Function evaluate_collection_slice

crates/gitql-engine/src/engine_evaluator.rs:297–318

(
    env: &mut Environment,
    expr: &SliceExpr,
    titles: &[String],
    object: &Vec<Box<dyn Value>>,
)

}

fn evaluate_collection_slice(
    env: &mut Environment,
    expr: &SliceExpr,
    titles: &[String],
    object: &Vec<Box<dyn Value>>,
) -> Result<Box<dyn Value>, String> {
    let array = evaluate_expression(env, &expr.collection, titles, object)?;

    let start = if let Some(start_expr) = &expr.start {
        Some(evaluate_expression(env, start_expr, titles, object)?)
    } else {
        None
    };

    let end = if let Some(end_expr) = &expr.end {
        Some(evaluate_expression(env, end_expr, titles, object)?)
    } else {
        None
    };

    array.slice_op(&start, &end)
}

fn evaluate_prefix_unary(
    env: &mut Environment,