Fixed PDF generate to use toc.metadata.

Makefile

@@ -4,6 +4,7 @@
 #################################################################################
 
 SITE_DIR  := _site
+RAW_DIR   := $(SITE_DIR)/raw
 CACHE_DIR := _cache
 TMP_DIR   := $(CACHE_DIR)/tmp
 

book/epub.md

@@ -66,6 +66,6 @@ src/plfa/part2/Substitution.lagda.md
 
 ## Acknowledgements
 ``` {.include shift-heading-level-by=1}
-_site/acknowledgements.md
+_site/raw/plfa/backmatter/acknowledgements.md
 src/plfa/backmatter/Fonts.lagda.md
 ```

book/epub.mk

@@ -7,8 +7,8 @@ MD_FILES          := README.md $(wildcard $(MD_DIR)/plfa/**/*.md)
 
 
 # Compile PLFA to an EPUB
-.PHONY: epub
+.PHONY: epub-build
-epub: $(SITE_DIR)/plfa.epub
+epub-build: $(SITE_DIR)/plfa.epub
 
 $(SITE_DIR)/plfa.epub: book/epub.md book/epub.css $(MD_FILES) $(EPUB_LUA_SCRIPTS) | setup-install-pandoc
 	@$(PANDOC) \

book/pdf.mk

@@ -5,32 +5,50 @@ MD_DIR           := src
 LAGDA_TEX_DIR    := $(TMP_DIR)/lagda_tex
 TEX_DIR          := $(TMP_DIR)/tex
 
+# Convert MD_DIR/%.md to its modified source path
+define MD_PATH
+$(patsubst $(MD_DIR)/%/acknowledgements.md,$(RAW_DIR)/%/acknowledgements.md,\
+	$(patsubst $(PDF_DIR)/pdf.tex,$(RAW_DIR)/pdf.tex,$(1)))
+endef
+
 # Convert MD_DIR/%.lagda.md to LAGDA_TEX_DIR/%.lagda.tex
 define LAGDA_TEX_PATH
 $(patsubst $(MD_DIR)/%.lagda.md,$(LAGDA_TEX_DIR)/%.lagda.tex,$(1))
 endef
 
 # Convert MD_DIR/%.md to LAGDA_TEX_DIR/%.lagda.tex or TEX_DIR/%.tex
+#
+# NOTE: This logic is partially duplicated in hs/Main.hs:addTexPath:texPath.
+#
 define TEX_PATH
-$(patsubst $(PDF_DIR)/%,$(TEX_DIR)/%,\
+$(patsubst $(RAW_DIR)/%,$(TEX_DIR)/%,\
-	$(patsubst README.md,$(TEX_DIR)/plfa/frontmatter/README.tex,\
+	$(patsubst $(PDF_DIR)/%,$(TEX_DIR)/%,\
-		$(patsubst $(MD_DIR)/%.md,$(TEX_DIR)/%.tex,\
+		$(patsubst README.md,$(TEX_DIR)/plfa/frontmatter/README.tex,\
-			$(patsubst $(MD_DIR)/%.lagda.md,$(TEX_DIR)/%.tex,$(1)))))
+			$(patsubst $(MD_DIR)/%.md,$(TEX_DIR)/%.tex,\
+				$(patsubst $(MD_DIR)/%.lagda.md,$(TEX_DIR)/%.tex,$(1))))))
 endef
 
 # List source and intermediate files
 PDF_LUA_SCRIPTS  := $(wildcard $(PDF_LUA_DIR)/*.lua)
-PDF_STATIC_FILES := book/pdf.tex book/DejaVu-mononoki-Symbola-Droid.ttf
+PDF_STATIC_FILES := $(PDF_DIR)/pdf.tex $(PDF_DIR)/DejaVu-mononoki-Symbola-Droid.ttf
 MD_FILES         := README.md $(wildcard $(MD_DIR)/plfa/**/*.md)
-MD_FILES         := $(filter-out %Fonts.lagda.md,$(MD_FILES))
 LAGDA_MD_FILES   := $(filter %.lagda.md,$(MD_FILES))
 LAGDA_TEX_FILES  := $(call LAGDA_TEX_PATH,$(LAGDA_MD_FILES))
-TEX_FILES        := $(call TEX_PATH,$(MD_FILES) $(PDF_STATIC_FILES))
+TEX_FILES        := $(call TEX_PATH,$(MD_FILES) $(RAW_DIR)/pdf.tex $(PDF_STATIC_FILES))
+
+
+# Generated by Hakyll
+$(RAW_DIR)/pdf.tex: $(PDF_DIR)/pdf.tex $(MD_DIR)/plfa/toc.metadata
+	make build
+
+# Generated by Hakyll
+$(RAW_DIR)/plfa/backmatter/acknowledgements.md: $(MD_DIR)/plfa/backmatter/acknowledgements.md
+	make build
 
