Using Register Variables in VimScript

Question

I have the following code in vim Script(File name: file):

:execute "normal /\This\<CR>gg"
:let i=1
:execute "normal nxxcwThat".@=i

I am executing this code on the following file(File name: out):

This is line 1
This is line 2

I am using the following run command:

vim -s file out

And the output is:

This is line 1
That 1 is line 2

I do not understand why is space getting printed between That and 1 .
Also, I am slightly confused in how to use register variables when writing a vimscript. Could someone please explain?

Answer 1

That might be a bug. But is there a reason, you are using the expression-register to access the variable?

What works is to use, which looks more readable anyhow:

:execute "normal nxxcwThat".i