Overlapping Literal Match Indexes
Return overlapping literal-match UTF-16 offsets; distinct from a nonoverlapping replacement operation.
Description
Return overlapping literal-match UTF-16 offsets; distinct from a nonoverlapping replacement operation.
Overlapping literal matches can reveal repetitions that a replacement-oriented scan skips. For example, a repeated pattern may begin again inside the previous match.
When to use this tool
Return overlapping literal-match UTF-16 offsets; distinct from a nonoverlapping replacement operation.
- Prepare the supplied text, needle 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 text, needle. 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.offsets. Interpret false, null and empty lists using the distinctions below; they can be valid outputs.
Require a nonempty needle and repeatedly search literal occurrences while advancing the search start by one UTF-16 code unit. Return all matching offsets in ascending order.1
| Input field | Meaning and representation | Accepted input |
|---|---|---|
| text | text. | Text; at most 8,192 UTF-16 code units, subject to the grammar above |
| needle | needle. | Text; at most 8,192 UTF-16 code units, subject to the grammar above |
| Output field | Interpretation |
|---|---|
| result | Object containing the named outputs below. |
| result.offsets | The offsets list in the ordering and representation described above. |
{
"input": {
"text": "aaaa",
"needle": "aa"
},
"output": {
"result": {
"offsets": [
0,
1,
2
]
}
}
}Limitations and assumptions
- Offsets refer to the unchanged source. Matching is case-sensitive without regex or normalization, and a match may split a grapheme cluster even though its literal units agree.
- Text offsets and lengths use UTF-16 code units unless explicitly described as bytes or code points. CRLF, CR and LF are recognized as line endings; a terminal newline creates a final empty line in the shared line model.
- 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 a parser or language-aware editor when quoting, syntax or nested constructs matter. For plain text transforms, keep UTF-16 offsets, Unicode code points, grapheme clusters and UTF-8 byte offsets distinct; apply changes to the same source version used to calculate spans.
References
Similar or alternative tools
- Leftmost Longest Literal Match Selector
Select nonoverlapping leftmost-longest literal alternatives; equal lengths retain input alternative order.
- Enclosing Literal Wrapper Stripper
Strip one complete nonoverlapping enclosing literal wrapper, never internal or partial matches.