OpenEuphoria

Re: Include system

• Posted by Chris Bensler <bensler at nt.net> Dec 13, 2006
• 1125 views

ags wrote:
> 
> Hi All
> 
> I've just had a thought about the include system, well an observation really.
> 
> A program in a sub folder of an include file can say something like:
> }}}
<eucode>
> include ..\file_one.e
> </eucode>
{{{

> Which sucessfully includes a file from one directory level up.
> 
> But if that file_one.e includes another file from the folder it is in, eg
> file_two.e,
> the interpreter will not be able to locate it.
> 
> What is to stop the interpreter automatically searching the folder an include
> is actually in for any includes that file looks for?
> 
> Or would this break things? (even more 
> 
> I say this because of making library distributions--if you want to keep any
> demos in a sub folder you would want to include ..\something.ew (or include
> ..\include\something.ew) but if that file in turn includes stuff then things
> get broken.
> 
> Gary

No, it wouldn't break anything.
I beleive this issue is one of the final frontiers for the evolution of  Eu's
physical include system, and I've been suggesting (or wanting to, I can't
remember though I'm sure I mentioned it at least a few times) it for a long time.
I never really pushed it though since it first required being able to use
subfolders for includes, which is only officially possible since 3.0.

I've implemented it in my preprocessor and I'm trying to implement it in the Eu
opensource, if I can ever manage to spend enough time to figure out Robs code.

Here is how it works in my preprocessor to give an idea for those who may not
understand what is being talked about. Maybe someone else with more experience
with the Eu source code can implement it...

All I do in my preprocessor is keep track of the active include folder.

Currently Eu searches for includes
1. in the program folder
2. in the EUINC paths
3. in EUDIR/include path

With relative include paths Eu would search
1. in the active include folder
2. in the program folder
3. in the EUINC paths
4. in the EUDIR/include path

PS.
Just MNSHO, but I don't suggest using ..\ in an include statement, although I
can see the reason, it may not be avoidable and is not of particular concern if
the lib will only be used in a particular project.
Doing so means that the subfolder is bound to the parent folder.
I wouldn't say it's taboo, but it should be considered with the same weight as
using global declarations should.

Sorry, I can't fully explain why it's not desirable, but I can say that you can
do that sort of thing in PHP and I've found it to be problematic. I've been
avoiding having to code that way in PHP for a few years, so the issue is rather
vague now. Take it with a grain of salt.


Chris Bensler
~ The difference between ordinary and extraordinary is that little extra ~
http://empire.iwireweb.com - Empire for Euphoria