Description
Add length to a negative index and retain nonnegative indices.
An index map tracks where one item lands after a structural list operation. Zero-based element positions differ from boundary cursors, and missing destinations need a sentinel.
Add length to a negative index and retain nonnegative indices.
When to use this tool
Use List: List Negative Index Resolver when you need one item's position under an explicit list transformation.
How to use the tool and how it works
- Enter index, length. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read result. Expand result to inspect the returned fields.
Add length to a negative index and retain nonnegative indices. Return resolvedIndex and an independent inBounds flag.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| index | Zero-based position or diagnostic index under the calculation above; inspect any sentinel policy. | Required. Safe integer. |
| length | Length, count, or code length under the stated domain and unit convention. | Required. Safe integer. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| result | Result | Required. Object. |
| result.resolvedIndex | Resolved Index | Calculated result member: number. |
| result.inBounds | In Bounds | Calculated result member: boolean. |
{
"input": {
"index": -1,
"length": 5
},
"output": {
"result": {
"resolvedIndex": 4,
"inBounds": true
}
}
}Limitations and assumptions
- Out-of-range positions are reported rather than clamped or rejected; empty lists have no valid element.
- Outputs are nested inside result. Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Apply the operation to a small representative list when checking a consuming language's indexing and slicing semantics.
References
Similar or alternative tools
- List Index Distance From End
For one-based positions return length minus index; for zero-based positions return length minus one minus index.
- List Anchor Relative Index Sign
Subtract anchor from index using exact integers and return decimal distance plus a separate sign comparison.