Allergen

src/allergies.rs

@@ -1,54 +1,39 @@
-// Instructions
-// Given a person's allergy score, determine whether or not they're allergic to a given item,
-// and their full list of allergies.
-//
-// An allergy test produces a single numeric score which contains the information about all
-// the allergies the person has (that they were tested for).
-//
-// The list of items (and their value) that were tested are:
-//
-// eggs (1)
-// peanuts (2)
-// shellfish (4)
-// strawberries (8)
-// tomatoes (16)
-// chocolate (32)
-// pollen (64)
-// cats (128)
-// So if Tom is allergic to peanuts and chocolate, he gets a score of 34.
-//
-// Now, given just that score of 34, your program should be able to say:
-//
-// Whether Tom is allergic to any one of those allergens listed above.
-// All the allergens Tom is allergic to.
-// Note: a given score may include allergens not listed above (i.e. allergens that score 256, 512, 1024, etc.).
-// Your program should ignore those components of the score. For example,
-// if the allergy score is 257, your program should only report the eggs (1) allergy.
-
 pub struct Allergies(u32);
 
-#[derive(Debug, PartialEq, Eq)]
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
 pub enum Allergen {
-    Eggs,
-    Peanuts,
-    Shellfish,
-    Strawberries,
-    Tomatoes,
-    Chocolate,
-    Pollen,
-    Cats,
+    Eggs = 1 << 0,
+    Peanuts = 1 << 1,
+    Shellfish = 1 << 2,
+    Strawberries = 1 << 3,
+    Tomatoes = 1 << 4,
+    Chocolate = 1 << 5,
+    Pollen = 1 << 6,
+    Cats = 1 << 7,
 }
 
+const ALLERGENS: [Allergen; 8] = [
+        Allergen::Eggs,
+        Allergen::Peanuts,
+        Allergen::Shellfish,
+        Allergen::Strawberries,
+        Allergen::Tomatoes,
+        Allergen::Chocolate,
+        Allergen::Pollen,
+        Allergen::Cats
+];
+
 impl Allergies {
     pub fn new(score: u32) -> Self {
         Allergies(score)
     }
 
     pub fn is_allergic_to(&self, allergen: &Allergen) -> bool {
-        todo!("Determine if the patient is allergic to the '{allergen:?}' allergen.");
+        let allergen = *allergen as u32;
+        self.0 & allergen == allergen
     }
 
     pub fn allergies(&self) -> Vec<Allergen> {
-        todo!("Return the list of allergens contained within the score with which the Allergies struct was made.");
+        ALLERGENS.iter().filter(|allergen| self.is_allergic_to(allergen)).cloned().collect()
     }
 }