lexer

README

caddyfile lexer copied from caddy project.

Taken from the following commit:

commit ed4c2775e46b924d4851e04cc281633b1b2c15af
Author: Alexander Danilov <SmilingNavern@users.noreply.github.com>
Date:   Wed Aug 21 20:13:34 2019 +0300

    main: log caddy version on start (#2717)

License of the original code is included in LICENSE.APACHE file in this directory.

No signficant changes was made to the code (e.g. it is safe to update it from caddy repo).

The code is copied because caddy brings quite a lot of dependencies we don't use and this slows down many tools.

Documentation

Index

• type Dispenser
  • func NewDispenser(filename string, input io.Reader) Dispenser
  • func NewDispenserTokens(filename string, tokens []Token) Dispenser
  • func (d *Dispenser) ArgErr() error
  • func (d *Dispenser) Args(targets ...*string) bool
  • func (d *Dispenser) EOFErr() error
  • func (d *Dispenser) Err(msg string) error
  • func (d *Dispenser) Errf(format string, args ...interface{}) error
  • func (d *Dispenser) File() string
  • func (d *Dispenser) Line() int
  • func (d *Dispenser) Next() bool
  • func (d *Dispenser) NextArg() bool
  • func (d *Dispenser) NextBlock() bool
  • func (d *Dispenser) NextLine() bool
  • func (d *Dispenser) RemainingArgs() []string
  • func (d *Dispenser) SyntaxErr(expected string) error
  • func (d *Dispenser) Val() string
• type Token

Types

type Dispenser

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

Dispenser is a type that dispenses tokens, similarly to a lexer, except that it can do so with some notion of structure and has some really convenient methods.

func NewDispenser

func NewDispenser(filename string, input io.Reader) Dispenser

NewDispenser returns a Dispenser, ready to use for parsing the given input.

func NewDispenserTokens

func NewDispenserTokens(filename string, tokens []Token) Dispenser

NewDispenserTokens returns a Dispenser filled with the given tokens.

func (*Dispenser) ArgErr

func (d *Dispenser) ArgErr() error

ArgErr returns an argument error, meaning that another argument was expected but not found. In other words, a line break or open curly brace was encountered instead of an argument.

func (*Dispenser) Args

func (d *Dispenser) Args(targets ...*string) bool

Args is a convenience function that loads the next arguments (tokens on the same line) into an arbitrary number of strings pointed to in targets. If there are fewer tokens available than string pointers, the remaining strings will not be changed and false will be returned. If there were enough tokens available to fill the arguments, then true will be returned.

func (*Dispenser) EOFErr

func (d *Dispenser) EOFErr() error

EOFErr returns an error indicating that the dispenser reached the end of the input when searching for the next token.

func (*Dispenser) Err

func (d *Dispenser) Err(msg string) error

Err generates a custom parse-time error with a message of msg.

func (*Dispenser) Errf

func (d *Dispenser) Errf(format string, args ...interface{}) error

Errf is like Err, but for formatted error messages

func (*Dispenser) File

func (d *Dispenser) File() string

File gets the filename of the current token. If there is no token loaded, it returns the filename originally given when parsing started.

func (*Dispenser) Line

func (d *Dispenser) Line() int

Line gets the line number of the current token. If there is no token loaded, it returns 0.

func (*Dispenser) Next

func (d *Dispenser) Next() bool

Next loads the next token. Returns true if a token was loaded; false otherwise. If false, all tokens have been consumed.

func (*Dispenser) NextArg

func (d *Dispenser) NextArg() bool

NextArg loads the next token if it is on the same line. Returns true if a token was loaded; false otherwise. If false, all tokens on the line have been consumed. It handles imported tokens correctly.

func (*Dispenser) NextBlock

func (d *Dispenser) NextBlock() bool

NextBlock can be used as the condition of a for loop to load the next token as long as it opens a block or is already in a block. It returns true if a token was loaded, or false when the block's closing curly brace was loaded and thus the block ended. Nested blocks are not supported.

func (*Dispenser) NextLine

func (d *Dispenser) NextLine() bool

NextLine loads the next token only if it is not on the same line as the current token, and returns true if a token was loaded; false otherwise. If false, there is not another token or it is on the same line. It handles imported tokens correctly.

func (*Dispenser) RemainingArgs

func (d *Dispenser) RemainingArgs() []string

RemainingArgs loads any more arguments (tokens on the same line) into a slice and returns them. Open curly brace tokens also indicate the end of arguments, and the curly brace is not included in the return value nor is it loaded.

func (*Dispenser) SyntaxErr

func (d *Dispenser) SyntaxErr(expected string) error

SyntaxErr creates a generic syntax error which explains what was found and what was expected.

func (*Dispenser) Val

func (d *Dispenser) Val() string

Val gets the text of the current token. If there is no token loaded, it returns empty string.

type Token

type Token struct {
	File string
	Line int
	Text string
}

Token represents a single parsable unit.