ghul.project 0.48.3

ghul.project

Reads and checks a ghūl project's manifest — the ghul-project.json in a project's root directory that says what the project is called, where its sources are and what it depends on. Nothing here builds anything yet; this is the model and the reader that later commands are written against.

using it

use Ghul.Project.MANIFEST_LOCATION
use Ghul.Project.MANIFEST_READER

let path = MANIFEST_LOCATION.find_in("/path/to/project")

if path? then
    let outcome = MANIFEST_READER.read(IO.File.read_all_text(path!), path!)

    case outcome
    when manifest: ReadOutcome.OK then
        write_line(manifest.name)
    when ReadOutcome.PROBLEMS then
        for problem in manifest.problems do
            write_line("ghul: {problem.describe()}")
        od
    esac
fi

The reader takes text and the path it came from, and touches no file and no network itself. MANIFEST_LOCATION.find_in looks in one directory and does not search upwards: a project is what its own root says it is.

what a manifest says

{
    "name": "example-app",
    "version": "0.1.0",
    "kind": "program",
    "targets": ["wasm", "dotnet"],
    "sources": ["src/**/*.ghul"],
    "compiler": "64.5.38",
    "options": {
        "underscore-access": "private",
        "global-namespace": false,
        "default-use": ["Collections", "IO.Std.write_line"],
        "define": [],
        "suppress": [],
        "warn-as-error": []
    },
    "dependencies": {
        "ghul-core": { "git": "https://github.com/ghul-lang/ghul-core", "tag": "v1.2.0" },
        "parsing": { "git": "https://example.com/libs.git", "branch": "main", "directory": "parsing" },
        "scratch": { "path": "../scratch" }
    }
}

Only name is required. What the rest default to when the manifest leaves them out:

• version — nothing; a manifest does not need one
• kind — program
• targets — ["dotnet"]
• sources — ["src/**/*.ghul"]
• compiler — whatever compiler is installed
• options — the compiler's own defaults
• dependencies — nothing

Comments and a trailing comma are allowed, since a manifest is written by hand.

what it checks

Every problem in a manifest is reported, not only the first, and each one names the key it is about:

• a missing name, or one that is not a library name — lowercase letters, digits and -, starting with a letter
• a key that is not one the manifest may carry, at any level: the top level, inside options, inside a dependency, or inside a git dependency, so a misspelling is not silently ignored
• a kind or a target that is not one of the two
• a member or option whose value is of the wrong shape
• a dependency with both a git and a path, or with neither
• a git dependency with neither a tag nor a branch

A manifest with any of those in it is not a manifest, so reading one returns the problems rather than a model that is partly made up.

what is not here yet

The lockfile, a git dependency at a branch rather than a tag, and dependencies for the dotnet target are the tasks that follow. See ghul-lang/ghul#3211.