Smalltalk - Re: how can I improve this

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Re: how can I improve this

Posted by hernanmd on Sep 14, 2020; 8:19pm
URL: https://forum.world.st/how-can-I-improve-this-tp5121828p5121835.html

Hi Roelof,

Maybe something like this:

String>>hammingDistanceTo: aString
	" Answer the amount of substitutions between the receiver and aString. Both must be of equal length "

	^ (1 to: self size) count: [ : i | (self at: i) ~= (aString at: i) ]

El lun., 14 sept. 2020 a las 16:15, Roelof Wobben via Pharo-users (<[hidden email]>) escribió:

Hello,

I have solved the hamming challenge of exercism where I have to find in
how many places two strings are different.

my solution is :

distanceStrand1: aString strand2: aString2
     aString size == aString2 size
         ifFalse: [ DomainError signal: (self messageFor: aString
strand2: aString2) ].
     ^ (1 to: aString size)
         sumNumbers: [ :index |
             (aString at: index) == (aString2 at: index)
                 ifTrue: [ 0 ]
                 ifFalse: [ 1 ] ]

messageFor: aString strand2: aString2
     aString notEmpty & aString2 notEmpty
         ifTrue: [ ^ 'left and right strands must be of equal length' ].
     aString ifEmpty: [ ^ 'left strand must not be empty' ].
     ^ 'right strand must not be empty'

Can this be improved?

Roelof