Line Span Intersection Tool
Intersect a half-open UTF-16 selection with line-content spans; exclude separators and zero-length contacts.
Description
Intersect a half-open UTF-16 selection with line-content spans; exclude separators and zero-length contacts.
A selection can cover content on several lines while also crossing newline characters. Intersecting only line contents makes those per-line portions explicit.
When to use this tool
Intersect a half-open UTF-16 selection with line-content spans; exclude separators and zero-length contacts.
- Prepare the supplied text, start, end 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, start, end. 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.intersections. Interpret false, null and empty lists using the distinctions below; they can be valid outputs.
Validate start/end against text length. For each parsed line, intersect its content span with the selection and return a row only when the overlap has positive length.1
| Input field | Meaning and representation | Accepted input |
|---|---|---|
| text | text. | Text; at most 8,192 UTF-16 code units, subject to the grammar above |
| start | start. | Finite number |
| end | end. | Finite number |
| Output field | Interpretation |
|---|---|
| result | Object containing the named outputs below. |
| result.intersections | The intersections list in the ordering and representation described above. |
{
"input": {
"text": "ab\ncd",
"start": 1,
"end": 4
},
"output": {
"result": {
"intersections": [
{
"line": 1,
"start": 1,
"end": 2
},
{
"line": 2,
"start": 3,
"end": 4
}
]
}
}
}Limitations and assumptions
- Newline characters and empty intersections are excluded, so an empty selection returns no rows. Line numbers are one-based while all span offsets use zero-based UTF-16 units.
- 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.