Cabal-2.0.1.0: A framework for packaging Haskell software

Copyright | Isaac Jones 2006 Duncan Coutts 2007-2009
Maintainer | cabal-devel@haskell.org
Portability | portable
Safe Haskell | None
Language | Haskell2010

Distribution.Simple.Program.Types

Contents

- Program and functions for constructing them
- Configured program and related functions

Description

This provides an abstraction which deals with configuring and running programs. A `Program` is a static notion of a known program. A `ConfiguredProgram` is a `Program` that has been found on the current machine and is ready to be run (possibly with some user-supplied default args). Configuring a program involves finding its location and if necessary finding its version. There's reasonable default behavior for trying to find "foo" in PATH, being able to override its location, etc.

Synopsis

- data Program = Program {
  - programName :: String
  - programFindLocation :: Verbosity -> ProgramSearchPath -> IO (Maybe (FilePath, [FilePath]))
  - programFindVersion :: Verbosity -> FilePath -> IO (Maybe Version)
  - programPostConf :: Verbosity -> ConfiguredProgram -> IO ConfiguredProgram
  }
- type ProgramSearchPath = [ProgramSearchPathEntry]
- data ProgramSearchPathEntry
  - = ProgramSearchPathDir FilePath
  - | ProgramSearchPathDefault
- simpleProgram :: String -> Program
- data ConfiguredProgram = ConfiguredProgram {
  - programId :: String
  - programVersion :: Maybe Version
  - programDefaultArgs :: [String]
  - programOverrideArgs :: [String]
  - programOverrideEnv :: [(String, Maybe String)]
  - programProperties :: Map String String
  - programLocation :: ProgramLocation
  - programMonitorFiles :: [FilePath]
  }
- programPath :: ConfiguredProgram -> FilePath
- suppressOverrideArgs :: ConfiguredProgram -> ConfiguredProgram
- type ProgArg = String
- data ProgramLocation
  - = UserSpecified {
    - locationPath :: FilePath
    }
  - | FoundOnSystem {
    - locationPath :: FilePath
    }
- simpleConfiguredProgram :: String -> ProgramLocation -> ConfiguredProgram

# Program and functions for constructing them

data Program #

Represents a program which can be configured.

Note: rather than constructing this directly, start with `simpleProgram` and override any extra fields.

Constructors

Program |

Fields

- programName :: String

  The simple name of the program, eg. ghc

- programFindLocation :: Verbosity -> ProgramSearchPath -> IO (Maybe (FilePath, [FilePath]))

  A function to search for the program if its location was not specified by the user. Usually this will just be a call to `findProgramOnSearchPath`.

  It is supplied with the prevailing search path which will typically just be used as-is, but can be extended or ignored as needed.

  For the purpose of change monitoring, in addition to the location where the program was found, it returns all the other places that were tried.

- programFindVersion :: Verbosity -> FilePath -> IO (Maybe Version)

  Try to find the version of the program. For many programs this is not possible or is not necessary so it's OK to return Nothing.

- programPostConf :: Verbosity -> ConfiguredProgram -> IO ConfiguredProgram

  A function to do any additional configuration after we have located the program (and perhaps identified its version). For example it could add args, or environment vars.

Instances

Show Program # |
Methods showsPrec :: Int -> Program -> ShowS Source # show :: Program -> String Source # showList :: [Program] -> ShowS Source #

type ProgramSearchPath = [ProgramSearchPathEntry] #

A search path to use when locating executables. This is analogous to the unix `$PATH` or win32 `%PATH%` but with the ability to use the system default method for finding executables (`findExecutable` which on unix is simply looking on the `$PATH` but on win32 is a bit more complicated).

The default to use is `[ProgSearchPathDefault]` but you can add extra dirs either before, after or instead of the default, e.g. here we add an extra dir to search after the usual ones.

    ['ProgramSearchPathDefault', 'ProgramSearchPathDir' dir]

data ProgramSearchPathEntry #

Constructors

ProgramSearchPathDir FilePath | A specific dir
ProgramSearchPathDefault | The system default

Instances

Eq ProgramSearchPathEntry # |
Methods (==) :: ProgramSearchPathEntry -> ProgramSearchPathEntry -> Bool # (/=) :: ProgramSearchPathEntry -> ProgramSearchPathEntry -> Bool #
Generic ProgramSearchPathEntry # |
Associated Types type Rep ProgramSearchPathEntry :: * -> * Source # Methods from :: ProgramSearchPathEntry -> Rep ProgramSearchPathEntry x Source # to :: Rep ProgramSearchPathEntry x -> ProgramSearchPathEntry Source #
Binary ProgramSearchPathEntry # |
Methods put :: ProgramSearchPathEntry -> Put Source # get :: Get ProgramSearchPathEntry Source # putList :: [ProgramSearchPathEntry] -> Put Source #
type Rep ProgramSearchPathEntry # |
type Rep ProgramSearchPathEntry = D1 * (MetaData "ProgramSearchPathEntry" "Distribution.Simple.Program.Find" "Cabal-2.0.1.0" False) ((:+:) * (C1 * (MetaCons "ProgramSearchPathDir" PrefixI False) (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * FilePath))) (C1 * (MetaCons "ProgramSearchPathDefault" PrefixI False) (U1 *)))

simpleProgram :: String -> Program #

Make a simple named program.

By default we'll just search for it in the path and not try to find the version name. You can override these behaviours if necessary, eg:

    (simpleProgram "foo") { programFindLocation = ... , programFindVersion ... }

# Configured program and related functions

data ConfiguredProgram #

Represents a program which has been configured and is thus ready to be run.

These are usually made by configuring a `Program`, but if you have to construct one directly then start with `simpleConfiguredProgram` and override any extra fields.

