refactor: theme.vim --> theme.lua

autoload/utils.vim

@@ -27,21 +27,6 @@ function! utils#HasColorscheme(name) abort
   return !empty(globpath(&runtimepath, l:pat))
 endfunction
 
-" Generate random integers in the range [Low, High] in pure vim script,
-" adapted from https://stackoverflow.com/a/12739441/6064933
-function! utils#RandInt(Low, High) abort
-  " Use lua to generate random int. It is faster. Ref: https://stackoverflow.com/a/20157671/6064933
-  call v:lua.math.randomseed(localtime())
-  return v:lua.math.random(a:Low, a:High)
-endfunction
-
-" Selection a random element from a sequence/list
-function! utils#RandElement(seq) abort
-  let l:idx = utils#RandInt(0, len(a:seq)-1)
-
-  return a:seq[l:idx]
-endfunction
-
 " Custom fold expr, adapted from https://vi.stackexchange.com/a/9094/15292
 function! utils#VimFolds(lnum) abort
   " get content of current line and the line below
@@ -198,14 +183,3 @@ function! utils#MultiEdit(patterns) abort
     endfor
   endfor
 endfunction
-
-function! utils#add_pack(name) abort
-  let l:status = v:true
-  try
-    execute printf("packadd! %s", a:name)
-  catch /^Vim\%((\a\+)\)\=:E919/
-    let l:status = v:false
-  endtry
-
-  return l:status
-endfunction

core/themes.lua

@@ -0,0 +1,123 @@
+local utils = require('utils')
+
+local M = {}
+
+-- Theme to directory name mapping, because theme repo name is not necessarily
+-- the same as the theme name itself.
+M.theme2dir = {
+  gruvbox8 = "vim-gruvbox8",
+  onedark = 'onedark.nvim',
+  edge = 'edge',
+  sonokai = 'sonokai',
+  gruvbox_material = 'gruvbox-material',
+  nord = 'nord.nvim',
+  doom_one = 'doom-one.nvim',
+  everforest = 'everforest',
+  nightfox = 'nightfox.nvim',
+  kanagawa = 'kanagawa.nvim',
+  catppuccin = 'catppuccin'
+}
+
+M.gruvbox8 = function()
+  -- Italic options should be put before colorscheme setting,
+  -- see https://github.com/morhetz/gruvbox/wiki/Terminal-specific#1-italics-is-disabled
+  vim.g.gruvbox_italics = 1
+  vim.g.gruvbox_italicize_strings = 1
+  vim.g.gruvbox_filetype_hi_groups = 1
+  vim.g.gruvbox_plugin_hi_groups = 1
+
+  vim.cmd [[colorscheme gruvbox8_hard]]
+end
+
+M.onedark = function()
+  vim.cmd [[colorscheme onedark]]
+end
+
+M.edge = function()
+  vim.g.edge_enable_italic = 1
+  vim.g.edge_better_performance = 1
+
+  vim.cmd [[colorscheme edge]]
+end
+
+M.sonokai = function()
+  vim.g.sonokai_enable_italic = 1
+  vim.g.sonokai_better_performance = 1
+
+  vim.cmd [[colorscheme sonokai]]
+end
+
+M.gruvbox_material = function()
+  vim.g.gruvbox_material_enable_italic = 1
+  vim.g.gruvbox_material_better_performance = 1
+
+  vim.cmd [[colorscheme gruvbox-material]]
+end
+
+M.nord = function()
+  vim.cmd [[colorscheme nord]]
+end
+
+M.doom_one = function()
+
+  vim.cmd [[colorscheme doom-one]]
+end
+
+M.everforest = function()
+  vim.g.everforest_enable_italic = 1
+  vim.g.everforest_better_performance = 1
+
+  vim.cmd [[colorscheme everforest]]
+end
+
+M.nightfox = function()
+  vim.cmd [[colorscheme nordfox]]
+end
+
+
+M.kanagawa = function()
+  vim.cmd [[colorscheme kanagawa]]
+end
+
+M.catppuccin = function()
+  -- available option: latte, frappe, macchiato, mocha
+  vim.g.catppuccin_flavour = "frappe"
+
+  require("catppuccin").setup()
+
+  vim.cmd [[colorscheme catppuccin]]
+end
+
+
+--- Use a random theme from the pre-defined list of themes.
+M.rand_theme = function ()
+  local theme = utils.rand_element(vim.tbl_keys(M.theme2dir))
+
+  if not vim.tbl_contains(vim.tbl_keys(M), theme) then
+    local msg = "Invalid theme: " .. theme
+    vim.notify(msg, vim.log.levels.ERROR, { title = 'nvim-config' })
+
+    return
+  end
+
+  -- Load the theme, because all the themes are declared as opt plugins, the theme isn't loaded yet.
+  local status = utils.add_pack(M.theme2dir[theme])
+
+  if not status then
+    local msg = string.format("Theme %s is not installed. Run PackerSync to install.", theme)
+    vim.notify(msg, vim.log.levels.ERROR, { title = 'nvim-config' })
+
+    return
+  end
+
+  -- Set the theme.
+  M[theme]()
+
+  if vim.g.logging_level == 'debug' then
+    local msg = "Colorscheme: " .. theme
+
+    vim.notify(msg, vim.log.levels.DEBUG, { title = 'nvim-config' })
+  end
+end
+
+M.rand_theme()

