From 59287df01cc51c16b605414ee166a48ec66acc53 Mon Sep 17 00:00:00 2001
From: Gregory <neogen570@gmail.com>
Date: Mon, 1 Jun 2020 01:55:44 +0300
Subject: [PATCH] number_in_months done

---
 sml/week1/date.sml       | 14 +++++++
 sml/week1/date_tests.sml | 79 +++++++++++++++++++++++++++++++---------
 2 files changed, 75 insertions(+), 18 deletions(-)

diff --git a/sml/week1/date.sml b/sml/week1/date.sml
index c527ac9..64d4634 100644
--- a/sml/week1/date.sml
+++ b/sml/week1/date.sml
@@ -1,6 +1,10 @@
 (* year * month * day *)
 type Date = int * int * int
 
+fun |> (x, f) = f x
+
+infix |>
+
 fun fold f lst acc = 
     case lst of
         [] => acc
@@ -30,3 +34,13 @@ fun number_in_month (
         fold count_month dates 0
     end
 
+fun number_in_months (
+    dates: Date list,
+    months_to_find: int list
+): int =
+    let
+        fun count_months month acc = acc + number_in_month (dates, month)
+    in
+        fold count_months months_to_find 0
+    end
+
diff --git a/sml/week1/date_tests.sml b/sml/week1/date_tests.sml
index 2aec7c7..4a6de89 100644
--- a/sml/week1/date_tests.sml
+++ b/sml/week1/date_tests.sml
@@ -1,57 +1,100 @@
 use "test.sml";
 use "date.sml";
 
-
-val () = 
-    assert 
+val () =
+    assert
         (is_older ((1999, 12, 31), (1999, 12, 31)) = false)
         "is_older: same dates evaluates to false" 
 
-val () = 
-    assert 
+val () =
+    assert
         (is_older ((2000, 11, 28), (2000, 11, 29)) = true)
         "is_older: first date older than second by day" 
 
-val () = 
-    assert 
+val () =
+    assert
         (is_older ((1999, 12, 31), (1999, 11, 31)) = false)
         "is_older: first date greater by month" 
 
-val () = 
-    assert 
+val () =
+    assert
         (is_older ((1999, 12, 31), (1999, 11, 31)) = false)
         "is_older: first date greater by month" 
 
-val () = 
-    assert 
+val () =
+    assert
         (is_older ((2000, 12, 31), (1999, 12, 31)) = false)
         "is_older: first date greater by year" 
 
-val () = 
-    assert 
+val () =
+    assert
         (number_in_month ([(2000, 12, 31)], 12) = 1)
         "number_in_month: one date with exact month" 
 
-val () = 
+val () =
     let
         val dates = [(2000, 12, 31), (2000, 12, 31)]
         val month = 12
         val expect = 2
     in
-        assert 
+        assert
             (number_in_month (dates, month) = expect)
             "number_in_month: two date with exact month"
     end
 
-val () = 
+val () =
+    let
+        val dates = [(2000, 11, 31), (2000, 12, 31)]
+        val month = 11
+        val expect = 1
+    in
+        assert
+            (number_in_month (dates, month) = expect)
+            "number_in_month: two date but only one matches"
+    end
+
+val () =
     let
         val dates = []
         val month = 12
         val expect = 0
     in
-        assert 
+        assert
             (number_in_month (dates, month) = expect)
-            "number_in_month: empty list"
+            "number_in_month: empty list should return 0"
+    end
+
+val () =
+    let
+        val dates = []
+        val months = []
+        val expect = 0
+    in
+        assert
+            (number_in_months (dates, months) = expect)
+            "number_in_months: empty list should return 0"
+    end
+
+val () =
+    let
+        val dates = [(2000, 11, 31), (2000, 11, 31)]
+        val months = [11]
+        val expect = 2
+    in
+        assert
+            (number_in_months (dates, months) = expect)
+            "number_in_months: one month matches with two dates"
+    end
+
+val () =
+    let
+        val dates = [(2000, 11, 31), (2000, 12, 31),  (2000, 12, 31)]
+        val months = [11, 12]
+        val expect = 3
+    in
+        assert
+            (number_in_months (dates, months) = expect)
+            "number_in_months: multiple dates with same month"
     end
 
 val () = complete ()
\ No newline at end of file