Quiver is a set of utility libraries for Dart that makes using many Dart libraries easier and more convenient, or adds additional functionality.
API Docs can be found here: http://google.github.io/quiver-dart/docs/
Utilities for working with Futures, Streams and async computations.
FutureGroup
is collection of Futures that signals when all its child futures
have completed. Allows adding new Futures as long as it hasn't completed yet.
Useful when async tasks can spwn new async tasks and you need to wait for all of
them to complete.
StreamRouter
splits a Stream into mulltiple streams based on a set of
predicates.
CountdownTimer
is a simple countdown timer that fires events in regular
increments.
doWhileAsync
and reduceAsync
perform async computations on the elements of
on Iterables, waiting for the computation to complete before processing the
next element.
CreateTimer
and CreateTimerPeriodic
are typedefs that are useful for
passing Timer factories to classes and functions, increasing the testability of
code that depends on Timer.
Cache
is a semi-persistent, asynchronously accessed, mapping of keys to
values. Caches are similar to Maps, except that the cache implementation might
store values in a remote system, so all operations are asynchronous, and caches
might have eviction policies.
MapCache
is a Cache implementation backed by a Map.
Multimap
is an associative collection that maps keys to collections of
values. BiMap
is a bi-directional map and provides an inverse view, allowing
lookup of key by value.
visitDirectory
is a recursive directory lister that conditionally recurses
into sub-directories based on the result of a handler function.
count
, cycle
, enumerate
, merge
, range
, and zip
create, transform,
or combine Iterables in different ways, similar to Python's itertools.
min
, max
, and extent
retreive the minimum and maximum elements from an
iterable.
getTypeName
returns the name of a Type instance.
implements
and classImplements
determine if an instance or ClassMirror,
respectively, implement the interface represented by a Type instance. They
implement the behavior of is
for mirrors, except for generics.
getMemberMirror
searches though a ClassMirror and its class hierarchy for
a member. This makes up for the fact that ClassMirror.members
doesn't
contain members from interfaces or superclasses.
Method
wraps an InstanceMirror and Symbol to create a callable that invokes
a method on the instance. It in effect closurizes a method reflectively.
pattern.dart container utilities for work with Pattern
s and RegExp
s.
Glob
implements glob patterns that are commonly used with filesystem paths.
matchesAny
combines multiple Patterns into one, and allows for exclusions.
matchesFull
returns true if a Pattern matches an entire String.
escapeRegex
escapes special regex characters in a String so that it can be
used as a literal match inside of a RegExp.
isBlank
checks if a string is null
, empty or made of whitespace characters.
flip
flips the order of characters in a string.
nullToEmpty
turns null
to empty string, and returns non-empty strings
unchanged.
emptyToNull
turns empty string to null
, and returns non-empty strings
unchanged.
repeat
concatenates a string to itself a given number of times, for example:
repeat('la ', 3) => 'la la la '
It can also repeat in reverse, for example:
repeat(' og', -3) => 'go go go '
loop
allows you to loop through characters in a string starting and ending at
arbitrary indices. Out of bounds indices allow you to wrap around the string,
supporting a number of use-cases, including:
loop('lohel', -3, 2) => 'hello'
Like repeat
, but with better character-level control, e.g.:
loop('la ', 0, 8) => 'la la la' // no tailing space
loop('/path/to/some/file.txt', -3) => 'txt'
loop('top', 3, 0) => 'pot'
Clock
provides points in time relative to the current point in time, for
example: now, 2 days ago, 4 weeks from now, etc. For tesability, use Clock
rather than other ways of accessing time, like new DateTime()
, so that you
can use a fake time function in your tests to control time.
Now
is a typedef for functions that return the current time in microseconds,
since Clock deals in DateTime which only have millisecond accuracy.
FakeTimer
is a Timer that captures its duration and callback for use in tests.
FakeStopwatch
is a Stopwatch that uses a provided now()
function to get the
current time.