EDTFSet

Represents "one of a set" of dates (Level 2).

Interface

interface EDTFSet extends EDTFBase {
  type: 'Set';
  values: (EDTFDate | EDTFDateTime | EDTFSeason)[];
  earlier?: boolean;
  later?: boolean;
}

Properties

Property	Type	Description
type	'Set'	Type discriminator
values	Array	Values in the set
earlier	boolean?	True if set includes earlier dates
later	boolean?	True if set includes later dates

Inherited from EDTFBase

Property	Type	Description
level	2	Always Level 2
edtf	string	Original EDTF string
precision	Precision	Based on set contents
min	Date	Earliest possible date
max	Date	Latest possible date

Usage

Sets are enclosed in square brackets [] and represent "one of these":

import { parse, isEDTFSet } from '@edtf-ts/core';

const result = parse('[1667,1668,1670..1672]');

if (result.success && isEDTFSet(result.value)) {
  const set = result.value;

  console.log(set.values.length);  // Number of values in set
  for (const value of set.values) {
    console.log(value.edtf);
  }
}

Set Syntax

Simple Set

A comma-separated list of dates:

parse('[1667,1668,1669]');
// One of: 1667, 1668, or 1669

Set with Ranges

Use .. to specify ranges within a set:

parse('[1667,1668,1670..1672]');
// One of: 1667, 1668, 1670, 1671, or 1672

Earlier Values

Use .. at the start to include all earlier values:

parse('[..1760-12]');
// December 1760 or earlier

const result = parse('[..1760-12]');
if (result.success && isEDTFSet(result.value)) {
  console.log(result.value.earlier);  // true
}

Later Values

Use .. at the end to include all later values:

parse('[1760-12..]');
// December 1760 or later

const result = parse('[1760-12..]');
if (result.success && isEDTFSet(result.value)) {
  console.log(result.value.later);  // true
}

Examples

// Years
parse('[1667,1668,1669]');

// Months
parse('[2004-01,2004-02,2004-03]');

// Days
parse('[2004-06-01,2004-06-02,2004-06-03]');

// Mixed precision
parse('[1667,1668-12]');

// With ranges
parse('[1760..1765,1770]');

// Open-ended
parse('[..1760]');    // 1760 or earlier
parse('[1760..]');    // 1760 or later

Semantic Meaning

Sets express "one of" semantics:

const result = parse('[1667,1668,1669]');
// Meaning: The event occurred in ONE of 1667, 1668, or 1669
// (but we don't know which one)

This is different from Lists which express "all of" semantics.

Min/Max Bounds

The min and max properties span the entire set:

const result = parse('[1667,1668,1672]');
if (result.success) {
  console.log(result.value.min);  // 1667-01-01
  console.log(result.value.max);  // 1672-12-31
}

Type Guard

import { isEDTFSet } from '@edtf-ts/core';

const result = parse(input);
if (result.success && isEDTFSet(result.value)) {
  // TypeScript knows result.value is EDTFSet
  console.log(result.value.values);
}

Related

• EDTFList - "All of" semantics (curly braces)