src/Tools/Haskell/Haskell.thy

tuned;

(*  Title:      Tools/Haskell/Haskell.thy
    Author:     Makarius

Support for Isabelle tools in Haskell.
*)

theory Haskell
  imports Pure
begin

generate_file "Isabelle/Library.hs" = \<open>
{-  Title:      Isabelle/Library.hs
    Author:     Makarius
    LICENSE:    BSD 3-clause (Isabelle)

Basic library of Isabelle idioms.

See also \<^file>\<open>$ISABELLE_HOME/src/Pure/General/basics.ML\<close>, \<^file>\<open>$ISABELLE_HOME/src/Pure/library.ML\<close>.
-}

module Isabelle.Library (
  (|>), (|->), (#>), (#->),

  the, the_default,

  fold, fold_rev, single, map_index, get_index,

  proper_string, quote, space_implode, commas, commas_quote, cat_lines,
  space_explode, split_lines, trim_line, clean_name)
where

import Data.Maybe
import qualified Data.List as List
import qualified Data.List.Split as Split


{- functions -}

(|>) :: a -> (a -> b) -> b
x |> f = f x

(|->) :: (a, b) -> (a -> b -> c) -> c
(x, y) |-> f = f x y

(#>) :: (a -> b) -> (b -> c) -> a -> c
(f #> g) x = x |> f |> g

(#->) :: (a -> (c, b)) -> (c -> b -> d) -> a -> d
(f #-> g) x  = x |> f |-> g


{- options -}

the :: Maybe a -> a
the (Just x) = x
the Nothing = error "the Nothing"

the_default :: a -> Maybe a -> a
the_default x Nothing = x
the_default _ (Just y) = y


{- lists -}

fold :: (a -> b -> b) -> [a] -> b -> b
fold _ [] y = y
fold f (x : xs) y = fold f xs (f x y)

fold_rev :: (a -> b -> b) -> [a] -> b -> b
fold_rev _ [] y = y
fold_rev f (x : xs) y = f x (fold_rev f xs y)

single :: a -> [a]
single x = [x]

map_index :: ((Int, a) -> b) -> [a] -> [b]
map_index f = map_aux 0
  where
    map_aux _ [] = []
    map_aux i (x : xs) = f (i, x) : map_aux (i + 1) xs

get_index :: (a -> Maybe b) -> [a] -> Maybe (Int, b)
get_index f = get_aux 0
  where
    get_aux _ [] = Nothing
    get_aux i (x : xs) =
      case f x of
        Nothing -> get_aux (i + 1) xs
        Just y -> Just (i, y)


{- strings -}

proper_string :: String -> Maybe String
proper_string s = if null s then Nothing else Just s

quote :: String -> String
quote s = "\"" ++ s ++ "\""

space_implode :: String -> [String] -> String
space_implode = List.intercalate

commas, commas_quote :: [String] -> String
commas = space_implode ", "
commas_quote = commas . map quote

cat_lines :: [String] -> String
cat_lines = space_implode "\n"


space_explode :: Char -> String -> [String]
space_explode c = Split.split (Split.dropDelims (Split.whenElt (== c)))

split_lines :: String -> [String]
split_lines = space_explode '\n'

trim_line :: String -> String
trim_line line =
  case reverse line of
    '\n' : '\r' : rest -> reverse rest
    '\n' : rest -> reverse rest
    _ -> line

clean_name :: String -> String
clean_name = reverse #> dropWhile (== '_') #> reverse
\<close>

generate_file "Isabelle/Value.hs" = \<open>
{-  Title:      Haskell/Tools/Value.hs
    Author:     Makarius
    LICENSE:    BSD 3-clause (Isabelle)

Plain values, represented as string.

See also \<^file>\<open>$ISABELLE_HOME/src/Pure/General/value.ML\<close>.
-}

module Isabelle.Value
  (print_bool, parse_bool, parse_nat, print_int, parse_int, print_real, parse_real)
where

import Data.Maybe
import qualified Data.List as List
import qualified Text.Read as Read


{- bool -}

print_bool :: Bool -> String
print_bool True = "true"
print_bool False = "false"

parse_bool :: String -> Maybe Bool
parse_bool "true" = Just True
parse_bool "false" = Just False
parse_bool _ = Nothing


{- nat -}

parse_nat :: String -> Maybe Int
parse_nat s =
  case Read.readMaybe s of
    Just n | n >= 0 -> Just n
    _ -> Nothing


{- int -}

print_int :: Int -> String
print_int = show

parse_int :: String -> Maybe Int
parse_int = Read.readMaybe


{- real -}

print_real :: Double -> String
print_real x =
  let s = show x in
    case span (/= '.') s of
      (a, '.' : b) | List.all (== '0') b -> a
      _ -> s

parse_real :: String -> Maybe Double
parse_real = Read.readMaybe
\<close>

generate_file "Isabelle/Buffer.hs" = \<open>
{-  Title:      Isabelle/Buffer.hs
    Author:     Makarius
    LICENSE:    BSD 3-clause (Isabelle)

Efficient text buffers.

See also \<^file>\<open>$ISABELLE_HOME/src/Pure/General/buffer.ML\<close>.
-}

module Isabelle.Buffer (T, empty, add, content)
where

import Isabelle.Library


newtype T = Buffer [Char]

empty :: T
empty = Buffer []

add :: String -> T -> T
add s (Buffer cs) = Buffer (fold (:) s cs)

content :: T -> String
content (Buffer cs) = reverse cs
\<close>

generate_file "Isabelle/Properties.hs" = \<open>
{-  Title:      Isabelle/Properties.hs
    Author:     Makarius
    LICENSE:    BSD 3-clause (Isabelle)

Property lists.

See also \<^file>\<open>$ISABELLE_HOME/src/Pure/General/properties.ML\<close>.
-}

module Isabelle.Properties (Entry, T, defined, get, get_value, put, remove)
where

import qualified Data.List as List


type Entry = (String, String)
type T = [Entry]

defined :: T -> String -> Bool
defined props name = any (\(a, _) -> a == name) props

get :: T -> String -> Maybe String
get props name = List.lookup name props

get_value :: (String -> Maybe a) -> T -> String -> Maybe a
get_value parse props name =
  case get props name of
    Nothing -> Nothing
    Just s -> parse s

put :: Entry -> T -> T
put entry props = entry : remove (fst entry) props

remove :: String -> T -> T
remove name props =
  if defined props name then filter (\(a, _) -> a /= name) props
  else props
\<close>

generate_file "Isabelle/Markup.hs" = \<open>
{-  Title:      Haskell/Tools/Markup.hs
    Author:     Makarius
    LICENSE:    BSD 3-clause (Isabelle)

Quasi-abstract markup elements.

