Tokenize [String]

Separates a string into tokens. The tokenization method can be defined in the parameter (e.g., only tokenize by spaces or use all punctuation).

• SOURCE [STRING]: a list of strings. Each string is tokenized.

• RESULT [STRING]: the extracted tokens. Use the score aggregation parameter to define how occurrences of the same token are handled.
• PAIR [STRING, STRING]: the original string and the extracted tokens. Use the score aggregation parameter to define how occurrences of the same token are handled.

• Tokenization: the method to tokenize the input strings.
  • None: perform no tokenization
  • Spaces: all valid Unicode space characters
  • Spaces/Punctuation: Spaces + all valid Unicode punctuation characters
  • Spaces/Punctuation/Digits: Spaces/Punctuation + all valid Unicode digit characters
  • Spaces/Punctuation/Digits/Symbols: Spaces/Punctuation/Digits + all valid Unicode symbol characters
  • Custom Regular Expression: any regular expression
• Min token length: tokens whose character length is shorter than this value are discarded
• Gram type:
  • Word (default): each token is composed by UTF-8 word n-grams
  • Character: each token is composed by UTF-8 character n-grams
• Grams: allows to extract n-gram tokens (default is 1)
• Stemming: tokens can be stemmed for a specific language or left as they are
• Case-sensitive: if set to false, upper/lower case is ignored

Output scores can be aggregated and/or normalized.