Module visitor 

AST Visitor trait and walk functions for Shape.

This module provides a visitor pattern for traversing the AST. All variants are explicitly handled - no wildcards.

Per-Variant Expression Methods

The Visitor trait provides fine-grained per-variant methods for expressions. Each method has a default implementation that returns true (continue into children). Override only the variants you care about.

The visit order for each expression is:

1. visit_expr(expr) — coarse pre-visit hook; return false to skip entirely
2. visit_<variant>(expr, span) — per-variant hook; return false to skip children
3. Walk children recursively
4. leave_expr(expr) — post-visit hook

Traits

Visitor

A visitor trait for traversing Shape AST nodes.

Functions

walk_expr

Walk an expression - ALL VARIANTS HANDLED EXPLICITLY

walk_function

Walk a function definition

walk_item

Walk an item

walk_program

Walk a program, visiting all items

walk_query

Walk a query

walk_stmt

Walk a statement