Data.ReversedScientific

Provides a function that shows the somewhat "reversed" scientific notation of the big Integer number so that it is easier (more likely exact) to compare at quick glance two consequent numbers in such a notation by their order and values if they are located in the orderd list.

Documentation

showBignum :: Int -> Integer -> String

Two big positive Integer numbers in the ordered list of them are somewhat 'quickly' compared by values from left to right. If the number after "e" is greater than the other one respectively, the number is also greater than the other. If these values are equal, then the next shown Double values are compared (with the same rule). If they are also equal, then the difference between them can be likely find from the last two values (nevertheless, the numbers can differ if the values here are all pairwise equal! But the numbers are close in values one to another and so can represent just a subtle difference). This notation allows to reduce the difference in the lengths of big numbers in general case and to read the standard scientific notation not from right to left, but in a 'more usual' way — from left to right. If two numbers have different results of the function, then they are definitely unequal numbers.

Is intended to be used in the PhLADiPreLiO for big numbers output.

Example:

let a = 58702730574235423475087390582374507304750234705847047403750375034750723045720387502357280345
let b = 58738475082532745724057082370582054703750278402705730573074052705780857034750537507053278
showBignum 7 a == "e91~5.87...d92~345"
showBignum 7 b == "e88~5.87...d89~278"

As it is seen from the numbers after "e" the first one is greater than the second one. Nevertheless, if you append the three digits 345 (hence "d" in the notation meanitg a number of significant digits) to the end of the second one, the output here will be equivalent, but the modified second number will be greater than the first one.