module Main where
import Prelude hiding (catch)
import Control.Exception ( AsyncException(..), catch )
import Control.Monad.Error
import Data.Version
import Data.List
import System.IO
import System.Environment
import System.Directory (getHomeDirectory)
import System.FilePath ((</>))
import System.Console.Haskeline hiding (handle, catch, throwTo)
import System.Console.GetOpt
import System.Exit (ExitCode (..), exitWith, exitFailure)
import Language.Egison
import Language.Egison.Util
import qualified Paths_egison_tutorial as P
main :: IO ()
main = do args <- getArgs
let (actions, nonOpts, _) = getOpt Permute options args
let opts = foldl (flip id) defaultOptions actions
case opts of
Options {optShowHelp = True} -> printHelp
Options {optShowVersion = True} -> printVersionNumber
Options {optPrompt = prompt} -> do
env <- initialEnv
case nonOpts of
[] -> showBanner >> repl env prompt
_ -> printHelp
data Options = Options {
optShowVersion :: Bool,
optShowHelp :: Bool,
optPrompt :: String
}
defaultOptions :: Options
defaultOptions = Options {
optShowVersion = False,
optShowHelp = False,
optPrompt = "> "
}
options :: [OptDescr (Options -> Options)]
options = [
Option ['v', 'V'] ["version"]
(NoArg (\opts -> opts {optShowVersion = True}))
"show version number",
Option ['h', '?'] ["help"]
(NoArg (\opts -> opts {optShowHelp = True}))
"show usage information",
Option ['p'] ["prompt"]
(ReqArg (\prompt opts -> opts {optPrompt = prompt})
"String")
"set prompt string"
]
printHelp :: IO ()
printHelp = do
putStrLn "Usage: egison-tutorial [options]"
putStrLn ""
putStrLn "Options:"
putStrLn " --help Display this information"
putStrLn " --version Display egison version information"
putStrLn " --prompt string Set prompt of the interpreter"
putStrLn ""
exitWith ExitSuccess
printVersionNumber :: IO ()
printVersionNumber = do
putStrLn $ showVersion P.version
exitWith ExitSuccess
showBanner :: IO ()
showBanner = do
putStrLn $ "Egison Tutorial for Version " ++ showVersion P.version ++ " (C) 2013-2014 Satoshi Egi"
putStrLn $ "http://www.egison.org"
putStrLn $ "Welcome to Egison Tutorial!"
showFinishMessage :: IO ()
showFinishMessage = do
putStrLn $ "You have finished this section."
putStrLn $ "Thank you!"
showByebyeMessage :: IO ()
showByebyeMessage = do
putStrLn $ "Leaving Egison Tutorial.\nByebye."
yesOrNo :: String -> IO Bool
yesOrNo question = do
putStr $ question
putStr $ " (Y/n): "
hFlush stdout
input <- getLine
case input of
[] -> return True
('y':_) -> return True
('Y':_) -> return True
('n':_) -> return False
('N':_) -> return False
_ -> yesOrNo question
nth n = head . drop (n - 1)
selectSection :: Tutorial -> IO Section
selectSection tutorial@(Tutorial sections) = do
putStrLn $ take 30 $ repeat '='
putStrLn $ "List of sections in the tutorial"
putStrLn $ show tutorial
putStrLn $ take 30 $ repeat '='
putStrLn $ "Choose a section to learn."
n <- getNumber (length sections)
return $ nth n sections
getNumber :: Int -> IO Int
getNumber n = do
putStr $ "(1-" ++ show n ++ "): "
hFlush stdout
input <- getLine
case input of
('1':_) -> return 1
('2':_) -> return 2
('3':_) -> return 3
('4':_) -> return 4
('5':_) -> return 5
('6':_) -> return 6
('7':_) -> return 7
('9':_) -> return 9
_ -> do
putStrLn "Invalid input!"
getNumber n
repl :: Env -> String -> IO ()
repl env prompt = do
section <- selectSection tutorial
case section of
Section _ cs -> loop env cs True
where
settings :: MonadIO m => FilePath -> Settings m
settings home = setComplete completeEgison $ defaultSettings { historyFile = Just (home </> ".egison_history") }
loop :: Env -> [Content] -> Bool -> IO ()
loop env [] _ = do
liftIO $ showFinishMessage
liftIO $ repl env prompt
loop env (content:contents) b = (do
if b
then liftIO $ putStrLn $ show content
else return ()
home <- getHomeDirectory
input <- liftIO $ runInputT (settings home) $ getEgisonExprOrNewLine prompt
case input of
Left Nothing -> do
b <- yesOrNo "Do you want to quit?"
