add ex1 and ex2

exercise1/ex1.hs

+zipL :: ([Int],[Int]) -> [[Int]]
+zipL (xs,ys) | length xs /= length ys = [[]]
+zipL ([],[])     = []
+zipL (x:xs,y:ys) = [x,y] : zipL (xs,ys)
\ No newline at end of file

exercise2stack/.gitignore

+.stack-work/
+*~
\ No newline at end of file

exercise2stack/ChangeLog.md

+# Changelog for exercise2stack
+
+## Unreleased changes

exercise2stack/LICENSE

+Copyright ik (c) 2021
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+
+    * Neither the name of ik nor the names of other
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

exercise2stack/README.md

+# exercise2stack

exercise2stack/Setup.hs

+import Distribution.Simple
+main = defaultMain

exercise2stack/Sheet2/Task1/Main.hs

+import Tokens
+import System.Environment
+import Control.Exception
+import System.IO
+
+
+main :: IO ()
+main = catch main' noLex
+
+main' = do (fileName : _ ) <- getArgs 
+           sourceText <- readFile fileName
+           putStrLn ("Lexing : " ++ sourceText)
+           let lexedProg = alexScanTokens sourceText
+           putStrLn ("Lexed as " ++ (show lexedProg))
+
+noLex :: ErrorCall -> IO ()
+noLex e = do let err =  show e
+             hPutStr stderr ("Problem with Lexing : " ++ err)
+             return ()
\ No newline at end of file

exercise2stack/Sheet2/Task1/Tokens.x

+{ 
+module Tokens where 
+}
+
+%wrapper "basic" 
+$digit = 0-9     
+-- digits 
+$alpha = [a-zA-Z]    
+-- alphabetic characters
+
+tokens :-
+$white+       ; 
+  "--".*        ; 
+  let           { \s -> TokenLet } 
+  in            { \s -> TokenIn }
+  $digit+       { \s -> TokenInt (read s) } 
+  \=            { \s -> TokenEq }
+  \+            { \s -> TokenPlus }
+  \-            { \s -> TokenMinus }
+  \*            { \s -> TokenTimes }
+  \/            { \s -> TokenDiv }
+  \^            { \s -> TokenExp }
+  \(            { \s -> TokenLParen }
+  \)            { \s -> TokenRParen }
+  $alpha [$alpha $digit \_ \']*   { \s -> TokenVar s } 
+
+{ 
+-- Each action has type :: String -> Token 
+-- The token type: 
+data Token = 
+  TokenLet         | 
+  TokenIn          | 
+  TokenInt Int     |
+  TokenVar String  | 
+  TokenEq          |
+  TokenPlus        |
+  TokenMinus       |
+  TokenTimes       |
+  TokenDiv         |
+  TokenExp         |
+  TokenLParen      |
+  TokenRParen       
+  deriving (Eq,Show) 
+
+}
\ No newline at end of file

exercise2stack/Sheet2/Task2/Main.hs

+import Tokens
+import System.Environment
+import Control.Exception
+import System.IO
+
+
+main :: IO ()
+main = catch main' noLex
+
+main'  = do (fileName : _ ) <- getArgs 
+            sourceText <- readFile fileName
+            putStrLn ("Lexing : " ++ sourceText)
+            let lexedProg = (alexScanTokens sourceText)
+            putStrLn ("lexed as " ++ (show lexedProg))
+
+noLex :: ErrorCall -> IO ()
+noLex e = do let err =  show e
+             hPutStr stderr ("Problem with lexing: " ++ err)
+             return ()
\ No newline at end of file

