T.P.Highlighting: export `defaultStyle` [API Change]

This allows to be more explicit about using a default style, and
providing a single point of truth for its value. The variable is an
alias for `pygments`.

3 files changed, 11 insertions, 5 deletions

diff --git a/src/Text/Pandoc/App/Opt.hs b/src/Text/Pandoc/App/Opt.hs
index 94fabb95a..3b90901d0 100644
--- a/src/Text/Pandoc/App/Opt.hs
+++ b/src/Text/Pandoc/App/Opt.hs
@@ -36,6 +36,7 @@ import Data.Char (toLower)
 import Data.Maybe (fromMaybe)
 import GHC.Generics hiding (Meta)
 import Text.Pandoc.Filter (Filter (..))
+import Text.Pandoc.Highlighting (defaultStyleName)
 import Text.Pandoc.Logging (Verbosity (WARNING), LogMessage(..))
 import Text.Pandoc.Options (TopLevelDivision (TopLevelDefault),
                             TrackChanges (AcceptChanges),
@@ -773,7 +774,7 @@ defaultOpts = Opt
     , optEmbedResources        = False
     , optLinkImages            = False
     , optHtmlQTags             = False
-    , optHighlightStyle        = Just "pygments"
+    , optHighlightStyle        = Just defaultStyleName
     , optSyntaxDefinitions     = []
     , optTopLevelDivision      = TopLevelDefault
     , optHTMLMathMethod        = PlainMath
diff --git a/src/Text/Pandoc/Highlighting.hs b/src/Text/Pandoc/Highlighting.hs
index a748fe7eb..524e6dfba 100644
--- a/src/Text/Pandoc/Highlighting.hs
+++ b/src/Text/Pandoc/Highlighting.hs
@@ -1,7 +1,7 @@
 {-# LANGUAGE OverloadedStrings #-}
 {- |
    Module      : Text.Pandoc.Highlighting
-   Copyright   : Copyright (C) 2008-2024 John MacFarlane
+   Copyright   : Copyright (C) 2008-2025 John MacFarlane
    License     : GNU GPL, version 2 or above
 
    Maintainer  : John MacFarlane <[email protected]>
@@ -31,6 +31,7 @@ module Text.Pandoc.Highlighting ( highlightingStyles
                                 , styleToConTeXt
                                 , formatANSI
                                 -- * Styles
+                                , defaultStyle
                                 , pygments
                                 , espresso
                                 , zenburn
@@ -56,6 +57,10 @@ import Control.Monad.Except (throwError)
 import System.FilePath (takeExtension)
 import Text.Pandoc.Shared (safeRead)
 
+-- | The default highlighting style used by pandoc (pygments).
+defaultStyle :: Style
+defaultStyle = pygments
+
 highlightingStyles :: [(T.Text, Style)]
 highlightingStyles =
   [("pygments", pygments),
diff --git a/src/Text/Pandoc/Options.hs b/src/Text/Pandoc/Options.hs
index 43df5c27f..8e0046d0b 100644
--- a/src/Text/Pandoc/Options.hs
+++ b/src/Text/Pandoc/Options.hs
@@ -48,7 +48,7 @@ import Skylighting (SyntaxMap, defaultSyntaxMap)
 import Text.DocTemplates (Context(..), Template)
 import Text.Pandoc.Extensions
 import Text.Pandoc.Chunks (PathTemplate)
-import Text.Pandoc.Highlighting (Style, pygments)
+import Text.Pandoc.Highlighting (Style, defaultStyle)
 import Text.Pandoc.UTF8 (toStringLazy)
 import Data.Aeson.TH (deriveJSON)
 import Data.Aeson
@@ -115,7 +115,7 @@ instance FromJSON HTMLMathMethod where
         mburl <- m .:? "url"
         case method :: Text of
           "plain" -> return PlainMath
-          "webtex" -> return $ WebTeX $ 
+          "webtex" -> return $ WebTeX $
                          fromMaybe defaultWebTeXURL mburl
           "gladtex" -> return GladTeX
           "mathml" -> return MathML
@@ -375,7 +375,7 @@ instance Default WriterOptions where
                       , writerSlideLevel       = Nothing
                       , writerTopLevelDivision = TopLevelDefault
                       , writerListings         = False
-                      , writerHighlightStyle   = Just pygments
+                      , writerHighlightStyle   = Just defaultStyle
                       , writerSetextHeaders    = False
                       , writerListTables       = False
                       , writerEpubSubdirectory = "EPUB"