Fold¶
| Name | Mandatory | Description | Default | Type |
|---|---|---|---|---|
⬅️ Input |
The sequence to fold. | [Any] |
||
Output ➡️ |
The resulting value after folding the sequence. | Any |
||
Apply |
No | The function to apply to each item of the sequence. | none |
Shard[Shard] |
Initial |
No | The initial value of the accumulator. If not provided the shard will fail if the input sequence is empty. | none |
AnyVar(Any) |
Folds a sequence into a single value by applying an operation (specified in the Apply parameter) to each item of the sequence. The operation can transform the type. Note that this shard is able to use the $0 internal variable for the accumulated value and $i for the current index.
Details¶
Consider the following: [1 2 3 4 5] | Fold(Initial: 0 Apply: {Math.Subtract($0)})
This shard will be processed as follows:
- Each element of the sequence will be passed as input to Math.Subtract and the Accumulator($0) will be subtracted from it.
- The result will then be set as the new value of the Accumulator($0).
- First, $0 is initialized as the value specified in the Initial parameter
- 1 - 0 = 1 ($0 then becomes 1)
- 2 - 1 = 1 ($0 then becomes 1)
- 3 - 1 = 2 ($0 then becomes 2)
- 4 - 2 = 2 ($0 then becomes 2)
- 5 - 2 = 3 ($0 then becomes 3)
- The final value of $0 is then returned.
Do note that this instance of $0 is unique to the Reduce shard and do not exist outside of the context of its Apply parameter. Values set to this instance of $0 will not be reflected on other $0 created in a different call of another Reduce shard or any other shard that is also able to use $0.