Syntax

   FACTORY_DEF <ReaderKeyword> BranchingFactory
   [FACTORY_NAME <factory name>]
   [INPUT FEATURE_TYPE <feature type>
     [<attribute name> <attribute value>]*
     [<feature function>]*]*
   TARGET_FACTORY <factory target>
   [FALLBACK_TARGET_FACTORY <fallback factory target>]
   [MAXIMUM_COUNT <maximum loop>]
   [TEST <value> <operator> <value>]
   [OUTPUT (PASSED|FAILED|COUNT_EXCEEDED)
   FEATURE_TYPE <feature type>
     [<attribute name> <attribute value>]*
     [<feature function>]*]*

Overview

   This factory allows features to be explicitly routed to other factories. If
   present, the factory evaluates the expression defined by the TEST clause. If
   the result is true or there was no TEST clause, then the feature is output
   via the PASSED output tag and sent to the factory named <factory target>. If
   the evaluation is false, then the feature is output via the FAILED output tag
   and continues through the factory pipeline for regular processing.

   If the PASSED clause is not specified, then features that passed the test are
   sent directly to the factory identified by <factory target>. The PASSED
   clause is optional and provides a mechanism to perform operations on features
   before they are routed to the destination factory.

   If the <factory target> could not be found, then the feature will be routed
   to the <fallback factory target>, if one was specified. If no fallback was
   specified, or the fallback could not be found, then the factory will cause
   the translation to fail.

   The <factory target> can be specified as a constant name, the value of an
   attribute present on the feature being routed, or the result of a function
   call (which will be executed on the feature being routed).

   If the FAILED clause is not specified, then any features for which the TEST
   clause is false are destroyed.

   The MAXIMUM_COUNT clause specifies the maximum number of times that a feature
   is permitted to visit a particular factory. This can be used to guard against
   infinite loops; however, setting MAXIMUM_COUNT to -1 or "None" removes the
   restriction  on how many times a feature can go through the factory, thereby
   allowing infinite loops to occur. If not specified, the default value is 100.
   Sending the feature backwards through the pipeline is dangerous and should be
   used with extreme caution. If a feature does exceed the maximum allowed count,
   then it is output via the COUNT_EXCEEDED output tag.

   The difference between a maximum count value of -1 and "None" is in the
   attribute given to the exiting feature. If MAXIMUM_COUNT is not explicitly
   set to "None" in a factory definition, every feature which leaves the factory
   via the PASSED output tag has an attribute named

      <instance name>.BranchingFactory.Count

   This attribute contains the number of times that the feature has gone through
   the factory. <instance name> is the name of the BranchingFactory assigned by
   the FACTORY_NAME clause or is the automatically assigned name if the
   FACTORY_NAME clause is not specified.

   The TEST clause specifies the expression which determines if a feature is to
   go out via the PASSED output tag or the FAILED output tag.

   The <operator> must be one of <, >, =, !=, >=, or <=.

   The <value> may be a literal constant, an attribute name preceded by the
   value of operator(&), or an attribute value function. If it is an attribute
   value function, then the function will be executed on the current feature and
   the result will be used for the test.

   Example TEST clauses include:

      TEST @Area() < 100
      TEST &numLanes > 2
      TEST "Joe" = "Jerry"

Output Tags

   PASSED

      Features for which the TEST clause evaluates to true are output here
      before being sent to the factory specified by the TARGET_FACTORY clause.

   FAILED

      Features for which the TEST clause evaluates to false are output here
      before leaving the factory.

   COUNT_EXCEEDED

      Features that have entered the factory more than the value specified by
      MAXIMUM_COUNT are output here.