Contiguous Block Permutation Applier

Permute complete contiguous blocks using explicit positive block lengths and an exact zero-based permutation.

Description

Permute complete contiguous blocks using explicit positive block lengths and an exact zero-based permutation.

A contiguous block permutation rearranges whole adjacent groups while keeping the order inside each group. Exact partitioning prevents values from being dropped or duplicated accidentally.

When to use this tool

Permute complete contiguous blocks using explicit positive block lengths and an exact zero-based permutation.

Prepare the supplied values, blockLengths, order fields for this operation.
Compare the complete example with the representation used by your own input before carrying the result into another step.

How to use the tool and how it works

Enter values, blockLengths, order. Use the exact text syntax, units and index conventions explained below.
Run the tool. If input validation fails, correct the supplied fields before interpreting any result.
Read result.values. Interpret false, null and empty lists using the distinctions below; they can be valid outputs.

Require positive integer block lengths summing exactly to values.length. Require order to contain each block index once, split values by those lengths and concatenate blocks in the requested order.^[1]

Input field	Meaning and representation	Accepted input
values	values.	At most 128 strings, each at most 128 UTF-16 code units
blockLengths	block lengths.	List of finite numbers; bounded by the operation
order	order.	List of finite numbers; bounded by the operation

Output field	Interpretation
result	Object containing the named outputs below.
result.values	The values list in the ordering and representation described above.

json

{
  "input": {
    "values": [
      "a",
      "b",
      "c"
    ],
    "blockLengths": [
      2,
      1
    ],
    "order": [
      1,
      0
    ]
  },
  "output": {
    "result": {
      "values": [
        "c",
        "a",
        "b"
      ]
    }
  }
}

Limitations and assumptions

Block lengths are bounded to 128 each. The operation does not reverse block contents or infer a partition from values, and invalid or repeated permutation indexes are rejected.
Every declared top-level field is required and unexpected fields are rejected. Numeric inputs must be finite; ordinary text fields are bounded to 8,192 UTF-16 code units, with tighter operation-specific limits where stated.
Ordinary string lists have at most 128 entries of at most 128 code units each; numeric lists and matrices have separate bounded size checks. Nonfinite results and excessively large serialized outputs are rejected.
Indexes are zero-based and spans have an exclusive end unless explicitly stated otherwise. A valid false, null or empty-list result is distinct from malformed input.

Alternative or Complementary methods

Use explicit source-index maps when rearranging data or planning missing-value fills. Keep row-major coordinates, cyclic indexes and one-based occurrence numbers distinct, and inspect null donor positions before copying values.

References

Tool behavior and example: Contiguous Block Permutation Applier — tool.io

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