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• About
• Status
  • Breaking changes
• Installation
• Dependencies
• Usage examples
• API
• Authors
• License

About

Closed/open/semi-open interval data type, queries & operations.

Supports point & range queries and set operations with other intervals (union, intersection, difference).

Furthermore, a parser for ISO 80000-2 / ISO 31-11 interval notation is provided. See parse() for details.

Status

STABLE - used in production

Search or submit any issues for this package

Breaking changes

With version 3.0.0 the API has been updated to be largely functional rather than OOP, with all static (and most instance) Interval methods converted into standalone functions. The only class methods remaining are to implement these standard interfaces: ICompare, IContains, ICopy, IEquiv.

Installation

yarn add @thi.ng/intervals

ESM import:

import * as i from "@thi.ng/intervals";

Browser ESM import:

<script type="module" src="https://esm.run/@thi.ng/intervals"></script>

JSDelivr documentation

For Node.js REPL:

const i = await import("@thi.ng/intervals");

Package sizes (brotli'd, pre-treeshake): ESM: 1.61 KB

Dependencies

• @thi.ng/api
• @thi.ng/checks
• @thi.ng/dlogic
• @thi.ng/errors

Note: @thi.ng/api is in most cases a type-only import (not used at runtime)

Usage examples

One project in this repo's /examples directory is using this package:

| Screenshot | Description | Live demo | Source | |:---------------------------------------------------------------------------------------------------------------------|:-----------------------------------------------------------------|:----------------------------------------------------|:---------------------------------------------------------------------------------| | | Interactive pixel sorting tool using thi.ng/color & thi.ng/pixel | Demo | Source |

API

Generated API docs

import * as i from "@thi.ng/intervals";

// [0 .. +∞] (fully closed)
const a = i.withMin(0);

// [-∞ .. 1) (open on RHS)
const b = i.withMax(1, true);

const c = i.intersection(a, b);
c.toString();
// [0 .. 1)

// parse from string
i.interval("[0 .. 1)")
// Interval { l: 0, r: 1, lopen: false, ropen: true }

i.contains(c, 1);
// or
c.contains(1);
// false (because interval is open on RHS)

i.contains(c, 0.999999);
// true

// classify interval relative to point (true if RHS < x)
i.isBefore(c, -1)
// false

i.isBefore(c, 1)
// true

// classify interval relative to point (true if LHS > x)
i.isAfter(c, -1);
// true

i.isAfter(c, 1);
// false

// grow interval to include 2 => [0 ... 2]
const c2 = i.include(c, 2);

// sort order: LHS -> RHS
i.compare(c, c2);
// -1

// classify WRT given interval arg
// returns Classifier enum
i.classify(c, i.infinity());
// 3 (aka Classifier.SUBSET)

// create transformed interval
// (here scaled around centroid)
i.transform(c, (x) => x + (x - i.centroid(c)) * 2).toString();
// [-1 .. 2)

// iterator of decimated interval values
[...i.values(c, 0.25)];
// [ 0, 0.25, 0.5, 0.75 ]

// close RHS
c.ropen = false;

// iterator of 0.25-spaced values in interval
[...i.values(c, 0.25)];
// [ 0, 0.25, 0.5, 0.75, 1 ] => now includes 1

// iterator of n equidistant samples
[...i.samples(c, 4)]
// [ 0, 0.3333333333333333, 0.6666666666666666, 1 ]

// constrain values to interval (taking openness into account)
i.max(i.interval("(0..1)"), -2)
// 0.000001

// if given value is outside interval, uses opt epsilon value
// to return closest inside value (default: 1e-6)...
i.max(i.interval("(0..1)"), -2, 1e-3)
// 0.001

i.min(i.interval("(0..1)"), 2, 1e-3)
// 0.999

// clamp on both sides
i.clamp(i.interval("[0..1)"), -2, 1e-3)
// 0
i.clamp(i.interval("[0..1)"), 2, 1e-3)
// 0.999

Authors

• Karsten Schmidt (Main author)
• @oljeger

If this project contributes to an academic publication, please cite it as:

@misc{thing-intervals,
  title = "@thi.ng/intervals",
  author = "Karsten Schmidt and others",
  note = "https://thi.ng/intervals",
  year = 2018
}

License

© 2018 - 2026 Karsten Schmidt // Apache License 2.0