Description
Return leading run length and its parity for a selected bit value.
Bit positions are usually counted from the least-significant bit, while a displayed binary string has its own left-to-right indexing convention. Masks, fields and parity predicates describe a selected region or pattern; local agreement does not validate a complete encoded record.
Return leading run length and its parity for a selected bit value.
When to use this tool
Use Bitmask Leading Run Parity when checking the stated mask, field, parity or bit-index convention.
How to use the tool and how it works
- Enter word, width, bitValue. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read runLength, odd. Inspect odd before interpreting the associated values.
Return leading run length and its parity for a selected bit value. Require width 1..256, bitValue zero/one and bounded exact word; scan from the most-significant in-width bit until a mismatch, odd tests runLength modulo two.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| word | Word | Required. Text; maximum UTF-16 length 8192. Integer syntax: optional + or - and 1-128 decimal digits; leading zeros accepted. Apply the sign restriction above. |
| width | Width under the stated bit, interval or geometry convention; apply the field-specific units and bounds. | Required. Safe integer; minimum 1; maximum 256. |
| bitValue | Bit Value | Required. Safe integer. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| runLength | Run Length | Required. Safe integer. |
| odd | Parity of the leading selected-value run length, not parity of the complete word. | Required. Boolean. |
{
"input": {
"word": "240",
"width": 8,
"bitValue": 1
},
"output": {
"runLength": 4,
"odd": false
}
}Limitations and assumptions
- Leading zeros count within the declared width; this is run parity, not parity of the entire word.
- 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.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Choose an explicit bit order, word width and missing-position policy; use the complete record format and appropriate parsing or checksum methods for full validation.
References
Similar or alternative tools
- Bitmask Lane Parity Contribution
Return selected-lane set-bit parity and selected pattern.
- Parity Change From Toggle
Return parity after supplied bit toggles, canceling repeated positions.