exercise2stack/Sheet2/Task2/Tokens.x

+{ 
+module Tokens where 
+}
+
+%wrapper "posn" 
+$digit = 0-9     
+-- digits 
+$alpha = [a-zA-Z]    
+-- alphabetic characters
+
+tokens :-
+  $white+       ; 
+  "--".*        ; 
+  let           { \p s -> TokenLet p} 
+  in            { \p s -> TokenIn p }
+  $digit+       { \p s -> TokenInt p (read s) } 
+  \=            { \p s -> TokenEq p }
+  \+            { \p s -> TokenPlus p }
+  \-            { \p s -> TokenMinus p }
+  \*            { \p s -> TokenTimes p }
+  \/            { \p s -> TokenDiv p }
+  \^            { \p s -> TokenExp p }
+  \(            { \p s -> TokenLParen p }
+  \)            { \p s -> TokenRParen p }
+  $alpha [$alpha $digit \_ \’]*   { \p s -> TokenVar p s } 
+
+{ 
+-- Each action has type :: AlexPosn -> String -> Token 
+
+-- The token type: 
+data Token = 
+  TokenLet AlexPosn        | 
+  TokenIn  AlexPosn        | 
+  TokenInt AlexPosn Int    |
+  TokenVar AlexPosn String | 
+  TokenEq  AlexPosn        |
+  TokenPlus AlexPosn       |
+  TokenMinus AlexPosn      |
+  TokenTimes AlexPosn      |
+  TokenDiv AlexPosn        |
+  TokenExp AlexPosn        |
+  TokenLParen AlexPosn     |
+  TokenRParen AlexPosn      
+  deriving (Eq,Show) 
+
+tokenPosn :: Token -> String
+tokenPosn (TokenInt  (AlexPn a l c) n) = show(l) ++ ":" ++ show(c)
+tokenPosn (TokenVar  (AlexPn a l c) x) = show(l) ++ ":" ++ show(c)
+tokenPosn (TokenLet (AlexPn a l c)) = show(l) ++ ":" ++ show(c)
+tokenPosn (TokenIn  (AlexPn a l c)) = show(l) ++ ":" ++ show(c)
+tokenPosn (TokenEq  (AlexPn a l c)) = show(l) ++ ":" ++ show(c)
+tokenPosn (TokenPlus (AlexPn a l c)) = show(l) ++ ":" ++ show(c)
+tokenPosn (TokenMinus (AlexPn a l c)) = show(l) ++ ":" ++ show(c)
+tokenPosn (TokenTimes (AlexPn a l c)) = show(l) ++ ":" ++ show(c)
+tokenPosn (TokenDiv (AlexPn a l c)) = show(l) ++ ":" ++ show(c)
+tokenPosn (TokenExp (AlexPn a l c)) = show(l) ++ ":" ++ show(c)
+tokenPosn (TokenLParen (AlexPn a l c)) = show(l) ++ ":" ++ show(c)
+tokenPosn (TokenRParen (AlexPn a l c)) = show(l) ++ ":" ++ show(c)
+
+
+}
\ No newline at end of file

