https://github.com/hackergrrl/bisecting-between
:hocho: Produces a unique value that sorts between two other given values.
https://github.com/hackergrrl/bisecting-between
Last synced: 6 months ago
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:hocho: Produces a unique value that sorts between two other given values.
- Host: GitHub
- URL: https://github.com/hackergrrl/bisecting-between
- Owner: hackergrrl
- Created: 2016-03-02T20:51:45.000Z (over 9 years ago)
- Default Branch: master
- Last Pushed: 2016-07-05T18:22:38.000Z (almost 9 years ago)
- Last Synced: 2024-12-28T21:44:25.007Z (6 months ago)
- Language: JavaScript
- Homepage:
- Size: 8.79 KB
- Stars: 11
- Watchers: 2
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# bisecting-between
> Produces a unique value that sorts between two other given values.
## background
This module makes it easy to select a unique value between any two bisecting
numbers, where there are always unique values between any two such numbers. Read
more about [bisecting numbers
here](https://github.com/noffle/bisecting-numbers).
This module is inspired by Dominic Tarr's
[between](https://github.com/dominictarr/between) module. This module aims to
offer an equivalent API with the same key property of being commutative (i.e.
inserting between two items does not change the positions of nodes later in a
created list).
`between` is great, but the length of the identifier in the case of consecutive appends
and prepends is very expensive, growing linearly:
```js
var n = between(between.lo, between.hi)
for (var i=0; i < 100; i++) {
if (i % 10 === 0) {
console.log(n)
}
n = between(n, between.hi)
}
```
```
V
zy
zzzs
zzzzzV
zzzzzzy
zzzzzzzzs
zzzzzzzzzzV
zzzzzzzzzzzy
zzzzzzzzzzzzzs
zzzzzzzzzzzzzzzV
```
`bisecting-between` optimizes for minimizing the growth of string
length in the append and prepend cases, growing logarithmically:
```
0
A
K
U
e
o
y
18
1I
1S
```
This trade-off makes random insertions more growth expensive instead. In
certain applications (like text editors), long appends and prepends are far more
common.
## example
```js
> var between = require('bisecting-between')()
> between()
'0'
> between('A', 'B')
'A.0'
> between('A.0', between.hi)
A.1
> between('E.C', 'F')
'E.D'
```
## api
### var between = BisectingBetween(alphabet)
Returns a function (that generates values between two other values) across the
given string `alphabet` (where `alphabet.charAt(0)` is the zero value, the next
is 1, etc). If not provided, the alphabet is the string
`'0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'`.
### between(lo, hi)
Returns a [bisecting number](https://github.com/noffle/bisecting-numbers) that
is between two other bisecting numbers that will always sort as between `lo` and
`hi`.
### between.lo, between.hi
Fixed values that symbolize the absolute lowest and highest, respectively.
## install
With [npm](https://npmjs.org/) installed, run
```
$ npm install bisecting-between
```
## license
ISC