Utf16leBytesToCodeUnitsDecoder class
Convert UTF-16LE encoded bytes to utf16 code units by grouping 1-2 bytes to produce the code unit (0-(2^16)-1).
class Utf16leBytesToCodeUnitsDecoder extends Utf16BytesToCodeUnitsDecoder {
Utf16leBytesToCodeUnitsDecoder(List<int> utf16EncodedBytes, [
int offset = 0, int length, bool stripBom = true,
int replacementCodepoint = UNICODE_REPLACEMENT_CHARACTER_CODEPOINT]) :
super._fromListRangeIterator(
(new _ListRange(utf16EncodedBytes, offset, length)).iterator,
replacementCodepoint) {
if (stripBom && hasUtf16leBom(utf16EncodedBytes, offset, length)) {
skip();
}
}
int decode() {
utf16EncodedBytesIterator.moveNext();
int lo = utf16EncodedBytesIterator.current;
utf16EncodedBytesIterator.moveNext();
int hi = utf16EncodedBytesIterator.current;
return (hi << 8) + lo;
}
}
Extends
Utf16BytesToCodeUnitsDecoder > Utf16leBytesToCodeUnitsDecoder
Constructors
new Utf16leBytesToCodeUnitsDecoder(List<int> utf16EncodedBytes, [int offset = 0, int length, bool stripBom = true, int replacementCodepoint = UNICODE_REPLACEMENT_CHARACTER_CODEPOINT]) #
Utf16leBytesToCodeUnitsDecoder(List<int> utf16EncodedBytes, [
int offset = 0, int length, bool stripBom = true,
int replacementCodepoint = UNICODE_REPLACEMENT_CHARACTER_CODEPOINT]) :
super._fromListRangeIterator(
(new _ListRange(utf16EncodedBytes, offset, length)).iterator,
replacementCodepoint) {
if (stripBom && hasUtf16leBom(utf16EncodedBytes, offset, length)) {
skip();
}
}
Properties
final int current #
inherited from Utf16BytesToCodeUnitsDecoder
final int position #
inherited from Utf16BytesToCodeUnitsDecoder
int get position => utf16EncodedBytesIterator.position ~/ 2;
final int remaining #
inherited from Utf16BytesToCodeUnitsDecoder
int get remaining => (utf16EncodedBytesIterator.remaining + 1) ~/ 2;
final int replacementCodepoint #
inherited from Utf16BytesToCodeUnitsDecoder
final int replacementCodepoint
final _ListRangeIterator utf16EncodedBytesIterator #
inherited from Utf16BytesToCodeUnitsDecoder
final _ListRangeIterator utf16EncodedBytesIterator
Methods
void backup([int by = 1]) #
inherited from Utf16BytesToCodeUnitsDecoder
void backup([int by = 1]) {
utf16EncodedBytesIterator.backup(2 * by);
}
int decode() #
int decode() {
utf16EncodedBytesIterator.moveNext();
int lo = utf16EncodedBytesIterator.current;
utf16EncodedBytesIterator.moveNext();
int hi = utf16EncodedBytesIterator.current;
return (hi << 8) + lo;
}
List<int> decodeRest() #
inherited from Utf16BytesToCodeUnitsDecoder
Provides a fast way to decode the rest of the source bytes in a single call. This method trades memory for improved speed in that it potentially over-allocates the List containing results.
List<int> decodeRest() {
List<int> codeunits = new List<int>(remaining);
int i = 0;
while (moveNext()) {
codeunits[i++] = current;
}
if (i == codeunits.length) {
return codeunits;
} else {
List<int> truncCodeunits = new List<int>(i);
truncCodeunits.setRange(0, i, codeunits);
return truncCodeunits;
}
}
bool moveNext() #
inherited from Utf16BytesToCodeUnitsDecoder
Moves to the next element. Returns true if current contains the next
element. Returns false, if no element was left.
It is safe to invoke moveNext even when the iterator is already
positioned after the last element. In this case moveNext has no effect.
bool moveNext() {
_current = null;
if (utf16EncodedBytesIterator.remaining < 2) {
utf16EncodedBytesIterator.moveNext();
if (replacementCodepoint != null) {
_current = replacementCodepoint;
return true;
} else {
throw new ArgumentError(
"Invalid UTF16 at ${utf16EncodedBytesIterator.position}");
}
} else {
_current = decode();
return true;
}
}
void skip([int count = 1]) #
inherited from Utf16BytesToCodeUnitsDecoder
void skip([int count = 1]) {
utf16EncodedBytesIterator.skip(2 * count);
}