bits

A smallish Clojure library for transforming Java primitives into binary sequences and back again. Intended to help explore encodings. Particularly useful for float and double types.

Install

Leiningen/Boot:

[com.evanjbowling/bits "0.0.1"]

Clojure CLI/deps.edn:

com.evanjbowling/bits {:mvn/version "0.0.1"}

Quick Demo

Load the namespace:

(ns whose.ns
  (:require [com.evanjbowling.bits :as bits]))

View the binary encoding for a few shorts:

(->> ["7" "0" "-1"]
     (map bits/short-bits)
     clojure.pprint/pprint)

; ((0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1)
;  (0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0)
;  (1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1))

Examine some chars:

(->> ["A" "a" "µ"]
     (map bits/char-bits)
     clojure.pprint/pprint)

; ((0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 1)
;  (0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 1)
;  (0 0 0 0 0 0 0 0 1 0 1 1 0 1 0 1))

The floating point bit sequences are grouped [[sign] [exponent] [fraction]]:

(bits/float-bits "0.25")

; ([0] [0 1 1 1 1 1 0 1] [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0])

You can convert the bit sequence back to it's original form:

(bits/from-float-bits '([0] [0 1 1 1 1 1 0 1] [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]))

; 0.25

This is a great way to see what happens when you make the exponent all ones:

(bits/from-float-bits '([0] [1 1 1 1 1 1 1 1] [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]))

; Infinity

And then tweak the fraction bits too:

(bits/from-float-bits '([0] [1 1 1 1 1 1 1 1] [1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]))

; NaN

License

Copyright © 2019 Evan Bowling

Distributed under the MIT License