Flag is a lower-level API for creating a flag on a flag section.

MapLookuper returns a LookupEnvFunc that reads from a map instead of the environment.

MultiLookuper accepts multiple [LookupEnvFunc].

NewFlagSet creates a new root flag set.

WithLookupEnv defines a custom function for looking up environment variables.

BaseCommand is the default command structure.

FlagSection represents a group section of flags.

FlagSet is the root flag set for creating and managing flag sections.

RootCommand represents a command root for a parent or collection of subcommands.

ArgPredictor is an optional interface that [Command] can implement to declare predictions for their arguments.

Command is the interface for a command or subcommand.

Value is an extension of [flag.Value] which adds additional fields for setting examples and defining aliases.

AfterParseFunc is the type signature for functions that are called after flags have been parsed.

CommandFactory returns a new instance of a command.

LookupEnvFunc is the signature of a function for looking up environment variables.

Option is an option to the flagset.

ParserFunc is a function that parses a value into T, or returns an error.

PrinterFunc is a function that pretty-prints T.

SetterFunc is a function that sets *T to T.