minifloat.go

// This program will convert a "minifloat" in the format of 8 bits into decimal representation, assuming a -3 exponent bias.
// For example, this will convert 01011001 to 6.25.
// THIS PROGRAM DOES NOT COVER SPECIAL CASES! I'm too lazy to add this, I spent enough time making this already.
// Author: Eric Schneider
package main

import (
	"bufio"
	"fmt"
	"math"
	"os"
	"regexp"
)

func main(){
	reader := bufio.NewReader(os.Stdin)
	expression := regexp.MustCompile(`([01])([01]{3})([01]{4})`)

	for {
		fmt.Println("Enter your minifloat. If it isn't a minifloat, then the program will exit.")
		text, _ := reader.ReadString('\n')
		results := expression.FindStringSubmatch(text)

		if results == nil {
			break;
		}

		sign := get_sign(results[1])
		expobits := get_expobits(results[2])
		sigbits := get_sigbits(results[3])
		result := sign * expobits * sigbits

		fmt.Print(":")
		fmt.Println(result)
		fmt.Println()
	}
}

func get_sign(bit string) float64 {
	if bit == "0" {
		return 1
	} else {
		return -1
	}
}

func get_expobits(bits string) float64 {
	length := len(bits)
	ret := 0

	for i := 0; i < length; i++ {
		if bits[i] == '1' {
			ret += int(math.Pow(2, float64(i)))
		}
	}

	return math.Pow(2, float64(ret - 3))
}

func get_sigbits(bits string) float64 {
	length := len(bits)
	ret := 1.0

	for i := 0; i < length; i++ {
		if bits[i] == '1' {
			ret += math.Pow(2, float64(-1 * (i + 1)))
		}
	}

	return ret
}