feat: render list item bullet points in yaml

## Details

Request: #496

Adds ability to render bullet points in yaml, primarily for people that
use `obsidian` style metadata via `frontmatter`.

Requires user to install `yaml` parser so that lists / list items can be
queried for. New top level `yaml` configuration added similar to `html`
that allows the feature (and any others potentially added later) to be
disabled.

Values used for rendering are currently pulled from the same
configuration as `markdown` bullet point rendering, i.e. `bullet`.

Currently only the `icon` and `highlight` values are used and the only
rendering the happens is overlaying the icon. Any other `bullet`
features like padding and scope highlighting would need to be added
separately, can potentially be done if requested.

Author: MeanderingProgrammer

README.md

@@ -878,9 +878,9 @@ require('render-markdown').setup({
         -- More granular configuration mechanism, allows different aspects of buffers to have their own
         -- behavior. Values default to the top level configuration if no override is provided. Supports
         -- the following fields:
-        --   enabled, max_file_size, debounce, render_modes, anti_conceal, padding, heading, paragraph,
-        --   code, dash, bullet, checkbox, quote, pipe_table, callout, link, sign, indent, latex, html,
-        --   win_options
+        --   enabled, render_modes, max_file_size, debounce, anti_conceal, bullet, callout, checkbox,
+        --   code, dash, document, heading, html, indent, inline_highlight, latex, link, padding,
+        --   paragraph, pipe_table, quote, sign, win_options, yaml
 
