Trailing Comma - Snowflake

[ryaminal]

Curious what the thoughts are on supporting a trailing comma in SQL? Snowflake just announced support for this in their dialect. Example:

SELECT emp_id,
       name,
       dept,
FROM employees;

This doesn't appear to be handled by tree-sitter-sql yet(as it was just announced) but curious if this is something tree-sitter-sql wants to support? Or would it be better to make a dialect-specific repo?

[DerekStride]

I'm up for adding it! You interested in writing the PR?

[ryaminal]

yeah, i'll give it a go. do you want it behind a flag or anything?

[DerekStride]

Adding it to the existing behaviour is good

[matthias-Q]

Not sure if I am a fan of adding the trailing comma. This is a convenience addition by snowflake and - as of now - is only supported by snowflake. It saved me more than once to see an error in the highlighting, when having a trailing comma that my query engines (postgres/impala/athena) do not accept. Since this parser does not distinguish between dialects it would not through an error.

In this particular case it would not be wise to be permissive.