I wish to get this working:
 for i := 0 to Length(RStr)-1 do
 begin
   RStr[i] := RStr[i] xor (Key shr 8);
 ...

The first issue is that RStr[i] is not returning an integer which is needed for the
xor. Chr takes an integer and makes a character. Casting doesn't work. Anyone know
how to get the numeric value?  

Second, the text says that strings are immutable. Do I need to care about this here?
It says I can't change things in-situ, but must copy. Presumably I could have an
empty string and append the calculated value to it (using chr). Or does EWB
actually hide this from me? I don't think I've noticed this before, and I'd be
surprised if I hadn't done string edits before.
   
/Matthew Jones/

On 1/6/2014 9:02 AM, (Matthew Jones) wrote:
> The first issue is that RStr[i] is not returning an integer which is needed for the
> xor.

That would make using string and extracting characters not useable

> how to get the numeric value?

Use Ord()

So something like : Ord(RStr[i]) xor (Key shr 8);


> Second, the text says that strings are immutable. Do I need to care about this here?
> It says I can't change things in-situ, but must copy. Presumably I could have an
> empty string and append the calculated value to it (using chr). Or does EWB
> actually hide this from me? I don't think I've noticed this before, and I'd be
> surprised if I hadn't done string edits before.

Yes it does affect you - AFAIK EWB hides the string level operations
(for example appending strings and assigning back to one) but you can't
do character replacement like you want (i.e. RStr[i] := ...).
Doing append is probably best way to deal with this (  RStr2 :=  RStr2 +
Chr(...)) or alternative is to use Array of Char (in theory could be
faster but i highly doubt you'd notice so string would be simpler)

Raul

>  Anyone know
> how to get the numeric value?  

Ord(). Why didn't I think of that!

And the compiler complains with the assignment to the string position.

/Matthew Jones/

> So something like : Ord(RStr[i]) xor (Key shr 8);

I think I had to put in an extra set of parenthesis for some operation or other,
but you are spot on on everything else. Thank you.

/Matthew Jones/

Matthew,

<< The first issue is that RStr[i] is not returning an integer which is
needed for the xor. Chr takes an integer and makes a character. Casting
doesn't work. Anyone know how to get the numeric value? >>

As Raul noted - Ord():

http://www.elevatesoft.com/manual?action=viewtopic&id=ewb1&topic=Ord

<< Second, the text says that strings are immutable. Do I need to care about
this here? It says I can't change things in-situ, but must copy. Presumably
I could have an empty string and append the calculated value to it (using
chr). Or does EWB actually hide this from me? I don't think I've noticed
this before, and I'd be surprised if I hadn't done string edits before. >>

What you want is the TStringBuilder class in the WebCore unit.  It's not
documented yet, but will be in 1.03.  But, it's pretty self-explanatory and
allows you to do in-place character manipulation and assignment.

If you have any other questions, please let me know.

Tim Young
Elevate Software
www.elevatesoft.com

By the way, Tim, how is 1.03 coming?
Are we going to get our late christmas present?





"Tim Young [Elevate Software]" wrote:

Matthew,

<< The first issue is that RStr[i] is not returning an integer which is
needed for the xor. Chr takes an integer and makes a character. Casting
doesn't work. Anyone know how to get the numeric value? >>

As Raul noted - Ord():

http://www.elevatesoft.com/manual?action=viewtopic&id=ewb1&topic=Ord

<< Second, the text says that strings are immutable. Do I need to care about
this here? It says I can't change things in-situ, but must copy. Presumably
I could have an empty string and append the calculated value to it (using
chr). Or does EWB actually hide this from me? I don't think I've noticed
this before, and I'd be surprised if I hadn't done string edits before. >>

What you want is the TStringBuilder class in the WebCore unit.  It's not
documented yet, but will be in 1.03.  But, it's pretty self-explanatory and
allows you to do in-place character manipulation and assignment.

If you have any other questions, please let me know.

Tim Young
Elevate Software
www.elevatesoft.com

See ...

http://www.elevatesoft.com/forums?action=view&category=ewb&id=ewb_general&page=1&msg=4109#4109


aberas wrote:

By the way, Tim, how is 1.03 coming?
Are we going to get our late christmas present?





"Tim Young [Elevate Software]" wrote:

Matthew,

<< The first issue is that RStr[i] is not returning an integer which is
needed for the xor. Chr takes an integer and makes a character. Casting
doesn't work. Anyone know how to get the numeric value? >>

As Raul noted - Ord():

http://www.elevatesoft.com/manual?action=viewtopic&id=ewb1&topic=Ord

<< Second, the text says that strings are immutable. Do I need to care about
this here? It says I can't change things in-situ, but must copy. Presumably
I could have an empty string and append the calculated value to it (using
chr). Or does EWB actually hide this from me? I don't think I've noticed
this before, and I'd be surprised if I hadn't done string edits before. >>

What you want is the TStringBuilder class in the WebCore unit.  It's not
documented yet, but will be in 1.03.  But, it's pretty self-explanatory and
allows you to do in-place character manipulation and assignment.

If you have any other questions, please let me know.

Tim Young
Elevate Software
www.elevatesoft.com