the code

lua/comment_navigator/init.lua

@@ -0,0 +1,126 @@
+local plenary = require("plenary")
+
+local M = {}
+
+local function filter_comments(settings, content)
+    local cursor_position = vim.api.nvim_win_get_cursor(0)
+    local new_cursor = {1,0}
+
+    local numbers, values = {}, {}
+    local indentations = {}
+
+    for i, v in ipairs(content) do
+        local indent, line = string.match(v, settings.regex)
+        if line then
+            if settings.keep_indent then
+                numbers[#numbers+1] = i
+                values[#values+1] = indent .. line
+                table.insert(indentations, #indent)
+            else
+                numbers[#numbers+1] = i
+                values[#values+1] = line
+            end
+        end
+
+        -- set the cursor position to the comment under the cursor
+        -- or to the previous comment if not on a comment directly.
+        if new_cursor[1] == 1 then
+            if i == cursor_position[1] then
+                new_cursor = {math.max(#numbers,1), indentations[#indentations] or 0}
+            end
+        end
+    end
+
+    -- strip down indentation
+    if settings.keep_indent then
+        local min_indentation = math.huge
+        for _, indent in ipairs(indentations) do
+            min_indentation = min_indentation < indent and min_indentation or indent
+        end
+        for i = 1, #values, 1 do
+            values[i] = string.sub(values[i], min_indentation+1)
+        end
+    end
+    return numbers, values, new_cursor
+end
+
+function M.setup(options)
+    -- create a new module to support multiple file types
+    local module = {}
+
+    -- default settings
+    module.settings = {
+        regex = M.regex.c, -- the regex used to extract the comments (c-style default)
+        line_numbers = true, -- show the line numbers in the list
+        width = 100, -- width of the window
+        height = 50, -- height of the window
+        borderchars = { "─", "│", "─", "│", "╭", "╮", "╯", "╰" }, -- the borders, nil means no border
+        keep_indent = true, -- preserve the indentation of the file (shows the values in a hierarchical manner)
+    }
+
+    module.settings = vim.tbl_deep_extend("force", module.settings, options)
+
+    -- main entry point, opens the popup window
+    function module.open()
+        local settings = module.settings
+
+        local content_buffer = vim.api.nvim_buf_get_lines(0, 0, vim.api.nvim_buf_line_count(0), false)
+        local line_numbers, content, cursor_position = filter_comments(settings, content_buffer)
+
+        -- FIXME: this is a hotfix
+        -- removes an empty line at the end of the buffer
+        if content[#content] == "" then
+            table.remove(content, #content)
+        end
+
+        -- TODO: avoid module to be able to open multiple popups at the same time
+        module.state = line_numbers
+
+        -- create the buffer for the popup window
+        local buffer = vim.api.nvim_create_buf(false, true)
+        vim.api.nvim_buf_set_lines(buffer, -2, -1, true, content)
+        vim.api.nvim_buf_set_option(buffer, 'readonly', true)
+        vim.api.nvim_buf_set_keymap(buffer, "n", "<Enter>", "", {
+            callback = function()
+                module.go(buffer)
+            end
+        })
+        vim.api.nvim_buf_set_keymap(buffer, "n", "<Esc>",
+            "<cmd>lua vim.api.nvim_buf_delete(" .. buffer .. ", {})<CR>", {})
+
+        local win, _ = plenary.popup.create(buffer, {
+            title = "comment-navigator",
+            minwidth = settings.width,
+            minheight = settings.height,
+            maxheight = settings.height,
+            maxwidth = settings.width,
+            borderchars = settings.borderchars,
+        })
+
+        if settings.line_numbers then
+            vim.api.nvim_win_set_option(win, "number", true)
+        end
+
+        vim.api.nvim_win_set_cursor(win, cursor_position)
+    end
+
+    -- navigates to the comment under the cursor
+    function module.go(buffer)
+        local idx = vim.api.nvim__buf_stats(buffer).current_lnum
+        vim.api.nvim_buf_delete(buffer, {})
+
+        local line = module.state[idx]
+        vim.api.nvim_win_set_cursor(0,{line,0})
+    end
+
+    return module
+end
+
+M.regex = {
+    c = "(%s*)///%s*(.*)%s*",        -- /// comment
+    lua = "(%s*)%-%-%-%s*(.*)%s*",   -- --- comment
+    python = "(%s*)#:%s*(.*)%s*",    -- #: comment (not ## because of autoformatters…)
+    erb =  "(%s*)<%%%s?# *(.*) *%%>" -- <%# comment %>
+}
+
+return M