auto

Documentation

Overview

Package auto compiles a parsed validator grammar into a visual pushdown automaton and executes it. Compilation into a VPA may result in an exponential explosion, since fully converting a grammar to VPA is O(2^n^2). Rather use the mem package. It gives comparable speed and has no exponential behaviour. This package is just here to provide a benchmark against the mem package.

Index

• Variables
• type Auto
  • func Compile(g *ast.Grammar, options ...Option) (*Auto, error)
  • func (auto *Auto) MetricNumberOfStates() int
  • func (auto *Auto) Validate(p parse.Parser) (bool, error)
• type Option
  • func WithFieldNameTable() Option
  • func WithMaxBitSetSize(m int) Option
  • func WithRecordSimplificationRules() Option
• type PatternsSet
  • func NewPatternsSet() PatternsSet
  • func (this *PatternsSet) Add(x []*intern.Pattern) int
  • func (this *PatternsSet) Get(i int) []*intern.Pattern
  • func (this *PatternsSet) Index(x []*intern.Pattern) int
  • func (this *PatternsSet) Len() int

Variables

var ErrTooBig = errors.New("a state explosion has occured")

A maximum number is set for bitsets as an option, when it is exceeded the number of options to consider is too large and we recommend rather using the memoized version of katydid.

Types

type Auto

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

Auto is the structure that represents the automaton.

func Compile

func Compile(g *ast.Grammar, options ...Option) (*Auto, error)

Compile compiles a parsed validator grammar ast into a visual pushdown automaton.

func (*Auto) MetricNumberOfStates

func (auto *Auto) MetricNumberOfStates() int

func (*Auto) Validate

func (auto *Auto) Validate(p parse.Parser) (bool, error)

Validate executes an automaton with the given parser and returns whether the parser is valid given the automaton's original grammar.

type Option

type Option func(o *options)

func WithFieldNameTable

func WithFieldNameTable() Option

creates a lookup strings found in field name expressions.

func WithMaxBitSetSize

func WithMaxBitSetSize(m int) Option

func WithRecordSimplificationRules

func WithRecordSimplificationRules() Option

compiles a parsed validator grammar and optimizes it for the case where the input structures are records, by shrinking space with extra simplification rules. Do not use with XML, but JSON, Reflect and Protobufs are safe.

type PatternsSet

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

func NewPatternsSet

func NewPatternsSet() PatternsSet

func (*PatternsSet) Add

func (this *PatternsSet) Add(x []*intern.Pattern) int

func (*PatternsSet) Get

func (this *PatternsSet) Get(i int) []*intern.Pattern

func (*PatternsSet) Index

func (this *PatternsSet) Index(x []*intern.Pattern) int

func (*PatternsSet) Len

func (this *PatternsSet) Len() int