         -- Override for different buflisted values, @see :h 'buflisted'.
         buflisted = {},
@@ -899,6 +899,12 @@ require('render-markdown').setup({
         -- Mapping from treesitter language to user defined handlers.
         -- @see [Custom Handlers](doc/custom-handlers.md)
     },
+    yaml = {
+        -- Turn on / off all yaml rendering.
+        enabled = true,
+        -- Additional modes to render yaml.
+        render_modes = false,
+    },
 })
 ```
 

doc/render-markdown.txt

@@ -944,9 +944,9 @@ Default Configuration ~
             -- More granular configuration mechanism, allows different aspects of buffers to have their own
             -- behavior. Values default to the top level configuration if no override is provided. Supports
             -- the following fields:
-            --   enabled, max_file_size, debounce, render_modes, anti_conceal, padding, heading, paragraph,
-            --   code, dash, bullet, checkbox, quote, pipe_table, callout, link, sign, indent, latex, html,
-            --   win_options
+            --   enabled, render_modes, max_file_size, debounce, anti_conceal, bullet, callout, checkbox,
+            --   code, dash, document, heading, html, indent, inline_highlight, latex, link, padding,
+            --   paragraph, pipe_table, quote, sign, win_options, yaml
 
             -- Override for different buflisted values, @see :h 'buflisted'.
             buflisted = {},
@@ -965,6 +965,12 @@ Default Configuration ~
             -- Mapping from treesitter language to user defined handlers.
             -- @see [Custom Handlers](doc/custom-handlers.md)
         },
+        yaml = {
+            -- Turn on / off all yaml rendering.
+            enabled = true,
+            -- Additional modes to render yaml.
+            render_modes = false,
+        },
     })
 <
 

lua/render-markdown/config/overrides.lua

@@ -11,9 +11,9 @@ M.default = {
     -- More granular configuration mechanism, allows different aspects of buffers to have their own
     -- behavior. Values default to the top level configuration if no override is provided. Supports
     -- the following fields:
-    --   enabled, max_file_size, debounce, render_modes, anti_conceal, padding, heading, paragraph,
-    --   code, dash, bullet, checkbox, quote, pipe_table, callout, link, sign, indent, latex, html,
-    --   win_options
+    --   enabled, render_modes, max_file_size, debounce, anti_conceal, bullet, callout, checkbox,
+    --   code, dash, document, heading, html, indent, inline_highlight, latex, link, padding,
+    --   paragraph, pipe_table, quote, sign, win_options, yaml
 
     -- Override for different buflisted values, @see :h 'buflisted'.
     buflisted = {},

lua/render-markdown/config/yaml.lua

@@ -0,0 +1,20 @@
+---@class (exact) render.md.yaml.Config: render.md.base.Config
+
+---@class render.md.yaml.Cfg
+local M = {}
+
+---@type render.md.yaml.Config
+M.default = {
+    -- Turn on / off all yaml rendering.
+    enabled = true,
+    -- Additional modes to render yaml.
+    render_modes = false,
+}
+
+---@param spec render.md.debug.ValidatorSpec
+function M.validate(spec)
+    require('render-markdown.config.base').validate(spec)
+    spec:check()
+end
+
+return M

lua/render-markdown/core/handlers.lua

@@ -14,6 +14,7 @@ M.builtin = {
     latex = require('render-markdown.handler.latex'),
     markdown = require('render-markdown.handler.markdown'),
     markdown_inline = require('render-markdown.handler.markdown_inline'),
+    yaml = require('render-markdown.handler.yaml'),
 }
 
 ---called from state on setup

lua/render-markdown/handler/yaml.lua

@@ -0,0 +1,34 @@
+local Context = require('render-markdown.request.context')
+local Marks = require('render-markdown.lib.marks')
+local ts = require('render-markdown.core.ts')
+
+---@class render.md.handler.Yaml: render.md.Handler
+local M = {}
+
+---@param ctx render.md.handler.Context
+---@return render.md.Mark[]
+function M.parse(ctx)
+    local query = ts.parse(
+        'yaml',
+        [[
+            (block_sequence_item) @bullet
+        ]]
+    )
+    ---@type table<string, render.md.Render>
+    local renders = {
+        bullet = require('render-markdown.render.yaml.bullet'),
+    }
+    local context = Context.get(ctx.buf)
+    if context:skip(context.config.yaml) then
+        return {}
+    end
+    local marks = Marks.new(context, true)
+    context.view:nodes(ctx.root, query, function(capture, node)
+        local render = renders[capture]
+        assert(render, ('unhandled yaml capture: %s'):format(capture))
+        render:execute(context, marks, node)
+    end)
+    return marks:get()
+end
+
+return M

lua/render-markdown/health.lua

@@ -5,7 +5,7 @@ local state = require('render-markdown.state')
 local M = {}
 
 ---@private
-M.version = '8.7.1'
+M.version = '8.7.2'
 
 function M.check()
     M.start('versions')
@@ -23,16 +23,20 @@ function M.check()
     end
 
     local config = state.get(0)
-    local latex = config.latex
     local html = config.html
+    local latex = config.latex
+    local yaml = config.yaml
 
     M.ts_info('markdown', true, true)
     M.ts_info('markdown_inline', true, false)
+    if html.enabled then
+        M.ts_info('html', false, false)
+    end
     if latex.enabled then
         M.ts_info('latex', false, false)
     end
-    if html.enabled then
-        M.ts_info('html', false, false)
+    if yaml.enabled then
+        M.ts_info('yaml', false, false)
     end
 
     M.start('icons')

lua/render-markdown/init.lua

@@ -37,6 +37,7 @@ local M = {}
 ---@field quote render.md.quote.Config
 ---@field sign render.md.sign.Config
 ---@field win_options render.md.window.Configs
+---@field yaml render.md.yaml.Config
 
 ---@private
 ---@type boolean
@@ -101,6 +102,7 @@ M.default = {
     win_options = require('render-markdown.config.win_options').default,
     overrides = require('render-markdown.config.overrides').default,
     custom_handlers = require('render-markdown.config.handlers').default,
+    yaml = require('render-markdown.config.yaml').default,
 }
 
 ---@param opts? render.md.UserConfig

lua/render-markdown/lib/config.lua

@@ -38,6 +38,7 @@ function Config.new(root, enabled, buf)
         quote = root.quote,
         sign = root.sign,
         win_options = root.win_options,
+        yaml = root.yaml,
     }
     config = vim.deepcopy(config)
     for _, name in ipairs({ 'buflisted', 'buftype', 'filetype' }) do
@@ -103,6 +104,7 @@ function Config.validate(spec)
     spec:nested('quote', require('render-markdown.config.quote').validate)
     spec:nested('sign', require('render-markdown.config.sign').validate)
     spec:nested('win_options', require('render-markdown.config.win_options').validate)
+    spec:nested('yaml', require('render-markdown.config.yaml').validate)
 end
 
 return Config

lua/render-markdown/render/yaml/bullet.lua

@@ -0,0 +1,61 @@
+local Base = require('render-markdown.render.base')
+local list = require('render-markdown.lib.list')
+
+---@class render.md.yaml.bullet.Data
+---@field icon? string
+---@field highlight? string
+
+---@class render.md.render.yaml.Bullet: render.md.Render
+---@field private config render.md.bullet.Config
+local Render = setmetatable({}, Base)
+Render.__index = Render
+
+---@protected
+---@return boolean
+function Render:setup()
+    self.config = self.context.config.bullet
+    if self.context:skip(self.config) then
+        return false
+    end
+    return true
+end
+
+---@protected
+function Render:run()
+    ---@type render.md.bullet.Context
+    local ctx = {
+        level = self.node:level_in('block_sequence', 'document'),
+        index = self.node:sibling_count('block_sequence_item'),
+        value = '-',
+    }
+    local icon = Render.get_string(self.config.icons, ctx)
+    local highlight = Render.get_string(self.config.highlight, ctx)
+    if not icon or not highlight then
+        return
+    end
+    self.marks:start('bullet', self.node, {
+        virt_text = { { icon, highlight } },
+        virt_text_pos = 'overlay',
+    })
+end
+
+---@private
+---@param values render.md.bullet.String
+---@param ctx render.md.bullet.Context
+---@return string?
+function Render.get_string(values, ctx)
+    if type(values) == 'table' then
+        local value = list.cycle(values, ctx.level)
+        if type(value) == 'table' then
+            return list.clamp(value, ctx.index)
+        else
+            return value
+        end
+    elseif type(values) == 'function' then
+        return values(ctx)
+    else
+        return values
+    end
+end
+
+return Render