Replace `--epub-chapter-level` with `--split-level`.

Rationale: we need this splitting level now not just in
EPUB but in chunked HTML.

`--epub-chapter-level` will still function as a deprecated
synonynm. `epub-chapter-level` will also continue to work in
defaults files, ande `epub_chapter_level` will still work for
Lua marshalling.

[API changes]

Text.Pandoc.App.Opt: remove `optEpubChapterLevel`, add
`optSplitLevel`.

Text.Pandoc.Options: remove `writerEpubChapterLevel`, add
`writerSplitLevel`.

6 files changed, 29 insertions, 13 deletions

diff --git a/src/Text/Pandoc/App/CommandLineOptions.hs b/src/Text/Pandoc/App/CommandLineOptions.hs
index d2a82b5a4..fc636e438 100644
--- a/src/Text/Pandoc/App/CommandLineOptions.hs
+++ b/src/Text/Pandoc/App/CommandLineOptions.hs
@@ -782,16 +782,29 @@ options =
                   "FILE")
                  "" -- "Directory of fonts to embed"
 
-    , Option "" ["epub-chapter-level"]
+    , Option "" ["split-level"]
                  (ReqArg
                   (\arg opt ->
                       case safeStrRead arg of
                            Just t | t >= 1 && t <= 6 ->
-                                    return opt { optEpubChapterLevel = t }
+                                    return opt { optSplitLevel = t }
+                           _      -> optError $ PandocOptionError
+                                    "split level must be a number between 1 and 6")
+                 "NUMBER")
+                 "" -- "Header level at which to split documents in chunked HTML or EPUB"
+
+    , Option "" ["epub-chapter-level"]
+                 (ReqArg
+                  (\arg opt -> do
+                      deprecatedOption "--epub-chapter-level"
+                                       "use --split-level"
+                      case safeStrRead arg of
+                           Just t | t >= 1 && t <= 6 ->
+                                    return opt { optSplitLevel = t }
                            _      -> optError $ PandocOptionError
-                                    "chapter level must be a number between 1 and 6")
+                                    "split level must be a number between 1 and 6")
                  "NUMBER")
-                 "" -- "Header level at which to split chapters in EPUB"
+                 "" -- "Header level at which to split documents in chunked HTML or EPUB"
 
