DOC-001: Complete Comprehensive API Reference

[ajitpratap0]

Summary

Expand API_REFERENCE.md from current 200 lines to comprehensive coverage of all packages (60%+ missing).

Problem

API_REFERENCE.md only covers basics - missing documentation for majority of API surface area.

Missing Coverage

• pkg/sql/ast - AST nodes (100+ types)
• pkg/sql/keywords - keyword system
• pkg/errors - error handling
• pkg/metrics - observability
• Advanced features in tokenizer and parser

Action Items

1. Document all packages with full API coverage:
   • pkg/gosqlx - high-level API (all 4+ functions)
   • pkg/sql/tokenizer - tokenization internals
   • pkg/sql/parser - parsing methods
   • pkg/sql/ast - ALL AST node types (100+)
   • pkg/sql/keywords - keyword classification
   • pkg/models - core data structures
   • pkg/errors - structured error system
   • pkg/metrics - performance monitoring
2. Add code examples for each major function
3. Document all AST node types with usage examples
4. Add architecture diagrams
5. Create searchable index

Acceptance Criteria

• 100% API coverage (all public types and functions)
• Examples for all major functions
• Cross-references to guides and tutorials
• Search-friendly format
• Generated from godoc where possible

Technical Details

Priority: Medium
Effort: Medium (40h)
Phase: Phase 3 - UX & Documentation
Dependencies: None

Structure

API_REFERENCE.md
├── High-Level API (pkg/gosqlx)
├── Tokenizer (pkg/sql/tokenizer)
├── Parser (pkg/sql/parser)
├── AST Nodes (pkg/sql/ast)
│   ├── Statements
│   ├── Expressions
│   ├── Clauses
│   └── Operators
├── Keywords (pkg/sql/keywords)
├── Models (pkg/models)
├── Errors (pkg/errors)
└── Metrics (pkg/metrics)

[ajitpratap0]

PR Created: #123

Comprehensive API Reference documentation has been significantly expanded in PR #123.

Changes Summary

AST Section Expansion (~1,100 new lines):

• ✅ Documented all 50+ AST node types
• ✅ Complete documentation for DML statements (SELECT, INSERT, UPDATE, DELETE, MERGE)
• ✅ Complete documentation for DDL statements (CREATE TABLE/VIEW/MATERIALIZED VIEW/INDEX, ALTER, DROP)
• ✅ CTE and Set Operations documentation (WITH, UNION, EXCEPT, INTERSECT)
• ✅ All expression types (Binary, Unary, Case, Cast, In, Between, Exists, Subquery, Any, All)
• ✅ Grouping set types (ROLLUP, CUBE, GROUPING SETS)
• ✅ Window function types (WindowSpec, WindowFrame, WindowFrameBound)
• ✅ Object pool functions and visitor pattern examples
• ✅ Type assertion examples for common use cases

Documentation Statistics:

• AST section: ~150 lines → 1,200+ lines
• Total documentation: ~2,900 lines → ~4,000 lines

This builds on the research phase completed earlier (documented in docs/DOC-001-COMPLETION-SUMMARY.md) which included comprehensive documentation for Keywords Package, Errors Package, and Metrics Package.

🤖 Generated with Claude Code