diff --git a/token/token.go b/token/token.go
index d50eb36..2c9f5d3 100644
--- a/token/token.go
+++ b/token/token.go
@@ -13,6 +13,9 @@
 	Slash              // /
 	LParen             // (
 	RParen             // )
+	Ident              // identifier (e.g. "f", "x")
+	Comma              // ,
+	Equals             // =
 	EOF                // end of input
 )
 
@@ -33,6 +36,12 @@
 		return "("
 	case RParen:
 		return ")"
+	case Ident:
+		return "Ident"
+	case Comma:
+		return ","
+	case Equals:
+		return "="
 	case EOF:
 		return "EOF"
 	default: