Module username

Utilities to work with usernames and pull information out of it.

Username Parsing

The parse_username function is used to parse a username and extract information from its labels. The function takes a parser, which is used to parse the labels from the username.

The parser is expected to implement the UsernameLabelParser trait, which has two methods:

• parse_label: This method is called for each label in the username, and is expected to return whether the label was used or ignored.
• build: This method is called after all labels have been parsed, and is expected to consume the parser and store any relevant information.

The parser can be a single parser or a tuple of parsers. Tuple parsers all receive all labels, unless wrapped by a ExclusiveUsernameParsers, in which case the first parser that consumes a label will stop the iteration over the parsers.

Parsers are to return UsernameLabelState::Used in case they consumed the label, and UsernameLabelState::Ignored in case they did not. This way the parser-caller (e.g. parse_username) can decide whether to fail on ignored labels.

Username Composing

Composing a username is the opposite of “Username Parsing”, and is used to suffix labels to a username.

Structs

• ComposeError
  std::error::Error returned in case composing of a username, using Composer went wrong, somehow.
• Composer
  Composer struct used to compose a username into a String, with labels, all separated by the given SEPARATOR. Empty labels aren’t allowed.
• ExclusiveUsernameParsers
  Wrapper type that can be used with a tuple of UsernameLabelParsers in order for it to stop iterating over the parsers once there was one that consumed the label.
• UsernameLabels
  Opaque string labels parsed collected using the UsernameOpaqueLabelParser.
• UsernameOpaqueLabelParser
  A UsernameLabelParser which collects all labels from the username, without any specific parsing logic.

Enums

• UsernameLabelState
  The parse state of a username label.

Constants

• DEFAULT_USERNAME_LABEL_SEPARATOR
  The default username label separator used by most built-in rama support.

Traits

• UsernameLabelParser
  A parser which can parse labels from a username.
• UsernameLabelWriter
  A type that can write itself as label(s) to compose into a username with labels. Often used by passing it to compose_username.

Functions

• compose_username
  Compose a username into a username together with its labels.
• compose_username_with_separator
  Compose a username into a username together with its labels, using a custom separator instead of the default (DEFAULT_USERNAME_LABEL_SEPARATOR)
• parse_username
  Parse a username, extracting the username (first part) and passing everything else to the UsernameLabelParser.
• parse_username_with_separator
  Parse a username, extracting the username (first part) and passing everything else to the UsernameLabelParser.