                    }
+                                    Symbol::Divide => {
+                                        nn1.div_assign(nn2);
+                                    }
+                                    _ => {}
+                                }
+                            } else {
+                                counter = counter_2;
+                                n1 = nn1;
+                                break;
+                            }
+
+                            counter_2 += 1;
+                        }
+                    }
+                }
+                None => {}
+            }
+
+            match s {
+                Symbol::Minus => {
+                    n1.sub_assign(n2);
+                }
+                Symbol::Plus => {
+                    n1.add_assign(n2);
+                }
+                _ => {}
+            }
+        }
+
+        counter += 1;
+    }
+
+    n1
+}
+
 fn main() {
     let pattern = match std::env::args().nth(1) {
         None => {
@@ -69,13 +157,14 @@ fn main() {
 
     let (symbols, numbers) = parse(pattern);
 
-    println!("{:?}", symbols);
-    println!("{:?}", numbers);
+    // println!("{:?}", symbols);
+    // println!("{:?}", numbers);
 
-    let mut counter = 0;
-    let mut n1 = numbers.get(0).expect("expect at least the first value");
-    while counter < symbols.len() {
-        let mut n2 = numbers.get(counter+1).expect("expect at least a second value");
-        counter +=1;
+    if symbols.len() < 1 || symbols.len() + 1 != numbers.len() {
+        println!("The input is malformed");
+        process::exit(2);
     }
+
+    let res = calcul(symbols, numbers);
+    println!("{res}");
 }