Characters class Null safety
The characters of a string.
A character is a Unicode Grapheme cluster represented
by a substring of the original string.
The Characters
class is an Iterable of those strings.
However, unlike most iterables, many of the operations are
eager. Since the underlying string is known in its entirety,
and is known not to change, operations which select a subset of
the elements can be computed eagerly, and in that case the
operation returns a new Characters
object.
The iterator provided by Characters is a CharacterRange which allows iterating the independent characters in both directions, but which also provides ways to select other ranges of characters in different ways.
- Implemented types
- Available Extensions
Constructors
- Characters(String string)
-
Creates a Characters allowing iteration of
the characters of
string
.factory
Properties
- first → String
-
Returns the first element.
read-onlyinherited
- hashCode → int
-
The hash code of string.
read-onlyoverride
- isEmpty → bool
-
Whether this collection has no elements.
read-onlyinherited
- isNotEmpty → bool
-
Whether this collection has at least one element.
read-onlyinherited
- iterator → CharacterRange
-
Iterator over the characters of this string.
read-onlyoverride
- iteratorAtEnd → CharacterRange
-
Iterator over the characters of this string.
read-only
- last → String
-
Returns the last element.
read-onlyinherited
- length → int
-
Returns the number of elements in this.
read-onlyinherited
- runtimeType → Type
-
A representation of the runtime type of the object.
read-onlyinherited
- single → String
-
Checks that this iterable has only one element, and returns that element.
read-onlyinherited
- string → String
-
The string to iterate over.
read-only
Methods
-
any(
bool test(String element)) → bool -
Checks whether any element of this iterable satisfies
test
.inherited -
cast<
R> () → Iterable< R> -
Provides a view of this iterable as an iterable of
R
instances.inherited -
characterAt(
int position) → Characters -
Returns the single-character sequence of the
position
th character. -
contains(
covariant String singleCharacterString) → bool -
Whether
singleCharacterString
occurs in this sequence of characters.override -
containsAll(
Characters other) → bool -
Whether this sequence of characters contains
other
as a subsequence. -
elementAt(
int index) → String -
Returns the
index
th element.inherited -
endsWith(
Characters other) → bool -
Whether this string ends with the characters of
other
. -
every(
bool test(String element)) → bool -
Checks whether every element of this iterable satisfies
test
.inherited -
expand<
T> (Iterable< T> toElements(String element)) → Iterable<T> -
Expands each element of this Iterable into zero or more elements.
inherited
-
findFirst(
Characters characters) → CharacterRange? -
Finds the first occurrence of
characters
in this string. -
findLast(
Characters characters) → CharacterRange? -
Finds the last occurrence of
characters
. -
firstWhere(
bool test(String element), {String orElse()?}) → String -
Returns the first element that satisfies the given predicate
test
.inherited -
fold<
T> (T initialValue, T combine(T previousValue, String element)) → T -
Reduces a collection to a single value by iteratively combining each
element of the collection with an existing value
inherited
-
followedBy(
Iterable< String> other) → Iterable<String> -
Returns the lazy concatenation of this iterable and
other
.inherited -
forEach(
void action(String element)) → void -
Invokes
action
on each element of this iterable in iteration order.inherited -
getRange(
int start, [int? end]) → Characters -
Eagerly selects the range of characters from
start
toend
. -
join(
[String separator = ""]) → String -
Converts each element to a String and concatenates the strings.
inherited
-
lastWhere(
bool test(String element), {String orElse()?}) → String -
Returns the last element that satisfies the given predicate
test
.inherited -
map<
T> (T toElement(String e)) → Iterable< T> -
The current elements of this iterable modified by
toElement
.inherited -
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a non-existent method or property is accessed.
inherited
-
reduce(
String combine(String value, String element)) → String -
Reduces a collection to a single value by iteratively combining elements
of the collection using the provided function.
inherited
-
replaceAll(
Characters pattern, Characters replacement) → Characters -
Replaces
pattern
withreplacement
. -
replaceFirst(
Characters pattern, Characters replacement) → Characters -
Replaces the first occurrence of
pattern
withreplacement
. -
singleWhere(
bool test(String element), {String orElse()?}) → String -
Returns the single element that satisfies
test
.inherited -
skip(
int count) → Characters -
Eagerly selects all but the first
count
characters.override -
skipLast(
int count) → Characters -
Eagerly selects all but the last
count
characters. -
skipLastWhile(
bool test(String)) → Characters - Eagerly selects a leading sequence of characters.
-
skipWhile(
bool test(String)) → Characters -
Eagerly selects a trailing sequence of characters.
override
-
split(
Characters pattern, [int maxParts = 0]) → Iterable< Characters> -
Splits this sequence of characters at each occurrence of
pattern
. -
startsWith(
Characters other) → bool -
Whether this string starts with the characters of
other
. -
take(
int count) → Characters -
Eagerly selects the first
count
characters.override -
takeLast(
int count) → Characters -
Eagerly selects the last
count
characters. -
takeLastWhile(
bool test(String)) → Characters - Eagerly selects a trailing sequence of characters.
-
takeWhile(
bool test(String)) → Characters -
Eagerly selects a leading sequence of characters.
override
-
toList(
{bool growable = true}) → List< String> -
Creates a List containing the elements of this Iterable.
inherited
-
toLowerCase(
) → Characters - The characters of the lower-case version of string.
-
toSet(
) → Set< String> -
Creates a Set containing the same elements as this iterable.
inherited
-
toString(
) → String -
The string content of these characters.
override
-
toUpperCase(
) → Characters - The characters of the upper-case version of string.
-
where(
bool test(String)) → Characters -
Eagerly selects a subset of the characters.
override
-
whereType<
T> () → Iterable< T> -
Returns a new lazy Iterable with all elements that have type
T
.inherited
Operators
-
operator +(
Characters other) → Characters -
The characters of the concatenation of this and
other
. -
operator ==(
Object other) → bool -
Whether
other
to another Characters with the same string.override
Constants
- empty → const Characters
-
An empty Characters containing no characters.
StringCharacters("")