Cabal-1.22.4.0: 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 | Haskell98

Distribution.Simple.Program.Db

Contents

- The collection of configured programs we can run
  - Query and manipulate the program db
  - Query and manipulate the program db

Description

This provides a `ProgramDb` type which holds configured and not-yet configured programs. It is the parameter to lots of actions elsewhere in Cabal that need to look up and run programs. If we had a Cabal monad, the `ProgramDb` would probably be a reader or state component of it.

One nice thing about using it is that any program that is registered with Cabal will get some "configure" and ".cabal" helpers like --with-foo-args --foo-path= and extra-foo-args.

There's also a hook for adding programs in a Setup.lhs script. See hookedPrograms in `UserHooks`. This gives a hook user the ability to get the above flags and such so that they don't have to write all the PATH logic inside Setup.lhs.

Synopsis

- data ProgramDb
- emptyProgramDb :: ProgramDb
- defaultProgramDb :: ProgramDb
- restoreProgramDb :: [Program] -> ProgramDb -> ProgramDb
- addKnownProgram :: Program -> ProgramDb -> ProgramDb
- addKnownPrograms :: [Program] -> ProgramDb -> ProgramDb
- lookupKnownProgram :: String -> ProgramDb -> Maybe Program
- knownPrograms :: ProgramDb -> [(Program, Maybe ConfiguredProgram)]
- getProgramSearchPath :: ProgramDb -> ProgramSearchPath
- setProgramSearchPath :: ProgramSearchPath -> ProgramDb -> ProgramDb
- modifyProgramSearchPath :: (ProgramSearchPath -> ProgramSearchPath) -> ProgramDb -> ProgramDb
- userSpecifyPath :: String -> FilePath -> ProgramDb -> ProgramDb
- userSpecifyPaths :: [(String, FilePath)] -> ProgramDb -> ProgramDb
- userMaybeSpecifyPath :: String -> Maybe FilePath -> ProgramDb -> ProgramDb
- userSpecifyArgs :: String -> [ProgArg] -> ProgramDb -> ProgramDb
- userSpecifyArgss :: [(String, [ProgArg])] -> ProgramDb -> ProgramDb
- userSpecifiedArgs :: Program -> ProgramDb -> [ProgArg]
- lookupProgram :: Program -> ProgramDb -> Maybe ConfiguredProgram
- updateProgram :: ConfiguredProgram -> ProgramDb -> ProgramDb
- configuredPrograms :: ProgramDb -> [ConfiguredProgram]
- configureProgram :: Verbosity -> Program -> ProgramDb -> IO ProgramDb
- configureAllKnownPrograms :: Verbosity -> ProgramDb -> IO ProgramDb
- lookupProgramVersion :: Verbosity -> Program -> VersionRange -> ProgramDb -> IO (Either String (ConfiguredProgram, Version, ProgramDb))
- reconfigurePrograms :: Verbosity -> [(String, FilePath)] -> [(String, [ProgArg])] -> ProgramDb -> IO ProgramDb
- requireProgram :: Verbosity -> Program -> ProgramDb -> IO (ConfiguredProgram, ProgramDb)
- requireProgramVersion :: Verbosity -> Program -> VersionRange -> ProgramDb -> IO (ConfiguredProgram, Version, ProgramDb)

# The collection of configured programs we can run

data ProgramDb Source

The configuration is a collection of information about programs. It contains information both about configured programs and also about programs that we are yet to configure.

The idea is that we start from a collection of unconfigured programs and one by one we try to configure them at which point we move them into the configured collection. For unconfigured programs we record not just the `Program` but also any user-provided arguments and location for the program.

Instances

Read ProgramDb |
Show ProgramDb |
Binary ProgramDb |

emptyProgramDb :: ProgramDb Source

defaultProgramDb :: ProgramDb Source

restoreProgramDb :: [Program] -> ProgramDb -> ProgramDb Source

The Read/Show instance does not preserve all the unconfigured `Programs` because `Program` is not in Read/Show because it contains functions. So to fully restore a deserialised `ProgramDb` use this function to add back all the known `Program`s.

- It does not add the default programs, but you probably want them, use `builtinPrograms` in addition to any extra you might need.

