Add horizontal break support from PR 13

# Details

Adds just the horizontal break feature from:
#13

Co-Authored-By: Dmitriy <dmitriy@shabaev.com>

Author: MeanderingProgrammer

README.md

@@ -11,6 +11,7 @@ Plugin to improve viewing Markdown files in Neovim
 - Changes `conceallevel` between `rendered` and `raw` view based on configuration
 - Supports rendering `markdown` injected into other file types
 - Highlights headings with different groups depending on level and replaces `#`
+- Updates horizontal breaks with full-width lines
 - Highlights code blocks and inline code to better stand out
 - Replaces bullet points with provided character based on level
 - Replaces block quote leading `>` with provided character
@@ -58,6 +59,8 @@ require('render-markdown').setup({
             (atx_h6_marker)
         ] @heading)
 
+        (thematic_break) @dash
+
         (fenced_code_block) @code
 
         [
@@ -85,6 +88,8 @@ require('render-markdown').setup({
     render_modes = { 'n', 'c' },
     -- Characters that will replace the # at the start of headings
     headings = { '󰲡 ', '󰲣 ', '󰲥 ', '󰲧 ', '󰲩 ', '󰲫 ' },
+    -- Character to use for the horizontal break
+    dash = '—',
     -- Character to use for the bullet points in lists
     bullets = { '●', '○', '◆', '◇' },
     -- Character that will replace the > at the start of block quotes
@@ -113,6 +118,8 @@ require('render-markdown').setup({
                 'markdownH6',
             },
         },
+        -- Horizontal break
+        dash = 'LineNr',
         -- Code blocks
         code = 'ColorColumn',
         -- Bullet points in list

demo/sample.md

@@ -33,6 +33,8 @@ if __name__ == "__main__":
 2. Item 2
 3. Item 3
 
+---
+
   > Quote line 1
   > Quote line 2
 

doc/render-markdown.txt

@@ -1,4 +1,4 @@
-*render-markdown.txt*           For 0.9.5           Last change: 2024 April 01
+*render-markdown.txt*           For 0.9.5           Last change: 2024 April 11
 
 ==============================================================================
 Table of Contents                          *render-markdown-table-of-contents*
@@ -31,6 +31,7 @@ Plugin to improve viewing Markdown files in Neovim
 - Changes `conceallevel` between `rendered` and `raw` view based on configuration
 - Supports rendering `markdown` injected into other file types
 - Highlights headings with different groups depending on level and replaces `#`
+- Updates horizontal breaks with full-width lines
 - Highlights code blocks and inline code to better stand out
 - Replaces bullet points with provided character based on level
 - Replaces block quote leading `>` with provided character
@@ -85,6 +86,8 @@ modified by the user.
                 (atx_h6_marker)
             ] @heading)
 
+            (thematic_break) @dash
+    
             (fenced_code_block) @code
 
             [
@@ -112,6 +115,8 @@ modified by the user.
         render_modes = { 'n', 'c' },
         -- Characters that will replace the # at the start of headings
         headings = { '󰲡 ', '󰲣 ', '󰲥 ', '󰲧 ', '󰲩 ', '󰲫 ' },
+        -- Character to use for the horizontal break
+        dash = '—',
         -- Character to use for the bullet points in lists
         bullets = { '●', '○', '◆', '◇' },
         -- Character that will replace the > at the start of block quotes
@@ -140,6 +145,8 @@ modified by the user.
                     'markdownH6',
                 },
             },
+            -- Horizontal break
+            dash = 'LineNr',
             -- Code blocks
             code = 'ColorColumn',
             -- Bullet points in list

lua/render-markdown/handler/markdown.lua

@@ -33,6 +33,13 @@ M.render = function(namespace, root)
                 virt_text_pos = 'overlay',
                 hl_eol = true,
             })
+        elseif capture == 'dash' then
+            local width = vim.api.nvim_win_get_width(0)
+            local virt_text = { state.config.dash:rep(width), highlights.dash }
+            vim.api.nvim_buf_set_extmark(0, namespace, start_row, 0, {
+                virt_text = { virt_text },
+                virt_text_pos = 'overlay',
+            })
         elseif capture == 'code' then
             vim.api.nvim_buf_set_extmark(0, namespace, start_row, 0, {
                 end_row = end_row,

lua/render-markdown/init.lua

@@ -13,6 +13,7 @@ local M = {}
 
 ---@class UserHighlights
 ---@field public heading? UserHeadingHighlights
+---@field public dash? string
 ---@field public code? string
 ---@field public bullet? string
 ---@field public table? UserTableHighlights
@@ -29,6 +30,7 @@ local M = {}
 ---@field public file_types? string[]
 ---@field public render_modes? string[]
 ---@field public headings? string[]
+---@field public dash? string
 ---@field public bullets? string[]
 ---@field public quote? string
 ---@field public conceal? UserConceal
@@ -49,6 +51,8 @@ function M.setup(opts)
                 (atx_h6_marker)
             ] @heading)
 
+            (thematic_break) @dash
+
             (fenced_code_block) @code
 
             [
@@ -71,6 +75,7 @@ function M.setup(opts)
         file_types = { 'markdown' },
         render_modes = { 'n', 'c' },
         headings = { '󰲡 ', '󰲣 ', '󰲥 ', '󰲧 ', '󰲩 ', '󰲫 ' },
+        dash = '—',
         bullets = { '●', '○', '◆', '◇' },
         quote = '┃',
         conceal = {
@@ -90,6 +95,7 @@ function M.setup(opts)
                     'markdownH6',
                 },
             },
+            dash = 'LineNr',
             code = 'ColorColumn',
             bullet = 'Normal',
             table = {

lua/render-markdown/state.lua

@@ -8,6 +8,7 @@
 
 ---@class Highlights
 ---@field public heading HeadingHighlights
+---@field public dash string
 ---@field public code string
 ---@field public bullet string
 ---@field public table TableHighlights
@@ -24,6 +25,7 @@
 ---@field public file_types string[]
 ---@field public render_modes string[]
 ---@field public headings string[]
+---@field public dash string
 ---@field public bullets string[]
 ---@field public quote string
 ---@field public conceal Conceal