<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div>On 22.08.2009, at 12:39, Trygve Reenskaug wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: 'Lucida Grande'; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div bgcolor="#ffffff" text="#000000"><i>Object>>asOop<br> "Primitive. Answer a SmallInteger whose value is half of the receiver's<span class="Apple-converted-space"> </span><br> object pointer (interpreting object pointers as 16-bit signed quantities)..."</i><br><br><i>ProtoObject>>identityHash<br> "Answer a SmallInteger whose value is related to the receiver's identity..."<br></i>This is pretty vague, but the term 'Hash' indicates that many objects can share the same value. So it is clearly cannot be used as the objectID.<br><br>The Morph>>printOn: implementation is less than ideal because it should apply to all objects, not only Morphs. Also, it should use 'asOop' rather than 'identityHash' to let us hope for uniqueness.</div></span></blockquote><div><br></div><div>You might have overlooked that both these methods are identical.</div><br><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: 'Lucida Grande'; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div bgcolor="#ffffff" text="#000000">In short:<br><ul><li>Smalltalk claims to be object oriented and I regard it as a serious flaw that the object ID is not explicitly visible.</li></ul></div></span></blockquote><div><br></div><div>What if there simply *is* no object ID?</div><br><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: 'Lucida Grande'; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div bgcolor="#ffffff" text="#000000"><ul><li>We probably need a 64-bit VM to represent it properly, e.g., using the standardized definition of OID, but a value that is guaranteed to be unique within the current set of objects would be acceptable..</li></ul></div></span></blockquote><div><br></div><div>What is the "standardized definition of OID"?</div><div><br></div><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: 'Lucida Grande'; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div bgcolor="#ffffff" text="#000000"><ul><li>I regard it as a bug that Object>>printOn: does not present some kind of object ID.</li></ul></div></span></blockquote><div><br></div>Has never bothered me.</div><br><div> <span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Lucida Grande; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><div style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; "><div style="font-family: Helvetica; "><span class="Apple-style-span" style="font-family: Helvetica; ">- Bert -</span></div><br class="Apple-interchange-newline"></div></span> </div><br></body></html>