ModuleCabal-3.12.1.0Haskell2010

Distribution.Simple.Program.Types

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.

6 types
3 values

PackageCabal-3.12.1.0
Exports9
LanguageHaskell2010
LicenceBSD-3-Clause
SourceTypes.hs

Program and functions for constructing them

3 declarations

datadata Program

Represents a program which can be configured.

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

Constructors

Program
- 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.
- programNormaliseArgs :: Maybe Version -> PackageDescription -> [String] -> [String]
  A function that filters any arguments that don't impact the output from a commandline. Used to limit the volatility of dependency hashes when using new-build.

Instances1Show

Show ProgramDefined in Cabal-3.12.1.0 · Distribution.Simple.Program.Types

typetype 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]

We also use this path to set the environment when running child processes.

The ProgramDb is created with a ProgramSearchPath to which we prependProgramSearchPath to add the ones that come from cli flags and from configurations. Then each of the programs that are configured in the db inherits the same path as part of configureProgram.

datadata ProgramSearchPathEntry

Constructors

ProgramSearchPathDir FilePath
A specific dir
ProgramSearchPathDefault
The system default

Instances5Eq, Generic, Binary, Structured, Rep

Eq ProgramSearchPathEntryDefined in Cabal-3.12.1.0 · Distribution.Simple.Program.Types
Generic ProgramSearchPathEntryDefined in Cabal-3.12.1.0 · Distribution.Simple.Program.Types
Binary ProgramSearchPathEntryDefined in Cabal-3.12.1.0 · Distribution.Simple.Program.Types
Structured ProgramSearchPathEntryDefined in Cabal-3.12.1.0 · Distribution.Simple.Program.Types
type Rep ProgramSearchPathEntry = D1 ('MetaData "ProgramSearchPathEntry" "Distribution.Simple.Program.Types" "Cabal-3.12.1.0-fc60" 'False) (C1 ('MetaCons "ProgramSearchPathDir" 'PrefixI 'False) (S1 ('MetaSel 'Nothing 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 FilePath)) :+: C1 ('MetaCons "ProgramSearchPathDefault" 'PrefixI 'False) U1)Defined in Cabal-3.12.1.0 · Distribution.Simple.Program.Types

Configured program and related functions

6 declarations

datadata 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
- 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).

Instances7Eq, Read, Show, Generic, Binary, Structured, …

Eq ConfiguredProgramDefined in Cabal-3.12.1.0 · Distribution.Simple.Program.Types
Read ConfiguredProgramDefined in Cabal-3.12.1.0 · Distribution.Simple.Program.Types
Show ConfiguredProgramDefined in Cabal-3.12.1.0 · Distribution.Simple.Program.Types
Generic ConfiguredProgramDefined in Cabal-3.12.1.0 · Distribution.Simple.Program.Types
Binary ConfiguredProgramDefined in Cabal-3.12.1.0 · Distribution.Simple.Program.Types
Structured ConfiguredProgramDefined in Cabal-3.12.1.0 · Distribution.Simple.Program.Types
type Rep ConfiguredProgram = D1 ('MetaData "ConfiguredProgram" "Distribution.Simple.Program.Types" "Cabal-3.12.1.0-fc60" 'False) (C1 ('MetaCons "ConfiguredProgram" 'PrefixI 'True) (((S1 ('MetaSel ('Just "programId") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 String) :*: S1 ('MetaSel ('Just "programVersion") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (Maybe Version))) :*: (S1 ('MetaSel ('Just "programDefaultArgs") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 [String]) :*: S1 ('MetaSel ('Just "programOverrideArgs") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 [String]))) :*: ((S1 ('MetaSel ('Just "programOverrideEnv") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 [(String, Maybe String)]) :*: S1 ('MetaSel ('Just "programProperties") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (Map String String))) :*: (S1 ('MetaSel ('Just "programLocation") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 ProgramLocation) :*: S1 ('MetaSel ('Just "programMonitorFiles") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 [FilePath])))))Defined in Cabal-3.12.1.0 · Distribution.Simple.Program.Types

valueprogramPath :: ConfiguredProgram -> FilePath

The full path of a configured program.

valuesuppressOverrideArgs :: ConfiguredProgram -> ConfiguredProgram

Suppress any extra arguments added by the user.

typetype ProgArg = String

datadata 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
- locationPath :: FilePath
FoundOnSystem
The program was found automatically.
- locationPath :: FilePath

Instances7Eq, Read, Show, Generic, Binary, Structured, …

Eq ProgramLocationDefined in Cabal-3.12.1.0 · Distribution.Simple.Program.Types
Read ProgramLocationDefined in Cabal-3.12.1.0 · Distribution.Simple.Program.Types
Show ProgramLocationDefined in Cabal-3.12.1.0 · Distribution.Simple.Program.Types
Generic ProgramLocationDefined in Cabal-3.12.1.0 · Distribution.Simple.Program.Types
Binary ProgramLocationDefined in Cabal-3.12.1.0 · Distribution.Simple.Program.Types
Structured ProgramLocationDefined in Cabal-3.12.1.0 · Distribution.Simple.Program.Types
type Rep ProgramLocation = D1 ('MetaData "ProgramLocation" "Distribution.Simple.Program.Types" "Cabal-3.12.1.0-fc60" 'False) (C1 ('MetaCons "UserSpecified" 'PrefixI 'True) (S1 ('MetaSel ('Just "locationPath") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 FilePath)) :+: C1 ('MetaCons "FoundOnSystem" 'PrefixI 'True) (S1 ('MetaSel ('Just "locationPath") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 FilePath)))Defined in Cabal-3.12.1.0 · Distribution.Simple.Program.Types

valuesimpleConfiguredProgram :: String -> ProgramLocation -> ConfiguredProgram

Make a simple ConfiguredProgram.

simpleConfiguredProgram "foo" (FoundOnSystem path)