Module validators 

Field-level validators.

Standalone helpers invoked from generated validate methods on Create / Update input structs. Each returns Ok(()) on success or a redacted CoolError::Validation whose public message names the field but never echoes the rejected value (so PII does not leak via 422 bodies).

Functions

validate_email

Pragmatic email check: requires exactly one @, non-empty local and domain parts, at least one . in the domain, and no whitespace. Not a full RFC 5322 grammar — that grammar admits forms (quoted local parts, IP literals) banks rarely accept anyway. Reject early; let real KYC flows do deeper validation.

validate_iso4217

ISO 4217 currency codes are 3 ASCII uppercase letters. We do not enforce the registered set here — that table churns and is downstream policy. Banks typically pin allowed currencies via a separate allow-list anyway.

validate_length

validate_range_decimal

Decimal-typed @range enforcement. The parser accepts integer bounds (@range(min: 0, max: 100)) on both Int and Decimal fields; the i64 bounds are promoted to Decimal here so monetary fields can declare the same shape as integer counters. Banks routinely write things like amount Decimal @range(min: 0) to forbid negative amounts at the framework layer — without this, the validator silently no-ops and out-of-range values reach the database.

validate_range_i64

validate_uri