| Portability | non-portable (ExistentialQuantification) |
|---|---|
| Maintainer | cabal-devel@haskell.org |
| Safe Haskell | None |
Distribution.Simple.Command
Contents
Description
This is to do with command line handling. The Cabal command line is
organised into a number of named sub-commands (much like darcs). The
CommandUI abstraction represents one of these sub-commands, with a name,
description, a set of flags. Commands can be associated with actions and
run. It handles some common stuff automatically, like the --help and
command line completion flags. It is designed to allow other tools make
derived commands. This feature is used heavily in cabal-install.
- data CommandUI flags = CommandUI {
- commandName :: String
- commandSynopsis :: String
- commandUsage :: String -> String
- commandDescription :: Maybe (String -> String)
- commandNotes :: Maybe (String -> String)
- commandDefaultFlags :: flags
- commandOptions :: ShowOrParseArgs -> [OptionField flags]
- commandShowOptions :: CommandUI flags -> flags -> [String]
- data CommandParse flags
- = CommandHelp (String -> String)
- | CommandList [String]
- | CommandErrors [String]
- | CommandReadyToGo flags
- commandParseArgs :: CommandUI flags -> Bool -> [String] -> CommandParse (flags -> flags, [String])
- getNormalCommandDescriptions :: [Command action] -> [(String, String)]
- helpCommandUI :: CommandUI ()
- data ShowOrParseArgs
- usageDefault :: String -> String -> String
- usageAlternatives :: String -> [String] -> String -> String
- mkCommandUI :: String -> String -> [String] -> flags -> (ShowOrParseArgs -> [OptionField flags]) -> CommandUI flags
- hiddenCommand :: Command action -> Command action
- data Command action
- commandAddAction :: CommandUI flags -> (flags -> [String] -> action) -> Command action
- noExtraFlags :: [String] -> IO ()
- data CommandType
- data CommandSpec action = forall flags . CommandSpec (CommandUI flags) (CommandUI flags -> Command action) CommandType
- commandFromSpec :: CommandSpec a -> Command a
- commandsRun :: CommandUI a -> [Command action] -> [String] -> CommandParse (a, CommandParse action)
- data OptionField a = OptionField {
- optionName :: Name
- optionDescr :: [OptDescr a]
- type Name = String
- option :: SFlags -> LFlags -> Description -> get -> set -> MkOptDescr get set a -> OptionField a
- multiOption :: Name -> get -> set -> [get -> set -> OptDescr a] -> OptionField a
- liftOption :: (b -> a) -> (a -> b -> b) -> OptionField a -> OptionField b
- viewAsFieldDescr :: OptionField a -> FieldDescr a
- data OptDescr a
- = ReqArg Description OptFlags ArgPlaceHolder (ReadE (a -> a)) (a -> [String])
- | OptArg Description OptFlags ArgPlaceHolder (ReadE (a -> a)) (a -> a) (a -> [Maybe String])
- | ChoiceOpt [(Description, OptFlags, a -> a, a -> Bool)]
- | BoolOpt Description OptFlags OptFlags (Bool -> a -> a) (a -> Maybe Bool)
- type Description = String
- type SFlags = [Char]
- type LFlags = [String]
- type OptFlags = (SFlags, LFlags)
- type ArgPlaceHolder = String
- type MkOptDescr get set a = SFlags -> LFlags -> Description -> get -> set -> OptDescr a
- reqArg :: Monoid b => ArgPlaceHolder -> ReadE b -> (b -> [String]) -> MkOptDescr (a -> b) (b -> a -> a) a
- reqArg' :: Monoid b => ArgPlaceHolder -> (String -> b) -> (b -> [String]) -> MkOptDescr (a -> b) (b -> a -> a) a
- optArg :: Monoid b => ArgPlaceHolder -> ReadE b -> b -> (b -> [Maybe String]) -> MkOptDescr (a -> b) (b -> a -> a) a
- optArg' :: Monoid b => ArgPlaceHolder -> (Maybe String -> b) -> (b -> [Maybe String]) -> MkOptDescr (a -> b) (b -> a -> a) a
- noArg :: Eq b => b -> MkOptDescr (a -> b) (b -> a -> a) a
- boolOpt :: (b -> Maybe Bool) -> (Bool -> b) -> SFlags -> SFlags -> MkOptDescr (a -> b) (b -> a -> a) a
- boolOpt' :: (b -> Maybe Bool) -> (Bool -> b) -> OptFlags -> OptFlags -> MkOptDescr (a -> b) (b -> a -> a) a
- choiceOpt :: Eq b => [(b, OptFlags, Description)] -> MkOptDescr (a -> b) (b -> a -> a) a
- choiceOptFromEnum :: (Bounded b, Enum b, Show b, Eq b) => MkOptDescr (a -> b) (b -> a -> a) a
Command interface
data CommandUI flags
Constructors
| CommandUI | |
Fields
| |
commandShowOptions :: CommandUI flags -> flags -> [String]
Show flags in the standard long option command line format
data CommandParse flags
Constructors
| CommandHelp (String -> String) | |
| CommandList [String] | |
| CommandErrors [String] | |
| CommandReadyToGo flags |
Instances
| Functor CommandParse |
Arguments
| :: CommandUI flags | |
| -> Bool | Is the command a global or subcommand? |
| -> [String] | |
| -> CommandParse (flags -> flags, [String]) |
Parse a bunch of command line arguments
getNormalCommandDescriptions :: [Command action] -> [(String, String)]
Helper function for creating globalCommand description
helpCommandUI :: CommandUI ()
Constructing commands
data ShowOrParseArgs
usageDefault :: String -> String -> String
Default usage documentation text for commands.
usageAlternatives :: String -> [String] -> String -> String
Create usage documentation from a list of parameter configurations.
