asciismalltalkvisualworks

Visual Works smalltalk, how to convert Ascii values to characters

using visualworks, in small talk, I'm receiving a string like '31323334' from a network connection.

I need a string that reads '1234' so I need a way of extracting two characters at a time, converting them to what they represent in ascii, and then building a string of them...

Is there a way to do so?

EDIT(7/24): for some reason many of you are assuming I will only be working with numbers and could just truncate 3s or read every other char. This is not the case, examples of strings read could include any keys on the US standard keyboard (a-z, A-Z,0-9,punctuation/annotation such as {}*&^%$...)

Solution

  • Following along the lines of what Max started to suggest:

    x := '31323334'.
in := ReadStream on: x.
out := WriteStream on: String new.
[ in atEnd ] whileFalse: [ out nextPut: (in next digitValue * 16 + (in next digitValue)) asCharacter ].
newX := out contents.

    newX will have the result '1234'. Or, if you start with:

    x := '454647'

    You will get a result of 'EFG'.

    Note that digitValue might only recognize upper case hex digits, so an asUppercase may be needed on the string before processing.