Function writeRoot

graphql/dgraph/graphquery.go:153–178

writeRoot writes the root function as well as any ordering and paging specified in q. Only uid(0x123, 0x124), type(...) and eq(Type.Predicate, ...) functions are supported at root. Multiple arguments for `eq` filter will be required in case of resolving `entities` query.

(b *strings.Builder, q *dql.GraphQuery)

// Only uid(0x123, 0x124), type(...) and eq(Type.Predicate, ...) functions are supported at root.
// Multiple arguments for `eq` filter will be required in case of resolving `entities` query.
func writeRoot(b *strings.Builder, q *dql.GraphQuery) {
	if q.Func == nil {
		return
	}

	switch {
	// TODO: Instead of the hard-coded strings "uid", "type", etc., use the
	// pre-defined constants in dql/parser.go such as dql.uidFunc, dql.typFunc,
	// etc. This of course will require that we make these constants public.
	case q.Func.Name == "uid":
		x.Check2(b.WriteString("(func: "))
		writeUIDFunc(b, q.Func.UID, q.Func.Args)
	case q.Func.Name == "type" && len(q.Func.Args) == 1:
		x.Check2(b.WriteString(fmt.Sprintf("(func: type(%s)", q.Func.Args[0].Value)))
	case q.Func.Name == "eq":
		x.Check2(b.WriteString("(func: eq("))
		writeFilterArguments(b, q.Func.Args)
		x.Check2(b.WriteRune(')'))
	case q.Func.Name == "similar_to":
		x.Check2(b.WriteString("(func: similar_to("))
		writeFilterArguments(b, q.Func.Args)
		x.Check2(b.WriteRune(')'))
	}
	writeOrderAndPage(b, q, true)
	x.Check2(b.WriteRune(')'))
}

func writeFilterArguments(b *strings.Builder, args []dql.Arg) {
	for i, arg := range args {