implemented getNumBeads

src/Abacus.hs

@@ -24,7 +24,7 @@ License along with this program.  If not, see
 
 -}
 
-module Abacus (Abacus, newAbacus) where
+module Abacus (Abacus, newAbacus, getNumBeads) where
 
 import Abacus.Internal
 
@@ -40,4 +40,8 @@ newAbacus beads rungs = if beads < 1 || rungs < 1
   then Nothing
   else Just $ Abacus beads $ replicate rungs 0
 
+-- | Returns the number of beads per rung in an abacus
+getNumBeads :: Abacus -> Int
+getNumBeads = abacusNumBeads
+
 --jl

test/AbacusSpec.hs

@@ -21,14 +21,16 @@ License along with this program.  If not, see
 
 module AbacusSpec (spec) where
 
+import Data.Maybe (fromJust)
 import Test.Hspec (Spec, context, describe, it, shouldBe)
 
 import Abacus
 import Abacus.Internal
 
 spec :: Spec
-spec = describe "Abacus"
+spec = describe "Abacus" $ do
   newAbacusSpec
+  getNumBeadsSpec
 
 newAbacusSpec :: Spec
 newAbacusSpec = describe "newAbacusSpec" $ mapM_
@@ -42,4 +44,18 @@ newAbacusSpec = describe "newAbacusSpec" $ mapM_
   , ( "no rungs", 10, 0, Nothing                    )
   ]
 
+getNumBeadsSpec :: Spec
+getNumBeadsSpec = describe "getNumBeads" $ mapM_
+  ( \(desc, input, expected) -> context desc $ let
+    actual = getNumBeads input
+    in it ("should be " ++ show expected) $
+      actual `shouldBe` expected
+  )
+  [ ( "one bead",  oneBead,  1  )
+  , ( "ten beads", tenBeads, 10 )
+  ] where
+    oneBead = build 1
+    tenBeads = build 10
+    build n = fromJust $ newAbacus n 10
+
 --jl