core/themes.vim

@@ -1,99 +0,0 @@
-let s:theme_setup_dict = {}
-
-function! s:theme_setup_dict.gruvbox8() dict abort
-  " Italic options should be put before colorscheme setting,
-  " see https://github.com/morhetz/gruvbox/wiki/Terminal-specific#1-italics-is-disabled
-  let g:gruvbox_italics=1
-  let g:gruvbox_italicize_strings=1
-  let g:gruvbox_filetype_hi_groups = 1
-  let g:gruvbox_plugin_hi_groups = 1
-  colorscheme gruvbox8_hard
-endfunction
-
-function! s:theme_setup_dict.onedark() dict abort
-  colorscheme onedark
-endfunction
-
-function! s:theme_setup_dict.edge() dict abort
-  let g:edge_enable_italic = 1
-  let g:edge_better_performance = 1
-  colorscheme edge
-endfunction
-
-function! s:theme_setup_dict.sonokai() dict abort
-  let g:sonokai_enable_italic = 1
-  let g:sonokai_better_performance = 1
-  colorscheme sonokai
-endfunction
-
-function! s:theme_setup_dict.gruvbox_material() dict abort
-  let g:gruvbox_material_enable_italic = 1
-  let g:gruvbox_material_better_performance = 1
-  colorscheme gruvbox-material
-endfunction
-
-function! s:theme_setup_dict.nord() dict abort
-  colorscheme nord
-endfunction
-
-function! s:theme_setup_dict.doom_one() dict abort
-  colorscheme doom-one
-endfunction
-
-function! s:theme_setup_dict.everforest() dict abort
-  let g:everforest_enable_italic = 1
-  let g:everforest_better_performance = 1
-  colorscheme everforest
-endfunction
-
-function! s:theme_setup_dict.nightfox() dict abort
-  colorscheme nordfox
-endfunction
-
-function! s:theme_setup_dict.kanagawa() dict abort
-  colorscheme kanagawa
-endfunction
-
-function! s:theme_setup_dict.catppuccin() dict abort
-  let g:catppuccin_flavour = "frappe" " latte, frappe, macchiato, mocha
-
-  lua require("catppuccin").setup()
-  colorscheme catppuccin
-endfunction
-
-" Theme to directory name mapping, because theme repo name is not necessarily
-" the same as the theme name itself.
-let s:theme2dir = {
-      \ 'gruvbox8' : 'vim-gruvbox8',
-      \ 'onedark': 'onedark.nvim',
-      \ 'edge' : 'edge',
-      \ 'sonokai': 'sonokai',
-      \ 'gruvbox_material': 'gruvbox-material',
-      \ 'nord': 'nord.nvim',
-      \ 'doom_one': 'doom-one.nvim',
-      \ 'everforest' :'everforest',
-      \ 'nightfox': 'nightfox.nvim',
-      \ 'kanagawa': 'kanagawa.nvim',
-      \ 'catppuccin': 'catppuccin'
-      \ }
-
-let s:theme = utils#RandElement(keys(s:theme2dir))
-let s:colorscheme_func = printf('s:theme_setup_dict.%s()', s:theme)
-
-if !has_key(s:theme_setup_dict, s:theme)
-  let s:msg = "Invalid colorscheme function: " . s:colorscheme_func
-  call v:lua.vim.notify(s:msg, 'error', {'title': 'nvim-config'})
-  finish
-endif
-
-let s:status = utils#add_pack(s:theme2dir[s:theme])
-if !s:status
-  echomsg printf("Theme %s not installed. Run PackerSync to install.", s:theme)
-  finish
-endif
-
-execute 'call ' . s:colorscheme_func
-if g:logging_level == 'debug'
-  let s:msg1 = "Colorscheme: " . s:theme
-  call v:lua.vim.notify(s:msg1, 'info', {'title': 'nvim-config'})
-endif

init.lua

@@ -26,7 +26,7 @@ local core_conf_files = {
   "autocommands.vim",
   "mappings.vim",
   "plugins.vim",
-  "themes.vim",
+  "themes.lua",
 }
 
 -- source all the core config files

lua/utils.lua

@@ -31,4 +31,30 @@ function M.get_nvim_version()
   return nvim_ver_str
 end
 
+
+--- Generate random integers in the range [Low, High], inclusive,
+--- adapted from https://stackoverflow.com/a/12739441/6064933
+--- @low: the lower value for this range
+--- @high: the upper value for this range
+function M.rand_int(low, high)
+  -- Use lua to generate random int, see also: https://stackoverflow.com/a/20157671/6064933
+  math.randomseed(os.time())
+
+  return math.random(low, high)
+end
+
+--- Select a random element from a sequence/list.
+--- @seq: the sequence to choose an element
+function M.rand_element(seq)
+  local idx = M.rand_int(1, #seq)
+
+  return seq[idx]
+end
+
+function M.add_pack(name)
+  local status, error = pcall(vim.cmd, "packadd " .. name)
+
+  return status
+end
+
 return M