[API Change] Add new module "Text.Pandoc.Format"

The module provides functions and types for format spec parsing and
processing.

The function `parseFormatSpec` was moved from Text.Pandoc.Extensions to
the new module and renamed to `parseFlavoredFormat`. It now operates in
a PandocMonad and is based on the updated types.

2 files changed, 19 insertions, 30 deletions

diff --git a/pandoc-lua-engine/src/Text/Pandoc/Lua/Module/Pandoc.hs b/pandoc-lua-engine/src/Text/Pandoc/Lua/Module/Pandoc.hs
index ec77e2df6..1fdc6fd65 100644
--- a/pandoc-lua-engine/src/Text/Pandoc/Lua/Module/Pandoc.hs
+++ b/pandoc-lua-engine/src/Text/Pandoc/Lua/Module/Pandoc.hs
@@ -206,32 +206,21 @@ functions =
     =?> "output string, or error triple"
 
   , defun "read"
-    ### (\content mformatspec mreaderOptions -> do
+    ### (\content mformatspec mreaderOptions -> unPandocLua $ do
+            let readerOpts = fromMaybe def mreaderOptions
             let formatSpec = fromMaybe "markdown" mformatspec
-                readerOpts = fromMaybe def mreaderOptions
-                readAction = getReader formatSpec >>= \case
-                  (TextReader r, es)       ->
-                    r readerOpts{readerExtensions = es}
-                      (case content of
-                         Left bs       -> toSources $ UTF8.toText bs
-                         Right sources -> sources)
-                  (ByteStringReader r, es) ->
-                    case content of
-                      Left bs -> r readerOpts{readerExtensions = es}
-                                   (BSL.fromStrict bs)
-                      Right _ -> liftPandocLua $ Lua.failLua
-                                 "Cannot use bytestring reader with Sources"
-            try (unPandocLua readAction) >>= \case
-              Right pd ->
-                -- success, got a Pandoc document
-                return pd
-              Left  (PandocUnknownReaderError f) ->
-                Lua.failLua . T.unpack $ "Unknown reader: " <> f
-              Left  (PandocUnsupportedExtensionError e f) ->
-                Lua.failLua . T.unpack $
-                "Extension " <> e <> " not supported for " <> f
-              Left e ->
-                throwM e)
+            getReader formatSpec >>= \case
+              (TextReader r, es)       ->
+                 r readerOpts{readerExtensions = es}
+                   (case content of
+                      Left bs       -> toSources $ UTF8.toText bs
+                      Right sources -> sources)
+              (ByteStringReader r, es) ->
+                 case content of
+                   Left bs -> r readerOpts{readerExtensions = es}
+                                (BSL.fromStrict bs)
+                   Right _ -> throwM $ PandocLuaError
+                              "Cannot use bytestring reader with Sources")
     <#> parameter (\idx -> (Left  <$> peekByteString idx)
                        <|> (Right <$> peekSources idx))
           "string|Sources" "content" "text to parse"
@@ -255,10 +244,10 @@ functions =
     =#> functionResult pushInline "Inline" "modified Inline"
 
   , defun "write"
-    ### (\doc mformatspec mwriterOpts -> do
+    ### (\doc mformatspec mwriterOpts -> unPandocLua $ do
+            let writerOpts = fromMaybe def mwriterOpts
             let formatSpec = fromMaybe "html" mformatspec
-                writerOpts = fromMaybe def mwriterOpts
-            unPandocLua $ getWriter formatSpec >>= \case
+            getWriter formatSpec >>= \case
               (TextWriter w, es)      -> Right <$>
                 w writerOpts{ writerExtensions = es } doc
               (ByteStringWriter w, es) -> Left <$>
diff --git a/pandoc-lua-engine/test/lua/module/pandoc.lua b/pandoc-lua-engine/test/lua/module/pandoc.lua
index 397182438..d61bcf3b0 100644
--- a/pandoc-lua-engine/test/lua/module/pandoc.lua
+++ b/pandoc-lua-engine/test/lua/module/pandoc.lua
@@ -266,7 +266,7 @@ return {
     test('unsupported extension', function ()
       assert.error_matches(
         function () pandoc.read('foo', 'gfm+empty_paragraphs') end,
-        'Extension empty_paragraphs not supported for gfm'
+        'The extension empty_paragraphs is not supported for gfm'
       )
     end),
     test('read with other indented code classes', function()
@@ -290,7 +290,7 @@ return {
     test('failing read', function ()
       assert.error_matches(
         function () pandoc.read('foo', 'nosuchreader') end,
-        'Unknown reader: nosuchreader'
+        'Unknown input format nosuchreader'
       )
     end)
   },