Trailing Space Span Finder
Find half-open UTF-16 spans of trailing ASCII spaces/tabs without treating newline characters as spaces.
Description
Find half-open UTF-16 spans of trailing ASCII spaces/tabs without treating newline characters as spaces.
Trailing horizontal whitespace can be hard to see in an editor. Returning source spans lets a caller highlight it without changing the document.
When to use this tool
Find half-open UTF-16 spans of trailing ASCII spaces/tabs without treating newline characters as spaces.
- Prepare the supplied text 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. 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.spans. Interpret false, null and empty lists using the distinctions below; they can be valid outputs.
For each parsed line, match a final nonempty run of ASCII spaces or tabs and return its one-based line number and half-open UTF-16 start/end offsets.1
| Input field | Meaning and representation | Accepted input |
|---|---|---|
| text | text. | 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.spans | The spans list in the ordering and representation described above. |
{
"input": {
"text": "a \n b\t"
},
"output": {
"result": {
"spans": [
{
"line": 1,
"start": 1,
"end": 2
},
{
"line": 2,
"start": 5,
"end": 6
}
]
}
}
}Limitations and assumptions
- Other Unicode whitespace is not selected. Newlines are excluded and the tool does not remove spans; a wholly space/tab line can be selected in full.
- 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
- Line Span Intersection Tool
Intersect a half-open UTF-16 selection with line-content spans; exclude separators and zero-length contacts.
- Multiple Span Edit Applier
Apply nonoverlapping half-open UTF-16 edits in original coordinates; duplicate starts and overlapping spans are rejected.