Regex Pattern Stage

Looks up matches to regular expressions in a dictionary and then tags the match with one or more semantic tags as an alternative representation(s).

Operates On:  Lexical Items with TOKEN flag

Configuration Parameters

• patterns (string, required) - The resource which contains the pattern database
  • See below for the format.
• maxLength (integer, optional) - The max length of text to test for regex, default is 25 characters.
  • For each token, the stage will increase the size by adding tokens before and after, until a match or the 25 character limit is reach

• caseInsensitive (boolean, optional) - If true, all regex will be process as case insensitive (default = true)
• boundaryFlags (string, optional) 
  • The tokens to process must be inside two vertex mark with this flags (e.g ["TEXT_BLOCK_SPLIT"])
• skipFlags (string array, optional) - Flags to be skipped by this stage
  • Tokens marked with this flags will be ignore by this stage, and no process will be performed.
• requiredFlags (string array, optional)
  • Tokens need to have all the specified flags, in order to be processed
• debug (boolean, optional)
  • Enable all debug log functionality of the stage, if any.

{
 "type":"RegexPatternStage",
 "patterns":"regex-provider:patterns",
 "maxLength": 25,
 "caseInsensitive": true
}

Example Output

In the following example, "What's your name" is in the dictionary as a regex for self-name, and there are also regex for number "[0-9]+" and "[0-9]+\\.[0-9]+" :

 V--------------------------------------[What's your name 12 @#$ 25 63.3]---------------------------------------V  
  ^-----[What's]-----V--[your]--V--[name]--V-----[12]-----V--[@#$]--V-----[25]-----V-----------[63.3]------------^  
  ^--[What]--V--[s]--^                     ^--[{number}]--^         ^--[{number}]--^-----[63]-----V-----[3]------^  
  ^-----[what's]-----^                                                             ^---------[{number}]----------^  
  ^--[what]--^                                                                     ^--[{number}]--^--[{number}]--^  
  ^-------------[{self-name}]--------------^                                       ^---------[{number}]----------^  
  ^-------------[{self-name}]--------------^  
  ^-------------[{self-name}]--------------^  
  ^-------------[{self-name}]--------------^

Output Flags

Lex-Item Flags:

• SEMANTIC_TAG - Identifies all lexical items which are semantic tags.

Resource Data

The regex pattern must have an "pattern dictionary" (a string to JSON map) which is a list of JSON records, indexed by entity ID. In addition, there may also be a pattern map and a token index.

Pattern (Regex) Dictionary Format

The only file which is absolutely required is the pattern dictionary. It is a series of JSON records, typically indexed by entity ID.

Each JSON record represents an entity. The format is as follows:

{
    "_id" : "ca84",
    "tags" : [ 
        "number"
    ],
    "patterns" : [ 
        "[0-9]+", 
        "[0-9]+\\.[0-9]+"
    ],
    "confidence" : 0.95
  . . . additional fields as needed go here . . . 
}

Notes

1. Multiple patterns can have the same entry.
2. Additional fielded data can be added to the record
   1. As needed by downstream processes.

Fields

• id (required, string) - Identifies the entity by unique ID. This identifier must be unique across all entries (across all dictionaries).
  • Typically this is an identifier with meaning to the larger application which is using the Language Processing Toolkit.
• tags (required, array of string) - The list of semantic tags which will be added to the interpretation graph whenever any of the patterns are matched.
  • These will all be added to the interpretation graph with the SEMANTIC_TAG flag.
• patterns (required, array of string) - A list of patterns to match in the content.
• splitMatch (optional, boolean) - Indicates if the partialmatch will create a regex tag even if a full match was not met. 
• confidence (optional, float) - Specifies the confidence level of the entity, independent of any patterns matched.
  • This is the confidence of the entry, in comparison to all of the other entries. Essentially, the likelihood that this entry, will be randomly encountered.

Other, Optional Fields

• display (optional, string) - What to show the user when browsing this entity.
• context (optional, object) - A context vector which can help disambiguate this entity from others with the same pattern.
  • Format TBD, but probably a list of weighted words, phrases and tags.