Object-Relational Language

Last modified: June 12 1998

Object-Relational Language

Introduction

Universal Financial Object

Mind Interchange Language

Currently, complete ORL specifications aren't available yet. Anyway, in you are interested, just become our partner and obtain full information in terms of our cooperation. To do so, just drop e-mail with your suggestions to Anton Kolonin.

Introduction

ORL is not just a language. Like for its parents, Smalltalk, Lisp, Prolog and SQL it is just a way of doing computing. That means, to use full power of ORL you need special software engine or even special computer. At this moment, C++ based engine for Windows is nearly ready to launch. Java based engine is coming and C++ based UNIX engine would be fine in future.

History

1987-1993. Oleg Vlasov's BOOL language at CTC Company, Chita, Russia

1993-1995. Anton Kolonin's visual D4 engine and language at CTC Company, Chita, Russia

1994-1997. Leonid Kouzine's object-relational mapping engine at FTC, Novosibirsk, Russia

1995-1997. Anton Kolonin's objective engine at STS Company, Novosibirsk, Russia

Concepts
The main ideas of ORL language are

Language semantics is nearly equal to underlying engine semantics. That means, no any "compilation" is needed to put source code into executable format or in other words, source code is equal to p-code.

ORL statements read from any stream (local file or remote URL) turn in ORL objects in memory and might be easily stored back into ORL statements into another stream. That is, no any additional protocol is required to communicate one engine with another on the network.

Each system engine itself is nothing else than ORL objects preloaded in memory at system startup. So, it is welcome to inherit system-defined objects features or even override system object's methods.

Object is similar to Process and Class is similar to Function. One difference between object and process is lifecycle (creation-destruction or startup-shutdown).
ORL engine functions

Data transfer between user-defined data structures and regular data sources as SQL databases, spreadsheet tables or flat files, etc.

Transparent manipulation with such an entities as object, class, method, process, input-output form, access right. Those objects are basics to specify another user-defined objects, classes, procedures, forms etc.

Object-oriented "object-attribute" and relational "entity-relational" approaches support for objects/entities manipulation.

Distributed referential integrity control.

ORL engine architecture

Engine is just a set of "system-defined" objects and methods.

Engine objects and methods structure is defined within ORL language.

Engine basic classes

Data classes

Value
Reference
Collection
Object

Functional classes

Class method or "free-lance" function
Data access operator within any method, function or other complex operator
Data access query within any method, function or other complex operator

Metadata classes

Class (just a class of "class" objects)
Attribute
Domain

ORL engine implementation

Intended to be realized in three ways

Single-user workplace

Single-user client workplace

Multi-user client-server with full application server features and transaction management

Originally written in Microsoft Visual C++, thought to be easily moved to Java. Communication support is Remote Automation/DCOM or TCP/IP sockets.

Object-Relational Language

Language semantics is adequate to underlying engine semantics.

Language allows manipulating with objects in regular object-oriented notation, but object access is powered by extended relational notation.

The basic entity for language and engine are not "class" but "object" - each class is just a regular instance of basic class "class" and all objects in system are instances of class "object".

Merging object-oriented "CLASS.METHOD" and relational "SELECT/UPDATE TABLE WHERE CONDITION" notations allows to perform any manipulations with any set of objects, say "TABLE(CONDITION).METHOD" or "CLASS(CONDITION).SELECT/UPDATE" .

The very basic elements of language are

Value

Reference

Collection

Object

Only one real language statement is "Query". What is going on during file input, is just direct translation of input file characters into query object and running such a query. In it's turn; query itself creates, modifies or even objects in memory.

Most important subjects of query processing are