See also \<^file>\<open>$ISABELLE_HOME/src/Pure/PIDE/markup.ML\<close>.
-}

module Isabelle.Markup (
  T, empty, is_empty, properties,

  nameN, name, xnameN, xname, kindN,

  bindingN, binding, entityN, entity, defN, refN,

  completionN, completion, no_completionN, no_completion,

  lineN, end_lineN, offsetN, end_offsetN, fileN, idN, positionN, position,

  expressionN, expression,

  citationN, citation,

  pathN, urlN, docN,

  markupN, consistentN, unbreakableN, indentN, widthN,
  blockN, block, breakN, break, fbreakN, fbreak, itemN, item,

  wordsN, words, no_wordsN, no_words,

  tfreeN, tfree, tvarN, tvar, freeN, free, skolemN, skolem, boundN, bound, varN, var,
  numeralN, numeral, literalN, literal, delimiterN, delimiter, inner_stringN, inner_string,
  inner_cartoucheN, inner_cartouche,
  token_rangeN, token_range,
  sortingN, sorting, typingN, typing, class_parameterN, class_parameter,

  antiquotedN, antiquoted, antiquoteN, antiquote,

  paragraphN, paragraph, text_foldN, text_fold,

  keyword1N, keyword1, keyword2N, keyword2, keyword3N, keyword3, quasi_keywordN, quasi_keyword,
  improperN, improper, operatorN, operator, stringN, string, alt_stringN, alt_string,
  verbatimN, verbatim, cartoucheN, cartouche, commentN, comment, comment1N, comment1,
  comment2N, comment2, comment3N, comment3,

  writelnN, writeln, stateN, state, informationN, information, tracingN, tracing,
  warningN, warning, legacyN, legacy, errorN, error, reportN, report, no_reportN, no_report,

  intensifyN, intensify,
  Output, no_output)
where

import Prelude hiding (words, error, break)

import Isabelle.Library
import qualified Isabelle.Properties as Properties
import qualified Isabelle.Value as Value


{- basic markup -}

type T = (String, Properties.T)

empty :: T
empty = ("", [])

is_empty :: T -> Bool
is_empty ("", _) = True
is_empty _ = False

properties :: Properties.T -> T -> T
properties more_props (elem, props) =
  (elem, fold_rev Properties.put more_props props)

markup_elem name = (name, (name, []) :: T)
markup_string name prop = (name, \s -> (name, [(prop, s)]) :: T)


{- misc properties -}

nameN :: String
nameN = \<open>Markup.nameN\<close>

name :: String -> T -> T
name a = properties [(nameN, a)]

xnameN :: String
xnameN = \<open>Markup.xnameN\<close>

xname :: String -> T -> T
xname a = properties [(xnameN, a)]

kindN :: String
kindN = \<open>Markup.kindN\<close>


{- formal entities -}

bindingN :: String; binding :: T
(bindingN, binding) = markup_elem \<open>Markup.bindingN\<close>

entityN :: String; entity :: String -> String -> T
entityN = \<open>Markup.entityN\<close>
entity kind name =
  (entityN,
    (if null name then [] else [(nameN, name)]) ++ (if null kind then [] else [(kindN, kind)]))

defN :: String
defN = \<open>Markup.defN\<close>

refN :: String
refN = \<open>Markup.refN\<close>


{- completion -}

completionN :: String; completion :: T
(completionN, completion) = markup_elem \<open>Markup.completionN\<close>

no_completionN :: String; no_completion :: T
(no_completionN, no_completion) = markup_elem \<open>Markup.no_completionN\<close>


{- position -}

lineN, end_lineN :: String
lineN = \<open>Markup.lineN\<close>
end_lineN = \<open>Markup.end_lineN\<close>

offsetN, end_offsetN :: String
offsetN = \<open>Markup.offsetN\<close>
end_offsetN = \<open>Markup.end_offsetN\<close>

fileN, idN :: String
fileN = \<open>Markup.fileN\<close>
idN = \<open>Markup.idN\<close>

positionN :: String; position :: T
(positionN, position) = markup_elem \<open>Markup.positionN\<close>


{- expression -}

expressionN :: String
expressionN = \<open>Markup.expressionN\<close>

expression :: String -> T
expression kind = (expressionN, if kind == "" then [] else [(kindN, kind)])


{- citation -}

citationN :: String; citation :: String -> T
(citationN, citation) = markup_string \<open>Markup.citationN\<close> nameN


{- external resources -}

pathN :: String; path :: String -> T
(pathN, path) = markup_string \<open>Markup.pathN\<close> nameN

urlN :: String; url :: String -> T
(urlN, url) = markup_string \<open>Markup.urlN\<close> nameN

docN :: String; doc :: String -> T
(docN, doc) = markup_string \<open>Markup.docN\<close> nameN


{- pretty printing -}

markupN, consistentN, unbreakableN, indentN :: String
markupN = \<open>Markup.markupN\<close>;
consistentN = \<open>Markup.consistentN\<close>;
unbreakableN = \<open>Markup.unbreakableN\<close>;
indentN = \<open>Markup.indentN\<close>;

widthN :: String
widthN = \<open>Markup.widthN\<close>

blockN :: String
blockN = \<open>Markup.blockN\<close>
block :: Bool -> Int -> T
block c i =
  (blockN,
    (if c then [(consistentN, Value.print_bool c)] else []) ++
    (if i /= 0 then [(indentN, Value.print_int i)] else []))

breakN :: String
breakN = \<open>Markup.breakN\<close>
break :: Int -> Int -> T
break w i =
  (breakN,
    (if w /= 0 then [(widthN, Value.print_int w)] else []) ++
    (if i /= 0 then [(indentN, Value.print_int i)] else []))

fbreakN :: String; fbreak :: T
(fbreakN, fbreak) = markup_elem \<open>Markup.fbreakN\<close>

itemN :: String; item :: T
(itemN, item) = markup_elem \<open>Markup.itemN\<close>


{- text properties -}

wordsN :: String; words :: T
(wordsN, words) = markup_elem \<open>Markup.wordsN\<close>

no_wordsN :: String; no_words :: T
(no_wordsN, no_words) = markup_elem \<open>Markup.no_wordsN\<close>


