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.

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.

• 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.

Instances

Show Program

Defined in Distribution.Simple.Program.Types

Methods

showsPrec :: Int -> Program -> ShowS

show :: Program -> String

showList :: [Program] -> ShowS

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

Defined in Distribution.Simple.Program.Find

Methods

(==) :: ProgramSearchPathEntry -> ProgramSearchPathEntry -> Bool

(/=) :: ProgramSearchPathEntry -> ProgramSearchPathEntry -> Bool

Generic ProgramSearchPathEntry

Defined in Distribution.Simple.Program.Find

Associated Types

type Rep ProgramSearchPathEntry :: Type -> Type

Methods

from :: ProgramSearchPathEntry -> Rep ProgramSearchPathEntry x

to :: Rep ProgramSearchPathEntry x -> ProgramSearchPathEntry

Binary ProgramSearchPathEntry

Defined in Distribution.Simple.Program.Find

Methods

put :: ProgramSearchPathEntry -> Put

get :: Get ProgramSearchPathEntry

putList :: [ProgramSearchPathEntry] -> Put

Structured ProgramSearchPathEntry

Defined in Distribution.Simple.Program.Find

Methods

structure :: Proxy ProgramSearchPathEntry -> Structure

structureHash' :: Tagged ProgramSearchPathEntry MD5

type Rep ProgramSearchPathEntry

Defined in Distribution.Simple.Program.Find

type Rep ProgramSearchPathEntry = D1 ('MetaData "ProgramSearchPathEntry" "Distribution.Simple.Program.Find" "Cabal-3.6.2.0-Gs52rnMRRrI82oZgek17JT" 'False) (C1 ('MetaCons "ProgramSearchPathDir" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 FilePath)) :+: C1 ('MetaCons "ProgramSearchPathDefault" 'PrefixI 'False) (U1 :: Type -> Type))

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

Defined in Distribution.Simple.Program.Types

Methods

(==) :: ConfiguredProgram -> ConfiguredProgram -> Bool

(/=) :: ConfiguredProgram -> ConfiguredProgram -> Bool

Read ConfiguredProgram

Defined in Distribution.Simple.Program.Types

Methods

readsPrec :: Int -> ReadS ConfiguredProgram

readList :: ReadS [ConfiguredProgram]

readPrec :: ReadPrec ConfiguredProgram

readListPrec :: ReadPrec [ConfiguredProgram]

Show ConfiguredProgram

Defined in Distribution.Simple.Program.Types

Methods

showsPrec :: Int -> ConfiguredProgram -> ShowS

show :: ConfiguredProgram -> String

showList :: [ConfiguredProgram] -> ShowS

Generic ConfiguredProgram

Defined in Distribution.Simple.Program.Types

Associated Types

type Rep ConfiguredProgram :: Type -> Type

Methods

from :: ConfiguredProgram -> Rep ConfiguredProgram x

to :: Rep ConfiguredProgram x -> ConfiguredProgram

Binary ConfiguredProgram

Defined in Distribution.Simple.Program.Types

Methods

put :: ConfiguredProgram -> Put

get :: Get ConfiguredProgram

putList :: [ConfiguredProgram] -> Put

Structured ConfiguredProgram

Defined in Distribution.Simple.Program.Types

Methods

structure :: Proxy ConfiguredProgram -> Structure

structureHash' :: Tagged ConfiguredProgram MD5

type Rep ConfiguredProgram

Defined in Distribution.Simple.Program.Types

type Rep ConfiguredProgram = D1 ('MetaData "ConfiguredProgram" "Distribution.Simple.Program.Types" "Cabal-3.6.2.0-Gs52rnMRRrI82oZgek17JT" '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])))))

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

Defined in Distribution.Simple.Program.Types

Methods

(==) :: ProgramLocation -> ProgramLocation -> Bool

(/=) :: ProgramLocation -> ProgramLocation -> Bool

Read ProgramLocation

Defined in Distribution.Simple.Program.Types

Methods

readsPrec :: Int -> ReadS ProgramLocation

readList :: ReadS [ProgramLocation]

readPrec :: ReadPrec ProgramLocation

readListPrec :: ReadPrec [ProgramLocation]

Show ProgramLocation

Defined in Distribution.Simple.Program.Types

Methods

showsPrec :: Int -> ProgramLocation -> ShowS

show :: ProgramLocation -> String

showList :: [ProgramLocation] -> ShowS

Generic ProgramLocation

Defined in Distribution.Simple.Program.Types

Associated Types

type Rep ProgramLocation :: Type -> Type

Methods

from :: ProgramLocation -> Rep ProgramLocation x

to :: Rep ProgramLocation x -> ProgramLocation

Binary ProgramLocation

Defined in Distribution.Simple.Program.Types

Methods

put :: ProgramLocation -> Put

get :: Get ProgramLocation

putList :: [ProgramLocation] -> Put

Structured ProgramLocation

Defined in Distribution.Simple.Program.Types

Methods

structure :: Proxy ProgramLocation -> Structure

structureHash' :: Tagged ProgramLocation MD5

type Rep ProgramLocation

Defined in Distribution.Simple.Program.Types

type Rep ProgramLocation = D1 ('MetaData "ProgramLocation" "Distribution.Simple.Program.Types" "Cabal-3.6.2.0-Gs52rnMRRrI82oZgek17JT" '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)))

simpleConfiguredProgram :: String -> ProgramLocation -> ConfiguredProgram

Make a simple ConfiguredProgram.

simpleConfiguredProgram "foo" (FoundOnSystem path)