Data parsing with annotated patterns

The subject disclosure pertains to data parsing with patterns or regular expressions. A mechanism is provided for annotating a regular expression with additional information regarding data extraction such as output fields and mapping of the output fields to sub-sections of matched data. A parser can utilize the annotation information to facilitate mapping and transfer of at least a portion of pattern matched data from a source to a destination. The disclosed systems and methods thus enable data to be exacted while it is being matched.