type Associativity uint

const (
	// AssociativityNone defines a token has no associativity
	AssociativityNone Associativity = iota
	// AssociativityLeft defines a token is left associative
	AssociativityLeft
	// AssociativityRight defines a token is right associative
	AssociativityRight
)

type Token struct {
	Type          Type
	Value         string
	Associativity Associativity
	Precedence    uint
}

type Tokens []Token

func Parse(s string) (tokens Tokens, err error)

type Type uint

const (
	TypeUnknown Type = iota
	TypeSpace
	TypeLParent
	TypeRParent
	TypeConstant
	TypeVariable
	TypeOperator
)