exercise2stack/Sheet2/Task3/MDLTokens.x

+{ 
+module MDLTokens where 
+}
+
+%wrapper "posn" 
+$digit = 0-9     
+-- digits 
+
+tokens :-
+$white+       ; 
+  "--".*        ; 
+  Forward        { (\p s -> TokenForward p)} 
+  Rotate         { (\p s -> TokenRotate p) }
+  [1-9]          { (\p s -> TokenDigit p (read s)) } 
+  $digit $digit+ { (\p s -> TokenInt p (read s)) }
+  Check          { (\p s -> TokenCheck p) }
+  If             { (\p s -> TokenIf p) }
+  Then           { (\p s -> TokenThen p) }
+  Else           { (\p s -> TokenElse p) }
+  L              { (\p s -> TokenLeft p) }
+  R              { (\p s -> TokenRight p) }
+  \;             { (\p s -> TokenSeq p )}
+  \(             { (\p s -> TokenLParen p) }
+  \)             { (\p s -> TokenRParen p) }
+
+{ 
+-- Each action has type :: AlexPosn -> String -> MDLToken 
+
+-- The token type: 
+data MDLToken = 
+  TokenForward AlexPosn        | 
+  TokenRotate  AlexPosn        | 
+  TokenDigit AlexPosn Int      |
+  TokenInt AlexPosn Int        | 
+  TokenCheck AlexPosn          |
+  TokenIf AlexPosn             |
+  TokenThen AlexPosn           |
+  TokenElse AlexPosn           |
+  TokenLeft AlexPosn           |
+  TokenRight AlexPosn          |
+  TokenSeq AlexPosn            |
+  TokenLParen AlexPosn         |
+  TokenRParen AlexPosn      
+  deriving (Eq,Show) 
+
+tokenPosn :: MDLToken -> String
+tokenPosn (TokenForward (AlexPn a l c)) = show(l) ++ ":" ++ show(c)
+tokenPosn (TokenRotate  (AlexPn a l c)) = show(l) ++ ":" ++ show(c)
+tokenPosn (TokenDigit  (AlexPn a l c) _) = show(l) ++ ":" ++ show(c)
+tokenPosn (TokenInt  (AlexPn a l c) _) = show(l) ++ ":" ++ show(c)
+tokenPosn (TokenCheck  (AlexPn a l c)) = show(l) ++ ":" ++ show(c)
+tokenPosn (TokenIf (AlexPn a l c)) = show(l) ++ ":" ++ show(c)
+tokenPosn (TokenThen (AlexPn a l c)) = show(l) ++ ":" ++ show(c)
+tokenPosn (TokenElse (AlexPn a l c)) = show(l) ++ ":" ++ show(c)
+tokenPosn (TokenLeft (AlexPn a l c)) = show(l) ++ ":" ++ show(c)
+tokenPosn (TokenRight (AlexPn a l c)) = show(l) ++ ":" ++ show(c)
+tokenPosn (TokenSeq (AlexPn a l c)) = show(l) ++ ":" ++ show(c)
+tokenPosn (TokenLParen (AlexPn a l c)) = show(l) ++ ":" ++ show(c)
+tokenPosn (TokenRParen (AlexPn a l c)) = show(l) ++ ":" ++ show(c)
+
+
+}
\ No newline at end of file

exercise2stack/Sheet2/Task3/Main.hs

+import MDLTokens
+import System.Environment
+import Control.Exception
+import System.IO
+
+
+main :: IO ()
+main = catch main' noParse
+
+main' = do (fileName : _ ) <- getArgs 
+           sourceText <- readFile fileName
+           putStrLn ("Parsing : " ++ sourceText)
+           let parsedProg = parseCalc (alexScanTokens sourceText)
+           putStrLn ("Parsed as " ++ (show parsedProg))
+
+noParse :: ErrorCall -> IO ()
+noParse e = do let err =  show e
+               hPutStr stderr err
+               return ()
\ No newline at end of file

exercise2stack/Sheet2/Task3/example.mdl

+Forward 10 ; 
+Rotate L ;
+If (Check 3) 
+ Then Rotate L ; Forward 1 ; Rotate R
+ Else Forward 3 ; Rotate L

exercise2stack/Sheet2/Task3/exampleErr.mdl

+Forward 10 ; 
+Rotate L ;
+If (Check 3) 
+ Then Rotate L ; Forward 1 ; Rotate R
+ Else Forward 3 ; Rotate L
+Rotate L

exercise2stack/app/Main.hs

+module Main where
+
+import Tokens
+import System.Environment
+import Control.Exception
+import System.IO
+
+main :: IO ()
+main = catch main' noLex
+
+main' = do (fileName : _) <- getArgs
+           sourceText <- readFile fileName
+           putStrLn $ "Lexing: " ++ sourceText
+           let lexedProg = alexScanTokens sourceText
+           putStrLn $ "Lexed as: " ++ (show lexedProg)
+
+noLex :: ErrorCall -> IO ()
+noLex e = do let err = show e
+             hPutStrLn stderr ("Problem with lexing :" ++ err)
+             return ()
\ No newline at end of file