Unexpected failure to compile with yamlfragment arrays.

As demonstrated by this gist:

https://get-ytt.io/#gist:https://gist.github.com/JollyWizard/4aa2acf3e9692fdb4ff022c6d771dcaf

... Leading a document with function that returns an ymlfragment array causes subsequent code to fail unless a document separator is used.

This problem can be fixed with a document separator.

https://get-ytt.io/#gist:https://gist.github.com/JollyWizard/https://gist.github.com/JollyWizard/f7513cd54d27e1ace608f1c5cf409442

I'm not sure of the full scope of this problem, but it may be related to another issue, where yaml fragment array functions get angry with different indentation levels.

https://gist.github.com/JollyWizard/ec838ba85382ba9a3821e36d83e5a103

Start by reproducing the failure from the linked gist in ytt, then compare it with the version that adds a document separator. Investigate the related gist covering different indentation levels. Done means yamlfragment arrays compile consistently without requiring an extra separator, with the relevant cases covered by tests.

Written by the indexing model from the issue text.