/*
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* Copyright 2012 ZXing authors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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@class ZXByteArray, ZXIntArray;
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/**
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* A simple, fast array of bits, represented compactly by an array of ints internally.
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*/
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@interface ZXBitArray : NSObject <NSCopying>
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/**
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* @return underlying array of ints. The first element holds the first 32 bits, and the least
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* significant bit is bit 0.
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*/
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@property (nonatomic, assign, readonly) int32_t *bits;
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@property (nonatomic, assign, readonly) int size;
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- (id)initWithSize:(int)size;
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- (int)sizeInBytes;
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/**
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* @param i bit to get
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* @return true iff bit i is set
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*/
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- (BOOL)get:(int)i;
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/**
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* Sets bit i.
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*
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* @param i bit to set
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*/
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- (void)set:(int)i;
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/**
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* Flips bit i.
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*
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* @param i bit to set
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*/
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- (void)flip:(int)i;
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/**
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* @param from first bit to check
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* @return index of first bit that is set, starting from the given index, or size if none are set
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* at or beyond this given index
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*/
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- (int)nextSet:(int)from;
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- (int)nextUnset:(int)from;
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/**
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* Sets a block of 32 bits, starting at bit i.
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*
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* @param i first bit to set
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* @param newBits the new value of the next 32 bits. Note again that the least-significant bit
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* corresponds to bit i, the next-least-significant to i+1, and so on.
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*/
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- (void)setBulk:(int)i newBits:(int32_t)newBits;
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/**
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* Sets a range of bits.
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*
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* @param start start of range, inclusive.
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* @param end end of range, exclusive
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*/
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- (void)setRange:(int)start end:(int)end;
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/**
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* Clears all bits (sets to false).
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*/
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- (void)clear;
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/**
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* Efficient method to check if a range of bits is set, or not set.
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*
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* @param start start of range, inclusive.
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* @param end end of range, exclusive
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* @param value if true, checks that bits in range are set, otherwise checks that they are not set
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* @return true iff all bits are set or not set in range, according to value argument
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* @throws NSInvalidArgumentException if end is less than or equal to start
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*/
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- (BOOL)isRange:(int)start end:(int)end value:(BOOL)value;
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- (void)appendBit:(BOOL)bit;
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/**
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* Appends the least-significant bits, from value, in order from most-significant to
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* least-significant. For example, appending 6 bits from 0x000001E will append the bits
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* 0, 1, 1, 1, 1, 0 in that order.
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*/
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- (void)appendBits:(int32_t)value numBits:(int)numBits;
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- (void)appendBitArray:(ZXBitArray *)other;
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- (void)xor:(ZXBitArray *)other;
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/**
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*
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* @param bitOffset first bit to start writing
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* @param array array to write into. Bytes are written most-significant byte first. This is the opposite
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* of the internal representation, which is exposed by {@link #getBitArray()}
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* @param offset position in array to start writing
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* @param numBytes how many bytes to write
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*/
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- (void)toBytes:(int)bitOffset array:(ZXByteArray *)array offset:(int)offset numBytes:(int)numBytes;
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/**
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* @return underlying array of ints. The first element holds the first 32 bits, and the least
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* significant bit is bit 0.
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*/
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- (ZXIntArray *)bitArray;
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/**
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* Reverses all bits in the array.
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*/
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- (void)reverse;
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@end
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