feat: lazy load providers

lua/feline/init.lua

@@ -3,6 +3,8 @@ local fn = vim.fn
 local api = vim.api
 local cmd = api.nvim_command
 
+local create_augroup = require('feline.utils').create_augroup
+
 local M = {}
 
 -- Parse configuration option with name config_name from config_dict and match its type
@@ -24,18 +26,6 @@ local function parse_config(config_dict, config_name, expected_type, default_val
     end
 end
 
--- Utility function to create augroups
-local function create_augroup(autocmds, name)
-    cmd('augroup ' .. name)
-    cmd('autocmd!')
-
-    for _, autocmd in ipairs(autocmds) do
-        cmd('autocmd ' .. table.concat(autocmd, ' '))
-    end
-
-    cmd('augroup END')
-end
-
 -- Update statusline of inactive windows on the current tabpage
 function M.update_inactive_windows()
     -- Uses vim.schedule to defer executing the function until after

lua/feline/presets/init.lua

@@ -1,15 +1,7 @@
--- Use an immutable table to only automatically load the preset that's are being used
-local M = setmetatable({}, {
-    __index = function(_, key)
-        local ok, result = pcall(require, 'feline.presets.' .. key)
-        if ok then return result else return nil end
-    end,
-
-    __newindex = function(_, _, _)
-    end,
-
-    __metatable = false
-})
-
-return M
+-- Use lazy_require to only load the preset that's are being used
+local lazy_require = require('feline.utils').lazy_require
 
+return {
+    default = lazy_require('feline.presets.default'),
+    noicon = lazy_require('feline.presets.noicon')
+}

lua/feline/providers/init.lua

@@ -1,42 +1,77 @@
-local vi_mode = require('feline.providers.vi_mode')
-local cursor = require('feline.providers.cursor')
-local file = require('feline.providers.file')
-local lsp = require('feline.providers.lsp')
-local git = require('feline.providers.git')
-
-local M = {
-    vi_mode = vi_mode.vi_mode,
-
-    position = cursor.position,
-    line_percentage = cursor.line_percentage,
-    scroll_bar = cursor.scroll_bar,
-
-    file_info = file.file_info,
-    file_size = file.file_size,
-    file_type = file.file_type,
-    file_encoding = file.file_encoding,
-
-    git_branch = git.git_branch,
-    git_diff_added = git.git_diff_added,
-    git_diff_removed = git.git_diff_removed,
-    git_diff_changed = git.git_diff_changed,
-
-    lsp_client_names = lsp.lsp_client_names,
-    diagnostic_errors = lsp.diagnostic_errors,
-    diagnostic_warnings = lsp.diagnostic_warnings,
-    diagnostic_hints = lsp.diagnostic_hints,
-    diagnostic_info = lsp.diagnostic_info,
+local lazy_require = require('feline.utils').lazy_require
+
+-- All available provider categories (lazy loaded)
+local provider_categories = {
+    vi_mode = lazy_require('feline.providers.vi_mode'),
+    cursor = lazy_require('feline.providers.cursor'),
+    file = lazy_require('feline.providers.file'),
+    lsp = lazy_require('feline.providers.lsp'),
+    git = lazy_require('feline.providers.git'),
+    custom = {}
+}
+
+-- Categories that each provider belongs to
+local get_provider_category = {
+    vi_mode = 'vi_mode',
+
+    position = 'cursor',
+    line_percentage = 'cursor',
+    scroll_bar = 'cursor',
+
+    file_info = 'file',
+    file_size = 'file',
+    file_type = 'file',
+    file_encoding = 'file',
+
+    git_branch = 'git',
+    git_diff_added = 'git',
+    git_diff_removed = 'git',
+    git_diff_changed = 'git',
+
+    lsp_client_names = 'lsp',
+    diagnostic_errors = 'lsp',
+    diagnostic_warnings = 'lsp',
+    diagnostic_hints = 'lsp',
+    diagnostic_info = 'lsp'
 }
 
-function M.add_provider(name, provider)
-    if M[name] then
-        vim.api.nvim_err_writeln(string.format(
-            "Provider %s already exists! Please try using another name",
-            name
-        ))
-    else
-        M[name] = provider
+-- Providers that have been loaded
+local loaded_providers = {}
+
+-- Utility functions to manage providers
+local utilities = {
+    -- Add a custom provider with specified name
+    add_provider = function(name, provider)
+        if get_provider_category[name] then
+            vim.api.nvim_err_writeln(string.format(
+                "Feline: error while adding provider: " ..
+                "Provider %s already exists! Please try using another name",
+                name
+            ))
+        else
+            provider_categories.custom[name] = provider
+            get_provider_category[name] = 'custom'
+        end
     end
-end
+}
 
-return M
+-- Return a metatable that automatically loads and returns providers when their name is indexed
+return setmetatable({}, {
+    __index = function(_, key)
+        -- If a provider hasn't been loaded, load it by accessing its category and indexing the name
+        -- which causes lazy_require to actually load the provider category
+        if not loaded_providers[key] then
+            local category = get_provider_category[key]
+
+            -- If a provider with that name isn't found, assume it's a utility function
+            -- and return that instead
+            if category then
+                loaded_providers[key] = provider_categories[category][key]
+            else
+                return utilities[key]
+            end
+        end
+
+        return loaded_providers[key]
+    end
+})

lua/feline/providers/lsp.lua

@@ -1,24 +1,25 @@
 local M = {}
 
 local api = vim.api
+local lsp = vim.lsp
 
 function M.is_lsp_attached(bufnr)
     bufnr = bufnr or api.nvim_get_current_buf()
 
-    return next(vim.lsp.buf_get_clients(bufnr)) ~= nil
+    return next(lsp.buf_get_clients(bufnr)) ~= nil
 end
 
 function M.get_diagnostics_count(severity, bufnr)
     bufnr = bufnr or api.nvim_get_current_buf()
 
-    local active_clients = vim.lsp.buf_get_clients(bufnr)
+    local active_clients = lsp.buf_get_clients(bufnr)
 
     if not active_clients then return nil end
 
     local count = 0
 
     for _, client in pairs(active_clients) do
-        count = count + vim.lsp.diagnostic.get_count(bufnr, severity, client.id)
+        count = count + lsp.diagnostic.get_count(bufnr, severity, client.id)
     end
 
     return count
@@ -34,7 +35,7 @@ end
 function M.lsp_client_names(_, winid)
     local clients = {}
 
-    for _, client in pairs(vim.lsp.buf_get_clients(api.nvim_win_get_buf(winid))) do
+    for _, client in pairs(lsp.buf_get_clients(api.nvim_win_get_buf(winid))) do
         clients[#clients+1] = client.name
     end
 

lua/feline/utils.lua

@@ -0,0 +1,33 @@
+-- Utility functions used across Feline
+local cmd = vim.api.nvim_command
+
+local M = {}
+
+-- Utility function to create augroups
+function M.create_augroup(autocmds, name)
+    cmd('augroup ' .. name)
+    cmd('autocmd!')
+
+    for _, autocmd in ipairs(autocmds) do
+        cmd('autocmd ' .. table.concat(autocmd, ' '))
+    end
+
+    cmd('augroup END')
+end
+
+-- Lazy require function
+-- Only actually `require()`s a module when it gets used
+function M.lazy_require(module)
+    return setmetatable({}, {
+        __index = function(_, key)
+            return require(module)[key]
+        end,
+
+        __newindex = function(_, _, _)
+        end,
+
+        __metatable = false
+    })
+end
+
+return M