Print pointer

[aurelCB]

Hi
how to properly cast string to pointer array and print
this code not work ( i probably for get so many things )

Code Select Expand

def a[5]:pointer
a[3]="new": a[4]="element"
MOVE win,0,60:PRINT win,#a[3]
MOVE win,0,80:PRINT win,#a[4]

[Brian]

Not an expert on pointers, but try:

MOVE win,0,60:PRINT win,#<STRING>a[3]
MOVE win,0,80:PRINT win,#<STRING>a[4]

Brian

[aurelCB]

Hi Brian
Something is really strange
but not work ,program just crush 
here is complete test program

Code Select Expand

'the lines program

DEF win:window
DEF l,t,w,h,size:int
'def a[5]:pointer
'open a window and add a menu
OPENWINDOW win,0,0,400,300,@SIZE|@MINBOX|@MAXBOX|@CAPTION,0,"Lines",&mainwindow

BEGINMENU win
MENUTITLE "Options"
MENUITEM "Clear",0,1
BEGINPOPUP "Line Size"
MENUITEM "1",0,2
MENUITEM "2",0,3
MENUITEM "3",0,4
ENDPOPUP
MENUITEM "Quit",0,5
ENDMENU
'draw the lines every 10 millesceonds

'MOVE win,20,20:PRINT win,STR$(@SIZE|@MINBOX|@MAXBOX|@CAPTION)
'MOVE win,20,40:PRINT win,STR$(@NOAUTODRAW)
def a[5]:pointer
a[3]="new": a[4]="element"
MOVE win,0,60:PRINT win,#<string>a[3]
MOVE win,0,80:PRINT win,#<string>a[4]
'
run = 1
'process messages until somebody closes us
waituntil win = 0 | run = 0
end
'this is the handler subroutine for the window
SUB mainwindow
SELECT @MESSAGE
CASE @IDCREATE
'center our window on creation
CENTERWINDOW win

CASE @IDCLOSEWINDOW

CLOSEWINDOW win

CASE @IDMENUPICK
SELECT @MENUNUM
CASE 1
RECT win,0,0,w,h,RGB(255,255,255),RGB(255,255,255)
CASE 2
CASE& 3
CASE& 4
SETLINESTYLE win,@LSSOLID,@MENUNUM - 1
size = @MENUNUM - 1
CASE 5
run = 0
ENDSELECT
CASE @IDMENUINIT

END SELECT
RETURN
END SUB

[GWS]

Hi Aurel,

This works ..

Code Select Expand


'the lines program

DEF win:window
DEF l,t,w,h,size:int

def a,b:string
def ptr1,ptr2:pointer

OPENWINDOW win,0,0,400,300,@SIZE|@MINBOX|@MAXBOX|@CAPTION,0,"Lines",&mainwindow

BEGINMENU win
MENUTITLE "Options"
MENUITEM "Clear",0,1
BEGINPOPUP "Line Size"
MENUITEM "1",0,2
MENUITEM "2",0,3
MENUITEM "3",0,4
ENDPOPUP
MENUITEM "Quit",0,5
ENDMENU

a = "new"
b = "element"

ptr1 = a :' point to start of string a
ptr2 = b :' point to start of string b

MOVE win,0,60:PRINT win,a + "   " + #<string>ptr1
MOVE win,0,80:PRINT win,b + "   " + #<string>ptr2

run = 1
'process messages until somebody closes us
waituntil win = 0 | run = 0
end

SUB mainwindow(),int
SELECT @MESSAGE
CASE @IDCREATE
CENTERWINDOW win :'center our window on creation
CASE @IDCLOSEWINDOW
CLOSEWINDOW win
CASE @IDMENUPICK
SELECT @MENUNUM
CASE 1
RECT win,0,0,w,h,RGB(255,255,255),RGB(255,255,255)
CASE 2
CASE& 3
CASE& 4
SETLINESTYLE win,@LSSOLID,@MENUNUM - 1
size = @MENUNUM - 1
CASE 5
run = 0
ENDSELECT
CASE @IDMENUINIT

END SELECT
RETURN(0)
END SUB


.. but I can't think it gets you very far 

I don't think you can have an array of pointers - and they would only be pointing to the start of each string, which are laid out in memory as strings of characters anyway.

You might be better putting your descriptors in a string array. ie: desc[0] = "new","element"
and referring to the one you require with an index value 0 or 1.  So desc[1] = "element".
You would then set the index you need in the program somewhere ..

Best wishes,

Graham

[aurelCB]

Hi Graham
and thanks for replay ...
yes i know that array of pointers is possible but i forget how casting work
so i think that i figured ..and i also interesting to see that pointer variable respond as array to

Code Select Expand

'casting string pointer...........
'this shows that pointer can hold each char of string array
pointer pa[5]
pointer p1,p2
'fill pointer array elements with strings...
pa[3]="new": pa[4]="element"
'set pointer with each element....
p1=pa[3]:p2=pa[4]
MOVE win,0,60:PRINT win,#<string>p1[0]
MOVE win,0,80:PRINT win,#<string>p1[1]
MOVE win,0,100:PRINT win,#<string>p1[2]
MOVE win,0,120:PRINT win,#<string>p1
MOVE win,0,150:PRINT win,#<string>p2