Added type alias to constrain values to a set (Iltotore#137)

rparree · Jun 16, 2023 · 7f3430f · 7f3430f
1 parent 20c29a3
commit 7f3430f
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diff --git a/main/src/io/github/iltotore/iron/constraint/any.scala b/main/src/io/github/iltotore/iron/constraint/any.scala
@@ -66,6 +66,17 @@ object any:
    */
   final class StrictEqual[V]
 
+  /**
+   * Tests strict equality with any one of the given values.
+   * @tparam V the values the input must be in.
+   * @example {{{
+   * type Digit = In[(0, 1, 2, 3, 4, 5, 6, 7, 8, 9)]
+   * }}}
+   */
+  type In[V <: NonEmptyTuple] = V match
+    case *:[h, EmptyTuple] => StrictEqual[h]
+    case *:[h, t]          => StrictEqual[h] | In[t]
+
   object True:
 
     inline given [A]: Constraint[A, True] with

diff --git a/main/test/src/io/github/iltotore/iron/testing/AnySuite.scala b/main/test/src/io/github/iltotore/iron/testing/AnySuite.scala
@@ -44,4 +44,10 @@ object AnySuite extends TestSuite:
       test - 0.assertRefine[StrictEqual[0]]
       test - 1.assertNotRefine[StrictEqual[0]]
     }
+
+    test("in") {
+      test - 0.assertRefine[In[(0, 1)]]
+      test - 1.assertRefine[In[(0, 1)]]
+      test - 2.assertNotRefine[In[(0, 1)]]
+    }
   }