{- inner syntax -}

tfreeN :: String; tfree :: T
(tfreeN, tfree) = markup_elem \<open>Markup.tfreeN\<close>

tvarN :: String; tvar :: T
(tvarN, tvar) = markup_elem \<open>Markup.tvarN\<close>

freeN :: String; free :: T
(freeN, free) = markup_elem \<open>Markup.freeN\<close>

skolemN :: String; skolem :: T
(skolemN, skolem) = markup_elem \<open>Markup.skolemN\<close>

boundN :: String; bound :: T
(boundN, bound) = markup_elem \<open>Markup.boundN\<close>

varN :: String; var :: T
(varN, var) = markup_elem \<open>Markup.varN\<close>

numeralN :: String; numeral :: T
(numeralN, numeral) = markup_elem \<open>Markup.numeralN\<close>

literalN :: String; literal :: T
(literalN, literal) = markup_elem \<open>Markup.literalN\<close>

delimiterN :: String; delimiter :: T
(delimiterN, delimiter) = markup_elem \<open>Markup.delimiterN\<close>

inner_stringN :: String; inner_string :: T
(inner_stringN, inner_string) = markup_elem \<open>Markup.inner_stringN\<close>

inner_cartoucheN :: String; inner_cartouche :: T
(inner_cartoucheN, inner_cartouche) = markup_elem \<open>Markup.inner_cartoucheN\<close>


token_rangeN :: String; token_range :: T
(token_rangeN, token_range) = markup_elem \<open>Markup.token_rangeN\<close>


sortingN :: String; sorting :: T
(sortingN, sorting) = markup_elem \<open>Markup.sortingN\<close>

typingN :: String; typing :: T
(typingN, typing) = markup_elem \<open>Markup.typingN\<close>

class_parameterN :: String; class_parameter :: T
(class_parameterN, class_parameter) = markup_elem \<open>Markup.class_parameterN\<close>


{- antiquotations -}

antiquotedN :: String; antiquoted :: T
(antiquotedN, antiquoted) = markup_elem \<open>Markup.antiquotedN\<close>

antiquoteN :: String; antiquote :: T
(antiquoteN, antiquote) = markup_elem \<open>Markup.antiquoteN\<close>


{- text structure -}

paragraphN :: String; paragraph :: T
(paragraphN, paragraph) = markup_elem \<open>Markup.paragraphN\<close>

text_foldN :: String; text_fold :: T
(text_foldN, text_fold) = markup_elem \<open>Markup.text_foldN\<close>


{- outer syntax -}

keyword1N :: String; keyword1 :: T
(keyword1N, keyword1) = markup_elem \<open>Markup.keyword1N\<close>

keyword2N :: String; keyword2 :: T
(keyword2N, keyword2) = markup_elem \<open>Markup.keyword2N\<close>

keyword3N :: String; keyword3 :: T
(keyword3N, keyword3) = markup_elem \<open>Markup.keyword3N\<close>

quasi_keywordN :: String; quasi_keyword :: T
(quasi_keywordN, quasi_keyword) = markup_elem \<open>Markup.quasi_keywordN\<close>

improperN :: String; improper :: T
(improperN, improper) = markup_elem \<open>Markup.improperN\<close>

operatorN :: String; operator :: T
(operatorN, operator) = markup_elem \<open>Markup.operatorN\<close>

stringN :: String; string :: T
(stringN, string) = markup_elem \<open>Markup.stringN\<close>

alt_stringN :: String; alt_string :: T
(alt_stringN, alt_string) = markup_elem \<open>Markup.alt_stringN\<close>

verbatimN :: String; verbatim :: T
(verbatimN, verbatim) = markup_elem \<open>Markup.verbatimN\<close>

cartoucheN :: String; cartouche :: T
(cartoucheN, cartouche) = markup_elem \<open>Markup.cartoucheN\<close>

commentN :: String; comment :: T
(commentN, comment) = markup_elem \<open>Markup.commentN\<close>


{- comments -}

comment1N :: String; comment1 :: T
(comment1N, comment1) = markup_elem \<open>Markup.comment1N\<close>

comment2N :: String; comment2 :: T
(comment2N, comment2) = markup_elem \<open>Markup.comment2N\<close>

comment3N :: String; comment3 :: T
(comment3N, comment3) = markup_elem \<open>Markup.comment3N\<close>


{- messages -}

writelnN :: String; writeln :: T
(writelnN, writeln) = markup_elem \<open>Markup.writelnN\<close>

stateN :: String; state :: T
(stateN, state) = markup_elem \<open>Markup.stateN\<close>

informationN :: String; information :: T
(informationN, information) = markup_elem \<open>Markup.informationN\<close>

tracingN :: String; tracing :: T
(tracingN, tracing) = markup_elem \<open>Markup.tracingN\<close>

warningN :: String; warning :: T
(warningN, warning) = markup_elem \<open>Markup.warningN\<close>

legacyN :: String; legacy :: T
(legacyN, legacy) = markup_elem \<open>Markup.legacyN\<close>

errorN :: String; error :: T
(errorN, error) = markup_elem \<open>Markup.errorN\<close>

reportN :: String; report :: T
(reportN, report) = markup_elem \<open>Markup.reportN\<close>

no_reportN :: String; no_report :: T
(no_reportN, no_report) = markup_elem \<open>Markup.no_reportN\<close>

intensifyN :: String; intensify :: T
(intensifyN, intensify) = markup_elem \<open>Markup.intensifyN\<close>


{- output -}

type Output = (String, String)

no_output :: Output
no_output = ("", "")
\<close>

generate_file "Isabelle/Completion.hs" = \<open>
{-  Title:      Isabelle/Completion.hs
    Author:     Makarius
    LICENSE:    BSD 3-clause (Isabelle)

Completion of names.

See also \<^file>\<open>$ISABELLE_HOME/src/Pure/General/completion.ML\<close>.
-}

module Isabelle.Completion (
    Name, T, names, none, make, markup_element, markup_report, make_report
  ) where

import qualified Data.List as List

import Isabelle.Library
import qualified Isabelle.Properties as Properties
import qualified Isabelle.Markup as Markup
import qualified Isabelle.XML.Encode as Encode
import qualified Isabelle.XML as XML
import qualified Isabelle.YXML as YXML


type Name = (String, (String, String))  -- external name, kind, internal name
data T = Completion Properties.T Int [Name]  -- position, total length, names

names :: Int -> Properties.T -> [Name] -> T
names limit props names = Completion props (length names) (take limit names)

none :: T
none = names 0 [] []

make :: Int -> (String, Properties.T) -> ((String -> Bool) -> [Name]) -> T
make limit (name, props) make_names =
  if name /= "" && name /= "_"
  then names limit props (make_names $ List.isPrefixOf $ clean_name name)
  else none

markup_element :: T -> (Markup.T, XML.Body)
markup_element (Completion props total names) =
  if not (null names) then
    let
      markup = Markup.properties props Markup.completion
      body =
        Encode.pair Encode.int
          (Encode.list (Encode.pair Encode.string (Encode.pair Encode.string Encode.string)))
          (total, names)
    in (markup, body)
  else (Markup.empty, [])

markup_report :: [T] -> String
markup_report [] = ""
markup_report elems =
  YXML.string_of $ XML.Elem (Markup.report, map (XML.Elem . markup_element) elems)

make_report :: Int -> (String, Properties.T) -> ((String -> Bool) -> [Name]) -> String
make_report limit name_props make_names =
  markup_report [make limit name_props make_names]
\<close>

generate_file "Isabelle/File.hs" = \<open>
{-  Title:      Isabelle/File.hs
    Author:     Makarius
    LICENSE:    BSD 3-clause (Isabelle)

File-system operations.

