Specifying and applying rules to data

Software stored in a non-transitory form on a computer-readable medium, for applying a rule to data from one or more data sources, the software including instructions for causing a computing system to:

• receive data from a first data source;
• process a particular data unit of an ordered plurality of data units derived at least in part from the data received from the first data source, the processing including:
• determining a first set of data units that includes an ordered subset of data units from the ordered plurality of data units, each data unit included in the ordered subset being related to the particular data unit and occurring before the particular data unit in the ordered plurality of data units;
• prior to applying the rule to the particular data unit, updating at least one state variable to a state that would result from iterating in order through the first set of data units and, for each data unit of the ordered subset, applying the rule to the data unit;
• and
• applying the rule to the particular data unit including reading the updated value of the state variable.

A computing system for applying a rule to data from one or more data sources, the computing system including:

• an input device or port configured to receive data from a first data source;
• at least one processor configured to process a particular data unit of an ordered plurality of data units derived at least in part from the data received from the first data source, the processing including:
• determining a first set of data units that includes an ordered subset of data units from the ordered plurality of data units, each data unit included in the ordered subset being related to the particular data unit and occurring before the particular data unit in the ordered plurality of data units;
• prior to applying the rule to the particular data unit, updating at least one state variable to a state that would result from iterating in order through the first set of data units and, for each data unit of the ordered subset, applying the rule to the data unit;
• and
• applying the rule to the particular data unit including reading the updated value of the state variable.

A computing system for applying a rule to data from one or more data sources, the computing system including:

• means for receiving data from a first data source;
• means for processing a particular data unit of an ordered plurality of data units derived at least in part from the data received from the first data source, the processing including:
• determining a first set of data units that includes an ordered subset of data units from the ordered plurality of data units, each data unit included in the ordered subset being related to the particular data unit and occurring before the particular data unit in the ordered plurality of data units;
• prior to applying the rule to the particular data unit, updating at least one state variable to a state that would result from iterating in order through the first set of data units and, for each data unit of the ordered subset, applying the rule to the data unit;
• and
• applying the rule to the particular data unit including reading the updated value of the state variable.