Support alternate property names for native field match

Allows properties to be specified using either the traditional format
'featureName.propertyName.fieldName' or the alternate format
'featureName(fieldName).propertyName', with fallback to support both
naming conventions. This applies to averageFieldLength and
firstOccurrenceImportance properties for the native field match feature.

Author: arnej27959

searchlib/src/vespa/searchlib/features/nativefieldmatchfeature.cpp

@@ -3,6 +3,7 @@
 #include "nativefieldmatchfeature.h"
 #include "valuefeature.h"
 #include "utils.h"
+#include <vespa/searchlib/fef/featurenamebuilder.h>
 #include <vespa/searchlib/fef/fieldinfo.h>
 #include <vespa/searchlib/fef/indexproperties.h>
 #include <vespa/searchlib/fef/itablemanager.h>
@@ -161,14 +162,26 @@ NativeFieldMatchBlueprint::setup(const IIndexEnvironment & env,
         {
             param.field = false;
         }
-        Property afl = env.getProperties().lookup(getBaseName(), "averageFieldLength", info->name());
+        std::string alt_name = FeatureNameBuilder()
+                .baseName(getBaseName())
+                .parameter(info->name())
+                .buildName();
+
+        Property afl = env.getProperties().lookup(alt_name, "averageFieldLength");
+        if (!afl.found()) {
+            afl = env.getProperties().lookup(getBaseName(), "averageFieldLength", info->name());
+        }
         if (afl.found()) {
             param.averageFieldLength = util::strToNum<uint32_t>(afl.get());
         }
 
-        param.firstOccImportance = util::strToNum<feature_t>
-            (env.getProperties().lookup(getBaseName(), "firstOccurrenceImportance", info->name()).
-             get(defaultFirstOccImportance));
+        std::string alt_importance = env.getProperties()
+                .lookup(alt_name, "firstOccurrenceImportance")
+                .get(defaultFirstOccImportance);
+        std::string importance = env.getProperties()
+                .lookup(getBaseName(), "firstOccurrenceImportance", info->name())
+                .get(alt_importance);
+        param.firstOccImportance = util::strToNum<feature_t>(importance);
 
         if (NativeRankBlueprint::useTableNormalization(env)) {
             const Table * fo = param.firstOccTable;