Define a PII detector

Define a PII detector

Usage

new_detector(
  id,
  class,
  label,
  pattern,
  capture = NULL,
  validate = NULL,
  checks = NULL,
  base = 0.8,
  base_without_context = NULL,
  context = NULL,
  negative = NULL,
  context_required = FALSE,
  canonical = NULL,
  describe = NULL,
  ignore_case = FALSE,
  column_label = NULL,
  column_pattern = NULL
)

Arguments

id

Unique identifier, e.g. "aadhaar".

class

Data class used by policies, e.g. "identity_strong".

label

Human-readable name.

pattern

ICU regular expression for candidates, or several (their matches are combined). Wrap it with bounded() so it does not match inside a longer token.

capture

Name of a capture group whose span is reported instead of the whole match, or NULL. Lets a pattern match a cue such as "Name:" without reporting it; much faster than a lookbehind.

validate

Function taking the matched strings (normalised text) and returning a logical vector; candidates returning FALSE are dropped.

checks

Short description of what validate checks, reported as a reason for each match (e.g. "Verhoeff checksum valid").

base

Confidence (0-1) of a validated match without supporting context, or a function taking the matched strings and returning one confidence per match (e.g. higher for a mobile number written with +91).

base_without_context

Confidence (0-1) used instead of base when no context keyword is found, or NULL. For patterns that are strong evidence with context but weak without it (a voter ID format alone could be a product code).

context

Regex (case-insensitive) of keywords that raise confidence when they appear near the match, or NULL.

negative

Regex (case-insensitive) of keywords that lower confidence, or NULL.

context_required

If TRUE, matches without supporting context are dropped. Use for patterns too generic to trust on their own.

canonical

Function mapping matched strings to a canonical form (used for consistent tokenisation). Defaults to removing spaces and hyphens and upper-casing.

describe

Optional function returning extra reasons per match (e.g. the PAN holder type).

ignore_case

Match the pattern case-insensitively.

column_label

Regex (case-insensitive) that, when it matches the caller's extra context (a column name), makes that context the label for column_pattern, or NULL. For detectors whose pattern needs a label in the text, so that a column named card_cvv labels its values.

column_pattern

Patterns used, reporting the whole match, only when column_label matches the extra context.

Value

An object of class cg_detector.

Examples

employee_id <- new_detector(
  id = "employee_id", class = "internal", label = "Employee ID",
  pattern = bounded("EMP[0-9]{6}"),
  context = "employee|staff"
)
employee_id$label
#> [1] "Employee ID"