UTF-16 Offset to Line and Column
Map a UTF-16 offset to one-based line/column with CRLF treated as one line separator; offsets inside CRLF retain their physical column.
Description
Map a UTF-16 offset to one-based line/column with CRLF treated as one line separator; offsets inside CRLF retain their physical column.
A zero-based UTF-16 offset can be displayed as a one-based line and column. Newline interiors need care because CRLF uses two code units for one line break.
When to use this tool
Map a UTF-16 offset to one-based line/column with CRLF treated as one line separator; offsets inside CRLF retain their physical column.
- Prepare the supplied text, offset 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, offset. 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.line, result.column, result.insideCrLf. Interpret false, null and empty lists using the distinctions below; they can be valid outputs.
Choose the last parsed line whose start is no greater than offset. Return its one-based number and offset-lineStart+1, and flag insideCrLf when offset lies between that line's CR and LF.1
| Input field | Meaning and representation | Accepted input |
|---|---|---|
| text | text. | Text; at most 8,192 UTF-16 code units, subject to the grammar above |
| offset | offset. | Integer from 0 to text.length inclusive |
| Output field | Interpretation |
|---|---|
| result | Object containing the named outputs below. |
| result.line | The line value under the stated formula or text convention. |
| result.column | The column value under the stated formula or text convention. |
| result.insideCrLf | Flag for inside cr lf under the exact condition described above. |
{
"input": {
"text": "a\r\nb",
"offset": 3
},
"output": {
"result": {
"line": 2,
"column": 1,
"insideCrLf": false
}
}
}Limitations and assumptions
- An offset at the next line start belongs to that next line. A CRLF interior column can exceed the content-end column, so the reverse line/column converter cannot represent every flagged position.
- 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 and Column to UTF-16 Offset
Map one-based logical line/UTF-16 content column to offset; columns inside separators are intentionally not accepted.
- Code Point Index to UTF-8 Byte Offset
Convert zero-based Unicode scalar index to UTF-8 byte offset; reject unpaired surrogates and count scalars rather than grapheme clusters.