## Query and manipulate the program db

addKnownProgram :: Program -> ProgramDb -> ProgramDb Source

Add a known program that we may configure later

addKnownPrograms :: [Program] -> ProgramDb -> ProgramDb Source

lookupKnownProgram :: String -> ProgramDb -> Maybe Program Source

knownPrograms :: ProgramDb -> [(Program, Maybe ConfiguredProgram)] Source

getProgramSearchPath :: ProgramDb -> ProgramSearchPath Source

Get the current `ProgramSearchPath` used by the `ProgramDb`. This is the default list of locations where programs are looked for when configuring them. This can be overridden for specific programs (with `userSpecifyPath`), and specific known programs can modify or ignore this search path in their own configuration code.

setProgramSearchPath :: ProgramSearchPath -> ProgramDb -> ProgramDb Source

Change the current `ProgramSearchPath` used by the `ProgramDb`. This will affect programs that are configured from here on, so you should usually set it before configuring any programs.

modifyProgramSearchPath :: (ProgramSearchPath -> ProgramSearchPath) -> ProgramDb -> ProgramDb Source

Modify the current `ProgramSearchPath` used by the `ProgramDb`. This will affect programs that are configured from here on, so you should usually modify it before configuring any programs.

userSpecifyPath Source

Arguments

:: String | Program name
-> FilePath | user-specified path to the program
-> ProgramDb |
-> ProgramDb |

User-specify this path. Basically override any path information for this program in the configuration. If it's not a known program ignore it.

userSpecifyPaths :: [(String, FilePath)] -> ProgramDb -> ProgramDb Source

Like `userSpecifyPath` but for a list of progs and their paths.

userMaybeSpecifyPath :: String -> Maybe FilePath -> ProgramDb -> ProgramDb Source

userSpecifyArgs Source

Arguments

:: String | Program name
-> [ProgArg] | user-specified args
-> ProgramDb |
-> ProgramDb |

User-specify the arguments for this program. Basically override any args information for this program in the configuration. If it's not a known program, ignore it..

userSpecifyArgss :: [(String, [ProgArg])] -> ProgramDb -> ProgramDb Source

Like `userSpecifyPath` but for a list of progs and their args.

userSpecifiedArgs :: Program -> ProgramDb -> [ProgArg] Source

Get any extra args that have been previously specified for a program.

lookupProgram :: Program -> ProgramDb -> Maybe ConfiguredProgram Source

Try to find a configured program

updateProgram :: ConfiguredProgram -> ProgramDb -> ProgramDb Source

Update a configured program in the database.

configuredPrograms :: ProgramDb -> [ConfiguredProgram] Source

List all configured programs.

## Query and manipulate the program db

configureProgram :: Verbosity -> Program -> ProgramDb -> IO ProgramDb Source

Try to configure a specific program. If the program is already included in the collection of unconfigured programs then we use any user-supplied location and arguments. If the program gets configured successfully it gets added to the configured collection.

Note that it is not a failure if the program cannot be configured. It's only a failure if the user supplied a location and the program could not be found at that location.

The reason for it not being a failure at this stage is that we don't know up front all the programs we will need, so we try to configure them all. To verify that a program was actually successfully configured use `requireProgram`.

configureAllKnownPrograms :: Verbosity -> ProgramDb -> IO ProgramDb Source

Try to configure all the known programs that have not yet been configured.

lookupProgramVersion :: Verbosity -> Program -> VersionRange -> ProgramDb -> IO (Either String (ConfiguredProgram, Version, ProgramDb)) Source

Check that a program is configured and available to be run.

Additionally check that the program version number is suitable and return it. For example you could require `AnyVersion` or ``orLaterVersion` (`Version` [1,0] [])`

It returns the configured program, its version number and a possibly updated `ProgramDb`. If the program could not be configured or the version is unsuitable, it returns an error value.

reconfigurePrograms :: Verbosity -> [(String, FilePath)] -> [(String, [ProgArg])] -> ProgramDb -> IO ProgramDb Source

reconfigure a bunch of programs given new user-specified args. It takes the same inputs as `userSpecifyPath` and `userSpecifyArgs` and for all progs with a new path it calls `configureProgram`.

requireProgram :: Verbosity -> Program -> ProgramDb -> IO (ConfiguredProgram, ProgramDb) Source

Check that a program is configured and available to be run.

It raises an exception if the program could not be configured, otherwise it returns the configured program.

requireProgramVersion :: Verbosity -> Program -> VersionRange -> ProgramDb -> IO (ConfiguredProgram, Version, ProgramDb) Source

Like `lookupProgramVersion`, but raises an exception in case of error instead of returning 'Left errMsg'.