[fmcmac]

Dialects: Snowflake, MySQL, Generic

Nested shapes avoid the recursion limit, overflowing the stack instead of returning RecursionLimitExceeded:

• MATCH_RECOGNIZE(PATTERN ((((a)))) ...)
• JSON_TABLE(... COLUMNS(NESTED PATH '$' COLUMNS(...)))
• Snowflake COPY_OPTIONS=(a=(a=(...)))
• Snowflake SELECT * FROM t JOIN t JOIN t ..., without parentheses

Added recursion guard for parse_pattern, parse_json_table_column_def, parse_key_value_options and the recursive call in parse_joins.

The depth tests overflow on main. Additional tests check that a flat 100-way PATTERN alternation and nested parenthesised joins still parse.

This PR was written with Claude Code. I have read and reviewed every line.

[LucaCappelletti94]

Most of the changes are AI-slopped documentation. Please only include actually necessary documentation, read it, and not just greenlight AI generated documentation.

The code itself looks okay.

[alamb]

Marking as draft as I think this PR is no longer waiting on feedback and I am trying to make it easier to find PRs in need of review. Please mark it as ready for review when it is ready for another look

[alamb]

Thanks for the contribution @fmcmac and the review @LucaCappelletti94

[fmcmac]

Mea culpa @LucaCappelletti94, I have removed the comments.

Rebased onto main. #2411 and #2422 cover the data type and interval paths, so I dropped those parts. I removed the parse_prefix change, because prefix caching covers the slowdown and the change rejected valid SQL. Tests now align with the existing style.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 80.00000% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 82.55%. Comparing base (50813ee) to head (7dcc189).

Files with missing lines	Patch %	Lines
src/parser/mod.rs	80.00%	0 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2440      +/-   ##
==========================================
+ Coverage   82.54%   82.55%   +0.01%     
==========================================
  Files          42       42              
  Lines       35553    35555       +2     
  Branches    35553    35555       +2     
==========================================
+ Hits        29346    29354       +8     
  Misses       2672     2672              
+ Partials     3535     3529       -6     

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