See also \<^file>\<open>$ISABELLE_HOME/src/Pure/General/file.ML\<close>.
-}

module Isabelle.File (setup, read, write, append) where

import Prelude hiding (read)
import System.IO (IO)
import qualified System.IO as IO

setup :: IO.Handle -> IO ()
setup h = do
  IO.hSetEncoding h IO.utf8
  IO.hSetNewlineMode h IO.noNewlineTranslation

read :: IO.FilePath -> IO String
read path =
  IO.withFile path IO.ReadMode (\h ->
    do setup h; IO.hGetContents h >>= \s -> length s `seq` return s)

write :: IO.FilePath -> String -> IO ()
write path s =
  IO.withFile path IO.WriteMode (\h -> do setup h; IO.hPutStr h s)

append :: IO.FilePath -> String -> IO ()
append path s =
  IO.withFile path IO.AppendMode (\h -> do setup h; IO.hPutStr h s)
\<close>

generate_file "Isabelle/XML.hs" = \<open>
{-  Title:      Isabelle/XML.hs
    Author:     Makarius
    LICENSE:    BSD 3-clause (Isabelle)

Untyped XML trees and representation of ML values.

See also \<^file>\<open>$ISABELLE_HOME/src/Pure/PIDE/xml.ML\<close>.
-}

module Isabelle.XML (Attributes, Body, Tree(..), wrap_elem, unwrap_elem, content_of)
where

import qualified Data.List as List

import Isabelle.Library
import qualified Isabelle.Properties as Properties
import qualified Isabelle.Markup as Markup
import qualified Isabelle.Buffer as Buffer


{- types -}

type Attributes = Properties.T
type Body = [Tree]
data Tree = Elem (Markup.T, Body) | Text String


{- wrapped elements -}

wrap_elem (((a, atts), body1), body2) =
  Elem ((\<open>XML.xml_elemN\<close>, (\<open>XML.xml_nameN\<close>, a) : atts), Elem ((\<open>XML.xml_bodyN\<close>, []), body1) : body2)

unwrap_elem
  (Elem ((\<open>XML.xml_elemN\<close>, (\<open>XML.xml_nameN\<close>, a) : atts), Elem ((\<open>XML.xml_bodyN\<close>, []), body1) : body2)) =
  Just (((a, atts), body1), body2)
unwrap_elem _ = Nothing


{- text content -}

add_content tree =
  case unwrap_elem tree of
    Just (_, ts) -> fold add_content ts
    Nothing ->
      case tree of
        Elem (_, ts) -> fold add_content ts
        Text s -> Buffer.add s

content_of body = Buffer.empty |> fold add_content body |> Buffer.content


{- string representation -}

encode '<' = "&lt;"
encode '>' = "&gt;"
encode '&' = "&amp;"
encode '\'' = "&apos;"
encode '\"' = "&quot;"
encode c = [c]

instance Show Tree where
  show tree =
    Buffer.empty |> show_tree tree |> Buffer.content
    where
      show_tree (Elem ((name, atts), [])) =
        Buffer.add "<" #> Buffer.add (show_elem name atts) #> Buffer.add "/>"
      show_tree (Elem ((name, atts), ts)) =
        Buffer.add "<" #> Buffer.add (show_elem name atts) #> Buffer.add ">" #>
        fold show_tree ts #>
        Buffer.add "</" #> Buffer.add name #> Buffer.add ">"
      show_tree (Text s) = Buffer.add (show_text s)

      show_elem name atts =
        unwords (name : map (\(a, x) -> a ++ "=\"" ++ show_text x ++ "\"") atts)

      show_text = concatMap encode
\<close>

generate_file "Isabelle/XML/Encode.hs" = \<open>
{-  Title:      Isabelle/XML/Encode.hs
    Author:     Makarius
    LICENSE:    BSD 3-clause (Isabelle)

XML as data representation language.

See also \<^file>\<open>$ISABELLE_HOME/src/Pure/PIDE/xml.ML\<close>.
-}

module Isabelle.XML.Encode (
  A, T, V,

  int_atom, bool_atom, unit_atom,

  tree, properties, string, int, bool, unit, pair, triple, list, variant
)
where

import Isabelle.Library
import qualified Isabelle.Value as Value
import qualified Isabelle.Properties as Properties
import qualified Isabelle.XML as XML


type A a = a -> String
type T a = a -> XML.Body
type V a = a -> Maybe ([String], XML.Body)


-- atomic values

int_atom :: A Int
int_atom = Value.print_int

bool_atom :: A Bool
bool_atom False = "0"
bool_atom True = "1"

unit_atom :: A ()
unit_atom () = ""


-- structural nodes

node ts = XML.Elem ((":", []), ts)

vector = map_index (\(i, x) -> (int_atom i, x))

tagged (tag, (xs, ts)) = XML.Elem ((int_atom tag, vector xs), ts)


-- representation of standard types

tree :: T XML.Tree
tree t = [t]

properties :: T Properties.T
properties props = [XML.Elem ((":", props), [])]

string :: T String
string "" = []
string s = [XML.Text s]

int :: T Int
int = string . int_atom

bool :: T Bool
bool = string . bool_atom

unit :: T ()
unit = string . unit_atom

pair :: T a -> T b -> T (a, b)
pair f g (x, y) = [node (f x), node (g y)]

triple :: T a -> T b -> T c -> T (a, b, c)
triple f g h (x, y, z) = [node (f x), node (g y), node (h z)]

list :: T a -> T [a]
list f xs = map (node . f) xs

variant :: [V a] -> T a
variant fs x = [tagged (the (get_index (\f -> f x) fs))]
\<close>

generate_file "Isabelle/XML/Decode.hs" = \<open>
{-  Title:      Isabelle/XML/Decode.hs
    Author:     Makarius
    LICENSE:    BSD 3-clause (Isabelle)

XML as data representation language.

