Use underlining layer from ansi-terminal >= 1.1

This adds styling for underline colors.

See also #183.

Author: jaspervdj

README.md

@@ -517,6 +517,15 @@ and `onRgb#101060` for a deep purple background).  Naturally, your terminal
 needs to support 24-bit RGB for this to work.  When creating portable
 presentations, it might be better to stick with the named colours listed above.
 
+To customize the color of the `underline`, combine the prefix with a color, for
+example:
+
+```yaml
+patat:
+    theme:
+        strong: [underline, underlineVividBlue]
+```
+
 ### Syntax Highlighting
 
 `patat` uses [Kate] Syntax Highlighting files.  `patat` ships with support for

flake.nix

@@ -20,6 +20,7 @@
         packages = [
           pkgs.cabal-install
           pkgs.entr
+          pkgs.wezterm
           haskell.goldplate
           haskell.stylish-haskell
           (haskell.ghc.withPackages (p: inputs.self.packages.${system}.default.buildInputs))

lib/Patat/Theme.hs

@@ -180,41 +180,41 @@ rgbToSgr layer rgbHex =
 
 --------------------------------------------------------------------------------
 sgrToString :: Ansi.SGR -> Maybe String
-sgrToString (Ansi.SetColor layer intensity color) = Just $
-    (\str -> case layer of
-        Ansi.Foreground -> str
-        Ansi.Background -> "on" ++ capitalize str) $
-    (case intensity of
-        Ansi.Dull  -> "dull"
-        Ansi.Vivid -> "vivid") ++
-    (case color of
-        Ansi.Black   -> "Black"
-        Ansi.Red     -> "Red"
-        Ansi.Green   -> "Green"
-        Ansi.Yellow  -> "Yellow"
-        Ansi.Blue    -> "Blue"
-        Ansi.Magenta -> "Magenta"
-        Ansi.Cyan    -> "Cyan"
-        Ansi.White   -> "White")
-
-sgrToString (Ansi.SetUnderlining Ansi.SingleUnderline) = Just "underline"
-
-sgrToString (Ansi.SetConsoleIntensity Ansi.BoldIntensity) = Just "bold"
-
-sgrToString (Ansi.SetItalicized True) = Just "italic"
-
-sgrToString (Ansi.SetRGBColor layer color) = Just $
-    (\str -> case layer of
-        Ansi.Foreground -> str
-        Ansi.Background -> "on" ++ capitalize str) $
-    "rgb#" ++ (toRGBHex $ toSRGB24 color)
+sgrToString sgr = case sgr of
+    Ansi.SetColor layer intensity color -> Just $ layerPrefix layer $
+        (case intensity of
+            Ansi.Dull  -> "dull"
+            Ansi.Vivid -> "vivid") ++
+        (case color of
+            Ansi.Black   -> "Black"
+            Ansi.Red     -> "Red"
+            Ansi.Green   -> "Green"
+            Ansi.Yellow  -> "Yellow"
+            Ansi.Blue    -> "Blue"
+            Ansi.Magenta -> "Magenta"
+            Ansi.Cyan    -> "Cyan"
+            Ansi.White   -> "White")
+
+    Ansi.SetUnderlining Ansi.SingleUnderline -> Just "underline"
+
+    Ansi.SetConsoleIntensity Ansi.BoldIntensity -> Just "bold"
+
+    Ansi.SetItalicized True -> Just "italic"
+
+    Ansi.SetRGBColor layer color -> Just $ layerPrefix layer $
+        "rgb#" ++ (toRGBHex $ toSRGB24 color)
+
+    _ -> Nothing
   where
     toRGBHex (RGB r g b) = concat $ map toHexByte [r, g, b]
     toHexByte x = showHex2 x ""
     showHex2 x | x <= 0xf = ("0" ++) . showHex x
                | otherwise = showHex x
 
-sgrToString _ = Nothing
+    layerPrefix layer str = case layer of
+        Ansi.Foreground -> str
+        Ansi.Background -> "on" ++ capitalize str
+        Ansi.Underlining -> "underline" ++ capitalize str
 
 
 --------------------------------------------------------------------------------

patat.cabal

@@ -33,7 +33,7 @@ Library
 
   Build-depends:
     aeson                >= 2.0   && < 2.3,
-    ansi-terminal        >= 0.6   && < 1.2,
+    ansi-terminal        >= 1.1   && < 1.2,
     ansi-wl-pprint       >= 0.6   && < 1.1,
     async                >= 2.2   && < 2.3,
     base                 >= 4.9   && < 5,
@@ -155,7 +155,7 @@ Test-suite patat-tests
 
   Build-depends:
     patat,
-    ansi-terminal    >= 0.6  && < 1.2,
+    ansi-terminal    >= 1.1  && < 1.2,
     base             >= 4.8  && < 5,
     directory        >= 1.2  && < 1.4,
     pandoc           >= 3.1  && < 3.7,

tests/golden/inputs/themes.md

@@ -4,9 +4,14 @@ patat:
     bulletListMarkers: '-+'
     emph: [onVividRed, underline]
     strong: [rgb#f08000, onRgb#101060]
+    header: [vividGreen, underline, underlineVividBlue]
 ...
 
+# Just a header
+
 - This is a simple list.
     * With _nested_ items.
     * One or two **bold**.
 - The list theming is customized a bit.
+
+WezTerm is suitable for viewing this presentation.

tests/golden/outputs/themes.md.dump

@@ -1,9 +1,13 @@
                                themes.md                                
 
+[58:5:12;4;92m# Just a header
+
   - This is a simple list.
       + With nested items.
       + One or two bold.
 
   - The list theming is customized a bit.
 
+WezTerm is suitable for viewing this presentation.
+
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