package parser

// TokenType represents the type of a token
type TokenType int

const (
	// Literals
	IDENT TokenType = iota
	NUMBER
	STRING

	// Operators
	ASSIGN // =
	PLUS   // +
	MINUS  // -
	STAR   // *
	SLASH  // /

	// Delimiters
	LPAREN // (
	RPAREN // )

	// Keywords
	VAR

	// Special
	EOF
	ILLEGAL
)

// Token represents a single token
type Token struct {
	Type    TokenType
	Literal string
	Line    int
	Column  int
}

// Precedence levels for Pratt parsing
type Precedence int

const (
	_ Precedence = iota
	LOWEST
	SUM     // +
	PRODUCT // *
	PREFIX  // -x, !x
	CALL    // function()
)

// precedences maps token types to their precedence levels
var precedences = map[TokenType]Precedence{
	PLUS:  SUM,
	MINUS: SUM,
	SLASH: PRODUCT,
	STAR:  PRODUCT,
}

// lookupIdent checks if an identifier is a keyword
func lookupIdent(ident string) TokenType {
	keywords := map[string]TokenType{
		"var": VAR,
	}

	if tok, ok := keywords[ident]; ok {
		return tok
	}
	return IDENT
}