Backup diff of Modules vs current(No. 3)

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[[Documentation]]
//[[Documentation]]

*Modules

This section is subject to modification.
A module is a set of rules packaged in a membrane with a module name definition:

**Name Spaces
>{ module('''modulename'''), '''Rule&#83;et''' }

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.
The Rule&#83;et is made available only when it is copied or 'loaded' outside the membrane.  The module system of LMNtal provides a loading mechanism of modules.

Currently, no syntax exists to prohibit a programmer from writing arbitrary qualified names, and, moreover, no syntax exists to abbreviate the module name part of 'exported' names.
A module can be defined either in the source file or in a separate file.  In the latter case, the module can be either in source code or in intermediate code.

**Compile-Time Module Loading
**Name Space

***Syntax
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 qualified atom name '''m'''.'''p''' can be referred to anywhere in the program.

 Definition
    { module(modulename), Process } 
 Use
    modulename.Atom
// 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.

Membranes that contain module uses will be supplied
with the copies of the rules
specified in the corresponding module definitions.
**Compile-Time Module Loading

When a program uses a qualified atom name of the form '''m'''.'''p''', the membrane that contains the qualified atom name will be supplied with a copy of the rules
specified in the module '''m'''.

***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) }.
 { 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 referred module. When module m needs to be looked up, the file ${LMNTAL_ROOT}/lmntal_lib/m.lmn is loaded, compiled and linked before the execution of the user program starts, where ${LMNTAL_ROOT} is the directory lmntal.jar is located at.
//***in SLIM ...
Modules defined in files in the $LMNTAL_HOME/installed/share/slim/lib directory or in the directories specified after the -I option of SLIM will be loaded, compiled (if not in the intermediate code) and linked before the exection of the user program starts.

//***in LMNtal Java ...

//Link-time module lookup is performed when the source file does not contain the definition of a referenced module.  When a 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.

**System rulesets

A '''system ruleset''' is a set of global rules, namely
rules applicable to every place in the membrane structure.
For instance, built-in arithmetics (that evaluates
x=1+2*3 to x=7, for example) is implemented as
system rulesets.

A programmer can define his/her own system ruleset by
defining the ''system_ruleset'' module.

//-There are three kinds of system rulesets:
//++Built-in system rulesets that cannot be modified by users
// ---Proxies for trans-membrane links fall into this category.
//---Currently, they are processed in InterpretedRuleset
//even when the translator is used.
//++Built-in system rulesets that are described in LMNtal and
//be modified
//---Arithmetics falls in this category, but the current implementation
//handles arithetics much like i.
//++LMNtal ?v???O??????????W???[???????????????isystem_ruleset?j

//i. ? ii. ??ATranslator ?????R???p?C????? runtiem.GlobalSystemRuleset
//?N???X????B
//??? iii. ??Aruntime.SystemRulesets ?N???X?????????B