 
 # Compile PLFA to a PDF
-.PHONY: pdf
+.PHONY: pdf-build
-pdf: $(SITE_DIR)/plfa.pdf
+pdf-build: $(SITE_DIR)/plfa.pdf
 
 $(SITE_DIR)/plfa.pdf: $(TEX_FILES)
 	@cd $(TEX_DIR) && latexmk -pdf -lualatex -use-make -halt-on-error pdf.tex
@@ -58,7 +76,6 @@ endef
 define MK_MD2TEX_RULE
 src := $(1)
 dst := $(2)
-ttl := $(3)
 $$(dst): $$(src) $(PDF_LUA_SCRIPTS) | setup-install-pandoc
 	@echo "Compile $$< to $$@"
 	@mkdir -p '$$(@D)'
@@ -68,7 +85,7 @@ $$(dst): $$(src) $(PDF_LUA_SCRIPTS) | setup-install-pandoc
 		--lua-filter=$(PDF_LUA_DIR)/remove-badges.lua -M badge-url=https://img.shields.io/badge/ \
 		--lua-filter=$(PDF_LUA_DIR)/latex-render-codeblocks.lua -M unchecked-files=README.md \
 		--lua-filter=$(PDF_LUA_DIR)/single-file-links.lua \
-		--lua-filter=$(PDF_LUA_DIR)/single-file-headers.lua -M default-title=$$(ttl) \
+		--lua-filter=$(PDF_LUA_DIR)/single-file-headers.lua \
 		$$< -o $$@
 endef
 
@@ -85,14 +102,14 @@ endef
 $(foreach static_file,\
 	$(PDF_STATIC_FILES),\
 	$(eval $(call MK_COPYSTATIC_RULE,\
-		$(static_file),\
+		$(call MD_PATH,$(static_file)),\
 		$(call TEX_PATH,$(static_file)))))
 
 # Compile .md files (from MD_DIR/%.md to TEX_DIR/%.tex)
 $(foreach md_file,\
-	$(filter-out %acknowledgements.md %.lagda.md,$(MD_FILES)),\
+	$(filter-out %.lagda.md,$(MD_FILES)),\
 	$(eval $(call MK_MD2TEX_RULE,\
-		$(md_file),\
+		$(call MD_PATH,$(md_file)),\
 		$(call TEX_PATH,$(md_file)))))
 
 # Compile .lagda.md files (from MD_DIR/%.md to LAGDA_TEX_DIR/%.lagda.tex)
@@ -102,12 +119,6 @@ $(foreach lagda_md_file,\
 		$(lagda_md_file),\
 		$(call LAGDA_TEX_PATH,$(lagda_md_file)))))
 
-# Compile acknowledgements (from SITE_DIR/acknowledgements.md to TEX_DIR/acknowledgements.tex)
-$(eval $(call MK_MD2TEX_RULE,\
-	$(SITE_DIR)/acknowledgements.md,\
-	$(TEX_DIR)/plfa/backmatter/acknowledgements.tex,\
-	Acknowledgements))
-
 # Compile .lagda.tex files (from LAGDA_TEX_DIR/%.lagda.tex to TEX_DIR/%.tex)
 $(foreach lagda_md_file,\
 	$(LAGDA_MD_FILES),\

book/pdf.tex

@@ -123,54 +123,45 @@
   \null\endgroup
 \end{titlepage}
 
-\frontmatter
+$for(parts)$
+
+% Open front, main, and back matter sections:
+$if(frontmatter)$
+\frontmatter%
 \setcounter{tocdepth}{0}
 