if b
then return ()
else do
b <- yesOrNo "Do you want to procced next?"
if b
then loop env contents True
else loop env (content:contents) False
Left (Just "") -> do
b <- yesOrNo "Do you want to procced next?"
if b
then loop env contents True
else loop env (content:contents) False
Right (Left (topExpr, _)) -> do
result <- liftIO $ runEgisonTopExpr env topExpr
case result of
Left err -> do
liftIO $ putStrLn $ show err
loop env (content:contents) False
Right env' -> loop env' (content:contents) False
Right (Right (expr, _)) -> do
result <- liftIO $ runEgisonExpr env expr
case result of
Left err -> do
liftIO $ putStrLn $ show err
loop env (content:contents) False
Right val -> do
liftIO $ putStrLn $ show val
loop env (content:contents) False)
`catch`
(\e -> case e of
UserInterrupt -> putStrLn "" >> loop env (content:contents) False
StackOverflow -> putStrLn "Stack over flow!" >> loop env (content:contents) False
HeapOverflow -> putStrLn "Heap over flow!" >> loop env (content:contents) False
_ -> putStrLn "error!" >> loop env (content:contents) False
)
data Tutorial = Tutorial [Section]
-- |title and contents
data Section = Section String [Content]
-- |explanation, examples, and exercises
data Content = Content String [String] [String]
instance Show Tutorial where
show = showTutorial
instance Show Section where
show = showSection
instance Show Content where
show = showContent
showTutorial :: Tutorial -> String
showTutorial (Tutorial sections) =
let n = length sections in
intercalate "\n" $ map (\(n, section) -> show n ++ ": " ++ show section) $ zip [1..n] sections
showSection :: Section -> String
showSection (Section title _) = title
showContent :: Content -> String
showContent (Content msg examples exercises) =
"====================\n" ++
msg ++ "\n" ++
(case examples of
[] -> ""
_ -> "\nExamples:\n" ++ (intercalate "\n" (map (\example -> " " ++ example) examples)) ++ "\n") ++
(case exercises of
[] -> ""
_ -> "\nExercises:\n" ++ (intercalate "\n" (map (\exercise -> " " ++ exercise) exercises)) ++ "\n") ++
"===================="
tutorial :: Tutorial
tutorial = Tutorial
[Section "Calculate numbers"
[
Content "We can do arithmetic operations with '+', '-', '*', and '/'."
["(+ 1 2)", "(* 10 20)"]
[],
Content "We can write nested expressions."
["(+ (* 10 20) 2)", "(/ (* 10 20) (+ 10 20))"]
["Try to calculate '(100 - 1) * (100 + 1)'."],
Content "We are supporting rational numbers."
["(+ 2/3 1/5)", "(/ 42 84)"]
[],
Content "We are supporting floats, too."
["(+ 10.2 1.3)", "(* 10.2 1.3)"]
[],
Content "you can convert a rational number to a float number with 'rtof'."
["(rtof 1/5)", "(rtof 1/100)"]
[],
Content "We can handle collections of numbers.\nWe construct collections with '{}'."
["{}", "{10}", "{1 2 3 4 5}"]
[],
Content "With a 'take' function, we can extract a head part of the collection.\nWe can construct a collection with '{}'."
["(take 0 {1 2 3 4 5})", "(take 3 {1 2 3 4 5})"]
[],
Content "We can handle infinite lists.\nFor example, 'nats' is an infinite list that contains all natural numbers.\nGet a collection of natural numbers of any length you like."
["(take 100 nats)"]
["Get first 1000 numbers from nats."],
Content "With a 'map' function, we can operate each element of the collection at onece."
["(take 100 (map (* $ 2) nats))", "(take 100 (map (modulo $ 3) nats))"]
[],
Content "We can create a \"partial\" function using '$' as an argument."
["((+ $ 10) 1)"]
[],
Content "With a 'foldl' function, we can gather together all elements of the collection using an operator you like."
["(foldl + 0 {1 2 3 4 5})", "(foldl * 1 {1 2 3 4 5})"]
["Try to get a sum of from 1 to 100?"],
Content "Try to create a sequce of numbers '{1 1/2 1/3 1/4 ... 1/100}'."
[]
[],
Content "Try to calculate '1 + 1/2 + 1/3 + 1/4 + ... + 1/100'.\nRemember that you can convert a rational number to a float number with 'rtof'."
["(rtof 2/3)"]
[],
Content "Try to calculate '1 + (1/2)^2 + (1/3)^2 + (1/4)^2 + ... + (1/100)^2'."
[]
[]
],
Section "Basics of functional programming"
[
Content "We can compare numbers using functions that return '#t' or '#f'.\n'#t' means the true.\n#f means the false.\nFunctions that return '#t' or '#f' are called \"predicates\"."
