From Erights

Revision as of 13:22, 9 June 2010

When you run a .e or (.updoc) file, it is given a loader called <this> which can be used to import .emaker files from the same directory (or from a sub-directory).

For example:

 # main.e
 def makeMyObject := <this:makeMyObject>
 def obj := makeMyObject()
 ...

 # makeMyObject.emaker
 def makeMyObject() {
   ...
 }

Using multiple modules

If a program is made up of multiple modules, a separate loader can be created for each one. Each module is given its own loader as <this>, as well as loaders for its dependencies. For example, here we have two modules. "prog" is a program that depends on a library called "libfoo".

 def makeTraceln := <unsafe:org.erights.e.elib.debug.makeTraceln>
 def makeELoader := <elang:interp.ELoaderAuthor>(makeTraceln)
 
 def <libfoo> := makeELoader(<file:.../libfoo>, ["this__uriGetter" => <libfoo>], "libfoo$")
 def <prog> := makeELoader(<file:.../prog>, ["this__uriGetter" => <prog>, => <libfoo>], "prog$")
 
 def app := <prog:makeApplication>(...)

• Within libfoo, the library can load other emakers from itself using e.g. <this:somefile>.
• Within prog, a file can load other emakers from prog using e.g. <this:somefile>, or from libfoo using <libfoo:somefile>.

You could also wrap the <libfoo> given to prog to only expose its public API.

This avoids the need to set classpath and avoids conflicts between different packages.

See also

See [1] for details.