How Objective-C messaging works • Hacker News Board

Re: How Objective-C messaging works

#21

Post by aa0 » Sun, Aug 04, 2013, 3:32 AM UTC

pohl wrote: post #13

aa0 wrote: post #5

0xreadbook is not hexedecimal and disqualifies this whole post from any kind of intellectual redemption. Try 0xDEADBEEF,0xBAADF00D, or any constant listed here: http://en.wikipedia.org/wiki/Hexspeak

That's a bit overpedantic. It's a mnemonic for remembering the way the bytes are arranged in memory: "Ok, Bo: add re". Nobody complains that r, o, y, g, b, i, and v aren't actual colors, do they? Other than you, I mean. http://en.wikipedia.org/wiki/List_of_mnemonics

r=red, o=orange, y=yellow, etc.. No problem there.

What does K equal in hexadecimal? Well, it isn't defined for hexadecimal. K=20 is only defined in Base 21 and above.

Other than me? Hah, nice cheap shot, pole ;-)

Re: How Objective-C messaging works

#22

Post by pohl » Sun, Aug 04, 2013, 4:02 AM UTC

aa0 wrote: post #21

pohl wrote: post #13

Earlier quoted context omitted.

That's a bit overpedantic. It's a mnemonic for remembering the way the bytes are arranged in memory: "Ok, Bo: add re". Nobody complains that r, o, y, g, b, i, and v aren't actual colors, do they? Other than you, I mean. http://en.wikipedia.org/wiki/List_of_mnemonics

r=red, o=orange, y=yellow, etc.. No problem there. What does K equal in hexadecimal? Well, it isn't defined for hexadecimal. K=20 is only defined in Base 21 and above. Other than me? Hah, nice cheap shot, pole ;-)

The letters need only illustrate the positions and be memorable. No hex is required for this purpose.

Edit: The 0x communicates that the mnemonic is illustrating base 16, so your objection below is not valid.

Re: How Objective-C messaging works

#23

Post by aa0 » Sun, Aug 04, 2013, 4:10 AM UTC

pohl wrote: post #22

aa0 wrote: post #21

Earlier quoted context omitted.

r=red, o=orange, y=yellow, etc.. No problem there. What does K equal in hexadecimal? Well, it isn't defined for hexadecimal. K=20 is only defined in Base 21 and above. Other than me? Hah, nice cheap shot, pole ;-)

The letters need only illustrate the positions and be memorable. No hex is required for this purpose. Edit: The 0x communicates that the mnemonic is illustrating base 16, so your objection below is not valid.

Endian-ness changes when the base changes. For a clear explanation, actual hex is needed.

Re: How Objective-C messaging works

#24

Post by aa0 » Sun, Aug 04, 2013, 4:16 AM UTC

pohl wrote: post #22

aa0 wrote: post #21

Earlier quoted context omitted.

r=red, o=orange, y=yellow, etc.. No problem there. What does K equal in hexadecimal? Well, it isn't defined for hexadecimal. K=20 is only defined in Base 21 and above. Other than me? Hah, nice cheap shot, pole ;-)

The letters need only illustrate the positions and be memorable. No hex is required for this purpose. Edit: The 0x communicates that the mnemonic is illustrating base 16, so your objection below is not valid.

A byte is not a byte if its value exceeds 255.

Re: How Objective-C messaging works

#25

Post by dmishe » Sun, Aug 04, 2013, 7:46 PM UTC

stevejohnson wrote: post #9

Try these if you'd like an actual explanation of how Obj-C messaging works. http://www.mikeash.com/pyblog/friday-qa-2012-11-16-lets-buil... http://www.friday.com/bbum/2009/12/18/objc_msgsend-part-1-th...

Also, Mark Dalrymple series http://blog.bignerdranch.com/author/markd/