| 48 | } |
| 49 | |
| 50 | fn interleave(values: &[Value], constants: &[Aid]) -> Vec<Value> { |
| 51 | if values.is_empty() || constants.is_empty() { |
| 52 | values.to_owned() |
| 53 | } else { |
| 54 | let size: usize = values.len() + constants.len(); |
| 55 | // + 2, because we know there'll be a and v coming... |
| 56 | let mut result: Vec<Value> = Vec::with_capacity(size + 2); |
| 57 | |
| 58 | let mut next_value = 0; |
| 59 | let mut next_const = 0; |
| 60 | |
| 61 | for i in 0..size { |
| 62 | if i % 2 == 0 { |
| 63 | // on even indices we take from the result tuple |
| 64 | result.push(values[next_value].clone()); |
| 65 | next_value += 1; |
| 66 | } else { |
| 67 | // on odd indices we interleave an attribute |
| 68 | let a = constants[next_const].clone(); |
| 69 | result.push(Value::Aid(a)); |
| 70 | next_const += 1; |
| 71 | } |
| 72 | } |
| 73 | |
| 74 | result |
| 75 | } |
| 76 | } |
| 77 | |
| 78 | impl<P: Implementable> Implementable for PullLevel<P> { |
| 79 | fn dependencies(&self) -> Dependencies { |