1. Need Help Creating include files.
Hi all,
I need to know what I am doing wrong here:
I created an include file called var.e with the following type definitions.
-- var.e include file
-- Custom type definitions
type POSITIVE(atom x)
return x >= 0
end type
type NEGATIVE(atom x)
return x < 0
end type
Then I included the file var.e in my program like so:
include get.e
include var.e -- the include file that I created.
atom sum
POSITIVE pos_num
NEGATIVE neg_num
sequence press
pos_num = prompt_number("\nEnter a positve number only!!!: ", {})
neg_num = prompt_number("\nEnter a negaitve number only!!!: ", {})
sum = pos_num + neg_num
puts(1,"\n" & "Thank You. The positive number you entered was ")
? pos_num
puts(1,"\n" & "Thank You. The negative number you entered was ")
? neg_num
puts(1,"\n" & "The result of adding the numbers is ")
? sum
press = gets(0)
When I try to execute the prog, I get this error:
numinp2.ex:29
POSITIVE has not been declared
POSITIVE pos_num
^
What am I missing? I'm brand new to programming in Euphoria.
I'm using ver 2.4 on a Win XP machine, running in a DOS window.
I put the file var.e in the euphoria\include directory.
I set the environment variable and path according to instructions found on
the web site.
Any help would be appreciated.
Thanks
Martin
2. Re: Need Help Creating include files.
Martin Berger wrote:
>
> Hi all,
>
> I need to know what I am doing wrong here:
>
> I created an include file called var.e with the following type definitions.
>
> -- var.e include file
> -- Custom type definitions
>
>
> type POSITIVE(atom x)
> return x >= 0
> end type
>
> type NEGATIVE(atom x)
> return x < 0
> end type
These need to be declared as global if you want to use them outside of
the file in which they are declared.
global type POSITIVE(atom x)
return x >= 0
end type
global type NEGATIVE(atom x)
return x < 0
end type
A type has scope just like a function, and can be called just like a
regular function.
Matt Lewis
3. Re: Need Help Creating include files.
- Posted by Martin Berger <digitronics2004 at yahoo.com>
Feb 25, 2005
-
Last edited Feb 26, 2005
Matt
Let me see if I understand, Any function or type I put in an include file
has to be declared as a global?
Martin
4. Re: Need Help Creating include files.
- Posted by Brian Broker <bkb at cnw.com>
Feb 25, 2005
-
Last edited Feb 26, 2005
Martin Berger wrote:
>
> Hi all,
>
> I need to know what I am doing wrong here:
>
<snip>
> What am I missing? I'm brand new to programming in Euphoria.
> I'm using ver 2.4 on a Win XP machine, running in a DOS window.
>
> I put the file var.e in the euphoria\include directory.
> I set the environment variable and path according to instructions found on
> the web site.
>
> Any help would be appreciated.
>
> Thanks
>
> Martin
>
See section 2.4.2 (Scope) of the reference manual (Language Definition):
When you 'include' a Euphoria file in a main file (see 2.6 Special Top-Level
Statements), only the variables and routines declared using the 'global'
keyword are accessible or even visible to the main file. The other, non-
global, declarations in the included file are forgotten at the end of the
included file, and you will get an error message, "not declared", if you try
to use them in the main file.
So to fix your problem, do this:
-- var.e include file
-- Custom type definitions
global type POSITIVE(atom x)
return x >= 0
end type
global type NEGATIVE(atom x)
return x < 0
end type
-- Brian
5. Re: Need Help Creating include files.
- Posted by Matt Lewis <matthewwalkerlewis at gmail.com>
Feb 25, 2005
-
Last edited Feb 26, 2005
Martin Berger wrote:
>
> Matt
>
> Let me see if I understand, Any function or type I put in an include file
> has to be declared as a global?
Only if you want to allow code from other files to be able to use it. I
know, it sounds like you'll want to make everything global, but as you
write more complex include files, there will inevitably be plenty of
stuff that you don't want to be global. In general, it's a good idea to
keep as much local as possible, especially variables.
Matt Lewis
6. Re: Need Help Creating include files.
- Posted by Martin Berger <digitronics2004 at yahoo.com>
Feb 25, 2005
-
Last edited Feb 26, 2005
To Matt & Brian:
Thanks for responding, problem solved!!!!
