Module eval 

XPath AST evaluation phase.

This module provides the eval_node() function which evaluates a bound XPath AST at runtime. The AST must be bound using bind_node() before evaluation.

Supported Node Types

Currently implemented:

• Value - Literal values (string, integer, double, boolean, empty)
• ContextItem - Context item reference (.)
• VarRef - Variable references
• Expr - Sequence expressions
• If - Conditional expressions
• FunctionCall - Function calls (dispatched via eval_function)

Other node types return not_implemented errors for now.

Functions

eval_node

Evaluate an AST node and return the result.