by Andrew Brampton (bramp.net)
Collection of bit twiddling hacks. Think popcount or _pdep_u64. Works on both Dart VM and dart2js.
// Count the number of bits set.
0.bitCount(); // returns 0
1.bitCount(); // returns 1
2.bitCount(); // returns 1
3.bitCount(); // returns 2
0x10101010.bitCount(); // returns 4
// Find the position of set bits. For example:
//
// 7 6 5 4 3 2 1 0 (index)
// 0 1 0 0 0 0 1 1 (value 0x43 with 3 bits set)
// 2 1 0 (rank)
//
0x43.bitRank(0); // returns 0 (found at index 0)
0x43.bitRank(1); // returns 1 (found at index 1)
0x43.bitRank(2); // returns 6 (found at index 6)
0x43.bitRank(3); // returns -1 (not found)To run the tests:
dart test
dart test -p chromeTo publish:
dart analyze
# Bump the version in pubspec.yaml
# Update the CHANGELOG.md
dart pub lishThese algorithms were inspired by Bit Twiddling Hacks by Sean Eron Anderson
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