Description
Tokenize a restricted CSS declaration list with UTF-16 source spans and balanced strings/groups; comments and escaped property identifiers are unsupported.
CSS combines token syntax, property-specific value rules and layout/cascade processing. These are separate layers: splitting a declaration does not establish that its value is valid, and arithmetic on resolved lengths does not perform browser layout. Each tool here handles an explicit numeric representation or a stated lexical subset.
Tokenize a restricted CSS declaration list with UTF-16 source spans and balanced strings/groups; comments and escaped property identifiers are unsupported.
When to use this tool
Use this tool to tokenize a restricted CSS declaration list with UTF-16 source spans and balanced strings/groups; comments and escaped property identifiers are unsupported.
How to use the tool and how it works
- Enter text using the input definitions below.
- Run the operation. Resolve malformed-input errors before interpreting the result.
- Read result.declarations. Interpret signs, units, ordering and null values using the rules below.
Split the balanced comment-free list at top-level semicolons, skip empty pieces, and split each declaration at its first top-level colon. Normalize names and terminal !important flags, retaining each raw piece’s start/end UTF-16 offsets.1, 2
| Input field | Meaning and units | Accepted input |
|---|---|---|
| text | CSS-subset text to parse under the operation’s stated grammar. | Text, at most 8,192 UTF-16 code units; the stated grammar and narrower limits also apply. |
| Output field | Interpretation |
|---|---|
| result | Object containing the fields below. |
| result.declarations | Source-order declaration records including names, values, importance and raw piece spans. |
{
"input": {
"text": "a:1;b:2"
},
"output": {
"result": {
"declarations": [
{
"name": "a",
"value": "1",
"important": false,
"start": 0,
"end": 3
},
{
"name": "b",
"value": "2",
"important": false,
"start": 4,
"end": 7
}
]
}
}
}Limitations and assumptions
- Spans include the declaration piece’s surrounding whitespace but exclude its semicolon. Escaped property names and full CSS error recovery are unsupported.
- Lengths and times must already be resolved to consistent numeric units. Lexical helpers intentionally support smaller grammars than a full browser CSS parser; malformed supported-subset input causes an error.
- Every declared top-level input is required and unknown 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 within the absolute safe-integer magnitude; exact larger integers use decimal text. Source positions are zero-based UTF-16 offsets and span ends are exclusive unless a different convention is explicitly stated.
Alternative or Complementary methods
Use a full CSS parser or browser style/layout APIs when escape handling, error recovery, computed styles or the full cascade matter. These tools expose focused transformations and audits of supplied data.
References
Similar or alternative tools
- CSS Animation List Slot Pairing
Pair explicit animation names with cyclic duration/delay lists; no shorthand parsing, timing interpolation or special all/none expansion.
- CSS Duplicate Property Table
Audit declaration property duplicates with ordinary ASCII property folding and case-sensitive custom-property names; not a cascade engine.