Line Number Overlay Data
Build line-number overlay data without modifying source text; preserve UTF-16 source spans and an explicit starting label.
Description
Build line-number overlay data without modifying source text; preserve UTF-16 source spans and an explicit starting label.
Line-number overlays attach labels and source spans to existing line contents. The labels can start at an application-chosen number while offsets remain tied to the source text.
When to use this tool
Build line-number overlay data without modifying source text; preserve UTF-16 source spans and an explicit starting label.
- Prepare the supplied text, startNumber 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, startNumber. 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.lines. Interpret false, null and empty lists using the distinctions below; they can be valid outputs.
Validate a nonnegative integer startNumber. Parse lines and emit each assigned number, zero-based content start/end and text, increasing the number by one per line.1
| Input field | Meaning and representation | Accepted input |
|---|---|---|
| text | text. | Text; at most 8,192 UTF-16 code units, subject to the grammar above |
| startNumber | start number. | Integer from 0 to 1e9 inclusive |
| Output field | Interpretation |
|---|---|
| result | Object containing the named outputs below. |
| result.lines | The lines list in the ordering and representation described above. |
{
"input": {
"text": "a\nb",
"startNumber": 10
},
"output": {
"result": {
"lines": [
{
"number": 10,
"start": 0,
"end": 1,
"text": "a"
},
{
"number": 11,
"start": 2,
"end": 3,
"text": "b"
}
]
}
}
}Limitations and assumptions
- End offsets exclude newline characters. A terminal empty line is included, and numbers are labels rather than offsets; the tool neither renders an editor gutter nor changes the text.
- 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
- Consecutive Duplicate Line Collapser
Collapse only consecutive identical line contents, retaining each kept line separator; nonadjacent duplicates remain.
- Line and Column to UTF-16 Offset
Map one-based logical line/UTF-16 content column to offset; columns inside separators are intentionally not accepted.