make quasiquoter for text building

This commit is contained in:
Rhiannon Morris 2020-07-13 04:01:31 +02:00
parent 55a51464ee
commit 22185e3020
3 changed files with 265 additions and 92 deletions

160
make-pages/BuildVar.hs Normal file
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@ -0,0 +1,160 @@
{-# LANGUAGE TemplateHaskell #-}
module BuildVar (b) where
import Data.Char (isLower, isSpace, isDigit, isAlphaNum)
import Language.Haskell.TH
import Language.Haskell.TH.Quote
import Data.Text.Lazy.Builder
(Builder, fromText, fromString, singleton, toLazyText)
import Text.Read (readMaybe)
import Data.Text (Text)
import qualified Data.Text as Text
import Data.Text.Lazy (toStrict)
import Data.Foldable
import Data.Semigroup
data ChunkType = Lit | Var VarType deriving Show
data VarType =
Plain
| FromText
| Show
| Reindent !Int
| ReindentList !Int
deriving Show
type Chunk = (ChunkType, Text)
indent :: Int -> Text -> Builder
indent i str
| Text.all isSpace str = ""
| otherwise = replicateB i ' ' <> fromText str
reindent :: Int -> Text -> Builder
reindent i str =
fold $ mapInit (<> "\n") $
map2 (fromText . dropIndent) (indent i . dropIndent) ls
where
ls = dropWhile (Text.all isSpace) $ Text.lines str
ls' = filter (Text.any $ not . isSpace) ls
dropIndent = Text.drop minIndent
minIndent =
getMin $ option 0 id $ foldMap (Option . Just . Min . indentOf) ls'
indentOf = go 0 where
go n (' ' :. cs) = go (n + 1) cs
go n ('\t' :. cs) = go (((n `mod` 8) + 1) * 8) cs
go n _ = n
map2 _ _ [] = []
map2 f g (x:xs) = f x : map g xs
chunks :: Text -> [Chunk]
chunks = reverse . go "" [] . trimEnd where
go acc cs NilT = if Text.null acc' then cs else (Lit, acc') : cs
where acc' = toStrictText acc
-- $&: expands to nothing
go acc cs ('$' :. '&' :. rest) = go acc cs rest
-- $$: expands to one $
go acc cs ('$' :. '$' :. rest) = go (acc <> "$") cs rest
-- $*var: expands to (fromText $var)
go acc cs ('$' :. '*' :. rest) =
go "" ((Var FromText, var) : lit acc : cs) rest2
where (var, rest2) = splitVar rest
-- $^var: expands to (fromString (show $var))
go acc cs ('$' :. '^' :. rest) =
go "" ((Var Show, var) : lit acc : cs) rest2
where (var, rest2) = splitVar rest
-- $n*var (n a number): expands to builder var indented by n
-- $n.var: same but var is a list
go acc cs ('$' :. rest@(d :. _)) | isDigit d =
go "" ((Var ty, var) : lit acc : cs) rest3
where
(n', c :. rest2) = Text.span isDigit rest
n = read $ Text.unpack n'
(var, rest3) = splitVar rest2
ty = case c of
'*' -> Reindent n
'.' -> ReindentList n
_ -> error $ "unknown reindent type " ++ show c
-- $var: expands to that var's contents
go acc cs ('$' :. rest) =
go "" ((Var Plain, var) : lit acc : cs) rest2
where (var, rest2) = splitVar rest
go acc cs (c :. rest) = go (acc <> singleton c) cs rest
splitVar s
| (var, s') <- Text.span isAlphaNum s,
isLower (Text.head var)
= (var, s')
splitVar _ = error "invalid variable name"
lit s = (Lit, toStrictText s)
trimEnd = Text.dropWhileEnd isSpace
chunksWithReindent :: String -> [Chunk]
chunksWithReindent ('@':str)
| [(n',rest)] <- lex str,
Just n <- readMaybe n'
= chunks $ toStrictText $ reindent n $ Text.pack rest
chunksWithReindent str = chunks $ Text.pack str
toStrictText :: Builder -> Text
toStrictText = toStrict . toLazyText
chunksToExpQ :: [Chunk] -> ExpQ
chunksToExpQ cs = [|$expr :: Builder|] where
expr = foldl1 (\x y -> [|$x <> $y|]) $ map chunk1 cs
chunk1 (Lit, lit) = stringE $ Text.unpack lit
chunk1 (Var t, name) = case t of
Plain -> var
FromText -> [|fromText $var|]
Show -> [|fromString $ show $var|]
Reindent n -> [|reindent n $var|]
ReindentList n -> [|reindentList n $var|]
where var = varE (mkName $ Text.unpack name)
reindentList :: Int -> [Builder] -> Builder
reindentList n = fold . mapInit (<> "\n") . mapTail (replicateB n ' ' <>)
replicateB :: Int -> Char -> Builder
replicateB n c = fromText $ Text.replicate n $ Text.singleton c
mapInit :: (a -> a) -> [a] -> [a]
mapInit _ [] = []
mapInit _ [x] = [x]
mapInit f (x:xs) = f x : mapInit f xs
mapTail :: (a -> a) -> [a] -> [a]
mapTail _ [] = []
mapTail f (x:xs) = x : map f xs
b :: QuasiQuoter
b = QuasiQuoter {
quoteExp = chunksToExpQ . chunksWithReindent,
quotePat = error "can't use in a pattern",
quoteType = error "can't use in a type",
quoteDec = error "can't use at top level"
}
pattern NilT :: Text
pattern NilT <- (Text.null -> True)
where NilT = ""
infixr 5 :.
