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// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
// Use of this file is governed by the BSD 3-clause license that
// can be found in the LICENSE.txt file in the project root.
package antlr
import "strconv"
// Constants for serialization.
const (
ATNStateInvalidType = 0
ATNStateBasic = 1
ATNStateRuleStart = 2
ATNStateBlockStart = 3
ATNStatePlusBlockStart = 4
ATNStateStarBlockStart = 5
ATNStateTokenStart = 6
ATNStateRuleStop = 7
ATNStateBlockEnd = 8
ATNStateStarLoopBack = 9
ATNStateStarLoopEntry = 10
ATNStatePlusLoopBack = 11
ATNStateLoopEnd = 12
ATNStateInvalidStateNumber = -1
)
var ATNStateInitialNumTransitions = 4
type ATNState interface {
GetEpsilonOnlyTransitions() bool
GetRuleIndex() int
SetRuleIndex(int)
GetNextTokenWithinRule() *IntervalSet
SetNextTokenWithinRule(*IntervalSet)
GetATN() *ATN
SetATN(*ATN)
GetStateType() int
GetStateNumber() int
SetStateNumber(int)
GetTransitions() []Transition
SetTransitions([]Transition)
AddTransition(Transition, int)
String() string
hash() int
}
type BaseATNState struct {
// NextTokenWithinRule caches lookahead during parsing. Not used during construction.
NextTokenWithinRule *IntervalSet
// atn is the current ATN.
atn *ATN
epsilonOnlyTransitions bool
// ruleIndex tracks the Rule index because there are no Rule objects at runtime.
ruleIndex int
stateNumber int
stateType int
// Track the transitions emanating from this ATN state.
transitions []Transition
}
func NewBaseATNState() *BaseATNState {
return &BaseATNState{stateNumber: ATNStateInvalidStateNumber, stateType: ATNStateInvalidType}
}
func (as *BaseATNState) GetRuleIndex() int {
return as.ruleIndex
}
func (as *BaseATNState) SetRuleIndex(v int) {
as.ruleIndex = v
}
func (as *BaseATNState) GetEpsilonOnlyTransitions() bool {
return as.epsilonOnlyTransitions
}
func (as *BaseATNState) GetATN() *ATN {
return as.atn
}
func (as *BaseATNState) SetATN(atn *ATN) {
as.atn = atn
}
func (as *BaseATNState) GetTransitions() []Transition {
return as.transitions
}
func (as *BaseATNState) SetTransitions(t []Transition) {
as.transitions = t
}
func (as *BaseATNState) GetStateType() int {
return as.stateType
}
func (as *BaseATNState) GetStateNumber() int {
return as.stateNumber
}
func (as *BaseATNState) SetStateNumber(stateNumber int) {
as.stateNumber = stateNumber
}
func (as *BaseATNState) GetNextTokenWithinRule() *IntervalSet {
return as.NextTokenWithinRule
}
func (as *BaseATNState) SetNextTokenWithinRule(v *IntervalSet) {
as.NextTokenWithinRule = v
}
func (as *BaseATNState) hash() int {
return as.stateNumber
}
func (as *BaseATNState) String() string {
return strconv.Itoa(as.stateNumber)
}
func (as *BaseATNState) equals(other interface{}) bool {
if ot, ok := other.(ATNState); ok {
return as.stateNumber == ot.GetStateNumber()
}
return false
}
func (as *BaseATNState) isNonGreedyExitState() bool {
return false
}
func (as *BaseATNState) AddTransition(trans Transition, index int) {
if len(as.transitions) == 0 {
as.epsilonOnlyTransitions = trans.getIsEpsilon()
} else if as.epsilonOnlyTransitions != trans.getIsEpsilon() {
as.epsilonOnlyTransitions = false
}
if index == -1 {
as.transitions = append(as.transitions, trans)
} else {
as.transitions = append(as.transitions[:index], append([]Transition{trans}, as.transitions[index:]...)...)
// TODO: as.transitions.splice(index, 1, trans)
}
}
type BasicState struct {
*BaseATNState
}
func NewBasicState() *BasicState {
b := NewBaseATNState()
b.stateType = ATNStateBasic
return &BasicState{BaseATNState: b}
}
type DecisionState interface {
ATNState
getDecision() int
setDecision(int)
getNonGreedy() bool
setNonGreedy(bool)
}
type BaseDecisionState struct {
*BaseATNState
decision int
nonGreedy bool
}
func NewBaseDecisionState() *BaseDecisionState {
return &BaseDecisionState{BaseATNState: NewBaseATNState(), decision: -1}
}
func (s *BaseDecisionState) getDecision() int {
return s.decision
}
func (s *BaseDecisionState) setDecision(b int) {
s.decision = b
}
func (s *BaseDecisionState) getNonGreedy() bool {
return s.nonGreedy
}
func (s *BaseDecisionState) setNonGreedy(b bool) {
s.nonGreedy = b
}
type BlockStartState interface {
DecisionState
getEndState() *BlockEndState
setEndState(*BlockEndState)
}
// BaseBlockStartState is the start of a regular (...) block.
