Array selection

[aborruso]

Hi,
I create the b array in this way:

echo a="1.2.3.4" | mlr --ojson cat then put '$b=is_array(splitax($a,"."));'

[
{
  "a": "1.2.3.4",
  "b": true
}
]

Why I cannot select the first in this way

echo a="1.2.3.4" | mlr --ojson cat then put '$b=(splitax($a,"."))[1]'

I have this error

mlr: cannot parse DSL expression.
Parse error on token "[" at line 1 column 21.

But I can extract it in this way

echo a="1.2.3.4" | mlr --ojson cat then put '$b=(splitax($a,"."));$c=$b[1]'

Thank you

[johnkerl]

@aborruso this works:

$ echo a="1.2.3.4" | mlr --ojson cat then put '$b=splitax($a,".")[1]'
[
{
  "a": "1.2.3.4",
  "b": "1"
}
]

and it's a parser bug that this doesn't:

$ echo a="1.2.3.4" | mlr --ojson cat then put '$b=(splitax($a,"."))[1]'
[
{
  "a": "1.2.3.4",
  "b": "1"
}
]

[johnkerl]

Even with x = [1,2,3], x[1] is OK but (x)[1] is a parse fail :(