Add Mercurial library

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

3 files changed, 44 insertions, 1 deletions

diff --git a/pkg/config/lib/hg/hg.go b/pkg/config/lib/hg/hg.go
new file mode 100644
index 0000000..d06e5aa
--- /dev/null
+++ b/pkg/config/lib/hg/hg.go
@@ -0,0 +1,32 @@
+package hg
+
+import (
+	_ "embed"
+	"go.nc0.fr/svgu/pkg/config"
+	"go.starlark.net/starlark"
+	"go.starlark.net/starlarkstruct"
+	"sync"
+)
+
+var (
+	once = sync.Once{}
+	hg   = starlark.StringDict{}
+	//go:embed hg.star
+	hgFile string
+	hgErr  error
+)
+
+// LoadHgModule loads the Mercurial module.
+func LoadHgModule(t *starlark.Thread) (starlark.StringDict, error) {
+	once.Do(func() {
+		env := starlark.StringDict{
+			"module": starlark.NewBuiltin("module",
+				config.InternModule),
+			"make_module": starlark.NewBuiltin("mod",
+				starlarkstruct.MakeModule),
+		}
+		hg, hgErr = starlark.ExecFile(t, "hg.star", hgFile, env)
+	})
+
+	return hg, hgErr
+}
diff --git a/pkg/config/lib/hg/hg.star b/pkg/config/lib/hg/hg.star
new file mode 100644
index 0000000..dad8fdd
--- /dev/null
+++ b/pkg/config/lib/hg/hg.star
@@ -0,0 +1,8 @@
+# Utilities to index Go modules hosted on Mercurial repositories.
+
+_HG = "hg"
+
+hg = make_module(
+    "hg",
+    HG = _HG,
+)
diff --git a/pkg/config/starlark.go b/pkg/config/starlark.go
index 942479f..3f5c25c 100644
--- a/pkg/config/starlark.go
+++ b/pkg/config/starlark.go
@@ -3,6 +3,7 @@ package config
 import (
 	"fmt"
 	"go.nc0.fr/svgu/pkg/config/lib/git"
+	"go.nc0.fr/svgu/pkg/config/lib/hg"
 	"go.nc0.fr/svgu/pkg/types"
 	"go.starlark.net/starlark"
 )
@@ -36,8 +37,10 @@ func ExecConfig(fl string) (*types.Index, error) {
 // load loads a module from the given path.
 func load(t *starlark.Thread, module string) (starlark.StringDict, error) {
 	switch module {
-	case "git.star":
+	case "git.star": // git
 		return git.LoadGitModule(t)
+	case "hg.star": // mercurial
+		return hg.LoadHgModule(t)
 	default:
 		return nil, fmt.Errorf("unknown module %q", module)
 	}