feat: padding for inline code

## Details

Request: #274

Adds `inline_pad` option to `code` component which is used to add spaces
on both sides of inline code blocks.

In order to make offset calculations work correctly needed to make some
minor adjustments to the logic:

- Marks that do not specify an end use the start as the end rather than
  being ignored when adding offset to context
- A node overlaps with a range if its start is <= the end of the range,
  not strictly <, this is because ends are inclusive for these ranges

Author: MeanderingProgrammer

Diff for: README.md

@@ -381,10 +381,12 @@ require('render-markdown').setup({
         below = '▀',
         -- Highlight for code blocks
         highlight = 'RenderMarkdownCode',
-        -- Highlight for inline code
-        highlight_inline = 'RenderMarkdownCodeInline',
         -- Highlight for language, overrides icon provider value
         highlight_language = nil,
+        -- Padding to add to the left & right of inline code
+        inline_pad = 0,
+        -- Highlight for inline code
+        highlight_inline = 'RenderMarkdownCodeInline',
     },
     dash = {
         -- Turn on / off thematic break rendering
@@ -860,10 +862,12 @@ require('render-markdown').setup({
         below = '▀',
         -- Highlight for code blocks
         highlight = 'RenderMarkdownCode',
-        -- Highlight for inline code
-        highlight_inline = 'RenderMarkdownCodeInline',
         -- Highlight for language, overrides icon provider value
         highlight_language = nil,
+        -- Padding to add to the left & right of inline code
+        inline_pad = 0,
+        -- Highlight for inline code
+        highlight_inline = 'RenderMarkdownCodeInline',
     },
 })
 ```

Diff for: doc/render-markdown.txt

@@ -1,4 +1,4 @@
-*render-markdown.txt*         For 0.10.0         Last change: 2024 December 29
+*render-markdown.txt*          For 0.10.0         Last change: 2025 January 02
 
 ==============================================================================
 Table of Contents                          *render-markdown-table-of-contents*
@@ -437,10 +437,12 @@ Default Configuration ~
             below = '▀',
             -- Highlight for code blocks
             highlight = 'RenderMarkdownCode',
-            -- Highlight for inline code
-            highlight_inline = 'RenderMarkdownCodeInline',
             -- Highlight for language, overrides icon provider value
             highlight_language = nil,
+            -- Padding to add to the left & right of inline code
+            inline_pad = 0,
+            -- Highlight for inline code
+            highlight_inline = 'RenderMarkdownCodeInline',
         },
         dash = {
             -- Turn on / off thematic break rendering
@@ -910,10 +912,12 @@ Code Block Configuration ~
             below = '▀',
             -- Highlight for code blocks
             highlight = 'RenderMarkdownCode',
-            -- Highlight for inline code
-            highlight_inline = 'RenderMarkdownCodeInline',
             -- Highlight for language, overrides icon provider value
             highlight_language = nil,
+            -- Padding to add to the left & right of inline code
+            inline_pad = 0,
+            -- Highlight for inline code
+            highlight_inline = 'RenderMarkdownCodeInline',
         },
     })
 <

Diff for: lua/render-markdown/core/context.lua

@@ -127,7 +127,7 @@ function Context:get_offset(node)
     local result = 0
     local ranges = self.offsets[node.start_row] or {}
     for _, range in ipairs(ranges) do
-        if node.start_col < range[2] and node.end_col > range[1] then
+        if node.start_col <= range[2] and node.end_col > range[1] then
             result = result + range[3]
         end
     end

Diff for: lua/render-markdown/health.lua

@@ -5,7 +5,7 @@ local state = require('render-markdown.state')
 local M = {}
 
 ---@private
-M.version = '7.7.7'
+M.version = '7.7.8'
 
 function M.check()
     M.start('version')

Diff for: lua/render-markdown/init.lua

@@ -161,8 +161,9 @@ local M = {}
 ---@field public above? string
 ---@field public below? string
 ---@field public highlight? string
----@field public highlight_inline? string
 ---@field public highlight_language? string
+---@field public inline_pad? integer
+---@field public highlight_inline? string
 
 ---@class (exact) render.md.UserParagraph: render.md.UserBaseComponent
 ---@field public left_margin? number
@@ -470,10 +471,12 @@ M.default_config = {
         below = '▀',
         -- Highlight for code blocks
         highlight = 'RenderMarkdownCode',
-        -- Highlight for inline code
-        highlight_inline = 'RenderMarkdownCodeInline',
         -- Highlight for language, overrides icon provider value
         highlight_language = nil,
