E7E720 : Missing colon in Dictionary: >['beancount-language-server']}

[jahagirdar]

I am trying to enable vim-lsp
For this code block

if executable('beancount-language-server')
    var beancount_config = {
         'name': 'beancount-language-server',
         'cmd': {server_info->['beancount-language-server']}
     }
    #au User lsp_setup call lsp#register_server(beancount_config)
endif

I get the error message
Error detected while processing /home/vijayvithal/.vimrc[41]../home/vijayvithal/.vim/linters_prabirshreshta.vim:
line 6:
E720: Missing colon in Dictionary: >['beancount-language-server']}
Press ENTER or type command to continue

I have the following plugins installed related to LSP

  Plugin 'prabirshrestha/vim-lsp'
  Plugin 'prabirshrestha/asyncomplete.vim'
  Plugin 'prabirshrestha/asyncomplete-lsp.vim'
  Plugin 'w0rp/ale'

Note: I had previously raised this issue here vim/vim#1886 and was told it is a plugin issue.

[mattn]

Since you have a var declaration, you are likely writing Vim9script.
In Vim9script, the syntax for lambdas differs from that in vim8 script.