An apparatus for extracting selected information from a set of symbols includes said alignment module is configured to retrieve test patterns from a symbol input, and to attempt alignment of test patterns with a canonical pattern. Successful alignment between a particular test pattern and said canonical pattern indicates of existence of information of interest in a particular candidate pattern. Upon detection of a successful alignment, the alignment module passes information concerning the test pattern to a user. Additionally, in response to detecting an unsuccessful attempt to align the first test pattern and the canonical pattern, said alignment module passes, to said user, information concerning the first test pattern.