scan

Documentation

Overview

Package scan implements a scanner for Lisp source.

Index

• type Scanner
  • func New(r io.RuneReader) *Scanner
  • func (s *Scanner) Next() Token
• type Token
  • func (t Token) String() string
• type Type
  • func (i Type) String() string

Types

type Scanner

type Scanner struct {
	// contains filtered or unexported fields
}

Scanner holds state of Lisp tokens.

func New

func New(r io.RuneReader) *Scanner

New initialises a scanner for tokenizing Lisp data from a reader.

func (*Scanner) Next

func (s *Scanner) Next() Token

Next reads the next token from the underlying reader.

If an error is encountered, an error token will be returned with a message as its text.

type Token

type Token struct {
	Type Type
	Text string
}

Token represents a token or literal

func (Token) String

func (t Token) String() string

type Type

type Type int

Type identifies the lexical token types of Lisp data.

const (
	Illegal Type = iota
	Error
	EOF

	Comment

	Atom
	LeftParen
	RightParen
)

func (Type) String

func (i Type) String() string