["(eq? 1 1)", "(gt? 1 1)", "(lt? 1 1)", "(gte? 1 1)", "(lte? 1 1)"]
[],
Content "With a 'while' function, we can extract all head elements that satisfy the predicate.\n'primes' is a infinites list that contains all prime numbers."
["(while (lt? $ 100) primes)", "(while (lt? $ 1000) primes)"]
[],
Content "With a 'filter' function, we can extract all elements that satisfy the predicate.\n'We extract all prime numbers that are congruent to 1 modulo 4."
["(take 100 (filter (lambda [$p] (eq? (modulo p 4) 1)) primes))", "(take 200 (filter (lambda [$p] (eq? (modulo p 4) 1)) primes))"]
[],
Content "We use 'lambda' expressions to create functions.\nHere are simple 'lambda' examples."
["((lambda [$x] (+ x 1)) 10)", "((lambda [$x] (* x x)) 10)", "((lambda [$x $y] (* x y)) 10 20)"]
[],
Content "With a 'map2' function, we can combine two lists as follow."
["(take 100 (map2 * nats nats))", "(take 100 (map2 (lambda [$n $p] [n p]) nats primes))"]
[],
Content "We combine numbers using '[]'.\nThese things are called 'tuples'."
["[1 2]", "[1 2 3]"]
[],
Content "Note that a tuple that consists of only one elment is equal with that element itself."
["[1]", "[[[1]]]"]
[],
Content "Try to create a sequce of tuples '{[1 1] [1 2] [1 3] [1 4] [1 5] [1 6] [1 7] [1 8] [1 9]}'."
[]
[],
Content "Try to create a collections of sequce of tuples as follow.\n{{[1 1] [1 2] ... [1 9]}\n {[2 1] [2 2] ... [2 9]}\n ...\n {[9 1] [9 2] ... [9 9]}}"
[]
[],
Content "Try to create the multiplication table.\n{{[[1 1 1] [1 2 2] ... [1 9 9]}\n {[2 1 2] [2 2 4] ... [2 9 18]}\n ...\n {[9 1 9] [9 2 18] ... [9 9 81]}}}"
[]
[]
],
Section "Define your own functions"
[
Content "We can bind a value to a variable with a 'define' expression.\nWe can easily get the value we binded to the variable."
["(define $x 10)", "x"]
[],
Content "We can define a function. Let's define a function and test it."
["(define $f (lambda [$x] (+ x 1)))", "(f 10)", "(define $g (lambda [$x $y] (* x y)))", "(g 10 20)"]
[],
Content "We can write a recursive definition. Let's try that."
["(define $odds {1 @(map (+ $ 2) odds)})", "(take 10 odds)"]
[],
Content "Try to define 'evens' referring to 'odds' example above."
[]
[],
Content "We can define local variables with a 'let' expression."
["(let {[$x 10] [$y 20]} (+ x y))"]
[],
Content "Let's try 'if' expressions."
["(if #t 1 2)", "(let {[$x 10]} (if (eq? x 10) 1 2))"]
[],
Content "Using 'define' and 'if', we can write recursive functions as follow."
["(define $your-take (lambda [$n $xs] (if (eq? n 0) {} {(car xs) @(your-take (- n 1) (cdr xs))})))", "(your-take 10 nats)"]
[],
Content "Try to write a 'your-map' function.\nWe may need 'empty?' function inside 'your-map' function."
["(empty? {})"]
[],
Content "We can view all library functions on collections at \"http://www.egison.org/libraries/core/collection.html\"."
[]
[]
],
Section "Basic of pattern-matching"
[
Content "We can do pattern-matching against multisets."
["(match-all {1 2 3} (multiset integer) [<cons $x $xs> [x xs]])"]
[],
Content "We can do non-linear pattern-matching.\nTry the following expression with various targets."
["(match-all {1 2 1 3} (multiset integer) [<cons $x <cons ,x _>> x])"]
[],
Content "We can change the way of pattern-matching by changing \"matcher\".\nTry the following expressions."
["(match-all {1 2 3} (list integer) [<cons $x $xs> [x xs]])", "(match-all {1 2 3} (multiset integer) [<cons $x $xs> [x xs]])", "(match-all {1 2 3} (set integer) [<cons $x $xs> [x xs]])"]
[],
Content "We can do pattern-matching against a collection of collections as follow."
["(match-all {{1 2 3 4 5} {4 5 1} {6 1 7 4}} (list (multiset integer)) [<cons <cons $n _> <cons <cons ,n _> <cons <cons ,n _> _>>> n])"]
[],
Content "A pattern that has '^' ahead of which is called a not-pattern.\nA not-pattern matches when the target does not match against the pattern."
