booklit: Index | Files

package ast

import ""


Package Files

booklit.peg.go errors.go node.go

func Parse Uses

func Parse(filename string, b []byte, opts ...Option) (interface{}, error)

Parse parses the data from b using filename as information in the error messages.

func ParseFile Uses

func ParseFile(filename string, opts ...Option) (i interface{}, err error)

ParseFile parses the file identified by filename.

func ParseReader Uses

func ParseReader(filename string, r io.Reader, opts ...Option) (interface{}, error)

ParseReader parses the data from r using filename as information in the error messages.

type Cloner Uses

type Cloner interface {
    Clone() interface{}

Cloner is implemented by any value that has a Clone method, which returns a copy of the value. This is mainly used for types which are not passed by value (e.g map, slice, chan) or structs that contain such types.

This is used in conjunction with the global state feature to create proper copies of the state to allow the parser to properly restore the state in the case of backtracking.

type Invoke Uses

type Invoke struct {
    Function  string
    Arguments []Node

    Location Location

func (Invoke) Method Uses

func (node Invoke) Method() string

func (Invoke) Visit Uses

func (node Invoke) Visit(visitor Visitor) error

type Location Uses

type Location struct {
    Line   int
    Col    int
    Offset int

func UnpackError Uses

func UnpackError(err error) (error, Location, bool)

type Node Uses

type Node interface {
    Visit(Visitor) error

type Option Uses

type Option func(*parser) Option

Option is a function that can set an option on the parser. It returns the previous setting as an Option.

func AllowInvalidUTF8 Uses

func AllowInvalidUTF8(b bool) Option

AllowInvalidUTF8 creates an Option to allow invalid UTF-8 bytes. Every invalid UTF-8 byte is treated as a utf8.RuneError (U+FFFD) by character class matchers and is matched by the any matcher. The returned matched value, c.text and c.offset are NOT affected.

The default is false.

func Debug Uses

func Debug(b bool) Option

Debug creates an Option to set the debug flag to b. When set to true, debugging information is printed to stdout while parsing.

The default is false.

func Entrypoint Uses

func Entrypoint(ruleName string) Option

Entrypoint creates an Option to set the rule name to use as entrypoint. The rule name must have been specified in the -alternate-entrypoints if generating the parser with the -optimize-grammar flag, otherwise it may have been optimized out. Passing an empty string sets the entrypoint to the first rule in the grammar.

The default is to start parsing at the first rule in the grammar.

func GlobalStore Uses

func GlobalStore(key string, value interface{}) Option

GlobalStore creates an Option to set a key to a certain value in the globalStore.

func InitState Uses

func InitState(key string, value interface{}) Option

InitState creates an Option to set a key to a certain value in the global "state" store.

func MaxExpressions Uses

func MaxExpressions(maxExprCnt uint64) Option

MaxExpressions creates an Option to stop parsing after the provided number of expressions have been parsed, if the value is 0 then the parser will parse for as many steps as needed (possibly an infinite number).

The default for maxExprCnt is 0.

func Memoize Uses

func Memoize(b bool) Option

Memoize creates an Option to set the memoize flag to b. When set to true, the parser will cache all results so each expression is evaluated only once. This guarantees linear parsing time even for pathological cases, at the expense of more memory and slower times for typical cases.

The default is false.

func Recover Uses

func Recover(b bool) Option

Recover creates an Option to set the recover flag to b. When set to true, this causes the parser to recover from panics and convert it to an error. Setting it to false can be useful while debugging to access the full stack trace.

The default is true.

func Statistics Uses

func Statistics(stats *Stats, choiceNoMatch string) Option

Statistics adds a user provided Stats struct to the parser to allow the user to process the results after the parsing has finished. Also the key for the "no match" counter is set.

Example usage:

input := "input"
stats := Stats{}
_, err := Parse("input-file", []byte(input), Statistics(&stats, "no match"))
if err != nil {
b, err := json.MarshalIndent(stats.ChoiceAltCnt, "", "  ")
if err != nil {

type Paragraph Uses

type Paragraph []Sequence

func (Paragraph) Visit Uses

func (node Paragraph) Visit(visitor Visitor) error

type Preformatted Uses

type Preformatted []Sequence

func (Preformatted) Visit Uses

func (node Preformatted) Visit(visitor Visitor) error

type Sequence Uses

type Sequence []Node

func (Sequence) Visit Uses

func (node Sequence) Visit(visitor Visitor) error

type Stats Uses

type Stats struct {
    // ExprCnt counts the number of expressions processed during parsing
    // This value is compared to the maximum number of expressions allowed
    // (set by the MaxExpressions option).
    ExprCnt uint64

    // ChoiceAltCnt is used to count for each ordered choice expression,
    // which alternative is used how may times.
    // These numbers allow to optimize the order of the ordered choice expression
    // to increase the performance of the parser
    // The outer key of ChoiceAltCnt is composed of the name of the rule as well
    // as the line and the column of the ordered choice.
    // The inner key of ChoiceAltCnt is the number (one-based) of the matching alternative.
    // For each alternative the number of matches are counted. If an ordered choice does not
    // match, a special counter is incremented. The name of this counter is set with
    // the parser option Statistics.
    // For an alternative to be included in ChoiceAltCnt, it has to match at least once.
    ChoiceAltCnt map[string]map[string]int

Stats stores some statistics, gathered during parsing

type String Uses

type String string

func (String) Visit Uses

func (node String) Visit(visitor Visitor) error

type Visitor Uses

type Visitor interface {
    VisitString(String) error
    VisitInvoke(Invoke) error
    VisitSequence(Sequence) error
    VisitParagraph(Paragraph) error
    VisitPreformatted(Preformatted) error

Package ast imports 13 packages (graph) and is imported by 4 packages. Updated 2020-07-08. Refresh now. Tools for package owners.