From ba43937232c267dc42c198f07337a18c9717b892 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christoffer=20M=C3=BCller=20Madsen?=
 <christoffer@guava.space>
Date: Wed, 5 Apr 2017 12:19:03 +0200
Subject: [PATCH] add search for recipes by list of ingredients

---
 parse.scm | 31 +++++++++++++++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

diff --git a/parse.scm b/parse.scm
index f36e89b..3f964c0 100644
--- a/parse.scm
+++ b/parse.scm
@@ -42,6 +42,33 @@
                                       search-name)]))))
 
 (define contains-ingredient?
-  (lambda (recipe ingredient)
+  (lambda (recipe search-ingredient)
     (let ((ingredients (ingredients recipe)))
-      (ingredient-by-name ingredients ingredient))))
+      (ingredient-by-name ingredients search-ingredient))))
+
+(define contains-ingredients?
+  (lambda (recipe search-ingredients)
+    (let ((ingredients (ingredients recipe)))
+      (cond [(null? search-ingredients) #t]
+            [(ingredient-by-name ingredients
+                                 (car search-ingredients))
+             (contains-ingredients? recipe
+                                    (cdr search-ingredients))]
+            [else #f])
+      )))
+
+(define recipes-by-ingredients
+  (lambda (recipes search-ingredients list)
+    (if (null? recipes)
+        list
+        (let* ((recipe (car recipes))
+               (ingredients (ingredients recipe))
+               (contains? (contains-ingredients? recipe
+                                                 search-ingredients)))
+          (if contains?
+              (recipes-by-ingredients (cdr recipes)
+                                      search-ingredients
+                                      (cons recipe list))
+              (recipes-by-ingredients (cdr recipes)
+                                      search-ingredients
+                                      list))))))