Vim9: Not able to add a new field to a dict which is a dict member

[Yegappan Lakshmanan]

Hi,

The following Vim9 function fails with "E1141: Indexable type required":

======================================================

vim9script

def g:Test()
    var req = {}
    req.params = {}
    req.params.id = 10
    echomsg req
enddef

call g:Test()

======================================================

The following legacy function works:

======================================================

func g:Test()
    let req = {}
    let req.params = {}
    let req.params.id = 10
    echomsg req
endfunc

call g:Test()

======================================================

Am I missing something here?

Thanks,

Yegappan

[Bram Moolenaar]

The type of "req" is not specified. You initialize it with {}, which is
a dict with unknown member type. You assign it a dict in the second
line, but that doesn't change the type. In the third line you try to
access a member of an unknown. At this point we expect a list or a
dict, with an unknown we don't know what to do.

We could assume the ".id" indicates it should be a dict and turn this
into a runtime type check, but that may hide problems. Best is to
declare the type of "req":

var req: dict<dict<number>> = {}

Then it works.

--
Q: What kind of stuff do you do?
A: I collect hobbies.

/// Bram Moolenaar -- Br...@Moolenaar.net -- http://www.Moolenaar.net \\\
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