Choice, Sequence and Occurrence

These patterns are used to manage interaction between patterns.

This page discusses:

See Also
About Patterns

Choice

Enables to choose between several patterns. The first successful match is retained.

Important: You must provide at least one valid choice (a neutral resource or a field capture, for example), to avoid a pattern matching failure.

Content Properties
  • Literal value
  • Regular expression
  • Choice
  • Sequence
  • Reference definition
  • Analysis type
  • Rule
  • Capture fields: entity, link, attribute
  • Variable
None

Sequence

Defines a correspondence between several resources and one pattern or more:

  • Recognizes structure in flat documents such as Word or Excel
  • Is useful when a statement provides multiple result
  • Works with quantifiers (like a regular expression): pattern?, pattern, pattern*, pattern+

The sequence matching supports advanced capabilities:

  • Choice under occurrence
  • Nested sequence
  • Turn flat list into hierarchy
  • Recursive definition
Important: The sequence pattern does not match list partially.

Note: A single sequence pattern is compiled with nested structure patterns such as sequences, occurrences, choices, analysis types and pattern references.

Content Properties
Occurrences None

Occurrence

Defines how many consecutive resources should match the pattern underneath. Occurrences can contain additional sequence pattern.

Content Properties
  • Literal value
  • Regular expression
  • Choice
  • Sequence
  • Reference definition
  • Analysis type
  • Rule
  • Capture fields: entity, link, attribute
  • Variable

Multiplicity:

  • Optional
  • One
  • Zero or more
  • One or more