A good reason why SizeOf() refuses simple types?

tinman · **Posted:** Sun Nov 09, 2003 6:23 pm

As I ask in the subject - is there any *good* reason that SizeOf() refuses to compile when you try to get the size of a simple, built-in type?

Code:

DefType.w foo
Debug SizeOf(foo)
Debug SizeOf(w)
End

Yes, I know that it won't compile. But why have it work like that? Why can't the compiler just stick in the size and be done with it?

Codemonger · **Posted:** Sun Nov 09, 2003 6:58 pm

Problem is, how would you deal with this ?

Code:

DefType.w w,foo
 Debug SizeOf(foo) 
 Debug SizeOf(w)
End

Karbon · **Posted:** Sun Nov 09, 2003 7:43 pm

Maybe make it SizeOf(.w) to get the size of a type?

Kale · **Posted:** Sun Nov 09, 2003 7:49 pm

Code:

DefType.w foo 
Debug SizeOf(foo) 
Debug SizeOf(w) 
End

Of course this will not compile, the var 'w' has not been declared. Remember that in this line:

Code:

DefType.w foo

the '.w' is an assignment NOT a variable.

From the help:

Quote:

The SizeOf command can be used to find out the size of any complex Structure (it does not work on the simple built-in types such as word and float), Interface or even variables.

Which i guess should be re-edited as now it can get the size variables.

dmoc · **Joined:** Sat Apr 26, 2003 12:40 am **Posts:** 738

I think that, once compiled, there is no type info for simple types. If there was then things would slow down noticeably. Isn't this why Fred provides #LONG, #WORD, etc?

tinman · **Posted:** Mon Nov 10, 2003 12:51 am

Kale wrote:

Of course this will not compile, the var 'w' has not been declared.

Don't make me hit you with a stick, or something worse.

Code:

Structure blah
    a.w
    b.w
EndStructure

Debug SizeOf(blah)
End

Types are supported by SizeOf. Why not the built in types? Codemonger has a point with the w variable or w type ambiguity, but other languages manage it. Why can't PB?

Kale · **Posted:** Mon Nov 10, 2003 1:17 am

Quote:

Types are supported by SizeOf.

Only user defined types. Why would you need to know how big built-in types are, you already know?

tinman · **Posted:** Mon Nov 10, 2003 10:04 am

Kale wrote:

Quote:

Types are supported by SizeOf.

Only user defined types. Why would you need to know how big built-in types are, you already know?

Because I don't want my code littered with random 1, 2 and 4 values when SizeOf(type) will give it much more meaning. I know there are constants #SIZEOF_B but that's a bit crappy compared to everything being able to be done with SizeOf().

Another example of where this would be useful is building up data section tables of sizes for things - you won't have any variables to use SizeOf() with and again the constant method ain't that nice.

Something else I've just thought of (but can't test here at the mo) - since we have a separate OffsetOf(), can SizeOf tell you the size of a field in a structure? Like:

Code:

Structure blah
  a.w
  b.w
EndStructure

Debug SizeOf(blah\a)
End

I think that would be a pretty nifty addition too, if it doesn't already do that.

freak · **Posted:** Mon Nov 10, 2003 4:16 pm

Ok, for a workaround, you could use SizeOf(WORD) . There is a structure
with only one word inside. Same applys for the other types, too.

Timo

Num3 · **Posted:** Mon Nov 10, 2003 8:22 pm

Or even easier.... Read the manual

Quote:

Name Extension Memory consumption Range
Byte .b ->1 byte in memory -128 to +127
Word .w ->2 bytes in memory -32768 to +32767
Long .l -> 4 bytes in memory -2147483648 to +2147483647
Float .f -> 4 bytes in memory unlimited (see below)
String .s -> length of the string + 1 Up to 65536 characters

Psychophanta · **Posted:** Mon Nov 10, 2003 9:45 pm

In fact, my sincere opinion: SizeOf() lacks a little bit, because coherence fault.

Moreover, things like Sizeof(blah\a) should work

Fred · **Posted:** Tue Nov 11, 2003 12:49 pm

Supporting build-in types isn't a problem. But it raises a problem I have overlooked. What should do the compiler do if a variable is named like a type ? I think than Type should have an higher priority. Sounds ok ?

About the SizeOf(struct\field), it will be implemented.

freak · **Posted:** Tue Nov 11, 2003 1:47 pm

> I think than Type should have an higher priority. Sounds ok ?

It allready works like that:

Code:

POINT.l
Debug SizeOf(POINT)

Timo

Psychophanta · **Posted:** Tue Nov 11, 2003 7:09 pm

Fred say us:

Quote:

What should do the compiler do if a variable is named like a type ? I think than Type should have an higher priority. Sounds ok ?

Sounds ok, should be coherent, but i have an idea; what about use this syntax for SizeOf() ?: :idea:

Code:

f.f=4.5
debug SizeOf(.f);<-- this if we want know size of floats
debug SizeOf(f);<-- this in case we need to know the size of variable

Fred · **Posted:** Tue Nov 11, 2003 7:36 pm

A good idea IHMO. It will break the compatibility with the normal 'C like' SizeOf() so I will see what can be done.

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A good reason why SizeOf() refuses simple types?

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