Description
Select positive explicit HTTP qualities at or above a supplied unit threshold; q=0 remains excluded even at threshold zero.
HTTP field names are case-insensitive, while values follow each field’s own grammar. Repeated occurrences sometimes form lists but cannot always be combined. Quoted values, optional spaces/tabs and quality weights need their own treatment; the tools here use explicit field records or a stated text subset.1
Select positive explicit HTTP qualities at or above a supplied unit threshold; q=0 remains excluded even at threshold zero.
When to use this tool
Use this tool to select positive explicit HTTP qualities at or above a supplied unit threshold; q=0 remains excluded even at threshold zero.
How to use the tool and how it works
- Enter qualitiesJson, threshold using the field definitions below. For JSON text, serialize the explicit records in the shown shape.
- Run the operation. Correct input errors before interpreting an output.
- Read result.selected. Use the ordering, boundary rules and absence conditions described below.
Validate explicit token/q records and a threshold in [0,1]. Select records with q greater than zero and at least the threshold, retaining order.2
| Input field | Meaning and units | Accepted input |
|---|---|---|
| qualitiesJson | JSON array of {token, q} records; q is from 0 through 1 in thousandth steps. Token uses HTTP token syntax. | Text, at most 8,192 UTF-16 code units; the operation’s grammar also applies. |
| threshold | Quality threshold from 0 through 1; q = 0 remains excluded. | A finite number satisfying the operation’s stated comparisons. |
These are the decoded structures used in the example’s JSON text fields. Supply the corresponding serialized JSON strings as input.
{
"qualitiesJson": [
{
"token": "a",
"q": 0
},
{
"token": "b",
"q": 0.5
},
{
"token": "c",
"q": 1
}
]
}| Output field | Interpretation |
|---|---|
| result | Object containing the named fields below. |
| result.selected | Positive-quality records meeting the supplied threshold, in input order. |
{
"input": {
"qualitiesJson": "[{\"token\":\"a\",\"q\":0},{\"token\":\"b\",\"q\":0.5},{\"token\":\"c\",\"q\":1}]",
"threshold": 0.5
},
"output": {
"result": {
"selected": [
{
"token": "b",
"q": 0.5
},
{
"token": "c",
"q": 1
}
]
}
}
}Limitations and assumptions
- A zero threshold still excludes q = 0; no media-range precedence or header parsing occurs.
- Explicit header records have name and value strings. Names must use token syntax; supported value code units are tab or 32–255 excluding DEL. Byte budgets use that single-byte representation, not UTF-8 or HTTP/2 compression.
- Every declared top-level input field is required and unexpected fields are rejected. Ordinary strings are limited to 8,192 UTF-16 code units and lists to 128 entries, with tighter operation-specific bounds where stated. JSON text has bounded nesting and node counts.
- Numeric outputs must be finite and no larger in absolute magnitude than the safe-integer limit; operations returning exact large integers use decimal text. Positions are zero-based and spans end exclusively unless the operation explicitly states a different convention.
Alternative or Complementary methods
Choose field-specific parsing and combination rules rather than applying one policy to every header. Preserve occurrence order and use a full HTTP implementation for message framing and protocol-level decisions.
References
-
RFC 9110: HTTP Semantics — RFC Editor
-
Tool behavior and example: HTTP Quality Threshold Selector — tool.io
Similar or alternative tools
- HTTP Header Occurrence Selector
Select all explicit HTTP header occurrences by a token-name bank under case-insensitive lookup, retaining source indexes and original spellings.
- HTTP Quality Exclusion Partitioner
Partition explicitly supplied token quality weights into q=0 exclusions and positive candidates; validates HTTP thousandth precision, no negotiation inference.