In my experience with Pharo and other Smalltalks as well:
#printString is used for debugging, that's why the default
implementation shows the class name. It's implemented using #printOn:
#displayString (deprecated in Pharo*) is used to display the object in
the UI. It is implemented by means of #displayOn: (Dolphin used this
pattern)
#asString is the toString() equivalent of other languages. In some
cases `anObject asString asObject` should give the same object back
(e.g. in Date, Numbers, etc.). Most of the times it is the same string
as #printString, but it is not consistent.
Ej:
If you have aPerson:
aPerson printString -> "aPerson ('John Doe')"
aPerson displayString -> 'John Doe'
Regards,
(*) Why #displayString was deprecated?
Esteban A. Maringolo
2014/1/3 Frank Shearar <[email protected]>:
> On 3 January 2014 11:44, Otto Behrens <[email protected]> wrote:
>>> 'Conversion' implies using the resulting String in some further
>>> computation. 'Printing' usually implies displaying something to the
>>> user (and nothing more), or serialising to a file/network.
>>
>> What kinds of computation are you thinking of regarding a string? I
>> think I understand what you're saying, I'm just trying to make it a
>> bit more concrete in my mind.
>
> I just mean that sometimes you want to work with a string
> representation of a thing, and #asString is how you get it. For
> instance, a Symbol might printString as '#foo' while in its converted
> form it returns 'foo'.
>
>> The requirements of displaying something to the user and serialising
>> to a file/network are quite different, or not?
>
> You're right. I'm wrong in saying that #printString should be used to
> serialise anything. Actually, you'd probably use #storeString for
> serialising, if you weren't using Fuel.
>
> frank
>
