restructure

lexer/tokentype.go

@@ -0,0 +1,91 @@
+package lexer
+
+import "fmt"
+
+//go:generate stringer -type TokenType -linecomment -trimprefix TokenType
+type TokenType int
+
+const (
+	// single char tokens
+
+	TokenTypeLeftParen TokenType = iota
+	TokenTypeRightParen
+	TokenTypeLeftBrace
+	TokenTypeRightBrace
+	TokenTypeComma
+	TokenTypeDot
+	TokenTypeMinus
+	TokenTypePlus
+	TokenTypeSemicolon
+	TokenTypeSlash
+	TokenTypeStar
+
+	// 1-2 char token
+
+	TokenTypeBang
+	TokenTypeBangEq
+	TokenTypeEqual
+	TokenTypeEqualEqual
+	TokenTypeGreater
+	TokenTypeGreaterEq
+	TokenTypeLess
+	TokenTypeLessEq
+
+	// literals
+
+	TokenTypeIdentifier
+	TokenTypeString
+	TokenTypeNumber
+
+	// keywords
+
+	TokenTypeAnd
+	TokenTypeClass
+	TokenTypeElse
+	TokenTypeFalse
+	TokenTypeFun
+	TokenTypeFor
+	TokenTypeIf
+	TokenTypeNil
+	TokenTypeOr
+	TokenTypePrint
+	TokenTypeReturn
+	TokenTypeSuper
+	TokenTypeThis
+	TokenTypeTrue
+	TokenTypeVar
+	TokenTypeWhile
+
+	TokenTypeEOF
+)
+
+var KeywordTokenTypes = []TokenType{
+	TokenTypeClass,
+	TokenTypeFun,
+	TokenTypeVar,
+	TokenTypeFor,
+	TokenTypeIf,
+	TokenTypeReturn,
+	TokenTypeWhile,
+	TokenTypePrint,
+}
+
+type Token struct {
+	Type    TokenType
+	Lexeme  string
+	Literal any
+	Line    int
+}
+
+func (t Token) String() string {
+	return fmt.Sprintf("%s %s %+v", t.Type, t.Lexeme, t.Literal)
+}
+
+func IsKeyword(token *Token) bool {
+	for _, kt := range KeywordTokenTypes {
+		if token.Type == kt {
+			return true
+		}
+	}
+	return false
+}