encompass all opening and closing tokens with a single type, and implement them

parse/lex/lex.go

@@ -16,8 +16,8 @@ type TokenType int
 const (
 	BareString TokenType = iota
 	QuotedString
-	OpenParen
-	CloseParen
+	Open
+	Close
 	Err
 	eof
 )
@@ -162,9 +162,17 @@ func lexWhitespace(l *Lexer) lexerFunc {
 	case '"':
 		return lexQuotedString
 	case '(':
-		l.emit(OpenParen)
+		l.emit(Open)
 	case ')':
-		l.emit(CloseParen)
+		l.emit(Close)
+	case '[':
+		l.emit(Open)
+	case ']':
+		l.emit(Close)
+	case '{':
+		l.emit(Open)
+	case '}':
+		l.emit(Close)
 	default:
 		return lexBareString
 	}

parse/lex/lex_test.go

@@ -19,21 +19,21 @@ func TestLexer(t *T) {
 		"\"foo\nbar\" baz": {{QuotedString, "\"foo\nbar\""},
 							 {BareString, "baz"},
 							 {eof, ""}},
-		"( foo bar ) baz": {{OpenParen, "("},
+		"( foo bar ) baz": {{Open, "("},
 						    {BareString, "foo"},
 						    {BareString, "bar"},
-						    {CloseParen, ")"},
+						    {Close, ")"},
 						    {BareString, "baz"},
 						    {eof, ""}},
-		"((foo-bar))":     {{OpenParen, "("},
-							{OpenParen, "("},
+		"((foo-bar))":     {{Open, "("},
+							{Open, "("},
 							{BareString, "foo-bar"},
-							{CloseParen, ")"},
-							{CloseParen, ")"},
+							{Close, ")"},
+							{Close, ")"},
 						    {eof, ""}},
-		"(\"foo\nbar\")":  {{OpenParen, "("},
+		"(\"foo\nbar\")":  {{Open, "("},
 							{QuotedString, "\"foo\nbar\""},
-							{CloseParen, ")"},
+							{Close, ")"},
 							{eof, ""}},
 	}