Modules

A module is a set of rules packaged in a membrane with a module name definition.

Definition
   { module(modulename), RuleSet }

The RuleSet? takes effect only when it is copied or loaded outside the membrane. The module mechanism of LMNtal provides a loading mechanism of modules.

Name Space

A single-level global name space is available for the names of atoms. An atom name p can be qualified with a module name m. The resulting qualified atom name m.p can be referred to globally.

Currently, we have no means to prevent a programmer from writing arbitrary qualified names, and we have no means to abbreviate the module name part of 'exported' names.

Compile-Time Module Loading

Syntax

Use
   modulename.Atom

Membranes that contain module uses will be supplied with the copies of the rules specified in the corresponding module definitions.

Example

{ module(acc).
  acc.add(A),   acc.value(N) :- acc.value(A+N).
  acc.get(Res), acc.value(N) :- int(N) | Res=N, acc.value(N).
  acc.new                    :- acc.value(0) }.
{ acc.new, acc.add(3), acc.add(4), acc.get(N) }

Link-Time Module Loading

Link-time module lookup is performed when the source file does not contain the definition of a referenced module. When module m needs to be looked up, the file $LMNTAL_HOME/lib/src/m.lmn is loaded, compiled and linked before the execution of the user program starts, where $LMNTAL_HOME is the root directory of LMNtal.


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