Struct RegexFormat 

pub struct RegexFormat { /* private fields */ }

Regex-pattern validator — the catch-all shape for “value must match this format”. Reject the field with a user-supplied message when the pattern doesn’t match.

Used by #[form(regex = "...")] on derived form structs AND by the Field::regex / Field::phone / Field::url convenience constructors. The pattern is parsed once at construction time (panics if invalid — a hardcoded pattern can’t go wrong in production; user-supplied patterns are validated at cargo build time through the macro’s Regex::new(...) compile-time call).

Implementations

impl RegexFormat

pub fn new(pattern: &str, message: impl Into<String>) -> Self

Build a regex validator from a pattern + a human message. The pattern is compiled eagerly — use regex::Regex::new shape (no leading slash, no flags suffix). Panics on an invalid pattern; the derive macro catches this at build time by emitting the literal into the generated code.

Trait Implementations

impl Validator for RegexFormat

fn check(&self, field_name: &str, value: &str) -> Result<(), String>

Check the value. field_name is included for the error message. Return Ok(()) to accept, Err(message) to reject.