z

token/token.go

@@ -0,0 +1,67 @@
+package token
+
+type TokenType string
+
+type Token struct {
+	Type    TokenType
+	Literal string
+}
+
+const (
+	ILLEGAL = "ILLEGAL"
+	EOF     = "EOF"
+
+	// identifiers + literals
+	IDENT = "IDENT"
+	INT   = "INT"
+
+	// operators
+	PLUS     = "+"
+	MINUS    = "-"
+	ASSIGN   = "="
+	BANG     = "!"
+	ASTERISK = "*"
+	SLASH    = "/"
+
+	EQ     = "=="
+	NOT_EQ = "!="
+
+	// delimiters
+	COMMA     = ","
+	SEMICOLON = ";"
+
+	LPAREN = "("
+	RPAREN = ")"
+	LBRACE = "{"
+	RBRACE = "}"
+
+	LT = "<"
+	GT = ">"
+
+	// keywords
+	FUNCTION = "function"
+	LET      = "let"
+	IF       = "if"
+	ELSE     = "else"
+	TRUE     = "true"
+	FALSE    = "false"
+	RETURN   = "return"
+)
+
+var keywords = map[string]TokenType{
+	"fn":     FUNCTION,
+	"let":    LET,
+	"return": RETURN,
+	"if":     IF,
+	"else":   ELSE,
+	"true":   TRUE,
+	"false":  FALSE,
+}
+
+func LookupIdent(ident string) TokenType {
+	if tt, ok := keywords[ident]; ok {
+		return tt
+	}
+
+	return IDENT
+}