See also \<^file>\<open>$ISABELLE_HOME/src/Pure/PIDE/xml.ML\<close>.
-}

module Isabelle.XML.Decode (
  A, T, V,

  int_atom, bool_atom, unit_atom,

  tree, properties, string, init, bool, unit, pair, triple, list, variant
)
where

import Data.List ((!!))

import Isabelle.Library
import qualified Isabelle.Value as Value
import qualified Isabelle.Properties as Properties
import qualified Isabelle.XML as XML


type A a = String -> a
type T a = XML.Body -> a
type V a = ([String], XML.Body) -> a

err_atom = error "Malformed XML atom"
err_body = error "Malformed XML body"


{- atomic values -}

int_atom :: A Int
int_atom s =
  case Value.parse_int s of
    Just i -> i
    Nothing -> err_atom

bool_atom :: A Bool
bool_atom "0" = False
bool_atom "1" = True
bool_atom _ = err_atom

unit_atom :: A ()
unit_atom "" = ()
unit_atom _ = err_atom


{- structural nodes -}

node (XML.Elem ((":", []), ts)) = ts
node _ = err_body

vector atts =
  map_index (\(i, (a, x)) -> if int_atom a == i then x else err_atom) atts

tagged (XML.Elem ((name, atts), ts)) = (int_atom name, (vector atts, ts))
tagged _ = err_body


{- representation of standard types -}

tree :: T XML.Tree
tree [t] = t
tree _ = err_body

properties :: T Properties.T
properties [XML.Elem ((":", props), [])] = props
properties _ = err_body

string :: T String
string [] = ""
string [XML.Text s] = s
string _ = err_body

int :: T Int
int = int_atom . string

bool :: T Bool
bool = bool_atom . string

unit :: T ()
unit = unit_atom . string

pair :: T a -> T b -> T (a, b)
pair f g [t1, t2] = (f (node t1), g (node t2))
pair _ _ _ = err_body

triple :: T a -> T b -> T c -> T (a, b, c)
triple f g h [t1, t2, t3] = (f (node t1), g (node t2), h (node t3))
triple _ _ _ _ = err_body

list :: T a -> T [a]
list f ts = map (f . node) ts

option :: T a -> T (Maybe a)
option _ [] = Nothing
option f [t] = Just (f (node t))
option _ _ = err_body

variant :: [V a] -> T a
variant fs [t] = (fs !! tag) (xs, ts)
  where (tag, (xs, ts)) = tagged t
variant _ _ = err_body
\<close>

generate_file "Isabelle/YXML.hs" = \<open>
{-  Title:      Isabelle/YXML.hs
    Author:     Makarius
    LICENSE:    BSD 3-clause (Isabelle)

Efficient text representation of XML trees.  Suitable for direct
inlining into plain text.

See also \<^file>\<open>$ISABELLE_HOME/src/Pure/PIDE/yxml.ML\<close>.
-}

module Isabelle.YXML (charX, charY, strX, strY, detect, output_markup,
  buffer_body, buffer, string_of_body, string_of, parse_body, parse)
where

import qualified Data.Char as Char
import qualified Data.List as List

import Isabelle.Library
import qualified Isabelle.Markup as Markup
import qualified Isabelle.XML as XML
import qualified Isabelle.Buffer as Buffer


{- markers -}

charX, charY :: Char
charX = Char.chr 5
charY = Char.chr 6

strX, strY, strXY, strXYX :: String
strX = [charX]
strY = [charY]
strXY = strX ++ strY
strXYX = strXY ++ strX

detect :: String -> Bool
detect = any (\c -> c == charX || c == charY)


{- output -}

output_markup :: Markup.T -> Markup.Output
output_markup markup@(name, atts) =
  if Markup.is_empty markup then Markup.no_output
  else (strXY ++ name ++ concatMap (\(a, x) -> strY ++ a ++ "=" ++ x) atts ++ strX, strXYX)

buffer_attrib (a, x) =
  Buffer.add strY #> Buffer.add a #> Buffer.add "=" #> Buffer.add x

buffer_body :: XML.Body -> Buffer.T -> Buffer.T
buffer_body = fold buffer

buffer :: XML.Tree -> Buffer.T -> Buffer.T
buffer (XML.Elem ((name, atts), ts)) =
  Buffer.add strXY #> Buffer.add name #> fold buffer_attrib atts #> Buffer.add strX #>
  buffer_body ts #>
  Buffer.add strXYX
buffer (XML.Text s) = Buffer.add s

string_of_body :: XML.Body -> String
string_of_body body = Buffer.empty |> buffer_body body |> Buffer.content

string_of :: XML.Tree -> String
string_of = string_of_body . single


{- parse -}

-- split: fields or non-empty tokens

split :: Bool -> Char -> String -> [String]
split _ _ [] = []
split fields sep str = splitting str
  where
    splitting rest =
      case span (/= sep) rest of
        (_, []) -> cons rest []
        (prfx, _ : rest') -> cons prfx (splitting rest')
    cons item = if fields || not (null item) then (:) item else id


-- structural errors

err msg = error ("Malformed YXML: " ++ msg)
err_attribute = err "bad attribute"
err_element = err "bad element"
err_unbalanced "" = err "unbalanced element"
err_unbalanced name = err ("unbalanced element " ++ quote name)


-- stack operations

add x ((elem, body) : pending) = (elem, x : body) : pending

push "" _ _ = err_element
push name atts pending = ((name, atts), []) : pending

pop ((("", _), _) : _) = err_unbalanced ""
pop ((markup, body) : pending) = add (XML.Elem (markup, reverse body)) pending


-- parsing

parse_attrib s =
  case List.elemIndex '=' s of
    Just i | i > 0 -> (take i s, drop (i + 1) s)
    _ -> err_attribute

parse_chunk ["", ""] = pop
parse_chunk ("" : name : atts) = push name (map parse_attrib atts)
parse_chunk txts = fold (add . XML.Text) txts

parse_body :: String -> XML.Body
parse_body source =
  case fold parse_chunk chunks [(("", []), [])] of
    [(("", _), result)] -> reverse result
    ((name, _), _) : _ -> err_unbalanced name
  where chunks = split False charX source |> map (split True charY)

parse :: String -> XML.Tree
parse source =
  case parse_body source of
    [result] -> result
    [] -> XML.Text ""
    _ -> err "multiple results"
\<close>

generate_file "Isabelle/Pretty.hs" = \<open>
{-  Title:      Isabelle/Pretty.hs
    Author:     Makarius
    LICENSE:    BSD 3-clause (Isabelle)

Generic pretty printing module.

