feat: add relaxed quoting for qualified name tails

[pyramation]

feat: add relaxed quoting for qualified name tails

Summary

This PR reduces unnecessary quoting of identifiers that appear after a dot in qualified names (e.g., schema.name, table.column).

PostgreSQL's grammar accepts all keyword categories—including RESERVED_KEYWORD like select, from, table—in qualified name positions. The previous implementation was over-conservative, quoting keywords like float, interval, boolean even when they appeared after a dot where quoting isn't required.

Before: faker."float", faker."interval", pg_catalog."substring"
After: faker.float, faker.interval, pg_catalog.substring

Changes:

• Added quoteIdentifierAfterDot() method that only quotes for lexical reasons (uppercase, special chars, leading digits) not keyword reasons
• Added quoteDottedName(parts[]) helper that applies strict quoting to the first part and relaxed quoting to subsequent parts
• Updated FuncCall and CreateFunctionStmt to use quoteDottedName() for function names
• Updated RangeVar and ResTarget indirection handling to use quoteIdentifierAfterDot()
• Updated quoteQualifiedIdentifier() to use relaxed quoting for the tail component
• Removed unused nquotes variable from quoteIdentifier()
• Updated 14 snapshots to reflect the new unquoted output
• Added comprehensive QUOTING-RULES.md documentation explaining the quoting strategy, PostgreSQL background, algorithms, and contributor guidance

Review & Testing Checklist for Human

• Verify the grammar claim: Test that CREATE FUNCTION faker.float() RETURNS float AS $$ SELECT 1.0; $$ LANGUAGE sql and similar statements actually parse in PostgreSQL without quotes
• Check for missed call sites: Search for other patterns in deparser.ts that build dotted names (e.g., .join('.') patterns) that might need updating to use quoteDottedName()
• Verify FuncCall comparisons still work: The code compares name === 'pg_catalog.substring' etc. after quoting - verify these comparisons still match since the function names should remain unquoted
• Review QUOTING-RULES.md: Ensure the documentation accurately describes the strategy and is helpful for future contributors

Recommended test plan: Parse and deparse SQL like CREATE FUNCTION faker.float() RETURNS float AS $$ SELECT 1.0; $$ LANGUAGE sql and verify the output is valid PostgreSQL that can be re-parsed.

Notes

• Pre-existing test failures in the repo (tables-13.sql, tables-14.sql) are unrelated to this change - they involve case sensitivity issues with type names like AlertLevel vs alertlevel
• The quoteIdentifier() method remains unchanged as the strict PostgreSQL-faithful port for standalone identifiers
• The new QUOTING-RULES.md documentation covers: PostgreSQL identifier folding, keyword categories, the strict vs relaxed quoting algorithms, composition helpers, deparser integration rules, and common pitfalls

Link to Devin run: https://app.devin.ai/sessions/019c4a70e9164830aef1f807aad33e1d
Requested by: Dan Lynch (@pyramation)

[devin-ai-integration]

🤖 Devin AI Engineer

I'll be helping with this pull request! Here's what you should know:

✅ I will automatically:

• Address comments on this PR. Add '(aside)' to your comment to have me ignore it.
• Look at CI failures and help fix them

Note: I can only respond to comments from users who have write access to this repository.

⚙️ Control Options:

• Disable automatic comment and CI monitoring