https://github.com/llasram/hier-set

A Clojure hierarchical set.
https://github.com/llasram/hier-set

Last synced: about 2 months ago
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A Clojure hierarchical set.

• Host: GitHub
• URL: https://github.com/llasram/hier-set
• Owner: llasram
• License: epl-1.0
• Created: 2012-03-30T12:17:48.000Z (over 12 years ago)
• Default Branch: master
• Last Pushed: 2020-09-24T12:03:36.000Z (about 4 years ago)
• Last Synced: 2024-10-05T08:18:17.501Z (3 months ago)
• Language: Clojure
• Homepage:
• Size: 137 KB
• Stars: 7
• Watchers: 2
• Forks: 7
• Open Issues: 2
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

• awesome-clojure - Hierarchical set

README

        
# hier-set

Library providing a "hierarchical set" data structure.  The provided data

structure is set of elements with a defined hierarchical relationship.  An

element is considered to be in the set either if it is provided as a primary

set member or if it is a descendant of any such element.  Lookup in the set not

only determines set membership, but also finds all primary set members which

are ancestors of the lookup element.

The hierarchical relationship is defined by the element sort-order and a

separate containment predicate, with the following constraints:

* elements must sort prior to any descendants; and

* elements must contain all elements which sort between themselves and any

  descendant.

This is sufficient to represent simple hierarchical systems where the hierarchy

is implicit in the entities involved, such as the Java package system,

hierarchical filesystems, or IP networks.  It is inappropriate for modeling

complex, ad hoc hierarchies, such as the relationships between classes with

multiple inheritance.

## Usage

Add `hier-set` to the `:dependencies` list in your

[Leiningen](https://github.com/technomancy/leiningen) `project.clj`:

```clj

[hier-set "1.1.2"]

```

Primary usage is then through the `hier-set` and `hier-set-by` constructor

functions in the `hier-set.core` namespace.  In addition to set lookup as

described above, the `hier-set.core/ancestors` and `hier-set.core/descendants`

functions also provide access to lazy sequences of the ancestors and

descendants respectively of a provided key.

## Example

A trivial example:

```clj

(ns example.hier-set

  (:require [hier-set.core :as hs])

  (:use [hier-set.core :only [hier-set]])

(def with-starts? #(.startsWith %2 %1))

(def hs (hier-set with-starts? "ack" "foo" "foo.bar" "quux")

(get hs "bar")              ;;=> nil

(get hs "foo")              ;;=> ("foo")

(get hs "foo.bar.baz")      ;;=> ("foo.bar" "foo")

(hs/ancestors hs "bar")     ;;=> ()

(hs/ancestors hs "foo.baz") ;;=> ("foo")

(hs/descendants hs "foo")   ;;=> ("foo" "foo.bar")

```

## License

Copyright © 2012, 2014 Marshall Bockrath-Vandegrift.

Distributed under the Eclipse Public License either version 1.0 or (at

your option) any later version.