MLDB-1829 jseval rows

[jeremybarnes]

• Fixes crashes with JS contexts being mixed within jseval
• Adds an ExpressionValue type to JS that mirrors the real one
• Allows for arguments to be passed through in non-simplified form in jseval by adding a '!' to the variable names parameter, so that we can get full fidelity passing through jseval
• Moved js out of soa and into plugins/lang/js, removing the last hooks of the generic code to JS

[jeremybarnes]

Test failure is runner_test, which is completely unrelated and known spurious.

[guyd]

Consider adding a link to the description of simplified arguments.

[guyd]

+1 I reviewed briefly the code with only minor comments. I don't no the js code that well.

I agree with @FinchPowers that the exclamation mark might be confusing.

[FinchPowers]

J'ai fait une expérience.

Dataset

{'rowName' : 'row1', 'columns' : [['x', 'data', 0]]

Requête

SELECT jseval('return row;', 'row', {*}) FROM ds

Résultat

2016-07-20 09:48:09.426 javascript [
   {
      "columns" : [
         [ "jseval('return row;', 'row', {*}).0.0.0", "x", "NaD" ],
         [ "jseval('return row;', 'row', {*}).0.1", "data", "NaD" ],
         [
            "jseval('return row;', 'row', {*}).0.2",
            {
               "ts" : "1970-01-01T00:00:00Z"
            },
            "NaD"
         ]
      ],
      "rowHash" : "86065feec3521acc",
      "rowName" : "row1"
   }
]

Il me semble que chaque colonne est explosée en 3, soit le nom, la valeur et la date. Est-ce bien ce que l'on souhaite?

Aussi, je pense que le nom de la première colonne est incorrect. Il devrait se terminer par ).0.0 et non pas par ).0.0.0

"jseval('return row;', 'row', {*}).0.0.0"
"jseval('return row;', 'row', {*}).0.1"
"jseval('return row;', 'row', {*}).0.2"

[jeremybarnes]

@FinchPowers that behaviour is exactly the same as master; there is no change to the behaviour without an exclamation point. Structures are unfortunately broken out as [ [ key, [ value, ts ] ], ... ] and this behaviour is maintained to avoid breaking existing jseval scripts. If you use '!row' instead of 'row', you get much more reasonable behaviour, but I didn't want to break existing code and so you need to opt in using the '!'.

[FinchPowers]

Merci pour l'explication.