Playing with an AST

Idea would be to build a light AST as a first pass, then have the
unmarshaler and Document parser do what they need with it.

internal/unmarshaler/unmarshaler_test.go

@@ -0,0 +1,39 @@
+package unmarshaler_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/pelletier/go-toml/v2/internal/ast"
+	"github.com/pelletier/go-toml/v2/internal/unmarshaler"
+)
+
+func TestFromAst_KV(t *testing.T) {
+	t.Skipf("later")
+	root := ast.Root{
+		ast.Node{
+			Kind: ast.KeyValue,
+			Children: []ast.Node{
+				{
+					Kind: ast.Key,
+					Data: []byte(`Foo`),
+				},
+				{
+					Kind: ast.String,
+					Data: []byte(`hello`),
+				},
+			},
+		},
+	}
+
+	type Doc struct {
+		Foo string
+	}
+
+	x := Doc{}
+	err := unmarshaler.FromAst(root, &x)
+	require.NoError(t, err)
+	assert.Equal(t, Doc{Foo: "hello"}, x)
+}