-\tableofcontents
+\tableofcontents%
 \setcounter{tocdepth}{1}
-
+$endif$
-\input{plfa/frontmatter/dedication}
+$if(mainmatter)$
-\input{plfa/frontmatter/preface}
-\input{plfa/frontmatter/README}
-
 \mainmatter%
-
+$endif$
-\part{Part 1: Logical Foundations}
+$if(backmatter)$
-\input{plfa/part1/Naturals}
-\input{plfa/part1/Induction}
-\input{plfa/part1/Relations}
-\input{plfa/part1/Equality}
-\input{plfa/part1/Isomorphism}
-\input{plfa/part1/Connectives}
-\input{plfa/part1/Negation}
-\input{plfa/part1/Quantifiers}
-\input{plfa/part1/Decidable}
-\input{plfa/part1/Lists}
-
-\part{Part 2: Programming Language Foundations}
-\input{plfa/part2/Lambda}
-\input{plfa/part2/Properties}
-\input{plfa/part2/DeBruijn}
-\input{plfa/part2/More}
-\input{plfa/part2/Bisimulation}
-\input{plfa/part2/Inference}
-\input{plfa/part2/Untyped}
-\input{plfa/part2/Confluence}
-\input{plfa/part2/BigStep}
-
-\part{Part 3: Denotational Semantics}
-\input{plfa/part3/Denotational}
-\input{plfa/part3/Compositional}
-\input{plfa/part3/Soundness}
-\input{plfa/part3/Adequacy}
-\input{plfa/part3/ContextualEquivalence}
-
-\cleardoublepage%
-\phantomsection%
-
 \appendix
 \addcontentsline{toc}{part}{Appendices}
+$endif$
+
+% Only print title for main and back matter:
+$if(frontmatter)$
+% NOTE: Front matter titles are inserted via book/lua/single-file-headers.lua.
+$else$
+\part{$title$}
+$endif$
+
+% Include each section.
+$for(sections)$
+\input{$tex_path$}
+$endfor$
+
+% Close front, main, and back matter sections:
+$if(frontmatter)$
+$endif$
+$if(mainmatter)$
+\cleardoublepage%
+\phantomsection%
+$endif$
+$if(backmatter)$
+$endif$
+$endfor$
 
-\input{plfa/part2/Substitution}
-\input{plfa/backmatter/acknowledgements}
 \end{document}

hs/Hakyll/Web/Template/Context/Derived.hs

@@ -0,0 +1,22 @@
+{-# LANGUAGE RankNTypes #-}
+
+module Hakyll.Web.Template.Context.Derived where
+
+import Hakyll
+
+addDerivedField
+  :: String
+  -> (forall b. Context b -> [String] -> Item b -> Compiler ContextField)
+  -> Context a
+  -> Context a
+addDerivedField key derive ctx = Context $ \k a i ->
+  if k == key then
+    derive ctx a i
+  else do
+    fld <- unContext ctx k a i
+    return $
+      case fld of
+        -- If the field is a list, recursively derive the field for any list items.
+        ListField itemCtx items -> ListField (addDerivedField key derive itemCtx) items
+        -- Otherwise, simply return the field.
+        otherFld                -> otherFld

hs/Hakyll/Web/Template/Context/Metadata.hs

@@ -1,3 +1,5 @@
+{-# LANGUAGE OverloadedStrings #-}
+
 module Hakyll.Web.Template.Context.Metadata where
 
 import           Control.Monad ((<=<))
@@ -8,21 +10,43 @@ import qualified Data.Vector as V
 import           Hakyll
 import           Text.Printf (printf)
 
+-- |Create a context from a JSON object which loads the included file and uses it to generate a context.
+includeContext :: Context String -> Context Object
+includeContext ctx = Context $ \k a i -> do
+  let o = itemBody i
+  v <- lookupObject "include" o
+  identifier <- fromFilePath <$> toString v
+  unContext (ctx <> metadataContext ctx) k a =<< load identifier
+
 -- |Create a Context based on a JSON Object.
 objectContext :: Context String -> Context Object
-objectContext ctx = Context $ \k _ i ->
+objectContext ctx = Context $ \k _ i -> do
-  let o = itemBody i in
+  let o = itemBody i
-  case H.lookup (T.pack k) o of
+  decodeValue ctx =<< lookupObject k o
-    Just  v -> decodeValue ctx v
-    Nothing -> fail $ printf "Key '%s' undefined in context '%s'" k (show o)
 
