+: is erroneously interpreted as : within object comprehension

[NicholasHusin]

Given the following:

{ ['foo']+: [x] for x in [1]} + { ['foo']+: [x] for x in [2]}

The official implementation of jsonnet would output:

{
  "foo": [
    1,
    2
  ]
}

due to the +: used.

However, on sjsonnet, the + in +: seems to be ignored, resulting in

{ ['foo']+: [x] for x in [1]} + { ['foo']+: [x] for x in [2]}

being interpreted as:

{ ['foo']: [x] for x in [1]} + { ['foo']: [x] for x in [2]}

and resulting in:

{
  "foo": [
    2
  ]
}

This causes an inconsistency between jsonnet and sjsonnet.

[lihaoyi-databricks]

Should be fixed by https://github.com/databricks/sjsonnet/pull/155