Function unpack_string

datafusion/pruning/src/pruning_predicate.rs:1807–1809

returns the string literal of the scalar value if it is a string

(s: &ScalarValue)

/// returns the string literal of the scalar value if it is a string
fn unpack_string(s: &ScalarValue) -> Option<&str> {
    s.try_as_str().flatten()
}

fn extract_string_literal(expr: &Arc<dyn PhysicalExpr>) -> Option<&str> {
    if let Some(lit) = expr.downcast_ref::<phys_expr::Literal>() {