See also \<^file>\<open>$ISABELLE_HOME/src/Pure/General/pretty.ML\<close>.
-}

module Isabelle.Pretty (
  T, symbolic, formatted, unformatted,

  str, brk_indent, brk, fbrk, breaks, fbreaks, blk, block, strs, markup, mark, mark_str, marks_str,
  item, text_fold, keyword1, keyword2, text, paragraph, para, quote, cartouche, separate,
  commas, enclose, enum, list, str_list, big_list)
where

import Isabelle.Library hiding (quote, commas)
import qualified Data.List as List
import qualified Isabelle.Buffer as Buffer
import qualified Isabelle.Markup as Markup
import qualified Isabelle.XML as XML
import qualified Isabelle.YXML as YXML


data T =
    Block Markup.T Bool Int [T]
  | Break Int Int
  | Str String


{- output -}

output_spaces n = replicate n ' '

symbolic_text "" = []
symbolic_text s = [XML.Text s]

symbolic_markup markup body =
  if Markup.is_empty markup then body
  else [XML.Elem (markup, body)]

symbolic :: T -> XML.Body
symbolic (Block markup consistent indent prts) =
  concatMap symbolic prts
  |> symbolic_markup block_markup
  |> symbolic_markup markup
  where block_markup = if null prts then Markup.empty else Markup.block consistent indent
symbolic (Break wd ind) = [XML.Elem (Markup.break wd ind, symbolic_text (output_spaces wd))]
symbolic (Str s) = symbolic_text s

formatted :: T -> String
formatted = YXML.string_of_body . symbolic

unformatted :: T -> String
unformatted prt = Buffer.empty |> out prt |> Buffer.content
  where
    out (Block markup _ _ prts) =
      let (bg, en) = YXML.output_markup markup
      in Buffer.add bg #> fold out prts #> Buffer.add en
    out (Break _ wd) = Buffer.add (output_spaces wd)
    out (Str s) = Buffer.add s


{- derived operations to create formatting expressions -}

force_nat n | n < 0 = 0
force_nat n = n

str :: String -> T
str = Str

brk_indent :: Int -> Int -> T
brk_indent wd ind = Break (force_nat wd) ind

brk :: Int -> T
brk wd = brk_indent wd 0

fbrk :: T
fbrk = str "\n"

breaks, fbreaks :: [T] -> [T]
breaks = List.intersperse (brk 1)
fbreaks = List.intersperse fbrk

blk :: (Int, [T]) -> T
blk (indent, es) = Block Markup.empty False (force_nat indent) es

block :: [T] -> T
block prts = blk (2, prts)

strs :: [String] -> T
strs = block . breaks . map str

markup :: Markup.T -> [T] -> T
markup m = Block m False 0

mark :: Markup.T -> T -> T
mark m prt = if m == Markup.empty then prt else markup m [prt]

mark_str :: (Markup.T, String) -> T
mark_str (m, s) = mark m (str s)

marks_str :: ([Markup.T], String) -> T
marks_str (ms, s) = fold_rev mark ms (str s)

item :: [T] -> T
item = markup Markup.item

text_fold :: [T] -> T
text_fold = markup Markup.text_fold

keyword1, keyword2 :: String -> T
keyword1 name = mark_str (Markup.keyword1, name)
keyword2 name = mark_str (Markup.keyword2, name)

text :: String -> [T]
text = breaks . map str . words

paragraph :: [T] -> T
paragraph = markup Markup.paragraph

para :: String -> T
para = paragraph . text

quote :: T -> T
quote prt = blk (1, [str "\"", prt, str "\""])

cartouche :: T -> T
cartouche prt = blk (1, [str "\92<open>", prt, str "\92<close>"])

separate :: String -> [T] -> [T]
separate sep = List.intercalate [str sep, brk 1] . map single

commas :: [T] -> [T]
commas = separate ","

enclose :: String -> String -> [T] -> T
enclose lpar rpar prts = block (str lpar : prts ++ [str rpar])

enum :: String -> String -> String -> [T] -> T
enum sep lpar rpar = enclose lpar rpar . separate sep

list :: String -> String -> [T] -> T
list = enum ","

str_list :: String -> String -> [String] -> T
str_list lpar rpar = list lpar rpar . map str

big_list :: String -> [T] -> T
big_list name prts = block (fbreaks (str name : prts))
\<close>

generate_file "Isabelle/Term.hs" = \<open>
{-  Title:      Isabelle/Term.hs
    Author:     Makarius
    LICENSE:    BSD 3-clause (Isabelle)

Lambda terms, types, sorts.

See also \<^file>\<open>$ISABELLE_HOME/src/Pure/term.scala\<close>.
-}

module Isabelle.Term (
  Indexname,

  Sort, dummyS,

  Typ(..), dummyT, Term(..))
where

type Indexname = (String, Int)


type Sort = [String]

dummyS :: Sort
dummyS = [""]


data Typ =
    Type (String, [Typ])
  | TFree (String, Sort)
  | TVar (Indexname, Sort)
  deriving Show

dummyT :: Typ
dummyT = Type (\<open>\<^type_name>\<open>dummy\<close>\<close>, [])


data Term =
    Const (String, Typ)
  | Free (String, Typ)
  | Var (Indexname, Typ)
  | Bound Int
  | Abs (String, Typ, Term)
  | App (Term, Term)
  deriving Show
\<close>

generate_file "Isabelle/Term_XML/Encode.hs" = \<open>
{-  Title:      Isabelle/Term_XML/Encode.hs
    Author:     Makarius
    LICENSE:    BSD 3-clause (Isabelle)

XML data representation of lambda terms.

See also \<^file>\<open>$ISABELLE_HOME/src/Pure/term_xml.ML\<close>.
-}

{-# LANGUAGE LambdaCase #-}

module Isabelle.Term_XML.Encode (sort, typ, term)
where

import Isabelle.Library
import qualified Isabelle.XML as XML
import Isabelle.XML.Encode
import Isabelle.Term


sort :: T Sort
sort = list string

typ :: T Typ
typ ty =
  ty |> variant
   [\case { Type (a, b) -> Just ([a], list typ b); _ -> Nothing },
    \case { TFree (a, b) -> Just ([a], sort b); _ -> Nothing },
    \case { TVar ((a, b), c) -> Just ([a, int_atom b], sort c); _ -> Nothing }]

term :: T Term
term t =
  t |> variant
   [\case { Const (a, b) -> Just ([a], typ b); _ -> Nothing },
    \case { Free (a, b) -> Just ([a], typ b); _ -> Nothing },
    \case { Var ((a, b), c) -> Just ([a, int_atom b], typ c); _ -> Nothing },
    \case { Bound a -> Just ([int_atom a], []); _ -> Nothing },
    \case { Abs (a, b, c) -> Just ([a], pair typ term (b, c)); _ -> Nothing },
    \case { App a -> Just ([], pair term term a); _ -> Nothing }]
\<close>

generate_file "Isabelle/Term_XML/Decode.hs" = \<open>
{-  Title:      Isabelle/Term_XML/Decode.hs
    Author:     Makarius
    LICENSE:    BSD 3-clause (Isabelle)

XML data representation of lambda terms.