pattern (:.) :: Char -> Text -> Text
pattern c :. t <- (Text.uncons -> Just (c, t))
where c :. t = Text.cons c t
{-# COMPLETE NilT, (:.) :: Text #-}

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@ -1,6 +1,8 @@
module SinglePage (make) where
import Info hiding (Text)
import BuildVar
import Control.Exception
import qualified Data.Text as Strict
import qualified Data.Text.Lazy as Lazy
@ -26,80 +28,88 @@ make includeNsfw = toLazyText . make' includeNsfw
make' :: Bool -> Info -> Builder
make' includeNsfw (Info {date, title, tags, nsfwTags,
description, images, links}) =
"<!DOCTYPE html>\n" <>
"<html lang=en>\n" <>
"<meta charset=utf-8>\n" <>
"<link href=single.css rel=stylesheet>\n\n" <>
ifJust title (\t -> "<title>" <> esc t <> "</title>\n\n") <>
"<header>\n" <>
ifJust title (\t -> " <h1>" <> esc t <> "</h1>\n") <>
" <h2 class=date>" <> formatDate date <> "</h2>\n" <>
buttonBar title' includeNsfw images <>
"</header>\n\n" <>
"<main>\n" <>
" <img id=it src=\"" <> path0 <> "\">\n\n" <>
ifJust description (\d ->
" <div class=desc>\n" <>
" <h2>description</h2>\n" <>
indent 4 d <>
" </div>\n") <> "\n" <>
makeTags includeNsfw tags nsfwTags <>
extLinks includeNsfw links <>
"</main>\n\n" <>
"<footer>\n" <>
" <nav class=back>\n" <>
" <a href=../>back to gallery</a>\n" <>
" </nav>\n" <>
"</footer>\n"
description, images, links}) = [b|@0
<!DOCTYPE html>
<html lang=en>
<meta charset=utf-8>
$titleTag
<header>
$titleHeader
<h2 class=date>$formattedDate</date>
$buttonBar
</header>
<main>
<img id=it src="$*path0">
$descSection
$tagsList
$linksList
</main>
<footer>
<nav class=back>
<a href=../>back to gallery</a>
</nav>
</footer>
|]
where
path0' = let Image {path} = head images in path
path0 = fromText path0'
title' = fromMaybe path0' title
titleTag = ifJust title \t -> [b|<title>$*t</title>|]
titleHeader = ifJust title \t -> [b|<h1>$*t</h1>|]
formattedDate = formatDate date
buttonBar = makeButtonBar (fromMaybe path0 title) includeNsfw images
path0 = let Image {path} = head images in path
descSection = ifJust description makeDesc
tagsList = makeTags includeNsfw tags nsfwTags
linksList = extLinks includeNsfw links
makeDesc :: Strict.Text -> Builder
makeDesc desc = [b|@2
<div class=desc>
<h2>description</h2>
$4*desc
</div>
|]
ifJust :: Monoid b => Maybe a -> (a -> b) -> b
ifJust x f = maybe mempty f x
esc :: Strict.Text -> Builder
esc = foldMap esc1 . Strict.unpack where
esc1 '<' = "&lt;"
esc1 '>' = "&gt;"
esc1 '&' = "&amp;"
esc1 '"' = "&quot;"
esc1 '\'' = "&squot;"
esc1 c = singleton c
formatDate :: Day -> Builder
formatDate = fromString . formatTime defaultTimeLocale "%e %#B %Y"
buttonBar :: Strict.Text -> Bool -> [Image] -> Builder
buttonBar title includeNsfw allImages =
if null images then
throw $ NoEligibleImages title
else if length images == 1 then
mempty
else
" <nav id=variants class=buttonbar>\n" <>
" <h2>alts</h2>\n" <>
" <ul id=variantlist>\n" <>
List.foldl' (\b (i, im) -> b <> altButton i im) mempty iimages <>
" </ul>\n" <>
" </nav>\n"
makeButtonBar :: Strict.Text -> Bool -> [Image] -> Builder
makeButtonBar title includeNsfw allImages =
case length images of
0 -> throw $ NoEligibleImages title
1 -> ""
_ -> [b|@2
<nav id=variants class=buttonbar>
<h2>alts</h2>
<ul id=variantlist>
$6.alts
</ul>
</nav>
|]
where
images | includeNsfw = allImages
