vim9 exists() can't test whether a dictionary value is set in a function argument

[Christian J. Robinson]

    vim9script

 

    def Foo(bar: dict<string>)

        if exists('bar["a"]')

            echo "it exists"

        else

            echo "it doesn't exist"

        endif

    enddef

 

    Foo({'a': '...'})

    Foo({'b': '...'})

 

This should echo:

 

    it exists

    it doesn’t exist

 

But it echoes:

 

    it doesn’t exist

    it doesn’t exist

 

I have tried all kinds of combinations, including checking for l:bar[“a”] and a:bar[“a”].  The only thing that works is to assign the bar argument to a global variable and testing that instead, but that’s a kluge.

 

Regards,

Christian

 

[Bram Moolenaar]

Correct, function arguments are not visibile to exists() in a compiled
function. I notice that this isn't mentioned in the help, I'll update
that.

You should has has_key():

if bar->has_key("a")
echo 'it exists'


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