See also \<^file>\<open>$ISABELLE_HOME/src/Pure/term_xml.ML\<close>.
-}

module Isabelle.Term_XML.Decode (sort, typ, term)
where

import Isabelle.Library
import qualified Isabelle.XML as XML
import Isabelle.XML.Decode
import Isabelle.Term


sort :: T Sort
sort = list string

typ :: T Typ
typ ty =
  ty |> variant
  [\([a], b) -> Type (a, list typ b),
   \([a], b) -> TFree (a, sort b),
   \([a, b], c) -> TVar ((a, int_atom b), sort c)]

term :: T Term
term t =
  t |> variant
   [\([a], b) -> Const (a, typ b),
    \([a], b) -> Free (a, typ b),
    \([a, b], c) -> Var ((a, int_atom b), typ c),
    \([a], []) -> Bound (int_atom a),
    \([a], b) -> let (c, d) = pair typ term b in Abs (a, c, d),
    \([], a) -> App (pair term term a)]
\<close>

generate_file "Isabelle/UUID.hs" = \<open>
{-  Title:      Isabelle/UUID.hs
    Author:     Makarius
    LICENSE:    BSD 3-clause (Isabelle)

Universally unique identifiers.

See \<^file>\<open>$ISABELLE_HOME/src/Pure/General/uuid.scala\<close>.
-}

module Isabelle.UUID (
    T,
    parse_string, parse_bytes,
    string, bytes,
    random, random_string, random_bytes
  )
where

import Data.ByteString (ByteString)
import qualified Data.ByteString
import Data.UUID (UUID)
import qualified Data.UUID as UUID
import Data.UUID.V4 (nextRandom)


type T = UUID


{- parse -}

parse_string :: String -> Maybe T
parse_string = UUID.fromString

parse_bytes :: ByteString -> Maybe T
parse_bytes = UUID.fromASCIIBytes


{- print -}

string :: T -> String
string = UUID.toString

bytes :: T -> ByteString
bytes = UUID.toASCIIBytes


{- random id -}

random :: IO T
random = nextRandom

random_string :: IO String
random_string = string <$> random

random_bytes :: IO ByteString
random_bytes = bytes <$> random
\<close>

generate_file "Isabelle/Byte_Message.hs" = \<open>
{-  Title:      Isabelle/Byte_Message.hs
    Author:     Makarius
    LICENSE:    BSD 3-clause (Isabelle)

Byte-oriented messages.

See \<^file>\<open>$ISABELLE_HOME/src/Pure/PIDE/byte_message.ML\<close>
and \<^file>\<open>$ISABELLE_HOME/src/Pure/PIDE/byte_message.scala\<close>.
-}

module Isabelle.Byte_Message (
    write, write_line,
    read, read_block, trim_line, read_line,
    make_message, write_message, read_message,
    make_line_message, write_line_message, read_line_message
  )
where

import Prelude hiding (read)
import Data.Maybe
import Data.ByteString (ByteString)
import qualified Data.ByteString as ByteString
import qualified Data.ByteString.UTF8 as UTF8
import Data.Word (Word8)

import Control.Monad (when)
import Network.Socket (Socket)
import qualified Network.Socket as Socket
import qualified Network.Socket.ByteString as ByteString

import Isabelle.Library hiding (trim_line)
import qualified Isabelle.Value as Value


{- output operations -}

write :: Socket -> [ByteString] -> IO ()
write = ByteString.sendMany

newline :: ByteString
newline = ByteString.singleton 10

write_line :: Socket -> ByteString -> IO ()
write_line socket s = write socket [s, newline]


{- input operations -}

read :: Socket -> Int -> IO ByteString
read socket n = read_body 0 []
  where
    result = ByteString.concat . reverse
    read_body len ss =
      if len >= n then return (result ss)
      else
        (do
          s <- ByteString.recv socket (min (n - len) 8192)
          case ByteString.length s of
            0 -> return (result ss)
            m -> read_body (len + m) (s : ss))

read_block :: Socket -> Int -> IO (Maybe ByteString, Int)
read_block socket n = do
  msg <- read socket n
  let len = ByteString.length msg
  return (if len == n then Just msg else Nothing, len)

trim_line :: ByteString -> ByteString
trim_line s =
  if n >= 2 && at (n - 2) == 13 && at (n - 1) == 10 then ByteString.take (n - 2) s
  else if n >= 1 && (at (n - 1) == 13 || at (n - 1) == 10) then ByteString.take (n - 1) s
  else s
  where
    n = ByteString.length s
    at = ByteString.index s

read_line :: Socket -> IO (Maybe ByteString)
read_line socket = read_body []
  where
    result = trim_line . ByteString.pack . reverse
    read_body bs = do
      s <- ByteString.recv socket 1
      case ByteString.length s of
        0 -> return (if null bs then Nothing else Just (result bs))
        1 ->
          case ByteString.head s of
            10 -> return (Just (result bs))
            b -> read_body (b : bs)


{- messages with multiple chunks (arbitrary content) -}

make_header :: [Int] -> [ByteString]
make_header ns =
  [UTF8.fromString (space_implode "," (map Value.print_int ns)), newline]

make_message :: [ByteString] -> [ByteString]
make_message chunks = make_header (map ByteString.length chunks) ++ chunks

write_message :: Socket -> [ByteString] -> IO ()
write_message socket = write socket . make_message

parse_header :: ByteString -> [Int]
parse_header line =
  let
    res = map Value.parse_nat (space_explode ',' (UTF8.toString line))
  in
    if all isJust res then map fromJust res
    else error ("Malformed message header: " ++ quote (UTF8.toString line))

read_chunk :: Socket -> Int -> IO ByteString
read_chunk socket n = do
  res <- read_block socket n
  return $
    case res of
      (Just chunk, _) -> chunk
      (Nothing, len) ->
        error ("Malformed message chunk: unexpected EOF after " ++
          show len ++ " of " ++ show n ++ " bytes")

read_message :: Socket -> IO (Maybe [ByteString])
read_message socket = do
  res <- read_line socket
  case res of
    Just line -> Just <$> mapM (read_chunk socket) (parse_header line)
    Nothing -> return Nothing