+        -- Padding to add to the left & right of inline code
+        inline_pad = 0,
+        -- Highlight for inline code
+        highlight_inline = 'RenderMarkdownCodeInline',
     },
     dash = {
         -- Turn on / off thematic break rendering

Diff for: lua/render-markdown/lib/list.lua

@@ -90,11 +90,8 @@ end
 ---@private
 ---@param mark render.md.Mark
 function Marks:update_context(mark)
-    local end_col = mark.opts.end_col
-    if end_col == nil then
-        return
-    end
     local row, start_col = mark.start_row, mark.start_col
+    local end_col = mark.opts.end_col or start_col
     if mark.opts.conceal ~= nil then
         self.context.conceal:add(row, start_col, end_col, end_col - start_col)
     end

Diff for: lua/render-markdown/manager.lua

@@ -21,7 +21,7 @@ function M.setup()
             M.attach(args.buf)
         end,
     })
-    -- Window resizing is not buffer specific so is managed more globablly
+    -- Window resizing is not buffer specific so is managed more globally
     vim.api.nvim_create_autocmd('WinResized', {
         group = M.group,
         callback = function(args)

Diff for: lua/render-markdown/render/code_inline.lua

@@ -18,6 +18,22 @@ function Render:render()
     self.marks:add_over('code_background', self.node, {
         hl_group = self.code.highlight_inline,
     })
+    self:side_padding(self.node.start_row, self.node.start_col)
+    self:side_padding(self.node.end_row, self.node.end_col)
+end
+
+---@private
+---@param row integer
+---@param col integer
+function Render:side_padding(row, col)
+    local padding = self.code.inline_pad
+    if padding > 0 then
+        self.marks:add(true, row, col, {
+            priority = 0,
+            virt_text = { self:padding_text(padding) },
+            virt_text_pos = 'inline',
+        })
+    end
 end
 
 return Render

Diff for: lua/render-markdown/state.lua

@@ -176,6 +176,7 @@ function M.validate()
                 component_rules(code)
                     :type({ 'sign', 'language_name' }, 'boolean')
                     :type({ 'language_pad', 'left_margin', 'left_pad', 'right_pad', 'min_width' }, 'number')
+                    :type('inline_pad', 'number')
                     :type({ 'above', 'below', 'highlight', 'highlight_inline' }, 'string')
                     :type('highlight_language', { 'string', 'nil' })
                     :list('disable_background', 'string', 'boolean')

Diff for: lua/render-markdown/types.lua

@@ -132,8 +132,9 @@
 ---@field public above string
 ---@field public below string
 ---@field public highlight string
----@field public highlight_inline string
 ---@field public highlight_language? string
+---@field public inline_pad integer
+---@field public highlight_inline string
 
 ---@class (exact) render.md.Paragraph: render.md.BaseComponent
 ---@field public left_margin number

Diff for: tests/util.lua

@@ -38,15 +38,17 @@ end
 ---@field sign_text? string
 ---@field sign_hl_group? string
 ---@field priority? integer
-local MarkInfo = {}
-MarkInfo.__index = MarkInfo
+
+---@class render.md.MarkDetails: render.md.MarkInfo
+local MarkDetails = {}
+MarkDetails.__index = MarkDetails
 
 ---@param row integer
 ---@param col integer
 ---@param details vim.api.keyset.extmark_details
----@return render.md.MarkInfo
-function MarkInfo.new(row, col, details)
-    local self = setmetatable({}, MarkInfo)
+---@return render.md.MarkDetails
+function MarkDetails.new(row, col, details)
+    local self = setmetatable({}, MarkDetails)
     self.row = { row, details.end_row }
     self.col = { col, details.end_col }
     self.hl_eol = details.hl_eol
@@ -67,7 +69,7 @@ function MarkInfo.new(row, col, details)
 end
 
 ---@return integer[]
-function MarkInfo:priorities()
+function MarkDetails:priorities()
     local result = {}
 
     local row_offset = 0
@@ -87,10 +89,10 @@ function MarkInfo:priorities()
     return result
 end
 
----@param a render.md.MarkInfo
----@param b render.md.MarkInfo
+---@param a render.md.MarkDetails
+---@param b render.md.MarkDetails
 ---@return boolean
-function MarkInfo.__lt(a, b)
+function MarkDetails.__lt(a, b)
     local as, bs = a:priorities(), b:priorities()
     for i = 1, math.max(#as, #bs) do
         if as[i] ~= bs[i] then
@@ -467,11 +469,11 @@ end
 function M.actual_marks()
     local namespace = require('render-markdown.core.ui').namespace
     local marks = vim.api.nvim_buf_get_extmarks(0, namespace, 0, -1, { details = true })
-    ---@type render.md.MarkInfo[]
+    ---@type render.md.MarkDetails[]
     local actual = {}
     for _, mark in ipairs(marks) do
         local _, row, col, details = unpack(mark)
-        table.insert(actual, MarkInfo.new(row, col, details))
+        table.insert(actual, MarkDetails.new(row, col, details))
     end
     table.sort(actual)
     return actual