-isObject :: Value -> Bool
+-- |Decode a JSON Value to a context field.
-isObject (Object _) = True
+decodeValue :: Context String -> Value -> Compiler ContextField
-isObject _          = False
+decodeValue ctx (Array a) = do
+  objs <- mapM (makeItem <=< toObject) (V.toList a)
+  return $ ListField (includeContext ctx <> objectContext ctx) objs
+decodeValue _ctx (String s) = return . StringField $ T.unpack s
+decodeValue _ctx (Number n) = return . StringField $ show n
+decodeValue _ctx (Bool   b) = return . StringField $ show b
+decodeValue _ctx v          = fail $ printf "Unsupported value '%s'" (show v)
 
-isString :: Value -> Bool
+-- |Create a Context based on the Metadata.
-isString (String _) = True
+metadataContext :: Context String -> Context String
-isString _          = False
+metadataContext ctx = Context $ \k a i -> do
+  let identifier = itemIdentifier i
+  metadata <- getMetadata identifier
+  item <- makeItem metadata
+  unContext (objectContext ctx) k a item
+
+lookupObject :: String -> Object -> Compiler Value
+lookupObject k o = maybe ifNotFound ifFound (H.lookup (T.pack k) o)
+  where
+    ifFound    = return
+    ifNotFound = fail $ printf "Key '%s' undefined in context '%s'" k (show o)
 
 toObject :: MonadFail m => Value -> m Object
 toObject (Object o) = return o
@@ -31,23 +55,3 @@ toObject v          = fail $ printf "Not an object '%s'" (show v)
 toString :: MonadFail m => Value -> m String
 toString (String s) = return (T.unpack s)
 toString v          = fail $ printf "Not a string '%s'" (show v)
-
--- |Decode a JSON Value to a context field.
-decodeValue :: Context String -> Value -> Compiler ContextField
-decodeValue ctx (Array  a)
-  | V.all isObject a = do
-      objs <- mapM (makeItem <=< toObject) (V.toList a)
-      return $ ListField (objectContext ctx) objs
-  | V.all isString a = do
-      items <- mapM (load . fromFilePath <=< toString) (V.toList a)
-      return $ ListField ctx items
-decodeValue _ (String s) = return . StringField $ T.unpack s
-decodeValue _ (Number n) = return . StringField $ show n
-decodeValue _ (Bool   b) = return . StringField $ show b
-decodeValue _ v          = fail $ printf "Unsupported value '%s'" (show v)
-
--- |Create a Context based on the Metadata.
-metadataContext :: Context String -> Context String
-metadataContext ctx = Context $ \k a i ->
-  unContext (objectContext ctx) k a <=< makeItem <=< getMetadata $ itemIdentifier i
-

hs/Main.hs

@@ -3,15 +3,17 @@
 
 import           Control.Monad ((<=<), forM_)
 import           Data.Functor ((<&>))
+import           Data.List (isPrefixOf)
 import qualified Data.Text as T
 import           Hakyll
 import           Hakyll.Web.Agda
 import           Hakyll.Web.Routes.Permalink
 import           Hakyll.Web.Template.Numeric
+import           Hakyll.Web.Template.Context.Derived
 import           Hakyll.Web.Template.Context.Metadata
 import           Hakyll.Web.Template.Context.Title
 import           Hakyll.Web.Sass
-import           System.FilePath ((</>), takeDirectory)
+import           System.FilePath ((</>), takeDirectory, replaceExtensions, splitPath, joinPath)
 import qualified Text.CSL as CSL
 import qualified Text.CSL.Pandoc as CSL (processCites)
 import           Text.Pandoc (Pandoc(..), ReaderOptions(..), WriterOptions(..), Extension(..))
@@ -76,7 +78,8 @@ siteSectionContext = mconcat
 
 tableOfContentsContext :: Context String -> Context String
 tableOfContentsContext ctx = Context $ \k a _ -> do
-  m <- makeItem <=< getMetadata $ "src/plfa/toc.metadata"
+  metadata <- getMetadata "src/plfa/toc.metadata"
+  m <- makeItem metadata
   unContext (objectContext ctx) k a m
 
 acknowledgementsContext :: Context String
@@ -124,6 +127,32 @@ sassOptions = defaultSassOptions
   }
 
