Byte Array Field Slice Table

Slice explicitly bounded half-open byte field spans; overlaps remain allowed and observable.

Description

Slice explicitly bounded half-open byte field spans; overlaps remain allowed and observable.

A byte-field slice table can retain positions as well as the selected bytes. Fields may intentionally overlap.

When to use this tool

Slice explicitly bounded half-open byte field spans; overlaps remain allowed and observable.

Prepare the supplied bytes, spansJson 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 bytes, spansJson. 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.fields. Interpret false, null and empty lists using the distinctions below; they can be valid outputs.

Parse spansJson as ordered integer [start,end] pairs within bytes length. Return each span and the corresponding half-open slice in supplied order.^[1]

Input field	Meaning and representation	Accepted input
bytes	bytes.	List of integers from 0 to 255; at most 128 bytes
spansJson	JSON text, entered as one text field. The decoded structure is illustrated below; it is not a separate file.	Text

For the JSON text fields, the following decoded structures show the example records before they are serialized into input strings. Keep field names, list nesting and value types as shown.

json

[
  {
    "field": "spansJson",
    "decoded": [
      [
        1,
        3
      ]
    ]
  }
]

Output field	Interpretation
result	Object containing the named outputs below.
result.fields	The fields list in the ordering and representation described above.

json

{
  "input": {
    "bytes": [
      10,
      20,
      30
    ],
    "spansJson": "[[1,3]]"
  },
  "output": {
    "result": {
      "fields": [
        {
          "start": 1,
          "end": 3,
          "bytes": [
            20,
            30
          ]
        }
      ]
    }
  }
}

Limitations and assumptions

Zero-length and overlapping slices are accepted. No field schema, endian conversion or coverage requirement is inferred.
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.
Lists are limited to 128 entries. JSON text must meet bounded size and depth checks, and numeric outputs beyond the safe finite magnitude are rejected. Exact large integers use decimal strings.
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

Retain the field-width, bit-index and byte-order conventions when combining operations. Slicing, escaping, permutation and alignment are separate transforms; none supplies a complete framing or cryptographic protocol.

References

Tool behavior and example: Byte Array Field Slice Table — tool.io

Similar or alternative tools

Byte Array Escaping Inverse
Explicit byte-stuffing inverse with escape followed by reserved byte XOR 0x20; escape and sentinel must differ.
Byte Array Escaping Transform
Explicit byte-stuffing transform with escape followed by reserved byte XOR 0x20; escape and sentinel must differ.