darcs-2.11.0: a distributed, interactive, smart revision control system

Safe HaskellNone

Darcs.UI.Options.Util

Description

Constructing OptSpecs and OptDescrs

Synopsis

Documentation

type Flag = DarcsFlag

This type synonym is here for brevity and because we want to import the data constructors (but not the type) of DarcsFlag qualified.

type PrimDarcsOption v = forall a. PrimOptSpec DarcsOptDescr Flag a v

This is PrimOptSpec instantiated with 'DarcsOptDescr and Flag.

type DarcsOptDescr = Compose OptDescr ((->) AbsolutePath)

We do not instantiate the d in OptSpec d f directly with OptDescr. Instead we (post-) compose it with (->) AbsolutePath. Modulo newtype noise, this is the same as

 type 'DarcsOptDescr f = OptDescr (AbsolutePath -> f)

This is so we can pass a directory relative to which an option argument is interpreted (if it has the form of a relative path).

noArg :: [Char] -> [String] -> f -> String -> DarcsOptDescr f

Construct an 'DarcsOptDescr with no arguments.

strArg :: SingleArgOptDescr String f

Construct an 'DarcsOptDescr with a String argument.

optStrArg :: SingleArgOptDescr (Maybe String) f

Construct an 'DarcsOptDescr with an optional String argument.

absPathArg :: SingleArgOptDescr AbsolutePath f

Construct an 'DarcsOptDescr with an AbsolutePath argument.

absPathOrStdArg :: SingleArgOptDescr AbsolutePathOrStd f

Construct an 'DarcsOptDescr with an AbsolutePathOrStd argument.

optAbsPathArg :: [Char] -> [String] -> String -> (AbsolutePath -> f) -> String -> String -> DarcsOptDescr f

Construct an 'DarcsOptDescr with an optional AbsolutePath argument.

data RawOptSpec f v

The raw material from which multi-valued options are built. See withDefault.

Instances

withDefault :: Eq v => v -> [RawOptSpec Flag v] -> PrimDarcsOption v

Construct a PrimDarcsOption from a default value and a list of RawOptSpec.

Precondition: the list must have an entry for each possible value (type v).

singleNoArg :: [Char] -> [String] -> Flag -> String -> PrimDarcsOption Bool

Construct a Bool valued option with a single flag that takes no arguments and has no default flag.

The arguments are: short switches, long switches, flag value, help string.

singleStrArg :: [Char] -> [String] -> (String -> Flag) -> (Flag -> Maybe String) -> String -> String -> PrimDarcsOption (Maybe String)

Construct a Maybe String valued option with a single flag that takes a String argument and has no default flag.

The arguments are: short switches, long switches, flag constructor, single flag parser, help string.

multiStrArg :: [Char] -> [String] -> (String -> Flag) -> ([Flag] -> [String]) -> String -> String -> PrimDarcsOption [String]

Similar to singleStrArg, except that the flag can be given more than once. The flag arguments are collected in a list of Strings.

multiOptStrArg :: [Char] -> [String] -> (Maybe String -> Flag) -> ([Flag] -> [Maybe String]) -> String -> String -> PrimDarcsOption [Maybe String]

Similar to multiStrArg, except that the flag arguments are optional.

singleAbsPathArg :: [Char] -> [String] -> (AbsolutePath -> Flag) -> (Flag -> Maybe AbsolutePath) -> String -> String -> PrimDarcsOption (Maybe AbsolutePath)

Construct a Maybe AbsolutePath valued option with a single flag that takes an AbsolutePath argument and has no default flag.

The arguments are: short switches, long switches, flag constructor, single flag parser, help string.

multiAbsPathArg :: [Char] -> [String] -> (AbsolutePath -> Flag) -> ([Flag] -> [AbsolutePath]) -> String -> String -> PrimDarcsOption [AbsolutePath]

Similar to singleAbsPathArg, except that the flag can be given more than once. The flag arguments are collected in a list of AbsolutePaths.

deprecated :: [String] -> [RawOptSpec Flag v] -> PrimDarcsOption ()

A deprecated option. If you want to deprecate only some flags and not the whole option, extract the RawOptSpecs out of the original option and create a new deprecated option. The strings in the first argument are appended to the automatically generated error message in case additional hints should be provided.

data AbsolutePathOrStd

This is for situations where a string (e.g. a command line argument) may take the value "-" to mean stdin or stdout (which one depends on context) instead of a normal file path.

makeAbsolute :: AbsolutePath -> FilePath -> AbsolutePath

Take an absolute path and a string representing a (possibly relative) path and combine them into an absolute path. If the second argument is already absolute, then the first argument gets ignored. This function also takes care that the result is converted to Posix convention and normalized. Also, parent directories ("..") at the front of the string argument get canceled out against trailing directory parts of the absolute path argument.

Regarding the last point, someone more familiar with how these functions are used should verify that this is indeed necessary or at least useful.