Changes between Version 35 and Version 36 of Commentary/GSoCMultipleInstances

Timestamp:

06/25/12 06:52:22 (11 months ago)

Author:

phischu

Comment:

--

Commentary/GSoCMultipleInstances

@@ -77 +77 @@
 `ghc-pkg` is responsible for storing all information we have about installed packages. Depending on design decisions about the solver and the Cabal hash, further information may be required in `ghc-pkg`'s description format (see below).
 
+The following fields will be added to the description format:
+
+A field ''Way'' of type `[String]`. It tracks the way in which the package was compiled. It is a subset of `{v,d,p}`. "v" means vanilla, "d" means dynamic linking and "p" means profiling. Other ways may be added later.
+
+A timestamp of the time when the package was installed (or built?). It is used by GHC and Cabal to put a preference on the latest package of a certain version.
+
+A currently empty but extensible set of fields starting with "x-cabal-...". ghc-pkg ignores them when parsing. During the resolution phase cabal-install might use them to decide compatibility between packages.
+
+A field abi-hash that contains the ABI hash because it is now longer stored implicitly as part of the `InstalledPackageId`.
+
 == Simplistic dependency resolution ==
 
@@ -154 +164 @@
 Options are to either offer an interactive process where packages that look unused are suggested for removal, or to integrate with a sandbox mechanism. If, for example, dirty builds are usually installed into a separate package DB, that package DB could just be removed completely by a user from time to time.
 
+The garbage collection functionality is part of cabal-install not of ghc-pkg. As a first approximation gc does not remove files only unregisters packages from the `PackageDB`.
+
 == Currently open design decisions ==
 
@@ -233 +245 @@
 == Questions to remember ==
 
+Should the cabal version be part of the hash?
+
+Does the hash contain characters conflicting under windows?
+
 What about builtin packages like ghc-prim, base, rts and so on?