     , Option "" ["ipynb-output"]
                  (ReqArg
diff --git a/src/Text/Pandoc/App/Opt.hs b/src/Text/Pandoc/App/Opt.hs
index d106d9d15..762305170 100644
--- a/src/Text/Pandoc/App/Opt.hs
+++ b/src/Text/Pandoc/App/Opt.hs
@@ -126,10 +126,10 @@ data Opt = Opt
     , optHTMLMathMethod        :: HTMLMathMethod -- ^ Method to print HTML math
     , optAbbreviations         :: Maybe FilePath -- ^ Path to abbrevs file
     , optReferenceDoc          :: Maybe FilePath -- ^ Path of reference doc
+    , optSplitLevel            :: Int     -- ^ Header level at which to split documents in epub and chunkedhtml
     , optEpubSubdirectory      :: String -- ^ EPUB subdir in OCF container
     , optEpubMetadata          :: Maybe FilePath   -- ^ EPUB metadata
     , optEpubFonts             :: [FilePath] -- ^ EPUB fonts to embed
-    , optEpubChapterLevel      :: Int     -- ^ Header level at which to split chapters
     , optEpubCoverImage        :: Maybe FilePath -- ^ Cover image for epub
     , optEpubTitlePage         :: Bool -- ^ INclude title page in EPUB
     , optTOCDepth              :: Int     -- ^ Number of levels to include in TOC
@@ -207,10 +207,11 @@ instance FromJSON Opt where
        <*> o .:? "html-math-method" .!= optHTMLMathMethod defaultOpts
        <*> o .:? "abbreviations"
        <*> o .:? "reference-doc"
+       <*> ((o .:? "split-level") <|> (o .:? "epub-chapter-level"))
+             .!= optSplitLevel defaultOpts
        <*> o .:? "epub-subdirectory" .!= optEpubSubdirectory defaultOpts
        <*> o .:? "epub-metadata"
        <*> o .:? "epub-fonts" .!= optEpubFonts defaultOpts
-       <*> o .:? "epub-chapter-level" .!= optEpubChapterLevel defaultOpts
        <*> o .:? "epub-cover-image"
        <*> o .:? "epub-title-page" .!= optEpubTitlePage defaultOpts
        <*> o .:? "toc-depth" .!= optTOCDepth defaultOpts
@@ -559,7 +560,9 @@ doOpt (k,v) = do
       parseJSON v >>= \x -> return (\o -> o{ optEpubFonts = optEpubFonts o <>
                                                map unpack x })
     "epub-chapter-level" ->
-      parseJSON v >>= \x -> return (\o -> o{ optEpubChapterLevel = x })
+      parseJSON v >>= \x -> return (\o -> o{ optSplitLevel = x })
+    "split-level" ->
+      parseJSON v >>= \x -> return (\o -> o{ optSplitLevel = x })
     "epub-cover-image" ->
       parseJSON v >>= \x ->
              return (\o -> o{ optEpubCoverImage = unpack <$> x })
@@ -736,10 +739,10 @@ defaultOpts = Opt
     , optHTMLMathMethod        = PlainMath
     , optAbbreviations         = Nothing
     , optReferenceDoc          = Nothing
+    , optSplitLevel            = 1
     , optEpubSubdirectory      = "EPUB"
     , optEpubMetadata          = Nothing
     , optEpubFonts             = []
-    , optEpubChapterLevel      = 1
     , optEpubCoverImage        = Nothing
     , optEpubTitlePage         = True
     , optTOCDepth              = 3
diff --git a/src/Text/Pandoc/App/OutputSettings.hs b/src/Text/Pandoc/App/OutputSettings.hs
index 8e41e51fb..4fd30ff66 100644
--- a/src/Text/Pandoc/App/OutputSettings.hs
+++ b/src/Text/Pandoc/App/OutputSettings.hs
@@ -249,8 +249,8 @@ optToOutputSettings scriptingEngine opts = do
         , writerEpubSubdirectory = T.pack $ optEpubSubdirectory opts
         , writerEpubMetadata     = epubMetadata
         , writerEpubFonts        = optEpubFonts opts
-        , writerEpubChapterLevel = optEpubChapterLevel opts
         , writerEpubTitlePage    = optEpubTitlePage opts
+        , writerSplitLevel       = optSplitLevel opts
         , writerTOCDepth         = optTOCDepth opts
         , writerReferenceDoc     = optReferenceDoc opts
         , writerSyntaxMap        = syntaxMap
diff --git a/src/Text/Pandoc/Options.hs b/src/Text/Pandoc/Options.hs
index dbebb799c..f671dd279 100644
--- a/src/Text/Pandoc/Options.hs
+++ b/src/Text/Pandoc/Options.hs
@@ -316,8 +316,8 @@ data WriterOptions = WriterOptions
   , writerEpubSubdirectory  :: Text       -- ^ Subdir for epub in OCF
   , writerEpubMetadata      :: Maybe Text -- ^ Metadata to include in EPUB
   , writerEpubFonts         :: [FilePath] -- ^ Paths to fonts to embed
-  , writerEpubChapterLevel  :: Int            -- ^ Header level for chapters (separate files)
   , writerEpubTitlePage     :: Bool           -- ^ Include title page in epub
+  , writerSplitLevel        :: Int        -- ^ Header level at which to split EPUB or chunked HTML into separate files
   , writerTOCDepth          :: Int            -- ^ Number of levels to include in TOC
   , writerReferenceDoc      :: Maybe FilePath -- ^ Path to reference document if specified
   , writerReferenceLocation :: ReferenceLocation    -- ^ Location of footnotes and references for writing markdown
@@ -353,8 +353,8 @@ instance Default WriterOptions where
                       , writerEpubSubdirectory = "EPUB"
                       , writerEpubMetadata     = Nothing
                       , writerEpubFonts        = []
-                      , writerEpubChapterLevel = 1
                       , writerEpubTitlePage    = True
+                      , writerSplitLevel       = 1
                       , writerTOCDepth         = 3
                       , writerReferenceDoc     = Nothing
                       , writerReferenceLocation = EndOfDocument
diff --git a/src/Text/Pandoc/Writers/ChunkedHTML.hs b/src/Text/Pandoc/Writers/ChunkedHTML.hs
index f58733588..d71abe5e0 100644
--- a/src/Text/Pandoc/Writers/ChunkedHTML.hs
+++ b/src/Text/Pandoc/Writers/ChunkedHTML.hs
@@ -57,7 +57,7 @@ writeChunkedHTML opts (Pandoc meta blocks) = do
   let chunkedDoc = splitIntoChunks "%s-%i.html"
                      True
                      (Just 1)
-                     (writerEpubChapterLevel opts)
+                     (writerSplitLevel opts)
                      (Pandoc meta blocks)
   let topChunk =
         Chunk
diff --git a/src/Text/Pandoc/Writers/EPUB.hs b/src/Text/Pandoc/Writers/EPUB.hs
index 09eac0d75..832ddb0b2 100644
--- a/src/Text/Pandoc/Writers/EPUB.hs
+++ b/src/Text/Pandoc/Writers/EPUB.hs
@@ -541,7 +541,7 @@ pandocToEPUB version opts doc = do
   let chunkedDoc = splitIntoChunks "ch%n.xhtml"
                      (writerNumberSections opts)
                      Nothing
-                     (writerEpubChapterLevel opts)
+                     (writerSplitLevel opts)
                      (Pandoc meta blocks')