[KG] Create Initial Library Code

Issue: Create Initial Library

Goal

Establish the foundational infrastructure for the gitlab-code-parser library that will serve as the base for all language-specific parsers. This issue focuses on creating the core parsing framework, rule loading system, and common utilities that will be shared across all language implementations (Ruby, Python, JavaScript/TypeScript, etc.).

Scope

This issue encompasses the essential building blocks needed before any language-specific parsing can begin:

Core Library Components:

• Parser Core Module: Base traits and structures for language parsers
• Rule Loading System: Infrastructure for loading and managing ast-grep rules from YAML files
• Any AST Utilities: Common AST traversal and manipulation functions
• Configuration Management: System for parser configuration and options

Integration Points:

• ast-grep Integration: Core functionality for pattern matching and rule execution

File Structure

crates/parser-core/
├── src/
│   ├── lib.rs                 # Main library exports
│   ├── parser.rs              # Core Parser trait and implementation
│   ├── rules/
│   │   ├── mod.rs            # Rule loading and management
│   │   ├── loader.rs         # YAML rule file loader
│   │   └── executor.rs       # ast-grep rule execution
├── languages/                     # Language-specific rule files
│   ├── ruby/
│   │   ├── definitions.yaml
│   │   ├── references.yaml
│   │   └── imports.yaml
│   └── python/
│       ├── definitions.yaml
│       ├── references.yaml
│       └── imports.yaml