["(match-all {1 2 1 3} (multiset integer) [<cons $x ^<cons ,x _>> x])"]
[],
Content "An and-pattern matches when the all patterns matches the target.\nIt can be used like an as-pattern."
["(match-all {1 2 1 3} (multiset integer) [<cons $x (& ^<cons ,x _> $xs)> [x xs]])"]
[],
Content "An or-pattern matches when one of the patterns matches the target."
["(match-all {1 2 1 3} (multiset integer) [<cons $x (| <cons ,x _> ^<cons ,x _>)> x])"]
[],
Content "'list' has a special pattern-constructor 'join'.\n'join' divides a collection into two collections.\nTry the following expressions."
["(match-all {1 2 3 4 5} (list integer) [<join $xs $ys> [xs ys]])"]
[],
Content "We can enumerate two combination of numbers as follow."
["(match-all {1 2 3 4 5} (list integer) [<join _ <cons $x <join _ <cons $y _>>>> [x y]])"]
["Try to enumerate three combination of numbers."],
Content "Did we think how about \"n\" comination of the elements of the collection?\nWe already have a solution.\nWe can write a pattern that include '...' as the following demonstrations."
["(match-all {1 2 3 4 5} (list integer) [(loop $i [1 ,4] <join _ <cons $a_i ...>> _) a])", "(match-all {1 2 3 4 5} (list integer) [(loop $i [1 ,5] <join _ <cons $a_i ...>> _) a])", "(match-all {1 2 3 4 5} (list integer) [(loop $i [1 $n] <join _ <cons $a_i ...>> _) [n a]])"]
[],
Content "We can view a lot of demonstration of pattern-matching at \"http://www.egison.org/demonstrations/\"."
[]
[]
],
Section "Pattern-matching against infinite collections"
[
Content "We can write a pattern-matching against infinite lists even if that has infinite results.\nNote that Egison really enumurate all pairs of two natural numbers in the following example."
["(take 10 (match-all nats (set integer) [<cons $m <cons $n _>> [m n]]))"]
[],
Content "We can enumerate all two combinations of natural numbers as follow."
["(define $two-combs (match-all nats (list integer) [<join _ (& <cons $x _> <join _ <cons $y _>>)> [x y]]))", "(take 100 two-combs)"]
[],
Content "We can enumerate all pythagoras numbers as follow."
["(define $pyths (map (lambda [$x $y] (+ (* x x) (* y y))) two-combs))", "(take 100 pyths)"]
[],
Content "We have an infinite list of prime numers in 'primes'.\nCheck it with a 'take' function."
["(take 10 primes)"]
["What is the 100th prime number?"],
Content "We can get twin primes or triplet primes using pattern-matching as follow."
["(take 10 (match-all primes (list integer) [<join _ <cons $n <cons ,(+ n 2) _>>> [n (+ n 2)]]))", "(take 10 (match-all primes (list integer) [<join _ <cons $n <cons ,(+ n 2) <cons ,(+ n 6) _>>>> [n (+ n 2) (+ n 6)]]))", "(take 10 (match-all primes (list integer) [<join _ <cons $n <cons ,(+ n 4) <cons ,(+ n 6) _>>>> [n (+ n 2) (+ n 6)]]))"]
["What are the 100th twin primes?"],
Content "We prepared the 'p-f' function that prime-factorize a number.\nWe can play freely with numbers a lot of time."
["(take 100 (map p-f nats))"]
["Are there three successive natural numbers all of whose prime-factorization contain three primes? For example, '27=3*3*3' and '28=2*2*7' but '29=29', so the sequence '27', '28' and '29' is not that."]
],
Section "Writing scripts in Egison"
[
Content "Let's write a famous Hello world program in Egison.\nTry the following expression.\nIt is evaluated to the 'io-function'.\nTo execute an io-function, we use 'io' primitive as follow."
["(io (print \"Hello, world!\"))"]
[],
Content "We can execute multiple io-functions in sequence as follow.\nThe io-functions is executed from the head."
["(io (do {[(print \"a\")] [(print \"b\")] [(print \"c\")]} []))", "(io (do {[(write-string \"Type your name: \")] [(flush)] [$name (read-line)] [(print {@\"Hello, \" @name @\"!\"})]} []))"]
[],
Content "The following is a hello world program in Egison.\nTry to create a file with the following content and save it as \"hello.egi\", and execute it in the terminal as '% egison hello.egi'\n"
["(define $main (lambda [$args] (print \"Hello, world!\")))"]
[]
]
]