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Regex Plugin

The Regex plugin generates strings that match regular expression patterns, useful for codes, identifiers, and structured strings.

Pattern Generation​

Use regex() to generate strings matching a pattern:

schema Product {
  // 3 uppercase letters, dash, 4 digits
  sku: regex("[A-Z]{3}-[0-9]{4}")
}
// Output: "ABC-1234"

Common Patterns​

Alphanumeric Codes​

schema Code {
  // 32-character alphanumeric
  api_key: alphanumeric(32),

  // 6 digits
  otp: digits(6),

  // Semantic version
  version: semver()
}

Identifiers​

schema Identifiers {
  // Order number
  order_id: regex("ORD-[0-9]{8}"),

  // License key
  license: regex("[A-Z0-9]{5}-[A-Z0-9]{5}-[A-Z0-9]{5}"),

  // Reference code
  ref: regex("[A-Z]{2}[0-9]{6}")
}

Pattern Syntax​

Standard regex syntax is supported:

PatternMeaningExample
[A-Z]Uppercase letterA, B, Z
[a-z]Lowercase lettera, b, z
[0-9]Digit0, 5, 9
[A-Za-z]Any letterA, a, Z
[A-Za-z0-9]AlphanumericA, a, 5
{n}Exactly n times[A-Z]{3} → ABC
{n,m}n to m times[0-9]{2,4} → 12, 1234
?0 or 1 time[A-Z]? → "", A
*0 or more[A-Z]* → "", ABC
+1 or more[A-Z]+ → A, ABC
|Alternationcat|dog → cat, dog
()Grouping(ab)+ → ab, abab

Shorthand Functions​

FunctionDescriptionEquivalent Pattern
alphanumeric(n)n alphanumeric chars[A-Za-z0-9]{n}
digits(n)n digits[0-9]{n}
semver()Semantic version[0-9]+\.[0-9]+\.[0-9]+

Practical Examples​

Product Codes​

schema Product {
  // SKU: Category (2 letters) + ID (6 digits)
  sku: regex("[A-Z]{2}[0-9]{6}"),

  // Barcode: EAN-13
  barcode: regex("[0-9]{13}"),

  // Model number
  model: regex("[A-Z]{3}-[0-9]{3}[A-Z]")
}

Financial Identifiers​

schema Banking {
  // IBAN (simplified)
  iban: regex("[A-Z]{2}[0-9]{2}[A-Z0-9]{4}[0-9]{7}[A-Z0-9]{0,16}"),

  // SWIFT/BIC code
  swift: regex("[A-Z]{4}[A-Z]{2}[A-Z0-9]{2}([A-Z0-9]{3})?"),

  // Credit card (test pattern)
  card: regex("4[0-9]{15}")  // Visa-like
}

Reference Numbers​

schema Order {
  // Order reference: ORD-YYYYMMDD-NNNN
  reference: regex("ORD-202[0-9][0-1][0-9][0-3][0-9]-[0-9]{4}"),

  // Tracking number
  tracking: regex("[A-Z]{2}[0-9]{9}[A-Z]{2}")
}

API Keys​

schema APICredentials {
  // API key with prefix
  api_key: regex("sk_live_[A-Za-z0-9]{32}"),

  // Webhook secret
  webhook_secret: regex("whsec_[A-Za-z0-9]{32}"),

  // Access token
  access_token: alphanumeric(64)
}

Pattern Validation​

Use matches() in constraints to validate patterns:

schema Account {
  code: string,

  // Ensure code matches expected format
  assume matches("^[A-Z]{3}[0-9]{4}$", code)
}

However, it's usually better to use regex() directly — it generates valid values without needing retry logic.

Combining with Other Features​

schema Product {
  category: "electronics" | "clothing" | "food",

  // Category-specific SKU prefix
  sku: category == "electronics" ? regex("EL-[0-9]{6}") :
       category == "clothing" ? regex("CL-[0-9]{6}") :
       regex("FD-[0-9]{6}")
}

See Also​