String Adress wrong (*solved*)

String Adress wrong (*solved*) - Printable Version

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String Adress wrong (*solved*) - LCD - 06-18-2010

Strangely my proportional Print SUB from Tips section, with example, does not work anymore with the latest development version of ZXBC, because the address of text in b$ is returned incorrectly (in ROM).

Code:
DIM b$ AS STRING

b$="test"

PRINT PEEK(Uinteger,@b$)+2

It does not return the correct address and compiled program says "A Invalid argument" at the end.

Code:
DIM b$ AS STRING

dim adr as uinteger

b$="test"

adr=PEEK(Uinteger,@b$)+2

print adr

Does not change anything.

Code:
adr=@b$

comes with a "Undefined label '_test_b'." if used in SUBs

Re: String Adress wrong - boriel - 06-18-2010

LCD Wrote:Strangely my proportional Print SUB from Tips section, with example, does not work anymore with the latest development version of ZXBC, because the address of text in b$ is returned incorrectly (in ROM).

Code:
DIM b$ AS STRING b$="test" PRINT PEEK(Uinteger,@b$)+2
It does not return the correct address and compiled program says "A Invalid argument" at the end.

Code:
DIM b$ AS STRING dim adr as uinteger b$="test" adr=PEEK(Uinteger,@b$)+2 print adr
Does not change anything.

Code:
adr=@b$
comes with a "Undefined label '_test_b'." if used in SUBs

As expected this is due to the (@x + N) optimization. In fact, @b + 2 might be not constant since it's a mutable object (a string). This is something I have to study...

Re: String Adress wrong - LCD - 06-18-2010

boriel Wrote:As expected this is due to the (@x + N) optimization. In fact, @b + 2 might be not constant since it's a mutable object (a string). This is something I have to study...

So maybe if it is a mutable object, you can add a function like AddressOf(b$) or similar? It would be less tragic if only POKE STRING adress,String$ and PEEK (STRING,adress[,length]) would work.

Re: String Adress wrong - boriel - 06-19-2010

I have a question about your 1st example:
This code:

Code:
Print PEEK(Uinteger, @b)+2

is supposed to return the 1st string character?

Please, download again the new version (1.2.6-r1603f) from the Archive and try...

Re: String Adress wrong - LCD - 06-19-2010

boriel Wrote:I have a question about your 1st example:
This code:

Code:
Print PEEK(Uinteger, @b)+2
is supposed to return the 1st string character?

Please, download again the new version (1.2.6-r1603f) from the Archive and try...

This should print the address of the memory where the b$ String is stored, without leading bytes. I suppose, the String is stored with size description in the front, and it is not zero-terminated. Proportional print needs the address of the string to be handed over. This is the only way it can be done as POKE STRING address,String does not work. *)
I downloaded the f-version and it works now as it should be. Thank you!

*) Okay, this is not exactly true:

Code:
propprint(0,0,3,1,@textaddress)

textaddress:

asm

  defs "Testtext"

end asm

woulw work somehow too.