-- hybrid messages: line or length+block (with content restriction)

is_length :: ByteString -> Bool
is_length msg =
  not (ByteString.null msg) && ByteString.all (\b -> 48 <= b && b <= 57) msg

is_terminated :: ByteString -> Bool
is_terminated msg =
  not (ByteString.null msg) && (ByteString.last msg == 13 || ByteString.last msg == 10)

make_line_message :: ByteString -> [ByteString]
make_line_message msg =
  let n = ByteString.length msg in
    if is_length msg || is_terminated msg then
      error ("Bad content for line message:\n" ++ take 100 (UTF8.toString msg))
    else
      (if n > 100 || ByteString.any (== 10) msg then make_header [n + 1] else []) ++
      [msg, newline]

write_line_message :: Socket -> ByteString -> IO ()
write_line_message socket = write socket . make_line_message

read_line_message :: Socket -> IO (Maybe ByteString)
read_line_message socket = do
  opt_line <- read_line socket
  case opt_line of
    Nothing -> return Nothing
    Just line ->
      case Value.parse_nat (UTF8.toString line) of
        Nothing -> return $ Just line
        Just n -> fmap trim_line . fst <$> read_block socket n
\<close>

generate_file "Isabelle/Standard_Thread.hs" = \<open>
{-  Title:      Isabelle/Standard_Thread.hs
    Author:     Makarius
    LICENSE:    BSD 3-clause (Isabelle)

Standard thread operations.

See \<^file>\<open>$ISABELLE_HOME/src/Pure/Concurrent/standard_thread.ML\<close>
and \<^file>\<open>$ISABELLE_HOME/src/Pure/Concurrent/standard_thread.scala\<close>.
-}

{-# LANGUAGE NamedFieldPuns #-}

module Isabelle.Standard_Thread (
  ThreadId, Result,
  properties, change_properties,
  stop, is_stopped,
  fork_finally, fork)
where

import Data.Maybe
import Data.IORef
import System.IO.Unsafe

import Data.Map.Strict (Map)
import qualified Data.Map.Strict as Map
import Control.Exception.Base (SomeException)
import Control.Exception as Exception
import Control.Concurrent (ThreadId)
import qualified Control.Concurrent as Concurrent
import Control.Concurrent.Thread (Result)
import qualified Control.Concurrent.Thread as Thread
import qualified Isabelle.Properties as Properties


{- thread info -}

data Info = Info {props :: Properties.T, stopped :: Bool}
type Infos = Map ThreadId Info

lookup_info :: Infos -> ThreadId -> Maybe Info
lookup_info state id = Map.lookup id state

init_info :: ThreadId -> Infos -> (Infos, ())
init_info id infos = (Map.insert id (Info [] False) infos, ())


{- global state -}

{-# NOINLINE global_state #-}
global_state :: IORef Infos
global_state = unsafePerformIO (newIORef Map.empty)

get_info :: ThreadId -> IO (Maybe Info)
get_info id = do
  state <- readIORef global_state
  return $ lookup_info state id

map_info :: ThreadId -> (Info -> Info) -> IO ()
map_info id f =
  atomicModifyIORef' global_state
    (\infos ->
      case lookup_info infos id of
        Nothing -> (infos, ())
        Just info -> (Map.insert id (f info) infos, ()))


{- thread properties -}

my_info :: IO Info
my_info = do
  id <- Concurrent.myThreadId
  info <- get_info id
  return $ fromJust info

properties :: IO Properties.T
properties = props <$> my_info

change_properties :: (Properties.T -> Properties.T) -> IO ()
change_properties f = do
  id <- Concurrent.myThreadId
  map_info id (\info -> info {props = f (props info)})


{- stop -}

is_stopped :: IO Bool
is_stopped = stopped <$> my_info

stop :: ThreadId -> IO ()
stop id = map_info id (\info -> info {stopped = True})


{- fork -}

fork_finally :: IO a -> (Either SomeException a -> IO b) -> IO (ThreadId, IO (Result b))
fork_finally body finally = do
  (id, result) <-
    Exception.mask (\restore ->
      Thread.forkIO
        (Exception.try
          (do
            id <- Concurrent.myThreadId
            atomicModifyIORef' global_state (init_info id)
            restore body) >>= finally))
  return (id, result)

fork :: IO a -> IO (ThreadId, IO (Result a))
fork body = fork_finally body Thread.result
\<close>

generate_file "Isabelle/Server.hs" = \<open>
{-  Title:      Isabelle/Server.hs
    Author:     Makarius
    LICENSE:    BSD 3-clause (Isabelle)

TCP server on localhost.
-}

module Isabelle.Server (
  localhost_name, localhost, publish_text, publish_stdout,
  server
)
where

import Data.ByteString (ByteString)
import Control.Monad (forever, when)
import qualified Control.Exception as Exception
import Network.Socket (Socket)
import qualified Network.Socket as Socket
import qualified System.IO as IO

import Isabelle.Library
import qualified Isabelle.UUID as UUID
import qualified Isabelle.Byte_Message as Byte_Message
import qualified Isabelle.Standard_Thread as Standard_Thread


{- server address -}

localhost_name :: String
localhost_name = "127.0.0.1"

localhost :: Socket.HostAddress
localhost = Socket.tupleToHostAddress (127, 0, 0, 1)

publish_text :: String -> String -> UUID.T -> String
publish_text name address password =
  "server " ++ quote name ++ " = " ++ address ++ " (password " ++ quote (show password) ++ ")"

publish_stdout :: String -> String -> UUID.T -> IO ()
publish_stdout name address password = putStrLn (publish_text name address password)


{- server -}

server :: (String -> UUID.T -> IO ()) -> (Socket -> IO ()) -> IO ()
server publish handle =
  Socket.withSocketsDo $ Exception.bracket open (Socket.close . fst) (uncurry loop)
  where
    open :: IO (Socket, ByteString)
    open = do
      server_socket <- Socket.socket Socket.AF_INET Socket.Stream Socket.defaultProtocol
      Socket.bind server_socket (Socket.SockAddrInet 0 localhost)
      Socket.listen server_socket 50

      port <- Socket.socketPort server_socket
      let address = localhost_name ++ ":" ++ show port
      password <- UUID.random
      publish address password

      return (server_socket, UUID.bytes password)

    loop :: Socket -> ByteString -> IO ()
    loop server_socket password = forever $ do
      (connection, _) <- Socket.accept server_socket
      Standard_Thread.fork_finally
        (do
          line <- Byte_Message.read_line connection
          when (line == Just password) $ handle connection)
        (\finally -> do
          Socket.close connection
          case finally of
            Left exn -> IO.hPutStrLn IO.stderr $ Exception.displayException exn
            Right () -> return ())
      return ()
\<close>

end