diff --git a/token.go b/token.go
new file mode 100644
index 0000000..eb44066
--- /dev/null
+++ b/token.go
@@ -0,0 +1,132 @@
+package toml
+
+import (
+	"fmt"
+  "strconv"
+	"unicode"
+)
+
+// Define tokens
+type tokenType int
+
+const (
+	eof = -(iota + 1)
+)
+
+const (
+	tokenError tokenType = iota
+	tokenEOF
+	tokenComment
+	tokenKey
+	tokenString
+	tokenInteger
+	tokenTrue
+	tokenFalse
+	tokenFloat
+	tokenEqual
+	tokenLeftBracket
+	tokenRightBracket
+  tokenLeftParen
+  tokenRightParen
+	tokenDoubleLeftBracket
+	tokenDoubleRightBracket
+	tokenDate
+	tokenKeyGroup
+	tokenKeyGroupArray
+	tokenComma
+  tokenColon
+	tokenDollar
+  tokenStar
+  tokenQuestion
+	tokenDot
+	tokenDotDot
+	tokenEOL
+)
+
+var tokenTypeNames = []string{
+	"EOF",
+	"Comment",
+	"Key",
+	"String",
+	"Integer",
+	"True",
+	"False",
+	"Float",
+	"=",
+	"[",
+	"[",
+  "(",
+  ")",
+	"]]",
+	"[[",
+	"Date",
+	"KeyGroup",
+	"KeyGroupArray",
+	",",
+  ":",
+  "$",
+  "*",
+  "?",
+  ".",
+  "..",
+	"EOL",
+}
+
+type token struct {
+	Position
+	typ tokenType
+	val string
+}
+
+func (tt tokenType) String() string {
+	idx := int(tt)
+	if idx < len(tokenTypeNames) {
+		return tokenTypeNames[idx]
+	}
+	return "Unknown"
+}
+
+func (t token) Int() int {
+	if result, err := strconv.Atoi(t.val); err != nil {
+		panic(err)
+	} else {
+		return result
+	}
+}
+
+func (t token) String() string {
+	switch t.typ {
+	case tokenEOF:
+		return "EOF"
+	case tokenError:
+		return t.val
+	}
+
+	if len(t.val) > 10 {
+		return fmt.Sprintf("%.10q...", t.val)
+	}
+	return fmt.Sprintf("%q", t.val)
+}
+
+func isSpace(r rune) bool {
+	return r == ' ' || r == '\t'
+}
+
+func isAlphanumeric(r rune) bool {
+	return unicode.IsLetter(r) || r == '_'
+}
+
+func isKeyChar(r rune) bool {
+	// "Keys start with the first non-whitespace character and end with the last
+	// non-whitespace character before the equals sign."
+	return !(isSpace(r) || r == '\r' || r == '\n' || r == eof || r == '=')
+}
+
+func isDigit(r rune) bool {
+	return unicode.IsNumber(r)
+}
+
+func isHexDigit(r rune) bool {
+	return isDigit(r) ||
+		r == 'A' || r == 'B' || r == 'C' || r == 'D' || r == 'E' || r == 'F'
+}