Support dot notation on UPDATE ... SET

[asdine]

Currently, the UPDATE clause only accepts simple top-level fields foo.
We should be able to update nested fields or array indexes using dot notation.

UPDATE users SET a.3.name = [1, 2, 3];

Because nested values can be tricky, the SET clause must only set a value when it is possible. If we take the example above, the document must respect the following requirements in order to be settable:

• a is an array
• a.3 exists and is a document
• a.3.name may or may not exist (same rules as for top-level fields, see below)

Currently, the rule is: if the field doesn't exist, we create it, otherwise we replace it with the new value.
With this change, the rule still applies but only for the element of the dot notation path that is the most to the right.

Exception for arrays

INSERT INTO users (a) VALUES ([1, 0, 0]), ([2, 0]);
UPDATE users SET a.2 = 1;
SELECT * FROM users WHERE a.2 = 1;
{"a": [1, 0, 1]}

This example shows that the above rule must not apply for arrays. If the array index doesn't exist, it must not be created.

[asdine]

I'm reopening this issue as there are still some bugs in the proposed PR. The PR has been reverted and the issue is scheduled for v0.8

[tzzed]

When the field using backquotes with spaces like this some "field ", the spaces must be deleted or not?
inputs:
` some "field" ` OR `a.` b ` . c`
outputs :

`some "field" ` OR `a.b.c`

Spaces should be deleted.
Is the expected behaviour?

[tzzed]

Found the answer in TestParserPath.