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Revision as of 13:25, 9 June 2010 by ThomasLeonard (Talk)
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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, create a new directory and add two files. main.e is the main program:

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

makeMyObject.emaker is a support file:

 # makeMyObject.emaker
 def makeMyObject() {

Files imported using <this> also have the loader in their environment, and can import further files using it.

An ELoader also allows access to the raw files (use <this>.getRoot() to get a read-only directory object). This is useful for accessing icons, documentation, etc.

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.

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