[Hackage] #223: allow per-package configuration options in config file
#223: allow per-package configuration options in config file ---------------------------------+------------------------------------------ Reporter: duncan | Owner: Type: enhancement | Status: new Priority: normal | Milestone: Cabal-1.4 Component: cabal-install tool | Version: 1.2.3.0 Severity: normal | Keywords: Difficulty: normal | Ghcversion: 6.8.2 Platform: | ---------------------------------+------------------------------------------ Currently only a subset of the configure command line flags can be stored in cabal-install's config file. There is no particularly good reason for this. It should be reasonably straightforward to do it generically and allow all configure options to be kept in the config file. This may require some unification of the API for managing command line flags (the Simple.Command module) and the API for loading and saving from config flags (in ParseUtils). Once this is done, it should be straightforward to keep per-package config options as well as global options in the cabal-install config file. These could be used to augment the options used when configuring a package. The order of overriding in cabal-install is currently: {{{ savedConfig `mappend` configFlags }}} That is, the configure options from the config file are overridden by the ones supplied on the command line. With per-package saved config we would extend this to: {{{ globalSavedConfig `mappend` packageSavedConfig pkg `mappend` configFlags }}} ie per-package saved, overrides global saved, but command line still overrides everything. The slightly tricky bit is in how the api for config files and command line flags should be made to work better with each other, so that one set of information can be read/written from either source. The rest should be straightforward. -- Ticket URL: http://hackage.haskell.org/trac/hackage/ticket/223 Hackage http://haskell.org/cabal/ Hackage: Cabal and related projects
#223: allow per-package configuration options in config file ---------------------------------+------------------------------------------ Reporter: duncan | Owner: mnislaih Type: enhancement | Status: assigned Priority: normal | Milestone: Cabal-1.4 Component: cabal-install tool | Version: 1.2.3.0 Severity: normal | Resolution: Keywords: | Difficulty: normal Ghcversion: 6.8.2 | Platform: ---------------------------------+------------------------------------------ Changes (by mnislaih): * status: new => assigned * owner: => mnislaih Comment: I am working on this, wish me luck :) -- Ticket URL: http://hackage.haskell.org/trac/hackage/ticket/223#comment:1 Hackage http://haskell.org/cabal/ Hackage: Cabal and related projects
#223: allow per-package configuration options in config file ---------------------------------+------------------------------------------ Reporter: duncan | Owner: mnislaih Type: enhancement | Status: assigned Priority: normal | Milestone: Cabal-1.4 Component: cabal-install tool | Version: 1.2.3.0 Severity: normal | Resolution: Keywords: | Difficulty: normal Ghcversion: 6.8.2 | Platform: ---------------------------------+------------------------------------------ Comment (by mnislaih): Since this is not a trivial refactoring and I am not a usual committer, here is a plan write-up. == Problem == We have ConfigFlags, a data structure in typical database fashion, a dictionary of plain values composed of several fields. There are two main goals a) Be able to serialize it (done now via ParseUtils.FieldDescrs) b) Be able to manipulate it via command line flags (done via Command.Option) For a), we want a format that is human readable and modifiable. For b), we want to be able to specify the flags, with an expressivity comparable to the GetOpt language. Overall, we want to have a coherence and be able to reuse code. We may want to see these as two facets of the same problem and be able to specify them in one single place. (and in Haskell 98 of course) == Solution 1 == Specify b) via Distribution.Command.Option, and then convert those options to ParseUtils.FieldDescrs automatically, which can be serialized for b). The problem is that NoArg/OptArg options cannot really be converted to FieldDescrs. We are missing a proper name for the field in the serialized file, and since there are usually several Options of this kind associated to one field, we want to see them as defining the possible values of the field. But we cannot collect them, as the option description is missing a declarative reference to which record they modify in the data structure. {{{ option :: [Char] -> [String] -> String -> c -> d -> (c -> d -> ArgDescr a) -> Option a option ss ls d get set arg = Option ss ls d (arg get set) }}} There are getters and setters, but those are opaque functions. Hence, we can only automatically infer FieldDescrs for ReqArg options. The others must be inputed manually. This seems error prone and tricky to maintain to me, although it has the advantage of being the simplest refactoring among all the options. == Solution 2 == If we reify the record, then options can be given a more declarative type. {{{ option :: Record data field -> [Char] -> String -> String -> ArgDescr field -> Option field data Record data field = { get :: data -> field , set :: field -> data -> data }}} This is good enough to enable us to collect all the NoArg options related to one field, and condense a single FieldDescr out of it. == Solution 3 == But why stop there? We can put more metadata in the Record descriptor. {{{ interface :: OptInterface, desc :: String, shape :: Shape, ppr :: field -> Doc } data OptInterface { shortFlags :: [String], longFlags :: [String] } data Shape field = StringValued (String -> ReadS field) | Choice (Map OptInterface field) }}} So now it is possible to extract an Option directly from this structure. {{{ mkOption :: Record data field -> [Option data] }}} The definition of mkOption should be trivial. If the Record is StringValued then we get a single Option, otherwise we get an Option for every choice. And the same goes for FieldDescrs. {{{ mkFieldDescr :: Record data field -> FieldDescr data }}} For the row name in the file we just take the first longFlag, and if it has a Choice shape then we build the trivial parser for it. Otherwise we just use the parser provided in StringValued. Finally, we could just extend FieldDescr to accomodate the role of Record above. But this poses the minor issue that FieldDescr 'instances' are provided in CabalInstall, whereas they would be required by Cabal already in Distribution.Setup.hs So they will need to be moved there. -- Ticket URL: http://hackage.haskell.org/trac/hackage/ticket/223#comment:2 Hackage http://haskell.org/cabal/ Hackage: Cabal and related projects
#223: allow per-package configuration options in config file ---------------------------------+------------------------------------------ Reporter: duncan | Owner: mnislaih Type: enhancement | Status: assigned Priority: normal | Milestone: Cabal-1.4 Component: cabal-install tool | Version: 1.2.3.0 Severity: normal | Resolution: Keywords: | Difficulty: normal Ghcversion: 6.8.2 | Platform: ---------------------------------+------------------------------------------ Changes (by mnislaih): * cc: mnislaih@gmail.com (added) -- Ticket URL: http://hackage.haskell.org/trac/hackage/ticket/223#comment:3 Hackage http://haskell.org/cabal/ Hackage: Cabal and related projects
#223: allow per-package configuration options in config file ---------------------------------+------------------------------------------ Reporter: duncan | Owner: mnislaih Type: enhancement | Status: assigned Priority: normal | Milestone: Cabal-1.4 Component: cabal-install tool | Version: 1.2.3.0 Severity: normal | Resolution: Keywords: | Difficulty: normal Ghcversion: 6.8.2 | Platform: ---------------------------------+------------------------------------------ Comment (by duncan): Thanks for keeping us posted, it sounds like a very sensible plan. -- Ticket URL: http://hackage.haskell.org/trac/hackage/ticket/223#comment:4 Hackage http://haskell.org/cabal/ Hackage: Cabal and related projects
#223: allow per-package configuration options in config file ---------------------------------+------------------------------------------ Reporter: duncan | Owner: mnislaih Type: enhancement | Status: assigned Priority: normal | Milestone: Cabal-1.4 Component: cabal-install tool | Version: 1.2.3.0 Severity: normal | Resolution: Keywords: | Difficulty: normal Ghcversion: 6.8.2 | Platform: ---------------------------------+------------------------------------------ Comment (by guest): It would be useful to be able to specify flags in the config file for all the commands and not only for configure e.g. install's --root-cmd. This poses the question if it should be possible to specify different defaults for the same flag for two different commands. -- Ticket URL: http://hackage.haskell.org/trac/hackage/ticket/223#comment:5 Hackage http://haskell.org/cabal/ Hackage: Cabal and related projects
#223: allow per-package configuration options in config file ---------------------------------+------------------------------------------ Reporter: duncan | Owner: mnislaih Type: enhancement | Status: assigned Priority: normal | Milestone: Cabal-1.4 Component: cabal-install tool | Version: 1.2.3.0 Severity: normal | Resolution: Keywords: | Difficulty: normal Ghcversion: 6.8.2 | Platform: ---------------------------------+------------------------------------------ Changes (by guest): * cc: gwern0@gmail.com (added) -- Ticket URL: http://hackage.haskell.org/trac/hackage/ticket/223#comment:6 Hackage http://haskell.org/cabal/ Hackage: Cabal and related projects
#223: allow per-package configuration options in config file
---------------------------------+------------------------------------------
Reporter: duncan | Owner: mnislaih
Type: enhancement | Status: assigned
Priority: normal | Milestone: Cabal-1.4
Component: cabal-install tool | Version: 1.2.3.0
Severity: normal | Resolution:
Keywords: | Difficulty: very easy (<1 hour)
Ghcversion: 6.8.2 | Platform:
---------------------------------+------------------------------------------
Changes (by duncan):
* difficulty: normal => very easy (<1 hour)
Comment:
The config file now holds the options for the global command (things like
repos, cache dir etc), the install/upgrade command and the configure and
upload commands.
{{{
Thu Aug 21 22:05:55 BST 2008 Duncan Coutts
#223: allow per-package configuration options in config file ---------------------------------+------------------------------------------ Reporter: duncan | Owner: mnislaih Type: enhancement | Status: assigned Priority: normal | Milestone: Component: cabal-install tool | Version: 1.2.3.0 Severity: normal | Resolution: Keywords: | Difficulty: very easy (<1 hour) Ghcversion: 6.8.2 | Platform: ---------------------------------+------------------------------------------ Changes (by duncan): * milestone: Cabal-1.4 => Comment: The new config seems to be working. The fields that do not apply in the config file are now excluded. The remaining issue can be punted to a later milestone. -- Ticket URL: http://hackage.haskell.org/trac/hackage/ticket/223#comment:8 Hackage http://haskell.org/cabal/ Hackage: Cabal and related projects
participants (1)
-
Hackage