Refactor Core Documentation (README, SYNTAX, GLR) and Sync API Signatures

[ehwan]

This Pull Request refactors the project's markdown documentation files (README.md, SYNTAX.md, and GLR.md) to improve readability, translate all parts into clean, natural English, and update all code examples to reflect the actual API signatures defined in rusty_lr_core. It also establishes workspace guidelines for AI agents in .agents/AGENTS.md.

Proposed Changes

Documentation Refactoring

• README.md:
  • Rewrote sections in standard, natural English.
  • Updated the Quick Start section with a comprehensive expression calculator parser grammar.
  • Fixed method signatures in code examples (e.g., accept, expected_token, can_feed, trace, backtrace) to include the required &parser and &mut userdata arguments.
• SYNTAX.md:
  • Rewrote the entire reference guide in natural English.
  • Aligned all section headers with diagnostic URLs hardcoded in rusty_lr_parser/src/parser/parser.rs (e.g., #token-type-must-defined, #operator-precedence, #location-tracking).
  • Improved samples for regex patterns (*, +, ?, $sep()), groupings, and rule prioritization.
• GLR.md:
  • Translated and refined the Generalized LR parsing guide.
  • Corrected GLR API code samples to pass the required &mut userdata parameter.
  • Documented feed_location and dynamic branch pruning methods (Err propagation and *shift = false).

Project Customization Rules

• .agents/AGENTS.md (New):
  • Created a set of instructions for future AI agents, detailing guidelines on documentation synchronization, syntax changes formatting, bootstrap test execution, copy-pasteable PR creation, and Implementation Plan console outputting.

Verification

• Ran the parser bootstrap test script:

  ./scripts/bootstrap_test.sh

[gemini-code-assist]

Code Review

This pull request introduces comprehensive updates to the documentation and guidelines of RustyLR, including a new agent guidelines file, a rewritten GLR parsing guide, an updated main README, and a restructured syntax reference. The review feedback highlights several issues in the documentation examples, such as unbound variables in the GLR expression grammar, absolute local file URLs in the agent guidelines, misleading comments regarding token value extraction, and a missing return type in the userdata example.

Important

The consumer version of Gemini Code Assist on GitHub is being sunset. Starting June 18, 2026, new organization installations will be blocked, and all code review activity will officially cease on July 17, 2026.
For more details on the timeline and next steps, please review the Help Documentation.

[gemini-code-assist]

The link to SYNTAX.md uses an absolute local file URL (file:///wsl.localhost/...) pointing to your local WSL environment. This should be a relative link so that it works for other users and in different environments.

Suggested change

	- You must add a detailed explanation with examples inside [SYNTAX.md](file:///wsl.localhost/Ubuntu-22.04/home/ehwan/workspace/RustyLR/SYNTAX.md).
	- You must add a detailed explanation with examples inside [SYNTAX.md](../SYNTAX.md).

[gemini-code-assist]

The link to parser.rs uses an absolute local file URL pointing to your local WSL environment. This should be a relative link so that it works for other users and in different environments.

Suggested change

	- Preserve the exact header anchor names that are referenced as diagnostic URLs within the codebase (e.g., in [parser.rs](file:///wsl.localhost/Ubuntu-22.04/home/ehwan/workspace/RustyLR/rusty_lr_parser/src/parser/parser.rs)).
	- Preserve the exact header anchor names that are referenced as diagnostic URLs within the codebase (e.g., in [parser.rs](../rusty_lr_parser/src/parser/parser.rs)).