type BaseBlockStartState struct {
*BaseDecisionState
endState *BlockEndState
}
func NewBlockStartState() *BaseBlockStartState {
return &BaseBlockStartState{BaseDecisionState: NewBaseDecisionState()}
}
func (s *BaseBlockStartState) getEndState() *BlockEndState {
return s.endState
}
func (s *BaseBlockStartState) setEndState(b *BlockEndState) {
s.endState = b
}
type BasicBlockStartState struct {
*BaseBlockStartState
}
func NewBasicBlockStartState() *BasicBlockStartState {
b := NewBlockStartState()
b.stateType = ATNStateBlockStart
return &BasicBlockStartState{BaseBlockStartState: b}
}
// BlockEndState is a terminal node of a simple (a|b|c) block.
type BlockEndState struct {
*BaseATNState
startState ATNState
}
func NewBlockEndState() *BlockEndState {
b := NewBaseATNState()
b.stateType = ATNStateBlockEnd
return &BlockEndState{BaseATNState: b}
}
// RuleStopState is the last node in the ATN for a rule, unless that rule is the
// start symbol. In that case, there is one transition to EOF. Later, we might
// encode references to all calls to this rule to compute FOLLOW sets for error
// handling.
type RuleStopState struct {
*BaseATNState
}
func NewRuleStopState() *RuleStopState {
b := NewBaseATNState()
b.stateType = ATNStateRuleStop
return &RuleStopState{BaseATNState: b}
}
type RuleStartState struct {
*BaseATNState
stopState ATNState
isPrecedenceRule bool
}
func NewRuleStartState() *RuleStartState {
b := NewBaseATNState()
b.stateType = ATNStateRuleStart
return &RuleStartState{BaseATNState: b}
}
// PlusLoopbackState is a decision state for A+ and (A|B)+. It has two
// transitions: one to the loop back to start of the block, and one to exit.
type PlusLoopbackState struct {
*BaseDecisionState
}
func NewPlusLoopbackState() *PlusLoopbackState {
b := NewBaseDecisionState()
b.stateType = ATNStatePlusLoopBack
return &PlusLoopbackState{BaseDecisionState: b}
}
// PlusBlockStartState is the start of a (A|B|...)+ loop. Technically it is a
// decision state; we don't use it for code generation. Somebody might need it,
// it is included for completeness. In reality, PlusLoopbackState is the real
// decision-making node for A+.
type PlusBlockStartState struct {
*BaseBlockStartState
loopBackState ATNState
}
func NewPlusBlockStartState() *PlusBlockStartState {
b := NewBlockStartState()
b.stateType = ATNStatePlusBlockStart
return &PlusBlockStartState{BaseBlockStartState: b}
}
// StarBlockStartState is the block that begins a closure loop.
type StarBlockStartState struct {
*BaseBlockStartState
}
func NewStarBlockStartState() *StarBlockStartState {
b := NewBlockStartState()
b.stateType = ATNStateStarBlockStart
return &StarBlockStartState{BaseBlockStartState: b}
}
type StarLoopbackState struct {
*BaseATNState
}
func NewStarLoopbackState() *StarLoopbackState {
b := NewBaseATNState()
b.stateType = ATNStateStarLoopBack
return &StarLoopbackState{BaseATNState: b}
}
type StarLoopEntryState struct {
*BaseDecisionState
loopBackState ATNState
precedenceRuleDecision bool
}
func NewStarLoopEntryState() *StarLoopEntryState {
b := NewBaseDecisionState()
b.stateType = ATNStateStarLoopEntry
// False precedenceRuleDecision indicates whether s state can benefit from a precedence DFA during SLL decision making.
return &StarLoopEntryState{BaseDecisionState: b}
}
// LoopEndState marks the end of a * or + loop.
type LoopEndState struct {
*BaseATNState
loopBackState ATNState
}
func NewLoopEndState() *LoopEndState {
b := NewBaseATNState()
b.stateType = ATNStateLoopEnd
return &LoopEndState{BaseATNState: b}
}
// TokensStartState is the Tokens rule start state linking to each lexer rule start state.
type TokensStartState struct {
*BaseDecisionState
}
func NewTokensStartState() *TokensStartState {
b := NewBaseDecisionState()
b.stateType = ATNStateTokenStart
return &TokensStartState{BaseDecisionState: b}
}
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