Define Bool node (boolean literal)

[dennwc]

We already have a String literal node, and this PR goes one step further and defines a boolean literal node (Bool) in SemUAST.

The definition of the node is pretty streightforward: it's a boolean value that can be either "true" or "false".

This node type is useless for some drivers without #337.

Signed-off-by: Denys Smirnov denys@sourced.tech

[juanjux]

I approved, since this is worthy, simple and backwards compatible, but my approval doesn't imply I think we should upgrade all the drivers' annotations to use it immediately (see my comment here: #337 (comment)).

[bzz]

Did I get it right, that this change is a part of bigger scope of work on having better semantic annotations in UAST?

👍 but I concur with what @juanjux mentioned above on priorities.

[dennwc]

Right. I don't think we should update all drivers immediately. I will probably update 2-3 of them when I have some time just to make sure it works.

@bzz Correct, this is a part of a bigger change, but this change may span a few years. We can gradually improve the coverage of SemUAST types when it makes sense.

For Bool the definition is clear, but for other things, it won't be that easy. So right now I identified few common nodes across drivers that are low-hanging fruits and will try to define a schema for them to keep things going. But we have other more important tasks, of course.