Method evaluate_pattern_expression

graphlite/src/exec/executor.rs:9391–9432

Evaluate a pattern expression in WHERE clauses

(
        &self,
        pattern_expr: &crate::ast::PatternExpression,
        context: &ExecutionContext,
    )

    /// Evaluate a pattern expression in WHERE clauses
    fn evaluate_pattern_expression(
        &self,
        pattern_expr: &crate::ast::PatternExpression,
        context: &ExecutionContext,
    ) -> Result<Value, ExecutionError> {
        // For now, we'll implement a simplified pattern matching
        // In a full implementation, this would:
        // 1. Parse the pattern into a subgraph query
        // 2. Execute the pattern against the current graph context
        // 3. Return true if any matches are found

        // Check if we have a graph context
        let _graph_name = context.get_graph_name().map_err(|_| {
            ExecutionError::RuntimeError(
                "No graph context available for pattern evaluation".to_string(),
            )
        })?;

        // For now, return true if the pattern is valid (basic implementation)
        // TODO: Implement actual pattern matching logic
        log::debug!("Evaluating pattern expression: {:?}", pattern_expr.pattern);

        // Simplified implementation: check if pattern has nodes and edges
        let has_nodes = pattern_expr
            .pattern
            .elements
            .iter()
            .any(|elem| matches!(elem, crate::ast::PatternElement::Node(_)));

        let has_edges = pattern_expr
            .pattern
            .elements
            .iter()
            .any(|elem| matches!(elem, crate::ast::PatternElement::Edge(_)));

        // For now, return true if we have both nodes and edges (indicating a valid relationship pattern)
        // In a real implementation, this would execute the pattern against the graph
        let pattern_matches = has_nodes && has_edges;

        log::debug!("Pattern evaluation result: {}", pattern_matches);
        Ok(Value::Boolean(pattern_matches))
    }

    /// Execute UNWIND operation
    fn execute_unwind(