rewriting ex.3.1 page 41

Haskell Excercises & Code/Alejandro - Book of Monads/dist-newstyle/build/x86_64-windows/ghc-9.2.1/parsing-0.1.0.0/build/autogen/cabal_macros.h

@@ -20,6 +20,16 @@
   (major1) == 4 && (major2) <  16 || \
   (major1) == 4 && (major2) == 16 && (minor) <= 0)
 #endif /* MIN_VERSION_base */
+/* package mtl-2.2.2 */
+#ifndef VERSION_mtl
+#define VERSION_mtl "2.2.2"
+#endif /* VERSION_mtl */
+#ifndef MIN_VERSION_mtl
+#define MIN_VERSION_mtl(major1,major2,minor) (\
+  (major1) <  2 || \
+  (major1) == 2 && (major2) <  2 || \
+  (major1) == 2 && (major2) == 2 && (minor) <= 2)
+#endif /* MIN_VERSION_mtl */
 
 /* tool gcc-10.2.0 */
 #ifndef TOOL_VERSION_gcc

Haskell Excercises & Code/Alejandro - Book of Monads/dist-newstyle/cache/plan.json

@@ -1 +1 @@
-{"cabal-version":"3.6.2.0","cabal-lib-version":"3.6.2.0","compiler-id":"ghc-9.2.1","os":"windows","arch":"x86_64","install-plan":[{"type":"pre-existing","id":"base-4.16.0.0","pkg-name":"base","pkg-version":"4.16.0.0","depends":["ghc-bignum-1.2","ghc-prim-0.8.0","rts-1.0.2"]},{"type":"pre-existing","id":"ghc-bignum-1.2","pkg-name":"ghc-bignum","pkg-version":"1.2","depends":["ghc-prim-0.8.0"]},{"type":"pre-existing","id":"ghc-prim-0.8.0","pkg-name":"ghc-prim","pkg-version":"0.8.0","depends":["rts-1.0.2"]},{"type":"configured","id":"parsing-0.1.0.0-inplace","pkg-name":"parsing","pkg-version":"0.1.0.0","flags":{},"style":"local","pkg-src":{"type":"local","path":"C:\\Users\\Administrator\\Desktop\\Haskell first Principles\\haskell-deepidive\\Haskell Excercises & Code\\Alejandro - Book of Monads\\."},"dist-dir":"C:\\Users\\Administrator\\Desktop\\Haskell first Principles\\haskell-deepidive\\Haskell Excercises & Code\\Alejandro - Book of Monads\\dist-newstyle\\build\\x86_64-windows\\ghc-9.2.1\\parsing-0.1.0.0","depends":["base-4.16.0.0"],"exe-depends":[],"component-name":"lib"},{"type":"pre-existing","id":"rts-1.0.2","pkg-name":"rts","pkg-version":"1.0.2","depends":[]}]}
+{"cabal-version":"3.6.2.0","cabal-lib-version":"3.6.2.0","compiler-id":"ghc-9.2.1","os":"windows","arch":"x86_64","install-plan":[{"type":"pre-existing","id":"base-4.16.0.0","pkg-name":"base","pkg-version":"4.16.0.0","depends":["ghc-bignum-1.2","ghc-prim-0.8.0","rts-1.0.2"]},{"type":"pre-existing","id":"ghc-bignum-1.2","pkg-name":"ghc-bignum","pkg-version":"1.2","depends":["ghc-prim-0.8.0"]},{"type":"pre-existing","id":"ghc-prim-0.8.0","pkg-name":"ghc-prim","pkg-version":"0.8.0","depends":["rts-1.0.2"]},{"type":"pre-existing","id":"mtl-2.2.2","pkg-name":"mtl","pkg-version":"2.2.2","depends":["base-4.16.0.0","transformers-0.5.6.2"]},{"type":"configured","id":"parsing-0.1.0.0-inplace","pkg-name":"parsing","pkg-version":"0.1.0.0","flags":{},"style":"local","pkg-src":{"type":"local","path":"C:\\Users\\Administrator\\Desktop\\Haskell first Principles\\haskell-deepidive\\Haskell Excercises & Code\\Alejandro - Book of Monads\\."},"dist-dir":"C:\\Users\\Administrator\\Desktop\\Haskell first Principles\\haskell-deepidive\\Haskell Excercises & Code\\Alejandro - Book of Monads\\dist-newstyle\\build\\x86_64-windows\\ghc-9.2.1\\parsing-0.1.0.0","depends":["base-4.16.0.0","mtl-2.2.2"],"exe-depends":[],"component-name":"lib"},{"type":"pre-existing","id":"rts-1.0.2","pkg-name":"rts","pkg-version":"1.0.2","depends":[]},{"type":"pre-existing","id":"transformers-0.5.6.2","pkg-name":"transformers","pkg-version":"0.5.6.2","depends":["base-4.16.0.0"]}]}

