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+-- Our use of genericLength in easyList will cause our function to loop
+-- infinitely if we supply an infinite list. Fix this.
+
+
+-- It is not possible to decide whether a list has been defined as infinite. For
+-- this, there would have to be some reflection capabilities in the
+-- language. Only a finite limit on the list max. length can be set and checked.
+
+
+-- I was compiling the code of this chapter by 'cabal build'. There were some
+-- warnings and errors. I have fixed only the errors.
+--
+--   - in BloomFilter/Hash.hs, a part of the import statement for CSize had to
+--     be changed from '(CSize)' to '(CSize(..))' to import the data
+--     constructor, not only the type constructor.
+--
+--   - in BloomFilter.hs in the fromList function, the 'B hash . runSTUArray $'
+--     had to be changed to 'B hash $ runSTUArray $' for the code to compile.
+
+
+-- For testing, I was loading the code into ghci. For it to be able to find
+-- symbols from the lookup3.o file, I needed to convert it to a shared library
+--
+--   gcc ./dist-newstyle/build/x86_64-linux/ghc-9.6.7/rwh-bloomfilter-0.1/build/cbits/lookup3.o -shared -o liblookup3.so
+--
+-- and load the shared library on start of ghci
+--
+--   stack ghci --ghci-options "-L$(pwd) -llookup3"
+
+
+import BloomFilter.Easy
+import BloomFilter.Hash (Hashable, doubleHash)
+import Data.List (genericLength)
+import qualified BloomFilter as B
+
+-- Helper function for forcing evaluation of the easyList and fixedEasyList
+-- return value
+easyListLength l =
+  case l of
+    Left err -> error err
+    Right b  -> BloomFilter.Easy.length b
+
+-- Short length for more illustrative testing
+maxLength = 10
+
+fixedEasyList errRate values =
+  if isLongerThan values maxLength
+  then
+    Left $ "List longer than " ++ (show maxLength) ++ " elements"
+  else
+    case suggestSizing (genericLength values) errRate of
+      Left err            -> Left err
+      Right (bits,hashes) -> Right filt
+        where filt = B.fromList (doubleHash hashes) bits values
+
+isLongerThan values max = isLongerThan' values 0 max
+  where
+    isLongerThan' []     l max = False
+    isLongerThan' (v:vs) l max
+      | (l + 1) > max = True
+      | otherwise     = isLongerThan' vs (l + 1) max
+
+
+-- ghci> :l 26_a_1.hs
+-- [1 of 7] Compiling BloomFilter.Hash ( BloomFilter/Hash.hs, interpreted )
+--   ... <omitted warnings here>
+-- [2 of 7] Compiling BloomFilter.Internal ( BloomFilter/Internal.hs, interpreted )
+-- [3 of 7] Compiling BloomFilter.Mutable ( BloomFilter/Mutable.hs, interpreted )
+-- [4 of 7] Compiling BloomFilter      ( BloomFilter.hs, interpreted )
+-- [5 of 7] Compiling BloomFilter.Easy ( BloomFilter/Easy.hs, interpreted )
+-- [6 of 7] Compiling Main             ( 26_a_1.hs, interpreted )
+-- Ok, six modules loaded.
+
+-- ghci> l = easyList 0.2 [1..]
+-- ghci> easyListLength l
+-- *** Exception: stack overflow
+
+-- ghci> l = fixedEasyList 0.2 [1..]
+-- ghci> easyListLength l
+-- *** Exception: List longer than 10 elements
+-- CallStack (from HasCallStack):
+--   error, called at 26_a_1.hs:40:17 in main:Main
+
+-- ghci> l = fixedEasyList 0.2 [1..10]
+-- ghci> easyListLength l
+-- 34