Utility
Utility provides functionality to improve dart code and make things faster and more easy.
Donate (Thanks for being kind)
If you find utility useful.
Table of Contents
Lets Get Started
1. Depend on it
Add this to your package's pubspec.yaml
file:
dependencies:
utility: 1.0.3
2. Install it
You can install packages from the command line:
with pub
:
$ pub get
with Flutter
:
$ flutter packages get
3. Import it
Now in your Dart
code, you can use:
import 'package:utility/utility.dart';
Usage
List Operations
slice
Creates a slice of list
from start
up to end
exclusive
.
var list = [1, 2, 3, 4];
//It slices the list elements and hence modifies this list
list.slice(2); // list = [3, 4]
// Do not want to alter the list object ??
var list = [1, 2, 3, 4];
//It creates copy of list slices the list elements and creates new list
list.slice(2); // list = [3, 4]
removeFirst();
Removes items at 0
position in the list.
var list = <int>[1, 5, 2, 4];
var firstItem = list.removeFirst();
// altered list = [5, 2, 4];
random
returns random value
from list. If list is empty then it returns null
var list = <int>[1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
var randomValue = list.random(); // 3 // 3 will not be removed from list
// If remove = true is passed as argument then polled random item will be removed from list
// before list is
// [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
var randomValue list.random(remove: true); // 5
// after calling with remove = true
// [1, 2, 3, 4, 6, 7, 8, 9, 10]
// If secure = true is passed as argument then Random.secure() is used
var randomValue list.random(secure: true); // 5
isGrowable
returns true
if it is Growable list
otherwise false.
// On Non-Growable List
var list = List<dynamic>(8);
var isGrowable = list.isGrowable; // false
// On Growable List
var list2 = List<dynamic>();
var isGrowable = list2.isGrowable; // true
drop
removes n
number of elements from the beginning of list
//If used as method, it directly alter the list's object
var list = <int>[1, 2, 3, 4, 5];
list.drop(); // list = [2, 3, 4, 5];
var list = <int>[1, 2, 3, 4, 5];
list.drop(3); // list = [4, 5];
var list = <int>[1, 2, 3];
list.drop(5); // list = []; // does not throw error :D
//If used as function,
//it creates a new copy of the output and list's object is untouched
var list = <int>[1, 2, 3, 4, 5];
var newObject = list.dropRight(); // newObject = [1, 2, 3, 4];
var list = <int>[1, 2, 3, 4, 5];
var newObject = list.dropRight(3); // newObject = [1, 2];
var list = <int>[1, 2, 3];
var newObject = list.dropRight(5); // newObject = []; // does not throw error :D
dropRight
removes n
number of elements from the ending of list
//If used as method, it directly alter the list's object
var list = <int>[1, 2, 3, 4, 5];
list.dropRight(); // list = [1, 2, 3, 4];
var list = <int>[1, 2, 3, 4, 5];
list.dropRight(3); // list = [1, 2];
var list = <int>[1, 2, 3];
list.dropRight(5); // list = []; // does not throw error :D
//If used as function,
//it creates a new copy of the output and list's object is untouched
var list = <int>[1, 2, 3, 4, 5];
var newObject = list.dropRight(); // newObject = [1, 2, 3, 4];
var list = <int>[1, 2, 3, 4, 5];
var newObject = list.dropRight(3); // newObject = [1, 2];
var list = <int>[1, 2, 3];
var newObject = list.dropRight(5); // newObject = []; // does not throw error :D
dropRightWhile
starts removing elements
from the ending of list
until condition becomes false
.
var list = <int>[2, 1, 3, 4, 5];
list.dropRightWhile((element) => element >= 3); // list = [2, 1];
dropWhile
starts removing elements
from the starting of list
until condition becomes false
var list = <int>[2, 1, 3, 4, 5];
list.dropWhile((element) => element <= 3); // list = [4, 5];
flatten
Flattens
list a single level deep.
It returns newObject
of flattened list and does not affects the list object called-upon
var list = [2, [1, 3], [4, [1, [2]] ] ];
var newList = list.flatten(); // newList = [2, 1, 3, 4, [1, [2] ] ];
flattenDepth
Recursively flatten list up to depth times.
It returns newObject
of flattened list and does not affects the list object called-upon
var list = [2, [1, 3], [4, [1, [2]] ] ];
var newList = list.flattenDepth(1); // newList = [2, 1, 3, 4, [1, [2] ] ];
flatterDeep
Recursively flattens list.
It returns newObject
of deeply flattened list and does not affects the list object called-upon.
var list = [2, [1, 3], [4, [1, [2]] ] ];
var newList = list.flattenDeep(); // newList = [2, 1, 3, 4, 1, 2];
chunk
Creates a new list of elements split into groups the length of size
.
If list
can't be split evenly, the final chunk will be the remaining elements.
// It returns new Object of Chunked data;
var list = ['a', 'b', 'c', 'd'];
var newChunkedList = list.chunk(3);// newChunkedList = [['a', 'b', 'c'], ['d']];
compact
Creates an list of elements where the values of the list are not Falsey
.
Avoid calling it on fixed-length list.
//It alters the list object if the list is not fixed-length list.
var list = ['a', null, '', false, 'b'];
var compactedData = list.compact(); // ['a', 'b'];
//It returns new Object of compacted data;
var list = ['a', null, '', false, 'b'];
//here the list object is not altered
var compactedData_new_object = compact(list); // ['a', 'b'];
heapSort
Sorts the list in O(nLog(n))
time complexity.
var list = <int>[97, 4, 5, 26, 6];
// With `inPlace` set to `false` it returns new sorted list.
var newSortedList = list.heapSort(inPlace: false);
// newSortedList = [4, 5, 6, 26, 97];
var list = <int>[97, 04, 5, 26, 6];
// With `inPlace` set to `true (default)` it sorts the list in its place.
list.heapSort(); // list = [4, 5, 6, 26, 97];
Number Operations
>>> (mimic)
As dart don't have >>>
. So to achieve functionality of >>>
a mimic can be used.
