Description
Count the UTF-8 bytes of an explicit comment prefix without language-specific comment parsing.
Parsing depends on the chosen grammar, character encoding, offset unit, and treatment of escapes and delimiters. UTF-16 code-unit positions, Unicode code points, and UTF-8 byte offsets are not interchangeable. A boundary or token check supplies one part of a parser rather than validating an entire file.
Count the UTF-8 bytes of an explicit comment prefix without language-specific comment parsing.
When to use this tool
Use Comment Prefix Byte Count when you need the stated token boundary, offset, prefix, delimiter, or count component inside a larger parsing workflow.
How to use the tool and how it works
- Enter prefix. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read utf8Bytes. Use the output convention below.
Return utf8Bytes as the UTF-8 encoded length of prefix.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| prefix | Supplied text prefix; no full document context is inferred. | Required. Text; maximum UTF-16 length 8192. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| utf8Bytes | Encoded byte length, with isolated-surrogate replacement. | Required. Safe integer. |
{
"input": {
"prefix": "// "
},
"output": {
"utf8Bytes": 3
}
}Limitations and assumptions
- No comment syntax is recognized. Supplementary characters use multiple bytes and isolated UTF-16 surrogates are encoded with replacement; byte length differs from code-unit or grapheme count.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
Alternative or Complementary methods
Choose a parser for the intended complete grammar when context, nesting, encodings, or semantic validation matters. Keep byte, code-unit, and code-point coordinates explicit when combining results.
References
Similar or alternative tools
- Bracket Depth Prefix Balance
Inspect literal bracket prefix counts without handling strings, comments or escapes.
- CSV Quoted Newline Byte Offset
For every LF code unit return the UTF-8 byte length of the prefix before it as newlineByteOffsets, measured from the start of the supplied field including its opening quote.