refactor: programs as delimited sequences of statements

[dmfay]

eliminates the recently added conflicts, shaves a few seconds off compile time, and state count in the parser is cut by over half -- from 7151 states to 3087!

Other changes:

• compound_statement has been renamed to block
• create_function uses object_reference correctly
• we've lost parsing of 'string' function bodies but that was probably a bad idea to begin with

[matthias-Q]

Wow, I am really surprised hat these few change have such a big impact. I am really impressed! Thanks @dmfay

[matthias-Q]

In nvim-treesitter there is a indentens.scm, which refenrences compound_Statement. We should have added a copy of this to our repo as well, so that the tests fail here when we rename nodes.

[matthias-Q]

we've lost parsing of 'string' function bodies but that was probably a bad idea to begin with

what statements are you referring to? Can you give me an example?

[dmfay]

we've lost parsing of 'string' function bodies but that was probably a bad idea to begin with

what statements are you referring to? Can you give me an example?

there are a couple in the tests, for example

create or replace function public.fn()
  returns int
  language sql
as 'select 1;';

select 1; is now parsed as a literal instead of a statement in its own right. It could be a program if we could ensure that any single quotes internal to it didn't parse in the outer program, which is probably possible but gets complicated since return is a valid statement in a function body but nowhere else.

[DerekStride]

Wow this is great, the decrease in number of states is huge 🎉🎉🎉