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reworded requirements for section 3 Complex Constraints

From: Eric Prud'hommeaux <eric@w3.org>
Date: Fri, 6 Feb 2015 02:57:10 -0500
To: "Peter F. Patel-Schneider" <pfpschneider@gmail.com>
Cc: "public-rdf-shapes@w3.org" <public-rdf-shapes@w3.org>
Message-ID: <20150206075708.GA26296@w3.org>
* Eric Prud'hommeaux <eric@w3.org> [2015-02-06 01:56-0500]
> In ShapeRequirements, I've reworked the definitions in 2.5 in terms of
> shapes. Below is a simplified diff of the differences. With Holger's
> approval, I'll make these changes and then remove the shapes/classes
> objections.

I've reworded the requirements for Complex Constraints. The first
patch below replaces the umbrella requirement for Complex Constraints
with a specific requirement for Constraint Extensions because having
umbrella requirements is confusing and because that requirement
appeared to be about extensibility. The rest are re-definitions of
existing requirements. Again, with Holger's approval, I'll make these

--- Requirements/Complex Constraints	2015-02-06 02:50:54.408836654 -0500
+++ ShapeRequirements/Complex Constraints	2015-02-06 02:50:54.416832654 -0500
@@ -1,3 +1,5 @@
 === Complex Constraints ===
-The language should allow users to implement constraints that check complex conditions, with an expressivity as covered by the following sub-requirements (e.g. basic graph patterns, string and mathematical operations and comparison of multiple values).
+==== Constraint Extensions ====
+Shapes will have a defined extension mechanism enabling other languages to provide supplementary constraints, (e.g. basic graph patterns, string and mathematical operations and comparison of multiple values).
@@ -27,5 +29,5 @@
 ==== Expressivity: Non-Existence of Patterns ====
-Many constraints require that a certain pattern does not exist in the graph.
+Shapes will constraint on the absense as well as the presence of arcs.
@@ -37,5 +39,5 @@
 ==== Expressivity: String Operations ====
-Some constraints require building new strings out of other strings, and building new URIs out of other values.
+Shapes will provide string and URI manipulation.
@@ -47,5 +49,5 @@
 ==== Expressivity: Language Tags ====
-Some constraints require comparing language tags of RDF literals, e.g. to check that no language is used more than once per property. Also to produce multi-lingual error messages.
+Shapes will constrain on presence and uniqueness of language tags.
@@ -57,5 +59,5 @@
 ==== Expressivity: Mathematical Operations ====
-Some constraints require mathematical calculations and comparisons, e.g. area = width * height.
+Shapes will provide numeric manipulation.
@@ -67,5 +69,5 @@
 ==== Expressivity: Literal Value Comparison ====
-Some constraints require operators such as <, <=, != etc, either against constants or other values that are dynamically retrieved at query time. Includes date/time comparison.
+Shapes will provide numeric and date comparison.


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Received on Friday, 6 February 2015 07:57:14 UTC

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