// 20 >>> 3 = 6
var value = 20.zeroFillRightShift(3); // value = 6
zeroFillRightShift(int number, int amount)
As operator >>>
is not available in dart, So zeroFillRightShift
function helps to mimics the working of >>>
.
// var t = 20 >>> 3;
var t = zeroFillRightShift(20, 3); // 6
// Thus above function helps to provide operation of `>>>`
// 20 >>> 3 = 6
var value = 20.zeroFillRightShift(3); // value = 6
xor
It returns xor
operation.
// 20 ^ 3 = 23
var value = 20.xor(3); // value = 23
divide
It returns quotient
as integer on divison.
// ( In Python ) -> [20 // 10 = 2]
// ( In Dart ) -> [20 / 10 = 2.0] (oops) :p
// But we need 2 as result.
var value = 20.divide(10); // value = 2
var value = 20.divide(10.0); // value = 2
var value = (20.0).divide(10); // value = 2
var value = (20.0).divide(10.0); // value = 2
var dividend = 20;
var divisor = 10;
var value = dividend.divide(divisor); // value = 2
String Operations
slice
Creates a slice of string
from start
up to, but not including, end
.
var string = '__justkawal;
// It slices the string and returns modified string
var slicedString string.slice(2); // slicedString = 'justkawal';
enumVal
Returns the value
of the enum
enum justkawal {
just,
kawal,
}
'${justkawal.just}'.enumVal; // just
'${justkawal.kawal}'.enumVal; // kawal
toNumber
Returns converted number
'2604 '.toNumber; // 2604
' 26.04 '.toNumber; // 26.04
count
Counts
and returns
the number of occurrences of value.
'justkawal'.count('a'); // 2
'justkawal'.count('just'); // 1
'justkawal'.count('flutter'); // 0
isNumber
Returns true
, if the string
is number
other-wise false
'123'.isNumber; // true
'justkawal'.isNumber; // false
isBinary
Returns true
if the string
is binary
, other-wise false
'1010'.isBinary; // true
'justkawal'.isBinary; // false
isDecimal
Returns true
if the string
is decimal
, other-wise false
'123'.isDecimal; // true
'justkawal'.isDecimal; // false
isOctal
Returns true
if the string
is octal
, other-wise false
'123'.isOctal; // true
'justkawal'.isOctal; // false
isHex
Returns true
if the string
is good hex
, other-wise false
'123'.isHex; // true
'justkawal'.isHex; // false
deburr
Converts string from Latin-1
to normal basic latin letters
.
'hey kàwàl'.deburr; // hey kawal
unicodeWords
Returns list of unicode words
from the string.
'hey kàwàl'.unicodeWords; // [kàwàl]
asciiWords
Returns list of ascii words
from the string.
'hey kàwàl'.asciiWords; // [hey]
hasUnicodeWord
Returns true
if string contains any occurence of unicode word
other-wise false
.
'hey kàwàl'.hasUnicodeWord; // true
'hey'.hasUnicodeWord; // false
capitalize
Converts the first character of string to upper case
and the remaining to lower case
.
'justkawal'.capitalize; // Justkawal
'JUSTKAWAL'.capitalize; // Justkawal
lowerFirst
Converts the first character of string to lower case
.
'Justkawal'.lowerFirst; // justkawal
'JUSTKAWAL'.lowerFirst; // jUSTKAWAL
upperFirst
Converts the first character
of string to upper case
.
'justkawal'.upperFirst; // Justkawal
'jUSTKAWAL'.upperFirst; // JUSTKAWAL
words
Returns list of words
'kàwàl vu'.words; // ['kàwàl', 'vu']
Case Conversions
camelCase
Converts the string to camelCase
and returns it.
'___just__kawal__'.camelCase; // justKawal
' just Kawal '.camelCase; // justKawal
'-----just--Kawal--'.camelCase; // justKawal
kebabCase
Converts the string to kebabCase
and returns it.
'___hello__world__'.kebabCase(); // hello-world
' hello World '.kebabCase(); // hello-world
'-----hello--world--'.kebabCase(); // hello-world
lowerCase
Converts the string to lowerCase
and returns it.
'___hello__world__'.lowerCase(); // hello world
' hello World '.lowerCase(); // hello world
'-----hello--world--'.lowerCase(); // hello world
snakeCase
Converts the string to snakeCase
and returns it.
'___hello__world__'.snakeCase(); // hello_world
' helloWorld '.snakeCase(); // hello_world
'-----hello--world--'.snakeCase(); // hello_world
nameCase
Converts the string to nameCase
and returns it.
'___kaWaljeet__sInGH__'.nameCase(); // Kawaljeet Singh
' justKawal '.nameCase(); // Just Kawal
'-----kawaljeet--singh--'.nameCase(); // Kawaljeet Singh
repeat
Returns repeated string
, n
number of times
'justkawal'.repeat(1); // justkawal
'123'.repeat(2); // 123123
'1'.repeat(5); // 11111
pad
Pads the string on the left and right sides if it's shorter than length
.
Padding characters will be truncated if they can't be evenly divided by length
.
var pad1 = 'abc'.pad(8); // ' abc '
var pad2 = 'abc'.pad(8, '=_'); // '=_abc=_='
var pad3 = 'abc'.pad(3); // 'abc'
Features coming in next version
On-going implementation for future:
- Some more Functions