Arguments
| :: String | name |
| -> String | synopsis |
| -> [String] | usage alternatives |
| -> flags | initial/empty flags |
| -> (ShowOrParseArgs -> [OptionField flags]) | options |
| -> CommandUI flags |
Make a Command from standard GetOpt options.
hiddenCommand :: Command action -> Command action
Mark command as hidden. Hidden commands don't show up in the 'progname help' or 'progname --help' output.
Associating actions with commands
data Command action
commandAddAction :: CommandUI flags -> (flags -> [String] -> action) -> Command action
noExtraFlags :: [String] -> IO ()
Utility function, many commands do not accept additional flags. This action fails with a helpful error message if the user supplies any extra.
Building lists of commands
data CommandType
Constructors
| NormalCommand | |
| HiddenCommand |
data CommandSpec action
wraps a CommandUI together with a function that turns it into a Command.
By hiding the type of flags for the UI allows construction of a list of all UIs at the
top level of the program. That list can then be used for generation of manual page
as well as for executing the selected command.
Constructors
| forall flags . CommandSpec (CommandUI flags) (CommandUI flags -> Command action) CommandType |
commandFromSpec :: CommandSpec a -> Command a
Running commands
commandsRun :: CommandUI a -> [Command action] -> [String] -> CommandParse (a, CommandParse action)
Option Fields
data OptionField a
We usually have a data type for storing configuration values, where every field stores a configuration option, and the user sets the value either via command line flags or a configuration file. An individual OptionField models such a field, and we usually build a list of options associated to a configuration data type.
Constructors
| OptionField | |
Fields
| |
type Name = String
Constructing Option Fields
option :: SFlags -> LFlags -> Description -> get -> set -> MkOptDescr get set a -> OptionField a
Create an option taking a single OptDescr. No explicit Name is given for the Option, the name is the first LFlag given.
Arguments
| :: Name | |
| -> get | |
| -> set | |
| -> [get -> set -> OptDescr a] | MkOptDescr constructors partially applied to flags and description. |
| -> OptionField a |
Create an option taking several OptDescrs. You will have to give the flags and description individually to the OptDescr constructor.
Liftings & Projections
liftOption :: (b -> a) -> (a -> b -> b) -> OptionField a -> OptionField b
viewAsFieldDescr :: OptionField a -> FieldDescr a
to view as a FieldDescr, we sort the list of interfaces (Req > Bool > Choice > Opt) and consider only the first one.
Option Descriptions
data OptDescr a
An OptionField takes one or more OptDescrs, describing the command line interface for the field.
Constructors
| ReqArg Description OptFlags ArgPlaceHolder (ReadE (a -> a)) (a -> [String]) | |
| OptArg Description OptFlags ArgPlaceHolder (ReadE (a -> a)) (a -> a) (a -> [Maybe String]) | |
| ChoiceOpt [(Description, OptFlags, a -> a, a -> Bool)] | |
| BoolOpt Description OptFlags OptFlags (Bool -> a -> a) (a -> Maybe Bool) |
type Description = String
type SFlags = [Char]
Short command line option strings
type LFlags = [String]
Long command line option strings
type ArgPlaceHolder = String
OptDescr smart constructors
type MkOptDescr get set a = SFlags -> LFlags -> Description -> get -> set -> OptDescr a
reqArg :: Monoid b => ArgPlaceHolder -> ReadE b -> (b -> [String]) -> MkOptDescr (a -> b) (b -> a -> a) a
Create a string-valued command line interface.
reqArg' :: Monoid b => ArgPlaceHolder -> (String -> b) -> (b -> [String]) -> MkOptDescr (a -> b) (b -> a -> a) a
(String -> a) variant of reqArg
optArg :: Monoid b => ArgPlaceHolder -> ReadE b -> b -> (b -> [Maybe String]) -> MkOptDescr (a -> b) (b -> a -> a) a
Create a string-valued command line interface with a default value.
optArg' :: Monoid b => ArgPlaceHolder -> (Maybe String -> b) -> (b -> [Maybe String]) -> MkOptDescr (a -> b) (b -> a -> a) a
(String -> a) variant of optArg
noArg :: Eq b => b -> MkOptDescr (a -> b) (b -> a -> a) a
boolOpt :: (b -> Maybe Bool) -> (Bool -> b) -> SFlags -> SFlags -> MkOptDescr (a -> b) (b -> a -> a) a
boolOpt' :: (b -> Maybe Bool) -> (Bool -> b) -> OptFlags -> OptFlags -> MkOptDescr (a -> b) (b -> a -> a) a
choiceOpt :: Eq b => [(b, OptFlags, Description)] -> MkOptDescr (a -> b) (b -> a -> a) a
create a Choice option
choiceOptFromEnum :: (Bounded b, Enum b, Show b, Eq b) => MkOptDescr (a -> b) (b -> a -> a) a
create a Choice option out of an enumeration type. As long flags, the Show output is used. As short flags, the first character which does not conflict with a previous one is used.