Use a Juvix source file to define a package

[paulcadman]

Depends on:

• Use JuvixError instead of Text for errors in Package file loading #2459
• Add dependency on expressions in function default arguments #2462

This PR is part of a series implementing:

• Proposal: Use a Juvix source file to define a package instead of YAML #2336

This PR adds the package file loading function, including a file evaluation effect. It integrates this with the existing readPackage function and adds tests / smoke tests.

Package.juvix format

Instead of juvix.yaml (which is still supported currently) users can now place a Package.juvix file in the root of their project. The simplest Package.juvix file you can write is:

module Package;

import PackageDescription open;

package : Package := defaultPackage;

The PackageDescription module defines the Package type. Users can use "go-to definition" in their IDE from the Package file to see the documentation and definitions.

Users may also import Stdlib.Prelude in their Package file. This is loaded from the global project. No other module imports are supported.

Notes:

• If a directory contains both Package.juvix and juvix.yaml then Package.juvix is used in preference.

Default stdlib dependency

The Dependency type has a constructor called defaultStdlib. This means that any project can use the compiler builtin standard library dependency. With juvix.yaml this dependency is only available when the dependencies field is unspecified.

module Package;

import PackageDescription open;

package : Package := defaultPackage { dependencies := [defaultStdlib] };

Validation

As well as the standard type checking validation that the Juvix compiler provides additional validation is made on the file.

• The Package module must contain the identifier package and it must have type Package that's obtained from the global PackageDescription module.

• Every dependency specified in the Package.juvix must be unique.

• Closes Proposal: Use a Juvix source file to define a package instead of YAML #2336

Examples

Package with name and version

module Package;

import PackageDescription open;

package : Package :=
  defaultPackage {name := "a-package";
                  version := mkVersion 0 1 0};

Package with GitHub dependency

module Package;

import PackageDescription open;

package : Package :=
  defaultPackage {name := "a-package";
                  version := mkVersion 0 1 0;
                  dependencies := [defaultStdlib;
                                   github (org := "anoma";
                                           repo := "juvix-containers";
                                           ref := "v0.7.1")]};

Package with main and buildDir fields

module Package;

import Stdlib.Prelude open;
import PackageDescription open;

package : Package :=
  defaultPackage {name := "a-package";
                  version := mkVersion 0 1 0;
                  dependencies := [defaultStdlib;
                                   github (org := "anoma";
                                           repo := "juvix-containers";
                                           ref := "v0.7.1")];
                  buildDir := just "/tmp/build";
                  main := just "HelloWorld.juvix"
                };

[janmasrovira]

🛥️