Haskell Excercises & Code/Alejandro - Book of Monads/dist-newstyle/packagedb/ghc-9.2.1/parsing-0.1.0.0-inplace.conf

@@ -23,7 +23,7 @@ data-dir:
 
 hs-libraries:         HSparsing-0.1.0.0-inplace
 include-dirs:         C:\tools\msys64\mingw64\include
-depends:              base-4.16.0.0
+depends:              base-4.16.0.0 mtl-2.2.2
 haddock-interfaces:
     "C:\\Users\\Administrator\\Desktop\\Haskell first Principles\\haskell-deepidive\\Haskell Excercises & Code\\Alejandro - Book of Monads\\dist-newstyle\\build\\x86_64-windows\\ghc-9.2.1\\parsing-0.1.0.0\\doc\\html\\parsing\\parsing.haddock"
 

Haskell Excercises & Code/Alejandro - Book of Monads/monadic.hs

@@ -0,0 +1,13 @@
+{-# LANGUAGE FlexibleContexts #-}
+module MonadicCode where
+
+import Control.Monad.State as CMS
+
+
+-- implement `ap` yourself
+
+ap :: Monad m => m (a -> b) -> m a -> m b
+ap mf mx = do
+    f <- mf
+    x <- mx
+    return (f x) 

Haskell Excercises & Code/Alejandro - Book of Monads/parser.cabal

@@ -11,5 +11,6 @@ library
  exposed-modules: JSONParser
  ghc-options: -Wall -fwarn-tabs
  build-depends: base >=4.7 && <5
+                , mtl
  hs-source-dirs: .
  default-language: Haskell2010

Haskell Excercises & Code/Alejandro - Book of Monads/practice.hs

@@ -1,5 +1,7 @@
 module WithCounting where
 
+import Control.Monad.State as CMS
+
 -- Chapter 1. Exercises and Practice
 type WithCounter a = Int -> (a, Int)
 
@@ -23,10 +25,10 @@ pure x = \i -> (x, i)
 type State s a = s -> (a, s)
 
 -- rewrite next & pure
-next' :: State s a -> (a -> State s b) -> State s b
+next' :: CMS.State s a -> (a -> CMS.State s b) -> CMS.State s b
 f `next'` g = \i -> let (r, i') = f i in g r i'
 
-pure' :: a -> State s a
+pure' :: a -> CMS.State s a
 pure' x = \s -> (x, s) 
 
 -- 1.2
@@ -54,7 +56,7 @@ flatten :: Maybe (Maybe a) -> Maybe a
 flatten (Just (Just x)) = Just x
 flatten _               = Nothing
 
-flatten' oo = then_ oo id
-            -- case oo of 
-                Nothing -> Nothing
-                Just x -> id x ==> x
+-- flatten' oo = then_ oo id
+--             -- case oo of 
+--                 Nothing -> Nothing
+--                 Just x -> id x ==> x