Cyclic Index Normalizer
Normalize a signed integer index cyclically into a nonempty list; no negative-index clamping.
Description
Normalize a signed integer index cyclically into a nonempty list; no negative-index clamping.
Cyclic indexing wraps positive and negative positions into a finite range. A nonnegative modulo convention prevents negative array indexes after wrapping.
When to use this tool
Normalize a signed integer index cyclically into a nonempty list; no negative-index clamping.
- Prepare the supplied index, length 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 index, length. 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.normalizedIndex. Interpret false, null and empty lists using the distinctions below; they can be valid outputs.
Require a safe integer index and positive bounded length. Normalize the remainder with ((index%length)+length)%length and return an index from zero through length minus one.1
| Input field | Meaning and representation | Accepted input |
|---|---|---|
| index | index. | Integer from -Number.MAX_SAFE_INTEGER to Number.MAX_SAFE_INTEGER inclusive |
| length | length. | Integer from 1 to 1e9 inclusive |
| Output field | Interpretation |
|---|---|
| result | Object containing the named outputs below. |
| result.normalizedIndex | The normalized index value under the stated formula or text convention. |
{
"input": {
"index": -1,
"length": 5
},
"output": {
"result": {
"normalizedIndex": 4
}
}
}Limitations and assumptions
- This is wrapping rather than clamping. It does not read an array, and callers remain responsible for matching the supplied length to actual data.
- 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
Similar or alternative tools
- Adjacent Change Indexes
Return indexes whose value differs from the previous supplied string, not CSS change hints or a value transform.
- Alternating Sign Run Segmenter
Segment consecutive strictly alternating nonzero signs; zeros and equal adjacent signs break runs.