Support Tiers

This chapter records a practical support posture for PARC’s public surface.

It is meant to help downstream users judge which parts of the crate are the safest long-term integration points.

Tier 1: Core Consumer Surface

These are the most important public surfaces to depend on:

• driver
• parse
• ast
• visit
• span
• loc

These modules define the main parsing contract of the crate.

Tier 2: Debugging And Inspection Surface

These are public and useful, but more inspection-oriented than contract-critical:

• print
• Debug views of AST nodes
• formatted error text

They are valuable for debugging and tests, but long-lived tooling should still prefer structured data over formatted strings.

Tier 3: Contributor-Oriented Knowledge

These are important for contributors but should not be treated as downstream contracts:

• parser file organization under src/parser/
• helper-module layout
• incidental internal naming
• current implementation decomposition across grammar files

These details may evolve as the parser changes.

Consumer guidance

If you are building external tooling on top of PARC, bias toward Tier 1 surfaces first. Reach for Tier 2 when you need diagnostics or debugging support. Treat Tier 3 as implementation detail unless you are actively contributing to PARC itself.