C: allergies

c/allergies/src/allergies.c

@@ -0,0 +1,18 @@
+#include "allergies.h"
+
+bool is_allergic_to(const allergen_t all, const uint32_t val)
+{
+    return !!(val & (1 << all));
+}
+
+allergen_list_t get_allergens(uint32_t val)
+{
+    allergen_list_t list = { .count = 0 };
+    allergen_t i;
+
+    for (i=0; i<ALLERGEN_COUNT; ++i) {
+        list.allergens[i] = is_allergic_to(i, val);
+        list.count += list.allergens[i];
+    }
+    return list;
+}

c/allergies/src/allergies.h

@@ -0,0 +1,42 @@
+#ifndef ALLERGIES_H
+#define ALLERGIES_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+typedef enum {
+   ALLERGEN_EGGS = 0,
+   ALLERGEN_PEANUTS,
+   ALLERGEN_SHELLFISH,
+   ALLERGEN_STRAWBERRIES,
+   ALLERGEN_TOMATOES,
+   ALLERGEN_CHOCOLATE,
+   ALLERGEN_POLLEN,
+   ALLERGEN_CATS,
+   ALLERGEN_COUNT,
+} allergen_t;
+
+typedef struct {
+   int count;
+   bool allergens[ALLERGEN_COUNT];
+} allergen_list_t;
+
+// We could use macro...
+// #define is_allergic_to(allerg, val) (!!((val) & (1 << (allerg))))
+bool is_allergic_to(const allergen_t allergen, const uint32_t value);
+allergen_list_t get_allergens(uint32_t value);
+
+/* See GNUmakefile below for explanation
+ * https://github.com/braoult/exercism/blob/master/c/templates/GNUmakefile
+ */
+#if defined UNIT_TEST || defined DEBUG
+#include <stdio.h>
+#include <stdlib.h>
+#endif
+
+#ifdef  TESTALL
+#undef  TEST_IGNORE
+#define TEST_IGNORE() {}
+#endif
+
+#endif