Description
Audit explicit iCalendar BEGIN/END boundary tokens using a stack, retaining mismatches and unclosed components; not complete property/component semantic validation.
iCalendar separates content-line framing, property values, parameters and component nesting. TEXT escaping protects separators, while line folding is based on encoded octets. DATE, floating time, UTC and named-zone representations carry different information; a token-level operation does not resolve a timezone or expand recurrence rules.1
Audit explicit iCalendar BEGIN/END boundary tokens using a stack, retaining mismatches and unclosed components; not complete property/component semantic validation.
When to use this tool
Use this tool to audit explicit iCalendar BEGIN/END boundary tokens using a stack, retaining mismatches and unclosed components; not complete property/component semantic validation.
How to use the tool and how it works
- Enter boundaries using the field definitions below.
- Run the operation. Correct input errors before interpreting an output.
- Read result.valid, result.errors, result.unclosed. Use the ordering, boundary rules and absence conditions described below.
Read BEGIN/END boundaries case-insensitively with a stack. Pop matching ends; report mismatches without popping and return remaining unclosed components.2
| Input field | Meaning and units | Accepted input |
|---|---|---|
| boundaries | Explicit BEGIN:name and END:name tokens in source order. | Dense list of at most 128 strings, each at most 8,192 UTF-16 code units. |
| Output field | Interpretation |
|---|---|
| result | Object containing the named fields below. |
| result.valid | Whether no boundary mismatch or unclosed component remains. |
| result.errors | END-boundary mismatches with occurrence index, expected name and observed name. |
| result.unclosed | Remaining open component names in stack order. |
{
"input": {
"boundaries": [
"BEGIN:VCALENDAR",
"BEGIN:VEVENT",
"END:VCALENDAR"
]
},
"output": {
"result": {
"valid": false,
"errors": [
{
"index": 2,
"expected": "VEVENT",
"observed": "VCALENDAR"
}
],
"unclosed": [
"VCALENDAR",
"VEVENT"
]
}
}
}Limitations and assumptions
- Boundary token syntax errors raise an error; structural mismatch is a valid result with valid false.
- Content spans use zero-based UTF-16 offsets; fold limits use UTF-8 bytes including the continuation space. Token helpers handle the stated subset only, without a timezone database, recurrence engine or calendar import.
- 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
Keep content-line syntax, value escaping and timezone interpretation separate. Use a complete iCalendar implementation for recurrence expansion, timezone transitions and property-specific validation.
References
Similar or alternative tools
- iCalendar Content Line Name Parameter Split
Split an unfolded iCalendar content line at its unquoted first colon and semicolon parameter boundaries; value remains opaque, raw parameters retain quote-aware spelling, no RFC 6868 decoding or component validation.
- iCalendar Content Line Record Formatter
Format one unfolded iCalendar content line from explicit raw already-encoded parameter/value tokens; rejects CRLF injection, no automatic TEXT escaping or RFC 6868 parameter encoding.