Matches() returns true if a value matches a provided compiled regular expression pattern.

MaxChars() returns true if a value contains no more than n characters.

MinChars() returns true if a value contains at least n characters.

NotBlank() returns true if a value is not an empty string.

PermittedInt() returns true if a value is in a list of permitted integers.

Use the regexp.MustCompile() function to parse a regular expression pattern for sanity checking the format of an email address.

Define a new Validator type which contains a map of validation errors for our form fields.