vim mapleader no funciona como debería

Question

He configurado el mapleader en vim de la siguiente manera

let mapleader = ","

cuando lo intento

:echo mapleader

se muestra ,correctamente

sin embargo lo siguiente no funciona

nnoremap <leader>a :echo("\<leader\> works! It is set to <leader>")<CR>

y no puedo usar vimwiki porque no pude configurar el líder correctamente.

Después de mucha búsqueda en Google, me siento frustrado. Por favor ayuda.

También instalé gvim para usar vimwiki. Se puede acceder a todos los múltiples wikis configurados desde gvim, pero no desde vim.

A continuación se muestra mi archivo vimrc

" -----------------------------------------------------------------------------
" To make vimwiki properly
" -----------------------------------------------------------------------------
 set nocompatible            " put it on
 filetype plugin on
 syntax on

" -----------------------------------------------------------------------------
" end: To make vimwiki properly
" -----------------------------------------------------------------------------


set number            " line numbers
set hlsearch                  " Highlight search results
set incsearch                 " set increment search
set ignorecase                " case insensitive search, use \C anywhere with no space for case sensitive search
filetype off                  " required


" -----------------------------------------------------------------------------
" Basic mappings
" -----------------------------------------------------------------------------
let mapleader = ","
nnoremap <leader>a :echo("\<leader\> works! It is set to <leader>")<CR>




" -----------------------------------------------------------------------------
" start : Plugins
" -----------------------------------------------------------------------------


" Specify a directory for plugins
" - For Neovim: ~/.local/share/nvim/plugged
" - Avoid using standard Vim directory names like 'plugin'
call plug#begin('~/.vim/plugged')


Plug 'scrooloose/nerdtree'         " Navigate and manipulate files in a tree view.

Plug 'gruvbox-community/gruvbox'   " Gruvbox theme.

Plug 'junegunn/limelight.vim'      " Dim paragraphs above and below the active paragraph.


Plug 'junegunn/goyo.vim'           " Distraction free writing by removing UI elements and centering everything.

Plug 'vimwiki/vimwiki'

Plug 'godlygeek/tabular'           "The tabular plugin must come before vim-markdown.
Plug 'plasticboy/vim-markdown'     "The tabular plugin must come before vim-markdown.



call plug#end()



" -----------------------------------------------------------------------------
" End : Plugins
" -----------------------------------------------------------------------------

nmap <F6> :NERDTreeToggle<CR>   " open or close nerd tree by pressing F6
nmap <Leader>w <Plug>VimwikiIndex
nmap <Leader>dy <Plug>VimwikiMakeYesterdayDiaryNote






" -----------------------------------------------------------------------------
" start : Status line
" -----------------------------------------------------------------------------

" Heavily inspired by: https://github.com/junegunn/dotfiles/blob/master/vimrc
function! s:statusline_expr()
  let mod = "%{&modified ? '[+] ' : !&modifiable ? '[x] ' : ''}"
  let ro  = "%{&readonly ? '[RO] ' : ''}"
  let ft  = "%{len(&filetype) ? '['.&filetype.'] ' : ''}"
  let fug = "%{exists('g:loaded_fugitive') ? fugitive#statusline() : ''}"
  let sep = ' %= '
  let pos = ' %-12(%l : %c%V%) '
  let pct = ' %P'

  return '[%n] %f %<'.mod.ro.ft.fug.sep.pos.'%*'.pct
endfunction

let &statusline = s:statusline_expr()






" -----------------------------------------------------------------------------
" end : Status line
" -----------------------------------------------------------------------------



" -----------------------------------------------------------------------------
" start : Color settings
" -----------------------------------------------------------------------------

colorscheme gruvbox
" For Gruvbox to look correct in terminal Vim you'll want to source a palette
" script that comes with the Gruvbox plugin.
"
" Add this to your ~/.profile file:
"   source "$HOME/.vim/plugged/gruvbox/gruvbox_256palette.sh"

" Gruvbox comes with both a dark and light theme.
set background=dark

" Gruvbox has 'hard', 'medium' (default) and 'soft' contrast options.
let g:gruvbox_contrast_light='hard'

" This needs to come last, otherwise the colors aren't correct.
syntax on

" -----------------------------------------------------------------------------
" end : Color settings
" -----------------------------------------------------------------------------

" -----------------------------------------------------------------------------
" start : vimwiki
" -----------------------------------------------------------------------------
" vimwiki/vimwiki markdown syntax
" let g:vimwiki_list = [{'path': '~/vimwiki/', 'syntax': 'markdown', 'ext': '.md'}]


" start: vimwiki multiple wikis 
let wiki_1 = {}
let wiki_1.path = '~/vimwiki/'
let wiki_1.path_html = '~/vimwiki_html/'

let wiki_2 = {}
let wiki_2.path = '~/vimwiki/private/'
let wiki_2.path_html = '~/vimwiki/private_html/'

let wiki_3 = {}
let wiki_3.path = '~/vimwiki/technical/'
let wiki_3.path_html = '~/vimwiki/technical_html/'

let g:vimwiki_list = [wiki_1, wiki_2, wiki_3]
" end: vim multiple wikis
" -----------------------------------------------------------------------------
" end : vimwiki
" -----------------------------------------------------------------------------

Answer 1

Agregar la siguiente línea a .vimrc resolvió mi problema

let g:mapleader = ","

Answer 2

Descubrí que obtuve el resultado.

<leader> works! It is set to ','

después de configurar

:let mapleader = ","
:nnoremap <leader>a :echo("\<leader\> works! It is set to '<leader>'")<CR>

Recibí errores de antemano en relación con las comillas.

---

Personalmente, creo que prefiero mapear usando

map , <Leader>

Al realizar la prueba ,a, vimasegúrese de :source vimrcver los cambios implementados en vimrc.