Description
Take an exact logical suffix after dropping a prefix without expanding or automatically compacting source runs; count beyond total rejects.
Run-length records represent repeated observations without expanding them. Each record pairs a literal string value with a positive exact integer length; neighboring equal values can be valid but noncompact. Expanded offsets count observations rather than run records, and half-open ranges include their start while excluding their end.
Take an exact logical suffix after dropping a prefix without expanding or automatically compacting source runs; count beyond total rejects.
When to use this tool
Use this tool to take an exact logical suffix after dropping a prefix without expanding or automatically compacting source runs; count beyond total rejects.
How to use the tool and how it works
- Enter runsJson, count using the definitions below. Serialize JSON text fields in the decoded shape shown below.
- Run the operation. Resolve input-format errors before interpreting an output.
- Read result.runs, using the stated boundary, ordering, sign and absence conventions.
Require 0≤count≤expanded total and slice [count,total), retaining original run boundaries and positive pieces.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| runsJson | JSON array of {value,length} records: literal string value and positive exact decimal-string length. | Text, at most 8,192 UTF-16 code units; narrower grammar/range rules also apply. |
| count | Number of expanded observations to take/drop as exact decimal text, from zero through total. | Text, at most 8,192 UTF-16 code units; narrower grammar/range rules also apply. |
These decoded structures show the examples inside JSON text fields. Supply their serialized JSON strings as input.
{
"runsJson": [
{
"value": "a",
"length": "3"
},
{
"value": "a",
"length": "2"
},
{
"value": "b",
"length": "4"
}
]
}| Output field | Interpretation |
|---|---|
| result | Object containing the fields below. |
| result.runs | Resulting {value,length} records, with exact positive decimal lengths and the stated compaction policy. |
{
"input": {
"runsJson": "[{\"value\": \"a\", \"length\": \"3\"}, {\"value\": \"a\", \"length\": \"2\"}, {\"value\": \"b\", \"length\": \"4\"}]",
"count": "4"
},
"output": {
"result": {
"runs": [
{
"value": "a",
"length": "1"
},
{
"value": "b",
"length": "4"
}
]
}
}
}Limitations and assumptions
- Dropping the complete total returns an empty sequence; out-of-range counts reject instead of clamping.
- Run records contain string value and positive length as exact decimal integer text. Lengths and offset inputs support up to 256 decimal digits before operation-specific checks; results use decimal text and do not expand the repeated observations.
- Every declared outer field is required and unknown outer fields are rejected. Strings and JSON text have size limits, lists are bounded to 128 entries, and JSON nesting/node counts are bounded. Tighter operation-specific bounds stated above take precedence.
- Ordinary numeric outputs must be finite and within safe-integer magnitude. Exact large lengths/counts use decimal strings. Original record indexes and code-unit positions are zero-based; span ends are exclusive unless stated otherwise.
Alternative or Complementary methods
Use compaction for a canonical adjacent-run layout and boundary-aware operations when provenance matters. Retain exact decimal lengths rather than converting long totals to floating-point numbers.
References
Similar or alternative tools
- Run Length Record Prefix Take
Run lengths are positive exact integer decimal strings with literal string values, never expanded; take an exact logical prefix without expanding or automatically compacting source runs; count beyond total rejects.
- Run Length Record Adjacent Compaction
Run lengths are positive exact integer decimal strings with literal string values, never expanded; compact adjacent exactly equal values by summing exact lengths, not global deduplication.