Basic JSON importer

This basic importer takes a URL and pulls the JSON in as
weakly typed data -- lists and maps of basic types.

Addresses issue #20

clients/jsonImporter/jsonImporter.go

@@ -0,0 +1,83 @@
+package main
+
+import (
+	"encoding/json"
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+
+	"github.com/attic-labs/noms/chunks"
+	"github.com/attic-labs/noms/datas"
+	"github.com/attic-labs/noms/dbg"
+	"github.com/attic-labs/noms/types"
+)
+
+func nomsValueFromObject(o interface{}) types.Value {
+	switch oo := o.(type) {
+	case string:
+		return types.NewString(oo)
+	case bool:
+		return types.Bool(oo)
+	case float64:
+		return types.Float64(oo)
+	case nil:
+		return nil
+	case []interface{}:
+		out := types.NewList()
+		for _, v := range oo {
+			out = out.Append(nomsValueFromObject(v))
+		}
+		return out
+	case map[string]interface{}:
+		out := types.NewMap()
+		for k, v := range oo {
+			nv := nomsValueFromObject(v)
+			if nv != nil {
+				out = out.Set(types.NewString(k), nv)
+			}
+		}
+		return out
+	default:
+		fmt.Println(oo, "is of a type I don't know how to handle")
+	}
+	return nil
+}
+
+func main() {
+	flags := chunks.NewFlags()
+	flag.Parse()
+	cs := flags.CreateStore()
+	if cs == nil {
+		flag.Usage()
+		return
+	}
+
+	url := flag.Arg(0)
+	if url == "" {
+		flag.Usage()
+		return
+	}
+
+	res, err := http.Get(url)
+	dbg.Chk.NoError(err)
+
+	gameEventsJSON, err := ioutil.ReadAll(res.Body)
+	res.Body.Close()
+	dbg.Chk.NoError(err)
+
+	var events interface{}
+	err = json.Unmarshal(gameEventsJSON, &events)
+	dbg.Chk.NoError(err)
+
+	ds := datas.NewDataStore(cs)
+	roots := ds.Roots()
+
+	gameEvents := nomsValueFromObject(events)
+
+	ds.Commit(datas.NewRootSet().Insert(
+		datas.NewRoot().SetParents(
+			roots.NomsValue()).SetValue(
+			gameEvents)))
+
+}