 
+-- Convert MD_DIR/%.md to LAGDA_TEX_DIR/%.lagda.tex or TEX_DIR/%.tex
+--
+-- NOTE: This logic is partially duplicated in book/pdf.mk:TEX_PATH.
+--
+-- NOTE: This function assumes pdf.tex will be at TEX_DIR/.
+--
+addTexPath :: Context a -> Context a
+addTexPath = addDerivedField "tex_path" deriveTexPath
+  where
+    deriveTexPath :: Context a -> [String] -> Item a -> Compiler ContextField
+    deriveTexPath ctx a i = do
+      fld <- unContext ctx "include" a i
+      case fld of
+        StringField includePath -> return $ StringField (texPath includePath)
+        _ -> fail "Key 'include' does not return a String"
+
+    texPath :: FilePath -> FilePath
+    texPath fnDotMd
+      | fnDotMd == "README.md"                       = "plfa/frontmatter/README.tex"
+      | any (`isPrefixOf` fnDotMd) ["src/", "book/"] = dropTopDirectory (replaceExtensions fnDotMd ".tex")
+      | otherwise                                    = error ("textPath: cannot map " <> fnDotMd)
+
+    dropTopDirectory :: FilePath -> FilePath
+    dropTopDirectory = joinPath . tail . splitPath
+
+
 --------------------------------------------------------------------------------
 -- Build site
 --------------------------------------------------------------------------------
@@ -207,12 +236,24 @@ main = do
         >>= loadAndApplyTemplate "templates/default.html" siteContext
         >>= prettifyUrls
 
-    match "src/plfa/backmatter/acknowledgements.md" $ version "native" $ do
+    -- Compile raw version of acknowledgements used in constructing the PDF and EPUB
-      route   $ constRoute "versions/native/acknowledgements.native"
+    match "src/plfa/backmatter/acknowledgements.md" $ version "raw" $ do
+      route $ gsubRoute "src/" (const "raw/")
       compile $ getResourceBody
         >>= applyAsTemplate acknowledgementsContext
-        >>= readMarkdownWith siteReaderOptions
+        >>= loadAndApplyTemplate "templates/metadata.md" siteContext
-        <&> writeNativeWith siteWriterOptions
+
+    -- Compile raw version of index used in constructing the PDF
+    match "book/pdf.tex" $ do
+      route $ gsubRoute "book/" (const "raw/")
+      compile $ getResourceBody
+        >>= applyAsTemplate (addTexPath (tableOfContentsContext siteSectionContext))
+
+    -- Compile metadata XML used in constructing the EPUB
+    match "book/epub.xml" $ version "raw" $ do
+      route   $ constRoute "raw/epub.xml"
+      compile $ getResourceBody
+        >>= applyAsTemplate siteContext
 
     match "authors/*.metadata" $
       compile getResourceBody
@@ -354,15 +395,6 @@ writeHTML5With wopt (Item itemi doc) =
     Left err    -> error $ "Hakyll.Web.Pandoc.writePandocWith: " ++ show err
     Right item' -> Item itemi $ T.unpack item'
 
--- | Write a document as HTML using Pandoc, with the supplied options.
-writeNativeWith :: WriterOptions  -- ^ Writer options for Pandoc
-                -> Item Pandoc    -- ^ Document to write
-                -> Item String    -- ^ Resulting Markdown
-writeNativeWith wopt (Item itemi doc) =
-  case Pandoc.runPure $ Pandoc.writeNative wopt doc of
-    Left err    -> error $ "Hakyll.Web.Pandoc.writeNativeWith: " ++ show err
-    Right item' -> Item itemi $ T.unpack item'
-
 
 --------------------------------------------------------------------------------
 -- Supply snapshot as a field to the template

plfa.cabal

@@ -36,6 +36,7 @@ library
   hs-source-dirs:   hs
   exposed-modules:  Hakyll.Web.Agda
                   , Hakyll.Web.Template.Numeric
+                  , Hakyll.Web.Template.Context.Derived
                   , Hakyll.Web.Template.Context.Metadata
                   , Hakyll.Web.Template.Context.Title
                   , Hakyll.Web.Sass