Constructors

ConfiguredProgram |

Fields

- programId :: String

  Just the name again

- programVersion :: Maybe Version

  The version of this program, if it is known.

- programDefaultArgs :: [String]

  Default command-line args for this program. These flags will appear first on the command line, so they can be overridden by subsequent flags.

- programOverrideArgs :: [String]

  Override command-line args for this program. These flags will appear last on the command line, so they override all earlier flags.

- programOverrideEnv :: [(String, Maybe String)]

  Override environment variables for this program. These env vars will extend/override the prevailing environment of the current to form the environment for the new process.

- programProperties :: Map String String

  A key-value map listing various properties of the program, useful for feature detection. Populated during the configuration step, key names depend on the specific program.

- programLocation :: ProgramLocation

  Location of the program. eg. `/usr/bin/ghc-6.4`

- programMonitorFiles :: [FilePath]

  In addition to the `programLocation` where the program was found, these are additional locations that were looked at. The combination of ths found location and these not-found locations can be used to monitor to detect when the re-configuring the program might give a different result (e.g. found in a different location).

Instances

Eq ConfiguredProgram # |
Methods (==) :: ConfiguredProgram -> ConfiguredProgram -> Bool # (/=) :: ConfiguredProgram -> ConfiguredProgram -> Bool #
Read ConfiguredProgram # |
Methods readsPrec :: Int -> ReadS ConfiguredProgram Source # readList :: ReadS [ConfiguredProgram] Source # readPrec :: ReadPrec ConfiguredProgram Source # readListPrec :: ReadPrec [ConfiguredProgram] Source #
Show ConfiguredProgram # |
Methods showsPrec :: Int -> ConfiguredProgram -> ShowS Source # show :: ConfiguredProgram -> String Source # showList :: [ConfiguredProgram] -> ShowS Source #
Generic ConfiguredProgram # |
Associated Types type Rep ConfiguredProgram :: * -> * Source # Methods from :: ConfiguredProgram -> Rep ConfiguredProgram x Source # to :: Rep ConfiguredProgram x -> ConfiguredProgram Source #
Binary ConfiguredProgram # |
Methods put :: ConfiguredProgram -> Put Source # get :: Get ConfiguredProgram Source # putList :: [ConfiguredProgram] -> Put Source #
type Rep ConfiguredProgram # |

type Rep ConfiguredProgram = D1 * (MetaData "ConfiguredProgram" "Distribution.Simple.Program.Types" "Cabal-2.0.1.0" False) (C1 * (MetaCons "ConfiguredProgram" PrefixI True) ((:*:) * ((:*:) * ((:*:) * (S1 * (MetaSel (Just Symbol "programId") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * String)) (S1 * (MetaSel (Just Symbol "programVersion") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * (Maybe Version)))) ((:*:) * (S1 * (MetaSel (Just Symbol "programDefaultArgs") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * [String])) (S1 * (MetaSel (Just Symbol "programOverrideArgs") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * [String])))) ((:*:) * ((:*:) * (S1 * (MetaSel (Just Symbol "programOverrideEnv") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * [(String, Maybe String)])) (S1 * (MetaSel (Just Symbol "programProperties") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * (Map String String)))) ((:*:) * (S1 * (MetaSel (Just Symbol "programLocation") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * ProgramLocation)) (S1 * (MetaSel (Just Symbol "programMonitorFiles") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * [FilePath]))))))

programPath :: ConfiguredProgram -> FilePath #

The full path of a configured program.

suppressOverrideArgs :: ConfiguredProgram -> ConfiguredProgram #

Suppress any extra arguments added by the user.

type ProgArg = String #

data ProgramLocation #

Where a program was found. Also tells us whether it's specified by user or not. This includes not just the path, but the program as well.

Constructors

UserSpecified | The user gave the path to this program, eg. --ghc-path=/usr/bin/ghc-6.6

Fields

- locationPath :: FilePath

FoundOnSystem | The program was found automatically.

Fields

- locationPath :: FilePath

Instances

Eq ProgramLocation # |
Methods (==) :: ProgramLocation -> ProgramLocation -> Bool # (/=) :: ProgramLocation -> ProgramLocation -> Bool #
Read ProgramLocation # |
Methods readsPrec :: Int -> ReadS ProgramLocation Source # readList :: ReadS [ProgramLocation] Source # readPrec :: ReadPrec ProgramLocation Source # readListPrec :: ReadPrec [ProgramLocation] Source #
Show ProgramLocation # |
Methods showsPrec :: Int -> ProgramLocation -> ShowS Source # show :: ProgramLocation -> String Source # showList :: [ProgramLocation] -> ShowS Source #
Generic ProgramLocation # |
Associated Types type Rep ProgramLocation :: * -> * Source # Methods from :: ProgramLocation -> Rep ProgramLocation x Source # to :: Rep ProgramLocation x -> ProgramLocation Source #
Binary ProgramLocation # |
Methods put :: ProgramLocation -> Put Source # get :: Get ProgramLocation Source # putList :: [ProgramLocation] -> Put Source #
type Rep ProgramLocation # |

type Rep ProgramLocation = D1 * (MetaData "ProgramLocation" "Distribution.Simple.Program.Types" "Cabal-2.0.1.0" False) ((:+:) * (C1 * (MetaCons "UserSpecified" PrefixI True) (S1 * (MetaSel (Just Symbol "locationPath") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * FilePath))) (C1 * (MetaCons "FoundOnSystem" PrefixI True) (S1 * (MetaSel (Just Symbol "locationPath") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * FilePath))))

simpleConfiguredProgram :: String -> ProgramLocation -> ConfiguredProgram #

Make a simple `ConfiguredProgram`.

    simpleConfiguredProgram "foo" (FoundOnSystem path)