Slight improvement for the document-level error in case no key or table was found.

parse/document.go

@@ -21,8 +21,10 @@ func (t *parser) startDocument(p *parse.API) {
 			p.Handle(t.startTable)
 		case p.Peek(detectKey):
 			p.Handle(t.startKeyValuePair)
+		case p.Accept(a.EndOfFile):
+			p.Stop()
 		default:
-			p.ExpectEndOfFile()
+			p.Expected("key/value pair, table or array of tables")
 			return
 		}
 		if p.IsStoppedOrInError() {

parse/document_test.go

@@ -6,7 +6,7 @@ import (
 
 func TestComment(t *testing.T) {
 	for _, test := range []parseTest{
-		{``, `{}`, `unexpected end of file (expected comment) at start of file`},
+		{``, `{}`, ``},
 		{`#`, `{}`, ``},
 		{`# `, `{}`, ``},
 		{`# with data`, `{}`, ``},
@@ -20,3 +20,12 @@ func TestComment(t *testing.T) {
 		testParse(t, p, p.startDocument, test)
 	}
 }
+
+func TestInvalidDocument(t *testing.T) {
+	for _, test := range []parseTest{
+		{`!false!`, `{}`, `unexpected input (expected key/value pair, table or array of tables) at start of file`},
+	} {
+		p := newParser()
+		testParse(t, p, p.startDocument, test)
+	}
+}