Add support for Source Hut's Mercurial hosting

Signed-off-by: Nicolas Paul <n@nc0.fr>

2 files changed, 117 insertions, 2 deletions

diff --git a/doc/references.md b/doc/references.md
index ddd380a..ab16245 100644
--- a/doc/references.md
+++ b/doc/references.md
@@ -24,7 +24,11 @@ SVGU's Starlark environment is based on the
     + [index](#index)
     + [module](#module)
 - [Bazaar](#bazaar)
-    + [bzr.BAZAAR](#bzrbazaar)
+  + [bzr.BAZAAR](#bzrbazaar)
+  + [bzr.LAUNCHPAD_DEFAULT_INSTANCE](#bzrlaunchpad_default_instance)
+  + [bzr.LAUNCHPAD_DEFAULT_REV](#bzrlaunchpad_default_rev)
+  + [brz.LAUNCHPAD_DEFAULT_BRANCH](#brzlaunchpad_default_branch)
+  + [bzr.launchpad](#bzrlaunchpad)
 - [Fossil](#fossil)
     + [fossil.FOSSIL](#fossilfossil)
 - [Git](#git)
@@ -44,7 +48,10 @@ SVGU's Starlark environment is based on the
   + [git.bitbucket](#gitbitbucket)
   + [git.gitiles](#gitgitiles)
 - [Mercurial](#mercurial)
-    + [hg.MERCURIAL](#hgmercurial)
+  + [hg.MERCURIAL](#hgmercurial)
+  + [hg.SOURCEHUT_DEFAULT_INSTANCE](#hgsourcehut_default_instance)
+  + [hg.SOURCEHUT_DEFAULT_REV](#hgsourcehut_default_rev)
+  + [hg.sourcehut](#hgsourcehut)
 - [Subversion](#subversion)
     + [svn.SUBVERSION](#svnsubversion)
 
@@ -194,6 +201,22 @@ A macro that registers a module hosted on
 | `rev`      | `string` | The revision number. Defaults to [`bzr.LAUNCHPAD_DEFAULT_REV`](#bzrlaunchpad_default_rev)                         |
 | `instance` | `string` | The URL of the Launchpad instance. Defaults to [`bzr.LAUNCHPAD_DEFAULT_INSTANCE`](#bzrlaunchpad_default_instance) |
 
+#### Example
+
+```starlark
+load("@svgu/bzr", "bzr")
+
+index(domain = "go.example.com")
+
+# Will be available as `go.example.com/foo`.
+
+bzr.launchpad(
+    name = "foo",
+    user = "bar",
+    repo = "foo",
+)
+```
+
 ## Fossil
 
 The [fossil](../pkg/config/lib/fossil/fossil.star) module contains a set
@@ -551,6 +574,62 @@ module(
 )
 ```
 
+### hg.SOURCEHUT_DEFAULT_INSTANCE
+
+`"https://hg.sr.ht"` \
+A constant containing the default instance to use when the repository is hosted
+on [Source Hut Mercurial][sourcehut-hg-link] hosting.
+
+### hg.SOURCEHUT_DEFAULT_REV
+
+`"tip"` \
+A constant containing the default revision (branch, ...) to use when the
+repository is hosted on [Source Hut Mercurial][sourcehut-hg-link] hosting.
+
+### hg.sourcehut
+
+A macro that registers a module hosted on
+[Source Hut Mercurial][sourcehut-hg-link] hosting.
+
+> Note: Source Hut's Mercurial hosting is still in beta. Organization support
+> is not yet available.
+
+#### Parameters
+
+| Name       | Type     | Description                                                                                                  |
+|------------|----------|--------------------------------------------------------------------------------------------------------------|
+| `name`     | `string` | The name of the module.                                                                                      |
+| `user`     | `string` | The Source Hut user.                                                                                         |
+| `repo`     | `string` | The Source Hut repository name.                                                                              |
+| `instance` | `string` | The Source Hut instance to use. Default to [`hg.SOURCEHUT_DEFAULT_INSTANCE`](#hgsourcehut_default_instance). |
+| `rev`      | `string` | The revision (branch, ...) to use. Default to [`hg.SOURCEHUT_DEFAULT_REV`](#hgsourcehut_default_rev).        |
+
+#### Example
+
+```starlark
+load("@svgu/hg", "hg")
+
+index(domain = "go.example.com")
+
+# By default, the function assumes that the repository is hosted on
+# https://hg.sr.ht and the revision is `tip`.
+
+hg.sourcehut(
+    name = "foo",
+    user = "example",
+    repo = "foo",
+)
+
+# You can override the default revision and instance.
+hg.sourcehut(
+    name = "bar",
+    user = "example",
+    repo = "bar",
+    rev = "default",
+    instance = "https://hg.example.com",
+)
+```
+
 ## Subversion
 
 The [svn](../pkg/config/lib/svn/svn.star) (Subversion) module contains
@@ -610,3 +689,5 @@ module(
 [bazel-link]: https://bazel.build/
 
 [launchpad-bzr-link]: https://launchpad.net/bzr
+
+[sourcehut-hg-link]: https://hg.sr.ht/
diff --git a/pkg/config/lib/hg/hg.star b/pkg/config/lib/hg/hg.star
index 524578a..3cb647b 100644
--- a/pkg/config/lib/hg/hg.star
+++ b/pkg/config/lib/hg/hg.star
@@ -2,7 +2,41 @@
 
 _MERCURIAL = "hg"
 
+_SOURCEHUT_DEFAULT_INSTANCE = "https://hg.sr.ht"
+_SOURCEHUT_DEFAULT_REV = "tip"
+
+def _sourcehut(
+        name,
+        user,
+        repo,
+        rev = _SOURCEHUT_DEFAULT_REV,
+        instance = _SOURCEHUT_DEFAULT_INSTANCE):
+    """Register a module hosted on a Mercurial repository on Source Hut.
+
+    Args:
+        name (str): The name of the module.
+        user (str): The name of the user or organization that owns the
+            repository.
+        repo (str): The name of the repository.
+        rev (str): The revision to use. Defaults to `hg.SOURCEHUT_DEFAULT_REV`.
+        instance (str): The instance of Source Hut to use.
+            Defaults to `hg.SOURCEHUT_DEFAULT_INSTANCE`.
+    """
+
+    module(
+        name = name,
+        vcs = _MERCURIAL,
+        repo = "%s/~%s/%s" % (instance, user, repo),
+        dir = "%s/~%s/%s/browse{/dir}?rev=%s" %
+              (instance, user, repo, rev),
+        file = "%s/~%s/%s/browse{/dir}/{file}?rev=%s#L{line}" %
+               (instance, user, repo, rev),
+    )
+
 hg = make_module(
     "hg",
     MERCURIAL = _MERCURIAL,
+    SOURCEHUT_DEFAULT_INSTANCE = _SOURCEHUT_DEFAULT_INSTANCE,
+    SOURCEHUT_DEFAULT_REV = _SOURCEHUT_DEFAULT_REV,
+    sourcehut = _sourcehut,
 )