dartbag

A grab-bag of miscellaneous, lightweight utility code for Dart. Functionality includes (but is not limited to):

byte_data

• List<int>.asUint8List converts a List<int> to a Uint8List without copying, if possible.

collection

• flattenDeep recursively flattens nested Iterables into a single Iterable sequence.

• List.reverse reverses a List in place. rain

• List.rotateLeft rotates a List in place.

• List.sortWithKey sorts a List by computing and caching sort keys, which can be significantly faster if comparisons are expensive.

• List.sortWithAsyncKey is a version of sortWithKey that allows the sort key to be computed asynchronously.

• Iterable.startsWith returns whether one Iterable starts with the same sequence of elements as another Iterable.

• Iterable.padLeft and Iterable.padRight add elements to an Iterable to have a specified length.

• zipLongest is a version of zip that stops only after the longest Iterable is exhausted instead of the shortest.

• LinkedHashMap.sort.

• mergeMapss combines an Iterable of Maps into a single Map.

• Map<K, Future<V>>.wait waits for Future values in a Map (in parallel if possible).

comparable

• clamp clamps a Comparable object to be within a specified range.

• compareIterables compares two Iterables in a manner similar to string comparison.

• ComparableWrapper wraps a value in a Comparable interface with a specified comparison function.

debug

• assertsEnabled returns whether assert is enabled.

• currentDartFilePath returns the path to the current .dart file for Dart VM builds.

• staticType returns the static type of an object.

• String.escape escapes a String such that it can be used as a string literal in generated code.

matcher

• toStringMatches verifies that a tested value has a matching type and string representation.

math

• lcm computes the least-common-multiple of two integers.

• int.floorToMultipleOf, int.ceilToMultipleOf, and int.roundToMultipleOf provide different ways of rounding a non-negative integer to the nearest multiple of another.

• Rectangle.center returns the center of a Rectangle.

misc

• tryAs casts an object and returns null on failure instead of throwing a TypeError.

• chainIf allows conditional method chaining based on a condition.

• OutputParameter allows specifying output parameters from functions as a crude mechanism to return multiple values.

• int.padLeft converts an int to a String, left-padded with zeroes to have a minimum number of digits.

• String.lazySplit is a version of String.split that returns an Iterable to tokenize a String lazily.

• String.partialSplit is a version of String.split that limits the number of returned items.

• String.substringLoose is a version of String.substring with less strict bounds.

• Uri.updateQueryParameters adds or replaces query parameters in a Uri.

• bool.implies returns whether one bool logically implies another.

• Future.cast casts a Future<T> to a Future<R>.

• PollableFuture is an implementation of Future that allows synchronously retrieving the value if it has already been completed.

• hoursOnly, minutesOnly, secondsOnly, millisecondsOnly, and microsecondsOnly retrieve specific components of a Duration.

• DateTime.toStringWithOffset and DateTime.toIso8601StringWithOffset are versions of DateTime.toString and DateTime.totoIso8601String that include timezone offsets.

parse

• tryParseBool parses a bool from a String?.

• tryParseInt and tryParseDouble are wrappers around int.tryParse and double.tryParse that accept null arguments.

• List<Enum>.tryParse parses an Enum value from a String?.

• tryParseDuration parses a Duration from a String?.

random

• randMaxInt portably returns the maximum value allowed by Random.nextInt.

• Random.nextIntFrom returns a random integer in a specified range.

• lazyShuffler shuffles a List lazily.

• RepeatableRandom wraps an existing pseudo-random number generator to allow a random sequence to be easily restarted and to allow the seed to be retrieved.

readable_numbers

• readableDuration returns a Duration as a human-readable string.

• readableNumber returns a number as a human-readable string with SI prefixes and units.

timer

• ExpiringPeriodicTimer is a periodic Timer that automatically stops after a time limit.

tty

• getTerminalSize attempts to get the number of columns and lines of a terminal.

• wordWrap wraps a string to a maximum line length.

• ArgResults.parseOptionValue reduces some boilerplate when parsing option values from package:args.