Predefined(?) UDT "Point" in PBCC 5

[Arie Verheul]

If i declare in PBCC 5 an UDT named Point, with members x and y as single,
the compiler protests against this with "mismatch with prior definition".
However, as there is nothing included, there is not supposed to be any prior definition.

If i declare members x and y as Long, the compiler seems perfectly happy,
which suggests that inside PBCC 5 there lives a predefined UDT named Point,
with members x and y as Long.

I could not find anything about this in the help file.
I also checked the issue with PBCC 4, and found that it is specific for PBCC 5.
Should i consider this as a compiler bug, or is there some other explanation ?

Arie Verheul

#Compile Exe
#Dim All
#Break On

Type Point
    x As Single
    y As Single
End Type

Function PBMain () As Long

    Local Pt As Point

    Print Pt.x,Pt.y

    Pt.x = 10
    Pt.y = 15

    Print Pt.x,Pt.y

    WaitKey$

End Function

[Michael Mattias]

>Should i consider this as a compiler bug,

Assuming no other explanation is forthcoming, yes.

However, if an explanation is forthcoming, also yes, except here it would be a help file bug rather than a compiler or IDE bug.

Call me a purist, but if there is a predefined UDT in the belly of the compiler somewhere, that definition should be 'findable' in the documentation.

MCM

[Bob Zale]

This may shock you, Michael, but our compiler does not have a belly.

Bob Zale

[Michael Mattias]

I knew that because "belly" can't be found in the help file; i.e., no "belly bugs."

But "belly" does not cause a duplicate defintion error at compile time and POINT does.

[Tom Hanlin]

It rather looks as though the Windows POINT type is built into the current compilers. I'll file a query with R&D.

[Rodney Hicks]

This same subject came up in June, 2009!
http://www.powerbasic.com/support/pb...reserved+words

[Arie Verheul]

Thanks Michael. I felt exactly the same way.

Thanks Tom. I suppose we will hear about the outcome in due time.

You are right indeed Rodney, i did not notice that as i normally do not
follow the Windows programming forum.
I *suspect* that the type declaration was added accidentally, as it is
difficult to think of a good reason to do so, but i understand that
we will know soon.


Arie Verheul

[Gary Beene]

From Support, I was told it was in the compiler and was undocumented. I requested for it to be documented, along with any other UDTs the compiler handles for me.

Inquiring minds like to know.

[Arie Verheul]

I fully agree with that Gary.
In fact the variable declaration is included in the code.
Having undocumented variables included in your code would be asking for trouble.
At least it should be clear who owns this variable: the compiler or the user.

Arie Verheul

[Bob Zale]

There are no undocumented variables in PowerBASIC. The definition of a user-defined type for the POINT structure is included. This definition is identical to that documented in the API include files.

The CB.NM*** notification functions require the use of several other pre-defined UDT's (NMKEY, NMMOUSE, etc.), and the POINT structure is also required, as it is a member of NMMOUSE.

Bob Zale
PowerBASIC Inc.

[Arie Verheul]

Thanks Bob. That makes it clear.
So there are no internal variables included, but just UDT definitions,
and we are free to use these definitions also for our own purposes,
if a variable of the same type would be needed.

But still, and this is just a thought, would it in that case not be preferable
to use for the built in type definitions random generated names so that they
are not going to interfere with commonly used names ?

Arie Verheul

[Michael Mattias]

still, and this is just a thought, would it in that case not be preferable
to use for the built in type definitions random generated names so that they
are not going to interfere with commonly used names ?

No. It would be better to simply DOCUMENT all these things.

All it would take is one page in the help file, "Predefined UDTs", just like there are pages for the predefined equates.

And it would also help if one of my NSFs were adopted: on 'duplicate definition' error, include WHERE the symbol was first defined, be it in one of your files (including any #INCLUDEd files) or with a predefined symbol (UDT or equate).

eg,

   error 480  Duplicate definition . Symbol 'POINT' previously defined 
  {in file xxxx line yyy}|internally by compiler }

MCM

[Tom Hanlin]

The new predefined types are NmChar, NmHdr, NmKey, NmMouse, NmToolTipsCreated, Point, and PointAPI (which is the same as Point). These match the corresponding Win32API types, and were brought in to PowerBASIC to support new language features. They will be added to the documentation and IDE keywords.

[Michael Mattias]

> NmChar, NmHdr, NmKey, NmMouse, NmToolTipsCreated...

Added to PB/CC? Pray what for? They are not used by PB/CC.

For that matter, POINT and POINTAPI are also unused by PB/CC, since you only need for POINT for NMMOUSE, which is not used in PB/CC.

Oh, well, I know THIS is a losing battle. Maybe once it's properly documented and/or the error messages spiffed up it will be moot.

MCM

[Arie Verheul]

Overview of built in UDT's

From Tom's list and the API files the following overview
of built in UDT's may be compiled.
Most of them are pretty specific.

Arie Verheul

'' OVERVIEW OF BUILT IN UDT'S

Type Point
    x               As Long
    y               As Long
End Type

Type PointAPI
    x               As Long
    y               As Long
End Type

Type NMHdr
    hwndFrom        As Dword
    idfrom          As Dword
    Code            As Long
End Type

Type NMChar
    hdr             As NMHdr
    ch              As Dword
    dwItemPrev      As Dword
    dwItemNext      As Dword
End Type

Type NMKey
    hdr             As NMHdr
    nVKey           As Dword
    uFlags          As Dword
End Type

Type NMMouse
    hdr             As NMHdr
    dwItemSpec      As Dword
    dwItemData      As Dword
    pt              As PointAPI
    dwHitInfo       As Dword
End Type

Type NMToolTipsCReated
    hdr             As NMHdr
    hwndToolTips    As Dword
End Type

[Michael Mattias]

You forgot DIRDATA.. Unless you were just trying to show the undocumented stuff.

[Tom Hanlin]

If you need a list of the documented types, please see the documentation.

[Michael Mattias]

>If you need a list of the documented types, please see the documentation.

I tried to find same in the PB/CC 5.0.1 help file. I failed. I searched on TYPE, "user-defined", "predefined" forms thereof, and never found it.

Can anyone tell me what keys to hit and what to type to find this info in the help file?

Or, may I buy a vowel? Call a friend?

MCM

[Bob Zale]

Sure. A vowel will cost you $1,000. Got a credit card?