In h: internal-variables it mentions the "global" variable which is prefixed by g:. What would be the difference between:
let g:var = "xyz"
And:
let var = "xyz"
Does the absence of a prefix mean g:, or are they two different things?
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Depends on context: the scope default to different things depending on where its used (script local in scripts, function local in functions, i think. Plus there are buffer and window local, which are never defaults)– D. Ben Knoble ♦Jun 13, 2020 at 3:41
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1 Answer
In VimScript all variables have a scope. Or, better to say, they are organized into :h Dictionaries with reserved names. So echo g: is a perfectly valid command.
There are the following scopes (dictionaries) in no particular order:
g:Globals:Script-local (like "static" in C)l:Function-locala:Function argumentv:Vim internalb:Buffer localw:Window localt:Tab local
If scope is not given then v: is searched. If there's no such variable in v: then it's either s: or l: depending on the execution context. Also, while on the command line it's g:, as, obviously, neither s: nor l: applies in interactive mode.
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thanks, so if I execute
:let var = "new"then that goes into theg:dict because I haven't qualified its prefix/namespace?– David542Jun 13, 2020 at 6:40 -
1Interactively? Yes. You can always check it with
echo g:varorecho get(g:, 'var')– MattJun 13, 2020 at 6:43 -
1I did not know for nothing that could be interpreted as
s:... oO BTW, there is also a little issue with lambdas: we have to be explicit to use global variables, even interactively, while it's not the case inecho map(somelist, 'v:val > globalthreshold'). Jun 13, 2020 at 13:29 -
@LucHermitte Lambda is a kind of closure, so it's normal when it inherits default meaning of
l:,a:ands:as if executing in the outer scope. However, it's really strange that "global" lambda does not haveg:by default. Should it be called inconsistency or bug?– MattJun 13, 2020 at 14:20 -