A process for core library fixes and improvements

Request Feedback
38

Just to further the points in 3. a little, in addition to @pdamoc 's proof of concept with patching ELM_HOME linked above I’ve started dreaming up a format of how these “patched” snapshots could be described declaratively and applied.

I’m sure there is a bunch of other prior art in all of the elm-git-install and shelm-like tools that we could explore.

Here’s my noodling:

elm-patchwork.json

{
  "elmVersion": "0.19.1",
  "packages": {
    "elm/core": {
      "version": "1.0.5",
      "base": {
        "gitRepoUrl": "https://github.com/elm/core",
        "gitCommitHash": "84f38891468e8e153fc85a9b63bdafd81b24664e"
      },
      "patchPlan": [
        {
          "name": "List.concatMap performance improvements",
          "filePath": "./patches/elm-core-1.0.5-list-concatmap.patch"
        }
      ]
    }
  }
}

consumed by some tool into types like:

{-| The top-level type corresponding to the elm-patchwork.json file
-}
type alias Project =
    { elmVersion : String -- "0.19.1"
    , packages : List Package
    }


type alias Package =
    { name : String -- "elm/core"
    , version : String -- "1.0.5"
    , base : PackageBase
    , patches : List Patch
    }


type PackageBase
    = BaseFromGit
        { gitRepoUrl : String -- not strictly GitHub?
        , gitCommitHash : String -- this is how we'll download that package
        }
    | BaseFromFilesystem
        { folderPath : String -- "./patchwork/bases/elm/core/hacked-1.0.5"
        }


type alias Patch =
    { name : String -- "List.concat: performance improvement"
    , contents : PatchContents
    }


type PatchContents
    = PatchFromGit
        { gitRepoUrl : String -- not strictly GitHub?
        , gitCommitHash : String -- this is how we'll download that patch
        , filePath : String -- "patches/elm-core-1.0.5-list-concat.patch"
        }
    | PatchFromFilesystem
        { filePath : String -- "./patches/elm-core-1.0.5-list-concat.patch"
        }
3 Likes