renggli / dart-more

More Dart — Literally.

More Dart — Literally

A collection of extensively tested extensions that make Dart a better place:

Library	Description
async	Extensions to Stream.
cache	Caching strategies and their expiry policy.
char_matcher	Character classes, their composition, and operations on strings.
collection	Extensions to Iterable and new collection types.
comparator	Common comparators, and extensions to perform advanced operations.
diff	Tools for comparing lists.
feature	Information about the runtime environment.
functional	Types and features known from functional programming.
graph	Graph-theory objects and algorithms.
interval	Continuous interval data type over a comparable type.
math	Common mathematical functions.
number	Number types: fraction, complex, quaternion.
printer	Fluent interface to configure sophisticated formatter.
temporal	Extensions to DateTime and Duration types.
tuple	Tuple extension methods on generic records.

And there are more to come ...

This library is open source, stable and well tested. Development happens on GitHub. Feel free to report issues or create a pull-request there. General questions are best asked on StackOverflow.

The package is hosted on dart packages. Up-to-date class documentation is created with every release.

Misc

Installation

Follow the installation instructions on dart packages.

Import the all-including parent package:

import 'package:more/more.dart';

Or one or more of the specific packages into your Dart code:

import 'package:more/async.dart';
import 'package:more/cache.dart';
import 'package:more/char_matcher.dart';
import 'package:more/collection.dart';
import 'package:more/comparator.dart';
import 'package:more/diff.dart';
import 'package:more/feature.dart';
import 'package:more/functional.dart';
import 'package:more/graph.dart';
import 'package:more/interval.dart';
import 'package:more/math.dart';
import 'package:more/number.dart';
import 'package:more/printer.dart';
import 'package:more/temporal.dart';
import 'package:more/tuple.dart';

Contributing

The goal of the library is to provide a loose collection of carefully curated utilities that are not provided by the Dart standard library. All features must be well tested. New features must have significant advantages over alternatives, such as code reduction, readability improvement, speed increase, memory reduction, or improved accuracy. In case of doubt, consider filing a feature request before filing a pull request.

History

This library started in April 2013 as I was working through the puzzles of Project Euler and encountered some missing features in Dart. Over time the code grew and became more useful in many other places, so I created this reusable library.

Some parts of this library are inspired by similar APIs in Google Guava (Google core libraries for Java) and Apache Commons (a repository of reusable Java components).

License

The MIT License, see LICENSE.

dart-more's Issues

Always Nulls Last for Ascending or Descending sort

I am having trouble getting Ascending vs Descending sort working, always with nulls last. Imagine code like this:

    final orderingAsc = Ordering.natural<String>().nullsLast;
    final orderingDesc = Ordering.natural<String>().reversed.nullsLast;
...
              final sorter = sortAscending ? orderingAsc : orderingDesc;
              return sorter.compare(s1, s2);

I would expect null values ALWAYS to be at the BOTTOM -- then the non-null values will be sorted in Ascending or Descending order, depending on the sortAscending flag.

What am I doing wrong?

IntegerRange(10, 35, 10) isn't returning [10, 20, 30]

Hi Lukas, Long time no speak, hope you're doing well!

I love this library, but there seems to be an issue in the logic in IntegerRange for non-default step sizes. Sorry to be reporting this just after 3.9.0 got released 😄

Cheers, Michael

Multiset difference method should take Iterable<Object?> as argument

Multiset's difference function takes Iterable` which was fine before null safety. But with null safety this unnecessarily limits the uses.
For example

Multiset<E> diffSample<E>(Multiset<E> multiset, Iterable<E> iterable) =>  multiset.difference(iterable);

will fail unless you force E to extend from Object.

I guess this logic will apply to other collection related code, but did not search for them.

Python `range` equivalent

Does more have any Python range equivalent, i.e. a function returning an iterable from int start until int end, exclusive?

flutter pub get failing with More 3.7.0 and Flutter 3.0.2

• Run flutter create hello_world
• Add more: ^3.7.0 to the pubspec.yaml file
• Run flutter pub get

Got the following error:

$ flutter pub get 
Because every version of flutter_test from sdk depends on meta 1.7.0 and more >=3.6.0 depends on meta ^1.8.0, flutter_test from sdk is incompatible with more >=3.6.0.
So, because hello_world depends on both more ^3.7.0 and flutter_test from sdk, version solving failed.
Running "flutter pub get" in hello_world...                             
pub get failed (1; So, because hello_world depends on both more ^3.7.0 and flutter_test from sdk, version solving failed.)

Ordering example incorrect [documentation]

Minor documentation bug for Ordering class. The example:

var natural = new Ordering.natural();
natural.compare(1, 2);  // 1

Wouldn't the compare result be -1 signifying that 1 is less than 2?

`printer/null.dart` breaks DDC builds

I'm using this package for the iterable extensions, but ran into an issue when trying to use it on web using webdev serve.

When running with development settings, I get the following error: Uncaught SyntaxError: Unexpected token 'null' (at bimap.sound.ddc.js:108:7). This is caused by dart-lang/sdk#39595, which apparently never caught the eyes of the Dart team enough to fix. The package works properly in webdev release builds.

When I cloned locally, renamed null.dart to null_printer.dart and made the other necessary changes, the package worked as intended.

why data class is hidden?

for example, class Indexed in package:more/src/iterable/indexed.dart can't be accessed from other package.
but I want to use class for generics just like indexed<E>(list).map((Indexed<E> item) {}
any solution?
thanks in advance.

Iterable<T> insertBetween(T element) on Iterable<T>

Hey guys, I made this:

extension InsertBetweenExtension<T> on Iterable<T> {
  Iterable<T> insertBetween(T element) {
    final result = expand(
      (item) => [
        item,
        element,
      ],
    );

    return result.take(result.length - 1);
  }
}

It is useful in Flutter to insert dividers or paddings between widgets when you can't use the ListView.separated constructor (Row, Column, SliverList, etc.).

Row(
  crossAxisAlignment: CrossAxisAlignment.start,
  children: products
    .map<Widget>(
      (id) => Expanded(
        child: id != null ? ProductTile(id: id) : SizedBox.shrink(),
      ),
    )
    .insertBetween(SizedBox(width: 8.0))
    .toList(),
) 

Can it be an interesting addition to this package?

Merging map recursively

Hey,

Is there a way to do what this package do with More? https://pub.dev/packages/merge_map

It merges multiple Map recursively.

Q: Stream utilities PR

Hi!

Are you interested in a PR, which provides sliding window, but for streams, similar to https://github.com/renggli/dart-more/blob/main/lib/src/iterable/window.dart?

thanks

meta ^1.11.0 and every version of flutter from sdk depends on meta 1.10.0

Because more >=4.1.0 depends on meta ^1.11.0 and every version of flutter from sdk depends on meta 1.10.0, more >=4.1.0 is incompatible with flutter from sdk.
So, because shared_package depends on both flutter from sdk and more ^4.2.0, version solving failed.

I'm on the latest stable branch

[BitList] Consider making use of efficient implementations of popcount, ctz and clz if they become available.

For reference: dart-lang/sdk#52673

IntegerRange(500).contains(1000) is true

configuration

Dart: 1.18
OS: Windows 10 (64-bit)
More version: 3.8.2

example code

import "package:more/collection.dart";

void main() {
	final range = IntegerRange(500);
	print(range.contains(1000)); // true
}