Exercice completed

02/solutions/perform-simple-calculation/src/albert.rs

@@ -0,0 +1,59 @@
+//! Run this file with `cargo test --test 01_calc`.
+
+// TODO: Create an enum that represents three simple mathematical operations
+// (Add a number, subtract a number, and clamp a number).
+// Clamping a number `x` to the interval [l, r] means that after the operation
+// is performed, `x` cannot be smaller than `l` and cannot be larger than `r`.
+//
+// Then implement the `perform_calculation` function
+// (see tests) that receives a single `i32` number and the enum, which represents which
+// operation should be performed on it.
+// Hint: max(..) and min(..) methods of `i32` might come in handy.
+
+pub enum Op {
+    Add(i32),
+    Sub(i32),
+    Clamp{low: i32, high: i32}
+}
+
+pub fn perform_calculation(num: i32, op: Op) -> i32 {
+    match op {
+        Op::Add(x) => num + x,
+        Op::Sub(x) => num - x,
+        Op::Clamp{low,high} => num.max(low).min(high)
+    }
+}
+/// Below you can find a set of unit tests.
+#[cfg(test)]
+mod tests {
+    use super::{perform_calculation, Op};
+
+    #[test]
+    fn calc_add() {
+        assert_eq!(perform_calculation(0, Op::Add(1)), 1);
+        assert_eq!(perform_calculation(3, Op::Add(10)), 13);
+    }
+
+    #[test]
+    fn calc_sub() {
+        assert_eq!(perform_calculation(0, Op::Sub(10)), -10);
+        assert_eq!(perform_calculation(3000, Op::Sub(-5)), 3005);
+    }
+
+    /// Clamp makes sure that a value is between a minimum and maximum value
+    /// (inclusive).
+    /// clamp(1, 0, 8)     = 1
+    /// clamp(-5, 0, 8)    = 0
+    /// clamp(-5, -15, 9)  = -5
+    /// clamp(50, 0, 8)    = 8
+    /// clamp(50, 0, 80)   = 50
+    #[test]
+    fn calc_clamp() {
+        assert_eq!(perform_calculation(0, Op::Clamp { low: 0, high: 0 }), 0);
+        assert_eq!(perform_calculation(5, Op::Clamp { low: 0, high: 0 }), 0);
+        assert_eq!(perform_calculation(3, Op::Clamp { low: 2, high: 8 }), 3);
+        assert_eq!(perform_calculation(-5, Op::Clamp { low: 0, high: 10 }), 0);
+        assert_eq!(perform_calculation(50, Op::Clamp { low: 3, high: 10 }), 10);
+        assert_eq!(perform_calculation(50, Op::Clamp { low: 3, high: 100 }), 50);
+    }
+}

02/solutions/perform-simple-calculation/src/lib.rs

@@ -1 +1,3 @@
 #![allow(dead_code)]
+
+mod albert;