BitSet

This repository is a set of tools and Qt libraries for performing operations on binary data. Made for school project.

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Qt library

Provides classes for operations on individual bitsets as well as evaluating bitset expressions.

bitset command-line tool

Provides command-line interface for parsing bitset expressions. Expects a single argument - expression to parse. Returns string representation of resulting bitset if expression is correct and parsing error message otherwise. Runs like following:

bitset.exe 110 + 101 ^ 110 & 010

Expressions

Expression evaluator supports following symbols:

• Bitset as is -- a string of 0`s and 1`s
• Bitset read from file -- file@<filepath>@ will read a bitset from file at <filepath>. File must exist, be accessible, be text and contain nothing except 0 and 1. Error is thrown otherwise.
• ( and ) -- parenthesis for changing evaluation order.
• ! or ~ -- bitwise negation. Both mean exactly the same. ! might be a special character in your terminal, so ~ is more preferred.
• &, |, ^ -- bitwise AND, OR, XOR. Ordered from high-priority to low-priority. Both left and right operands must be bitsets.
• >> and << -- right and left shift. Left operand must be bitset and right one must be a number.
• + -- concatenation. Both left and right operand must be bitsets.

• The higher operator is in the list the higher priority it has.
• Be aware that string representation of bitsets are written from least-significant-bits on the left to MSB on the right. So 0100 is 2, not 4.
• If bitwise operation is performed on bitsets of different length, the shorter one gets filled with 0`s at the end to match the length of the longer one.
• All operands and operators may be separated by any number of whitespace characters. However, no whitespaces allowed inside bitset, number, file operator (including file path), shift operators.

Some examples of valid expressions and their results:

• 101 + 01 is 10101.
• 110 + 101 ^ 110 & 010 is 110111. & has higher priority than ^, and ^ is higher than +.
• 10001 | 1011 ^ file@operator.txt@ operator.txt is a text file in the working directory which contains string 101. So the expression is equivalent to 00001 | 1011 ^ 100 and is equal to 10001 since the shorter operand is filled by 0`s on the right side.
• 10 + 01|1& 1001. Whitespaces are ok.

Some incorrect expressions:

• 101 &
• +101 -- it's concatenation operator, not unary plus. So must have both operands.
• file@new folder/operand.txt@ -- no whitespaces allowed in file path.