scanner

Documentation

Index

• type Error
• type Position
• type Scanner
  • func New(r io.Reader) (*Scanner, error)
  • func (s *Scanner) AddKeyword(kw string, tok tokens.Token)
  • func (s *Scanner) Bytes() []byte
  • func (s *Scanner) Keyword(lit string) tokens.Token
  • func (s *Scanner) Scan() (tokens.Token, Position, string, []Error)
  • func (s *Scanner) String() string
  • func (s *Scanner) WithKeywords(kws map[string]tokens.Token) *Scanner
  • func (s *Scanner) WithoutKeywords(kws map[string]tokens.Token) (*Scanner, map[string]tokens.Token)

Types

type Error

type Error struct {
	Pos     Position
	Message string
}

Error represents a scanner error.

type Position

type Position struct {
	Offset int // start offset in bytes
	End    int // end offset in bytes
	Row    int // line number computed in bytes
	Col    int // column number computed in bytes
}

Position represents a point in the scanned source code.

type Scanner

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

Scanner is used to tokenize an input stream of Rego source code.

func New

func New(r io.Reader) (*Scanner, error)

New returns an initialized scanner that will scan through the source code provided by the io.Reader.

func (*Scanner) AddKeyword

func (s *Scanner) AddKeyword(kw string, tok tokens.Token)

AddKeyword adds a string -> token mapping to this Scanner instance.

func (*Scanner) Bytes

func (s *Scanner) Bytes() []byte

Bytes returns the raw bytes for the full source which the scanner has read in.

func (*Scanner) Keyword

func (s *Scanner) Keyword(lit string) tokens.Token

Keyword will return a token for the passed in literal value. If the value is a Rego keyword then the appropriate token is returned. Everything else is an Ident.

func (*Scanner) Scan

func (s *Scanner) Scan() (tokens.Token, Position, string, []Error)

Scan will increment the scanners position in the source code until the next token is found. The token, starting position of the token, string literal, and any errors encountered are returned. A token will always be returned, the caller must check for any errors before using the other values.

func (*Scanner) String

func (s *Scanner) String() string

String returns a human readable string of the current scanner state.

func (*Scanner) WithKeywords

func (s *Scanner) WithKeywords(kws map[string]tokens.Token) *Scanner

WithKeywords returns a new copy of the Scanner struct `s`, with the set of known keywords being that of `s` with `kws` added.

func (*Scanner) WithoutKeywords

func (s *Scanner) WithoutKeywords(kws map[string]tokens.Token) (*Scanner, map[string]tokens.Token)

WithoutKeywords returns a new copy of the Scanner struct `s`, with the set of known keywords being that of `s` with `kws` removed. The previously known keywords are returned for a convenient reset.