- 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>
* 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 changes. --- 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. -- -ericP office: +1.617.599.3509 mobile: +33.6.80.80.35.59 (eric@w3.org) Feel free to forward this message to any list for any purpose other than email address distribution. There are subtle nuances encoded in font variation and clever layout which can only be seen by printing this message on high-clay paper.
Received on Friday, 6 February 2015 07:57:14 UTC