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web-calculus

Document Schema

2005-10-29

This specification describes the structure of a web-calculus document schema. A schema is a meta document that describes the structure of a Node. [dtd]

Abstract

A schema is a document with a fixed structure that defines the namespace for a Node's Branch Names.

Overview

Design goals

  1. An unambiguous description of the structure of a Node is provided.

Schema structure

A schema is a Node of type <http://web-calculus.org/schema/Schema>. The <Schema> schema file provides a recursive definition of the structure of a schema. This specification provides an equivalent description of the structure in English.

Description

A <Schema> defines the namespace for a Node's Branch Names.

The schema URI is provided by the 'id' branch.

Each Branch is described by a 'child' branch of type <http://web-calculus.org/schema/Branch>. A <Branch> defines the branch Name, the number of occurrences per Node, and the expected Schema of the child Node.

The Branch 'name' branch

The 'name' branch defines the Name of the described Branch.

The Branch 'arity' branch

The 'arity' branch defines the number of occurrences of the described Branch within the described Node. The possible child node types are:

The Branch 'expected' branch

The 'expected' branch defines the expected Schema of the described Branch's child node. The possible child node types are:

Predefined schemas

In addition to the previously listed schema types, a set of primitive data types is defined.

<http://web-calculus.org/Boolean>

Represents a boolean value.

<http://web-calculus.org/Integer>

Represents an integer. There are no limits on the size of the represented integer.

<http://web-calculus.org/string/String>

Represents a character string.

Footnotes

[dtd] A web-calculus schema fills the same role as a W3C XML Schema, or DTD.

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