Author: schor
Date: Wed Mar 27 18:53:26 2013
New Revision: 1461793
URL: http://svn.apache.org/r1461793
Log:
no Jira - add a section on how type merging is done to the reference manual
Modified:
uima/uimaj/branches/filteredCompress-uima-2498/uima-docbook-references/src/docbook/ref.cas.xml
Modified:
uima/uimaj/branches/filteredCompress-uima-2498/uima-docbook-references/src/docbook/ref.cas.xml
URL:
http://svn.apache.org/viewvc/uima/uimaj/branches/filteredCompress-uima-2498/uima-docbook-references/src/docbook/ref.cas.xml?rev=1461793&r1=1461792&r2=1461793&view=diff
==============================================================================
---
uima/uimaj/branches/filteredCompress-uima-2498/uima-docbook-references/src/docbook/ref.cas.xml
(original)
+++
uima/uimaj/branches/filteredCompress-uima-2498/uima-docbook-references/src/docbook/ref.cas.xml
Wed Mar 27 18:53:26 2013
@@ -960,4 +960,30 @@ FSIterator it = cas.createFilteredIterat
defined features within them.</para>
</section>
</section>
+
+ <section id="ugr.ref.cas.typemerging">
+ <title>Type Merging</title>
+
+ <para>When annotators are combined in an aggregate, their defined type
systems are merged.
+ This is designed to support independent development of annotator
components. The merge
+ results in a single defined type system for CASes that flow through a
particular set of
+ annotators.</para>
+
+ <para>The basic operation of a type system merge is to iterate through all
the defined types,
+ and if two annotators define the same fully qualified type name,
+ to take the features defined for those types
+ and form a logical union of those features. This operation requires that
same-named features
+ have the same range type names. The resulting type system has features
comprising the union
+ of all features over all the various definitions for this type in
different annotators.
+ </para>
+
+ <para>Feature merging checks that for all features having the same name in
a type, that the
+ range type is identical; otherwise an error is signaled.</para>
+
+ <para>Types are combined for merging when their fully qualified names are
the same.
+ Two different definitions can be merged even if their supertype
definitions do not match, if
+ one supertype subsumes the other supertype; otherwise an error is
signaled. Likewise, two types
+ with the same name can be merged only if their features can be merged.
+ </para>
+ </section>
</chapter>
\ No newline at end of file
