Re: How to use <script> attribute in map command?

On 10/12/2014 07:52 AM, Павлов Николай Александрович wrote:
> On October 12, 2014 1:30:38 AM GMT+03:00, Yegappan Lakshmanan <yegappanl@gmail.com> wrote:
> > Hi,
>
> >>>>>>>
> >>>>>>> On Friday, October 10, 2014 12:04:17 PM UTC+2, jiaxing_wang
> > wrote:
> >>>>>>>> This wiki page:
> >>>>>>>>
> >>>>>>>>
> > http://vim.wikia.com/wiki/Mapping_keys_in_Vim_-_Tutorial_(Part_3)
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>
> >>>>>>>> says with the following maps in a script file:
> >>>>>>>>
> >>>>>>>>
> >>>>>>>> nnoremap \x /Topic
> >>>>>>>> nmap <script> ,f \x<CR>
> >>>>>>>>
> >>>>>>>>
> >>>>>>>> "In the second map command, ',f' is mapped to invoke \x which
> > is replaced with '/Topic'.
> >>>>>>>>
> >>>>>>>> If the user or some other plugin has defined a mapping for
> > '\x', then it is not used by ',f'."
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>
> >>>>>>>> But I tried and find '\x' is not remapped to '/Topic' as the
> > wiki says, so what does <script>
> >>>>>>>>
> >>>>>>>> really mean and how to use it?
> >>>>>>> Unfortunately the wiki example is wrong.
> >>>>>>>
> >>>>>>> Here's a short script that uses a mapping with <script>.
> >>>>>>>
> >>>>>>> function! s:SayHelloToUser() abort
> >>>>>>> echo printf("Hello %s!", $USER)
> >>>>>>> endfunction
> >>>>>>>
> >>>>>>> nmap <script> <Plug>SayHello :<C-U>call
> > <SID>SayHelloToUser()<CR>
> >>>>>>>
> >>>>>>> The <Plug> mapping is the hook that a user can map to, eg by
> > defining
> >>>>>>>
> >>>>>>> nmap <Leader>h <Plug>SayHello
> >>>>>>>
> >>>>>>> In the <Plug> mapping, <script> ensures that the right-hand
> > side of the
> >>>>>>> mapping will never be affected by user-defined mappings.
> >>>>>>>
> >>>>>>> For example, if <script> were missing and somebody had defined
> > a
> >>>>>>> command-line mode mapping for the character sequence 'cal',
> > then the
> >>>>>>> mapping will likely fail because 'cal' is mapped to whatever
> > the user
> >>>>>>> mapped it to. <script> protects from such disruptions.
> >>>>>> My example is a bit poor though, since in this case you might as
> > well
> >>>>>> just use :nnoremap to be safe from side-effects. But I hope I
> > got the
> >>>>>> point across.
> >>>>>>
> >>>>> Still don't understand the difference from :nnoremap, :-(
> >>>>> what's more, the :h :map-<script> seems to mean the same as the
> > wiki:
> >>>>>
> >>>>> *:map-<script>* *:map-script*
> >>>>> If the first argument to one of these commands is "<script>" and
> > it is used to
> >>>>> define a new mapping or abbreviation, the mapping will only remap
> > characters
> >>>>> in the {rhs} using mappings that were defined local to a script,
> > starting with
> >>>>> "<SID>". This can be used to avoid that mappings from outside a
> > script
> >>>>> interfere (e.g., when CTRL-V is remapped in mswin.vim), but do
> > use other
> >>>>> mappings defined in the script.
> >>>>> Note: ":map <script>" and ":noremap <script>" do the same thing.
> > The
> >>>>> "<script>" overrules the command name. Using ":noremap <script>"
> > is
> >>>>> preferred, because it's clearer that remapping is (mostly)
> > disabled.
> >>>>>
> >>>>> thanks.
> >>>> Ok, let's reuse my example and add an intermediate mapping.
> >>>>
> >>>> nnoremap <SID>SayHelloRedirect :<C-U>call
> > <SID>SayHelloToUser()<CR>
> >>>> nmap <script> <Plug>SayHello <SID>SayHelloRedirect
> >>>>
> >>>> In this case :nmap <script> (or :nnoremap <script>) allow the
> > <Plug>
> >>>> mapping to be remapped to the intermediate mapping. This would not
> > work
> >>>> with plain :nnoremap because it prevents all remapping.
> >>> But with <SID> used before SayHelloRedirect,
> >>> nmap <Plug>SayHello <SID>SayHelloRedirect
> >>> does the same thing, it will not be interfered by somebody mapping
> > 'SayHelloRedirect',
> >>> so what interference is <script> used to prevent?
> >>>
> >>> forgive my paranoia ;-)
> >>>>
> >>>> Personally I never use <script> and I agree with ZyX that it is
> > quite
> >>>> useless.
> >>>>
> >>>> You can find some discussion in the user manual, try this command:
> >>>>
> >>>> :h usr_41|/PIECES
> >>
> >> You're exactly right. <SID> is protection enough and that's why I
> > don't
> >> see the point of using <script>.
> >>
>
> > To understand the need for the <script> attribute, try using the
> > following two maps:
>
> > nnoremap <SID>\x /Topic
> > nnoremap ,f <SID>\x
>
> > In the above case, the {rhs} is not remapped.
>
> > nnoremap <SID>\x /Topic
> > nnoremap <script> ,f <SID>\x
>
> > In the above case, the {rhs} is remapped (due to the use of <script>).
>
> Nope. We do understand this, but your example is pointless because what you are achieving is just as well achieved with :map. Using script-specific prefix ensures that third-party mappings do not
> interfere. What I meant by functions is something like this:
>
> noremap <SID>(FindTopic) /Topic
> nnoremap <script> ,dt <SID>(FindTopic)dd
> onoremap <script> ,t <SID>(FindTopic)
> nnoremap <script> ,yt <SID>(FindTopic)yy
>
> This way user may safely remap 'd' or 'y' and plugin still can reuse code.
>
Yes, this is a valid example, thanks.
>
> > - Yegappan
>
> >>
> >> However, some people think differently. Try this command and you'll
> > find
> >> that there are many instances of <script> in the Vim runtime files:
> >>
> >> :vim /<script>/ $VIMRUNTIME/**/*.vim
> >>
> >> I see there's even one I'm responsible for, shame on me :)
> >>
>
>



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