randomness 0.1.0

randomness: ^0.1.0 copied to clipboard

Random strings, numbers. RNG with weights. Cryptographically secure options.

Getting started #

Add randomness: ^0.1.0 to pubspec.yaml and paste import 'package:randomness/randomness.dart';

Usage #

Random Numbers #

The following are equivalent to Random().nextInt(5). The Sets include and exclude can have points, or intervals with square brackets.

Randomness.randomInt(include: {0,1,2,3,4})
Randomness.randomInt(include: {[0,4]})
Randomness.randomInt(include: {0,1,[2,4]})
Randomness.randomInt(include: {[0,100]}, exclude: {5,[6,100]})

default is 1 to 1000 inclusive:

Randomness.randomInt()
//681

Cryptographically secure #

1 through 100 inclusive, cryptographically secure:

Randomness.randomInt(include: {[1,100]}, cryptographicallySecure: true)
//30

random double, cryptographically secure:

Randomness.randomDouble(min: -3, max: -1, cryptographicallySecure: true)
//-1.7392379311552753

Weighted probability #

Give weights. 2/3 chance of 0, 1/3 chance of 1, 2, 3, or 4:

Randomness.randomInt(include: {0,1,2,3,4}, weights: {0: 2, everythingElse: 1})

Ignores included elements not in weights. This will always give 0:

Randomness.randomInt(include: {0,1,2,3,4}, weights: {0:1})

Random Strings #

Default length is 10. Default doesn't generate spaces:

Randomness.randomString()
/*
-((f)4$=r4
*/

Strings include numbers, uppercase, lowercase, symbols, and spaces. This will generate numbers and spaces.

Randomness.randomString(length: 100, includeSpaces: true, excludeSymbols: true, excludeUppercase: true, excludeLowercase: true)
//3828 5491 304 0065273406 9 54745452 657207928  4469 078258338317555697369931555479 28159170 32561895

cryptographically secure String with half A's:

Randomness.randomString(length: 50, cryptographicallySecure: true, weights: {'A': 1, everythingElse: 1})
//ACAAAAAABAAAp3litAAAAAAwAAAAAAl$AEe4IAAtAA*A#)AA6[

random element from List, weights may not work with certain data types:

Randomness.randomFromList([{1,2}, 'a', 3], weights: {'a': 1, everythingElse: 1}, cryptographicallySecure: true)
//a

Random n-digit number. Returns a String since parsing would ignore 0's at the beginning, and cannot parse very large integers. The following gives average of half 4's, half 5, 6, 7, 8, or 9:

Randomness.randomNDigits(numberOfDigits: 100, excludeDigits: {0,1,2,3}, weights: {4:1, everythingElse:1})
//4944445978444496449444486964474547474444767454648456444448886854446774444444648654448475857444494895

Some helper functions #

Returns Map of occurrences of elements in a List:

countElementsInList([1, 2, 3, 1.0, 1])
//{1: {type: int, count: 2}, 1.0: {type: double, count: 1}, 2: {type: int, count: 1}, 3: {type: int, count: 1}}
countElementsInList([1, 2, 3, 1.0, 1], includeIndexes: true)
//{1: {type: int, count: 2, indexes: [0, 4]}, 1.0: {type: double, count: 1, indexes: [3]}, 2: {type: int, count: 1, indexes: [1]}, 3: {type: int, count: 1, indexes: [2]}}

Returns a List of all elements in a given range inclusive:

getRange([1,10])
//[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

Returns shuffled List, cryptographically secure option:

shuffleList([1, 2, 3, 1.0, 1], cryptographicallySecure: true)
//[3, 2, 1.0, 1, 1]

printMapElements or printListElements for each element on new line

printMapElements:

List randomNums = [];
for(int i = 0; i < 100; i++){
randomNums.add(Randomness.randomInt(include: {0,1,2,3}, weights: {0:7, 1:1, 2:1, 3:1}));
}
Map results = countElementsInList(randomNums);
printMapElements(results);
/*
0: {type: int, count: 68}
1: {type: int, count: 14}
2: {type: int, count: 13}
3: {type: int, count: 5}
* */

printListElements:

printListElements([1,2,3]);
/*
1
2
3
*/