In ruby, every object is reference type except for FixNum, NilClass,
TrueClass, FalseClass.
Let's consider FixNum only.
According to http://www.rubygarden.org/ruby?GCAndMemoryManagement, FixNum
takes only 4 bytes (on 32-bit machines).
Is it true?
If so, doesn't it have any other information except for the value itself?
How does ruby know that a FixNum is actually a FixNum instead of a reference
to an object when it doesn't have any information about the type?
I'm from C# background.
In C# (actually dotnet framework), values types are structures not just a
simple value.
only 31 bits. 1 bit is used as a flag to say "this is a ptr to object or it
is an immediate value stored in word"
-a
···
On Fri, 25 Jun 2004, Sam Sungshik Kong wrote:
Hello!
In ruby, every object is reference type except for FixNum, NilClass,
TrueClass, FalseClass.
Let's consider FixNum only.
According to http://www.rubygarden.org/ruby?GCAndMemoryManagement, FixNum
takes only 4 bytes (on 32-bit machines).
Is it true?
If so, doesn't it have any other information except for the value itself?
How does ruby know that a FixNum is actually a FixNum instead of a reference
to an object when it doesn't have any information about the type?
I'm from C# background.
In C# (actually dotnet framework), values types are structures not just a
simple value.
Could somebody resolve my confusion?
Thanks.
Sam
--
EMAIL :: Ara [dot] T [dot] Howard [at] noaa [dot] gov
PHONE :: 303.497.6469
A flower falls, even though we love it;
and a weed grows, even though we do not love it. --Dogen
According to http://www.rubygarden.org/ruby?GCAndMemoryManagement, FixNum
takes only 4 bytes (on 32-bit machines).
Is it true?
If so, doesn't it have any other information except for the value itself?
How does ruby know that a FixNum is actually a FixNum instead of a reference
to an object when it doesn't have any information about the type?
In Ruby, Fixnums have 31 bits; the missing bit (least significant one)
is used to mark it as a fixnum. This works because other objects will
be at even addresses.
I'm from C# background.
In C# (actually dotnet framework), values types are structures not just a
simple value.
Most objects in Ruby are indeed represented internally by structures;
take a look at ruby.h.
···
On Sat, Jun 26, 2004 at 02:38:05AM +0900, Sam Sungshik Kong wrote:
--
Running Debian GNU/Linux Sid (unstable)
batsman dot geo at yahoo dot com
We are using Linux daily to UP our productivity - so UP yours!
-- Adapted from Pat Paulsen by Joe Sloan
In ruby, every object is reference type except for FixNum, NilClass,
TrueClass, FalseClass.
Let's consider FixNum only.
According to http://www.rubygarden.org/ruby?GCAndMemoryManagement, FixNum
takes only 4 bytes (on 32-bit machines).
Is it true?
If so, doesn't it have any other information except for the value itself?
How does ruby know that a FixNum is actually a FixNum instead of a reference
to an object when it doesn't have any information about the type?
I'm from C# background.
In C# (actually dotnet framework), values types are structures not just a
simple value.
Could somebody resolve my confusion?
Ruby checks the least significant bit of the value. If this is set then the value is a direct value such as a fixnum, otherwise it's a reference to an object.
When Ruby is constructing a fixnum it left shifts the number one place then sets the LSB.
Wow, I'm so impressed that within 30 minutes I got 3 answers...
This group is very active, helpful, and enthusiastic.
Thanks all.
May I ask further questions related to the direct value type objects?
Now I understand how the FixNum is stored in the memory.
What about other value types - true, false, nil?
How are they distinguished from FixNum?
What are their sized?
Sorry to bother you guys with my beginner questions.
Sam
"Sam Sungshik Kong" <ssk@chol.nospam.net> wrote in message
news:nmZCc.1209$QR1.961@newssvr27.news.prodigy.com...
Hello!
In ruby, every object is reference type except for FixNum, NilClass,
TrueClass, FalseClass.
Let's consider FixNum only.
According to http://www.rubygarden.org/ruby?GCAndMemoryManagement, FixNum
takes only 4 bytes (on 32-bit machines).
Is it true?
If so, doesn't it have any other information except for the value itself?
How does ruby know that a FixNum is actually a FixNum instead of a
reference
···
to an object when it doesn't have any information about the type?
I'm from C# background.
In C# (actually dotnet framework), values types are structures not just a
simple value.
