feat(syntax)!: add additional syntax styles.

Introduce new styles options in order to be able to customize a
bit more the rose pine colorscheme syntax and not depend exclusively on
italic and bold style options. A new utility function was added in order
to add a custom hl property style for custom syntax styles.

lua/rose-pine.lua

@@ -179,7 +179,7 @@ local function set_highlights()
 
 		Boolean = { fg = palette.rose },
 		Character = { fg = palette.gold },
-		Comment = { fg = palette.subtle, italic = styles.italic },
+		Comment = { fg = palette.subtle, style = styles.comments },
 		Conditional = { fg = palette.pine },
 		Constant = { fg = palette.gold },
 		Debug = { fg = palette.rose },
@@ -188,10 +188,10 @@ local function set_highlights()
 		Error = { fg = palette.love },
 		Exception = { fg = palette.pine },
 		Float = { fg = palette.gold },
-		Function = { fg = palette.rose },
+		Function = { fg = palette.rose, style = styles.functions },
-		Identifier = { fg = palette.text },
+		Identifier = { fg = palette.text, style = styles.variables },
 		Include = { fg = palette.pine },
-		Keyword = { fg = palette.pine },
+		Keyword = { fg = palette.pine, style = styles.keywords },
 		Label = { fg = palette.foam },
 		LspCodeLens = { fg = palette.subtle },
 		LspCodeLensSeparator = { fg = palette.muted },
@@ -266,9 +266,9 @@ local function set_highlights()
 		mkdURL = { link = "markdownUrl" },
 
 		--- Identifiers
-		["@variable"] = { fg = palette.text, italic = styles.italic },
+		["@variable"] = { fg = palette.text, style = styles.variables },
-		["@variable.builtin"] = { fg = palette.love, bold = styles.bold },
+		["@variable.builtin"] = { fg = palette.love },
-		["@variable.parameter"] = { fg = palette.iris, italic = styles.italic },
+		["@variable.parameter"] = { fg = palette.iris },
 		["@variable.member"] = { fg = palette.foam },
 
 		["@constant"] = { fg = palette.gold },
@@ -303,7 +303,7 @@ local function set_highlights()
 		-- ["@type.qualifier"] = {},
 
 		-- ["@attribute"] = {},
-		["@property"] = { fg = palette.foam, italic = styles.italic },
+		["@property"] = { fg = palette.foam, style = styles.variables },
 
 		--- Functions
 		["@function"] = { fg = palette.rose },
@@ -857,7 +857,7 @@ local function set_highlights()
 		if highlight.blend ~= nil and (highlight.blend >= 0 and highlight.blend <= 100) and highlight.bg ~= nil then
 			highlight.bg = utilities.blend(highlight.bg, highlight.blend_on or palette.base, highlight.blend / 100)
 		end
-		vim.api.nvim_set_hl(0, group, highlight)
+		utilities.highlight(group, highlight)
 	end
 
 	--- Terminal

lua/rose-pine/config.lua

@@ -30,6 +30,10 @@ config.options = {
 	},
 
 	styles = {
+		comments = { italic = true },
+		functions = {},
+		keywords = { italic = true },
+		variables = {},
 		bold = true,
 		italic = true,
 		transparency = false,

lua/rose-pine/utilities.lua

@@ -44,4 +44,14 @@ function utilities.blend(fg, bg, alpha)
 	return string.format("#%02X%02X%02X", blend_channel(1), blend_channel(2), blend_channel(3))
 end
 
+---@param group string
+---@param hl table<string, boolean>
+function utilities.highlight(group, hl)
+	if hl.style then
+		hl = vim.tbl_extend("force", hl, hl.style)
+		hl.style = nil
+	end
+	vim.api.nvim_set_hl(0, group, hl)
+end
+
 return utilities