Set mappings dependent of file type

Question

To execute and debug different kind of programs, I mapped the function keys in the .vimrc-file.

E.g.

" save and execute perl
:noremap <F5> :w<CR>:!./%<CR>
" save and execute aql
:noremap <F9> :w<CR>:!db<%<CR>
" ...

Works so far. But I would like do press always F5 to save and execute. No matter which programming language!

So I tried to set a "syn_exec" variable in the syntax file (e.g. ~/.vim/syntax/dbquery.vim ~/.vim/after/syntax/perl.vim)

There I have:

" -- Syntax-File --
let syn_exec = [ '', '', '', '', '!db < %', '!db -E < %', '!db -csv < % | ~/db_tools/dev.pl' ]

" -- .vimrc --
:noremap <F5> :w<CR>:execute syn_exec[4]<CR>
:noremap <F6> :w<CR>:execute syn_exec[5]<CR>
" ...

So far so good. If I open a file, syn_exec is set and F5 executes the code.

If I open another file with another code type (:tabe ~/foo.pl), the syntax-file overwrites the "syn_exec" variable. Then I can execute the code of new opened file.

But if I change back to the previous tab, the "syn_exec" doesn't change again...

I think there is a very easy solution to map key concerning to the file-type / code-type. But I don't get it.

Answer 1

I would suggest you to define the variable syn_exec as a buffer variable

" -- Syntax-File --
let b:syn_exec = [ '', '', '', '', '!db < %', '!db -E < %', '!db -csv < % | ~/db_tools/dev.pl' ]

" -- .vimrc --
:noremap <F5> :w<CR>:execute b:syn_exec[4]<CR>
:noremap <F6> :w<CR>:execute b:syn_exec[5]<CR>
" ...

Answer 2

I am not sure if this is what you are looking for, but you can combine the keyword FileType with autocmd. Inside of a .vimrc:

autocmd FileType python map [COMMAND]
autocmd FileType cpp map [COMMAND]

If it recognizes that I have a python file (.py), the first key mapping is taken, and if it is C++, the second one is taken

---

In my .vimrc file:

autocmd FileType python map <buffer> <F9> :w<CR>:exec '!python3' shellescape(@%, 1)<CR>
autocmd FileType cpp    map <buffer> <F9> :w<CR>:!g++ % -std=c++20 -o %< && ./%< <CR>

Like this, it executes the program based on the FileType.