Running map() on a set may return an array

[philrz]

Repro is with Zed commit 3a40788.

Regarding the new map() function added in #4806, if I modify the complex value in the docs example to be a set type instead of an array, map() still returns a set.

$ zq -version
Version: v1.10.0-31-g3a40788b

$ echo '|["foo","bar","baz"]|' | zq -z 'yield map(this, upper)' -
|["BAR","BAZ","FOO"]|

However, if I put that set value inside of a record and have map() act on that value, now what comes back is an array.

$ echo '{m:|["foo","bar","baz"]|}' | zq -z 'yield map(m, upper)' -
["BAR","BAZ","FOO"]

[philrz]

Verified in Zed commit 07893a2.

Now the set value inside the record comes back from map() as a set.

$ zq -version
Version: v1.10.0-36-g07893a2b

$ echo '{m:|["foo","bar","baz"]|}' | zq -z 'yield map(m, upper)' -
|["BAR","BAZ","FOO"]|

Thanks @mattnibs!