| otherwise = filter (\Image {nsfw} -> not nsfw) allImages
iimages = zip [0..] images
alts = map (uncurry altButton) iimages
altButton :: Int -> Image -> Builder
altButton i (Image {label, path, nsfw}) =
" <li" <> nsfwClass <> ">\n" <>
" <input type=radio " <> checked <> "id=\"" <> idLabel <> "\" " <>
"name=variant autocomplete=off\n" <>
" value=\"" <> fromText path <> "\">\n" <>
" <label for=\"" <> idLabel <> "\">" <> fromText label <> "</label>\n"
altButton i (Image {label, path, nsfw}) = [b|@6
<li$nsfwClass>
<input type=radio$checked id="$idLabel" name=variant
autocomplete=off value="$*path">
<label for="$idLabel">$*label</label>
|]
where
nsfwClass = if nsfw then " class=nsfw" else ""
checked = if i == 0 then "checked " else ""
checked = if i == 0 then " checked" else ""
idLabel = escId label
escId :: Strict.Text -> Builder
@ -109,41 +119,40 @@ escId = foldMap esc1 . Strict.unpack where
| c < 'ÿ' && not (Char.isAlphaNum c || c == '-') = "_"
| otherwise = singleton c
indent :: Int -> Strict.Text -> Builder
indent n txt = spaces <> go (Strict.unpack txt) where
go "" = mempty
go "\n" = "\n"
go ('\n':cs) = singleton '\n' <> spaces <> go cs
go (c:cs) = singleton c <> go cs
spaces = fromString $ replicate n ' '
makeTags :: Bool -> [Strict.Text] -> [Strict.Text] -> Builder
makeTags includeNsfw sfwTags nsfwTags =
if null tags then mempty else
" <div class=tags>\n" <>
" <h2>tags</h2>\n" <>
" <ul>\n" <> foldMap makeTag tags <> " </ul>\n" <>
" </div>\n\n"
if null tags then "" else [b|@2
<div class=tags>
<h2>tags</h2>
<ul>
$6.tagList
</ul>
</div>
|]
where
tagList = map makeTag tags
makeTag t = [b|<li>$*t|]
tags = List.nub $ if includeNsfw then sfwTags else sfwTags <> nsfwTags
makeTag t = " <li>" <> fromText t <> "\n"
extLinks :: Bool -> [Link] -> Builder
extLinks includeNsfw links =
let links' =
if includeNsfw then links
else filter (\Link {nsfw} -> not nsfw) links in
if null links' then mempty else
" <div class=links>\n" <>
" <h2>links</h2>\n" <>
" <ul>\n" <>
foldMap extLink links' <>
" </ul>\n" <>
" </div>\n"
extLinks includeNsfw allLinks =
if null links then "" else [b|@2
<div class=links>
<h2>links</h2>
<ul>
$6.linkList
</ul>
</div>
|]
where
links | includeNsfw = allLinks
| otherwise = filter (\Link {nsfw} -> not nsfw) allLinks
linkList = map extLink links
extLink :: Link -> Builder
extLink (Link {title, url}) =
" <li>\n" <>
" <a href=\"" <> fromText url <> "\">\n" <>
" " <> fromText title <> "\n" <>
" </a>\n"
extLink (Link {title, url}) = [b|@6
<li>
<a href="$*url">
$*title
</a>
|]

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@ -9,7 +9,7 @@ maintainer: Rhiannon Morris <rhi@rhiannon.website>
executable make-pages
hs-source-dirs: .
main-is: Main.hs
other-modules: Info, SinglePage
other-modules: Info, SinglePage, BuildVar
default-language: Haskell2010
default-extensions:
BlockArguments,
@ -18,7 +18,10 @@ executable make-pages
DuplicateRecordFields,
LambdaCase,
NamedFieldPuns,
OverloadedStrings
OverloadedStrings,
PatternSynonyms,
QuasiQuotes,
ViewPatterns
build-depends:
base >= 4.12.0.0 && < 4.15,
containers ^>= 0.6.0.1,
@ -26,6 +29,7 @@ executable make-pages
bytestring ^>= 0.10.8.2,
text ^>= 1.2.3.1,
HsYAML ^>= 0.2.1.0,
optparse-applicative ^>= 0.15.1.0
optparse-applicative ^>= 0.15.1.0,
template-haskell ^>= 2.16.0.0
ghc-options:
-Wall -threaded -rtsopts -with-rtsopts=-N