Bit String Mask Replacement
Replace bit positions only where an equal-width explicit mask has one; preserve all unmasked source positions.
Description
Replace bit positions only where an equal-width explicit mask has one; preserve all unmasked source positions.
A selection mask can replace chosen bit positions while leaving the others intact.
When to use this tool
Replace bit positions only where an equal-width explicit mask has one; preserve all unmasked source positions.
- Prepare the supplied bits, mask, replacement 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 bits, mask, replacement. 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.bits. Interpret false, null and empty lists using the distinctions below; they can be valid outputs.
Require bits, mask and replacement to be equal-length binary strings. At each mask one take the replacement bit; at each mask zero retain the original.1
| Input field | Meaning and representation | Accepted input |
|---|---|---|
| bits | bits. | Text; at most 8,192 UTF-16 code units, subject to the grammar above |
| mask | mask. | Text; at most 8,192 UTF-16 code units, subject to the grammar above |
| replacement | replacement. | 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.bits | The bits value under the stated formula or text convention. |
{
"input": {
"bits": "0000",
"mask": "1010",
"replacement": "1111"
},
"output": {
"result": {
"bits": "1010"
}
}
}Limitations and assumptions
- No bit packing, numeric endianness or automatic length adjustment is applied.
- Every bitstring is at most 128 characters and contains only literal zero and one.
- All declared input fields are required and unexpected top-level fields are rejected. Numbers must be finite; lists are limited to 128 entries and ordinary text fields to 8,192 UTF-16 code units, with tighter limits where stated.
- JSON text inputs must parse within bounded nesting and size limits. Numeric outputs outside the safe finite range are rejected; large exact integer results use decimal strings. Indexes and half-open spans are zero-based unless a rank is explicitly described as one-based.
Alternative or Complementary methods
Choose a packed-integer or textual-bit representation deliberately before combining operations. Preserve the documented index direction, width and exclusive boundaries; do not substitute a rank query for select.
References
Similar or alternative tools
- Bit String Contained Mask Check
Check exact equal-width bit-mask left containment in right at each string position; no implicit padding or integer coercion.
- Bit String Disjoint Mask Check
Check exact equal-width bit-mask disjointness at each string position; no implicit padding or integer coercion.