src/plfa/toc.metadata

@@ -1,45 +1,48 @@
 ---
 parts:
-- title: "Front matter"
+- frontmatter: True
+  title: "Front matter"
   sections:
-  - src/plfa/frontmatter/dedication.md
+  - include: src/plfa/frontmatter/dedication.md
-  - src/plfa/frontmatter/preface.md
+  - include: src/plfa/frontmatter/preface.md
-  - README.md
+  - include: README.md
-- title: "Part 1: Logical Foundations"
+- mainmatter: True
+  title: "Part 1: Logical Foundations"
   sections:
-  - src/plfa/part1/Naturals.lagda.md
+  - include: src/plfa/part1/Naturals.lagda.md
-  - src/plfa/part1/Induction.lagda.md
+  - include: src/plfa/part1/Induction.lagda.md
-  - src/plfa/part1/Relations.lagda.md
+  - include: src/plfa/part1/Relations.lagda.md
-  - src/plfa/part1/Equality.lagda.md
+  - include: src/plfa/part1/Equality.lagda.md
-  - src/plfa/part1/Isomorphism.lagda.md
+  - include: src/plfa/part1/Isomorphism.lagda.md
-  - src/plfa/part1/Connectives.lagda.md
+  - include: src/plfa/part1/Connectives.lagda.md
-  - src/plfa/part1/Negation.lagda.md
+  - include: src/plfa/part1/Negation.lagda.md
-  - src/plfa/part1/Quantifiers.lagda.md
+  - include: src/plfa/part1/Quantifiers.lagda.md
-  - src/plfa/part1/Decidable.lagda.md
+  - include: src/plfa/part1/Decidable.lagda.md
-  - src/plfa/part1/Lists.lagda.md
+  - include: src/plfa/part1/Lists.lagda.md
 - title: "Part 2: Programming Language Foundations"
   sections:
-  - src/plfa/part2/Lambda.lagda.md
+  - include: src/plfa/part2/Lambda.lagda.md
-  - src/plfa/part2/Properties.lagda.md
+  - include: src/plfa/part2/Properties.lagda.md
-  - src/plfa/part2/DeBruijn.lagda.md
+  - include: src/plfa/part2/DeBruijn.lagda.md
-  - src/plfa/part2/More.lagda.md
+  - include: src/plfa/part2/More.lagda.md
-  - src/plfa/part2/Bisimulation.lagda.md
+  - include: src/plfa/part2/Bisimulation.lagda.md
-  - src/plfa/part2/Inference.lagda.md
+  - include: src/plfa/part2/Inference.lagda.md
-  - src/plfa/part2/Untyped.lagda.md
+  - include: src/plfa/part2/Untyped.lagda.md
-  - src/plfa/part2/Confluence.lagda.md
+  - include: src/plfa/part2/Confluence.lagda.md
-  - src/plfa/part2/BigStep.lagda.md
+  - include: src/plfa/part2/BigStep.lagda.md
 - title: "Part 3: Denotational Semantics"
   sections:
-  - src/plfa/part3/Denotational.lagda.md
+  - include: src/plfa/part3/Denotational.lagda.md
-  - src/plfa/part3/Compositional.lagda.md
+  - include: src/plfa/part3/Compositional.lagda.md
-  - src/plfa/part3/Soundness.lagda.md
+  - include: src/plfa/part3/Soundness.lagda.md
-  - src/plfa/part3/Adequacy.lagda.md
+  - include: src/plfa/part3/Adequacy.lagda.md
-  - src/plfa/part3/ContextualEquivalence.lagda.md
+  - include: src/plfa/part3/ContextualEquivalence.lagda.md
-- title: "Appendix"
+- backmatter: True
+  title: "Appendix"
   sections:
-  - src/plfa/part2/Substitution.lagda.md
+  - include: src/plfa/part2/Substitution.lagda.md
 - title: "Back matter"
   sections:
-  - src/plfa/backmatter/acknowledgements.md
+  - include: src/plfa/backmatter/acknowledgements.md
-  - src/plfa/backmatter/Fonts.lagda.md
+  - include: src/plfa/backmatter/Fonts.lagda.md
----
+---

templates/metadata.md

@@ -0,0 +1,22 @@
+---
+comment: This template is used to restore the standard PLFA metadata to Markdown files. It is used in raw writers.
+---
+
+---
+title       : $title$
+$if(authors)$
+author      :
+$for(authors)$
+  - $name$
+$endfor$
+$endif$
+description : $description$
+rights      : $rights$
+language    : $language$
+layout      : $layout$
+prev        : $prev$
+permalink   : $permalink$
+next        : $next$
+---
+
+$body$