logicgate

README

Logic Gates

github.com/chippyash/logicgate

What

Builds on Kelindar's Bitmap library to provide:

• functional equivalents to the bitmap declarative methods
• additional functions for some 'missing' methods
• some utility functions that wouldn't make it into the Bitmap library

Why

To provide the ability to write code functionally using bitmaps. Parameters to the functions are not changed, maintaining immutability.

To show that it is reasonably possible to take someone else's code and provide a different experience without harming the originator.

Kelindar's Bitmap library allows for very large bitmaps. His primary use case is categorisation, for which bit maps are a good candidate, particularly if you are trying to slim down your data storage. My use case was slightly different, but Kelindar's Bitmap serves the purpose as a highly efficient implementation.

The bit that was missing was the ability to compare bitmaps.

How

• Go 1.18+ The base version is dictated by the Bitmap library. This may change in the future.
• import "github.com/chippyash/logicgate"
• Read the unit tests to see how functions are used
• Run the examples/main.go program for example usage

Bitmap functional equivalents

• func And(a, b bitmap.Bitmap) bitmap.Bitmap
• func Or(a, b bitmap.Bitmap) bitmap.Bitmap
• func Xor(a, b bitmap.Bitmap) bitmap.Bitmap

Additional functions

• func Imply(a, b bitmap.Bitmap) bitmap.Bitmap
• func Nimply(a, b bitmap.Bitmap) bitmap.Bitmap
• func Nand(a, b bitmap.Bitmap) bitmap.Bitmap
• func Not(a bitmap.Bitmap) bitmap.Bitmap
• func Xnor(a, b bitmap.Bitmap) bitmap.Bitmap

Utility functions

• func Compare(a, b bitmap.Bitmap) (int, error)
• func RangeAll(src bitmap.Bitmap, fn func(k uint32, v bool))
• func Trim(a bitmap.Bitmap, bitLen uint32) bitmap.Bitmap

An example of what you can do

My first use for Bitmap was to categorise team games by the players in the team, the objective being to ensure that I hadn't gotten the same players playing together too often. That's where I hit a roadblock with Bitmap, it had no comparator. In a sense, this library is a response to that, and in particular the Xnor and associated Compare function. But once down the rabbit hole, off we must go!

examples/full_adder/main.go is a purely contrived attempt to produce a bitmap oriented electronic circuit as described in https://en.wikipedia.org/wiki/Adder_(electronics) It has no functional reason to exist, as there are far better ways to do these things. It exists only as a demonstration of the art of the possible.

Contributing

Feel free to submit a pull request to make changes or add functionality. Please ensure that changes are accompanied by relevant unit tests. I am particularly interested in efficiency improvements if you can make them, or edge cases if you find them, and of course the art of the possible as examples that others may learn from.

I cannot fix issues in the dependency chain. Please refer to the authors of a dependency.

Developing

• clone the repo
• go get -u ./...

References

Logic Gates

License

The library is licensed under the MIT License

Documentation

Index

• func And(a, b bitmap.Bitmap) bitmap.Bitmap
• func Imply(a, b bitmap.Bitmap) bitmap.Bitmap
• func Nand(a, b bitmap.Bitmap) bitmap.Bitmap
• func Nimply(a, b bitmap.Bitmap) bitmap.Bitmap
• func Nor(a, b bitmap.Bitmap) bitmap.Bitmap
• func Not(a bitmap.Bitmap) bitmap.Bitmap
• func Or(a, b bitmap.Bitmap) bitmap.Bitmap
• func Xnor(a, b bitmap.Bitmap) bitmap.Bitmap
• func Xor(a, b bitmap.Bitmap) bitmap.Bitmap

Functions

func And

func And(a, b bitmap.Bitmap) bitmap.Bitmap

And is the AND gate see https://en.wikipedia.org/wiki/AND_gate

func Imply

func Imply(a, b bitmap.Bitmap) bitmap.Bitmap

Imply is the IMPLY gate see https://en.wikipedia.org/wiki/IMPLY_gate Use utils.Trim(Imply(a,b), 1) to return the truthfulness of the expression

func Nand

func Nand(a, b bitmap.Bitmap) bitmap.Bitmap

Nand is the NAND gate see https://en.wikipedia.org/wiki/NAND_gate

func Nimply

func Nimply(a, b bitmap.Bitmap) bitmap.Bitmap

Nimply is the NIMPLY gate see https://en.wikipedia.org/wiki/NIMPLY_gate Use utils.Trim(Nimply(a,b), 1) to return the truthfulness of the expression

func Nor

func Nor(a, b bitmap.Bitmap) bitmap.Bitmap

Nor is the NOR gate see https://en.wikipedia.org/wiki/NOR_gate

func Not

func Not(a bitmap.Bitmap) bitmap.Bitmap

Not is the Inverter Gate see https://en.wikipedia.org/wiki/Inverter_(logic_gate)

func Or

func Or(a, b bitmap.Bitmap) bitmap.Bitmap

Or is the OR gate see https://en.wikipedia.org/wiki/OR_gate

func Xnor

func Xnor(a, b bitmap.Bitmap) bitmap.Bitmap

Xnor is the XNOR gate. see https://en.wikipedia.org/wiki/XNOR_gate

func Xor

func Xor(a, b bitmap.Bitmap) bitmap.Bitmap

Xor is the XOR Gate see https://en.wikipedia.org/wiki/XOR_gate