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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 (
"fmt"
"strconv"
)
// atom, set, epsilon, action, predicate, rule transitions.
//
// <p>This is a one way link. It emanates from a state (usually via a list of
// transitions) and has a target state.</p>
//
// <p>Since we never have to change the ATN transitions once we construct it,
// the states. We'll use the term Edge for the DFA to distinguish them from
// ATN transitions.</p>
type Transition interface {
getTarget() ATNState
setTarget(ATNState)
getIsEpsilon() bool
getLabel() *IntervalSet
getSerializationType() int
Matches(int, int, int) bool
}
type BaseTransition struct {
target ATNState
isEpsilon bool
label int
intervalSet *IntervalSet
serializationType int
}
func NewBaseTransition(target ATNState) *BaseTransition {
if target == nil {
panic("target cannot be nil.")
}
t := new(BaseTransition)
t.target = target
// Are we epsilon, action, sempred?
t.isEpsilon = false
t.intervalSet = nil
return t
}
func (t *BaseTransition) getTarget() ATNState {
return t.target
}
func (t *BaseTransition) setTarget(s ATNState) {
t.target = s
}
func (t *BaseTransition) getIsEpsilon() bool {
return t.isEpsilon
}
func (t *BaseTransition) getLabel() *IntervalSet {
return t.intervalSet
}
func (t *BaseTransition) getSerializationType() int {
return t.serializationType
}
func (t *BaseTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool {
panic("Not implemented")
}
const (
TransitionEPSILON = 1
TransitionRANGE = 2
TransitionRULE = 3
TransitionPREDICATE = 4 // e.g., {isType(input.LT(1))}?
TransitionATOM = 5
TransitionACTION = 6
TransitionSET = 7 // ~(A|B) or ~atom, wildcard, which convert to next 2
TransitionNOTSET = 8
TransitionWILDCARD = 9
TransitionPRECEDENCE = 10
)
var TransitionserializationNames = []string{
"INVALID",
"EPSILON",
"RANGE",
"RULE",
"PREDICATE",
"ATOM",
"ACTION",
"SET",
"NOT_SET",
"WILDCARD",
"PRECEDENCE",
}
//var TransitionserializationTypes struct {
// EpsilonTransition int
// RangeTransition int
// RuleTransition int
// PredicateTransition int
// AtomTransition int
// ActionTransition int
// SetTransition int
// NotSetTransition int
// WildcardTransition int
// PrecedencePredicateTransition int
//}{
// TransitionEPSILON,
// TransitionRANGE,
// TransitionRULE,
// TransitionPREDICATE,
// TransitionATOM,
// TransitionACTION,
// TransitionSET,
// TransitionNOTSET,
// TransitionWILDCARD,
// TransitionPRECEDENCE
//}
// TODO: make all transitions sets? no, should remove set edges
type AtomTransition struct {
*BaseTransition
}
func NewAtomTransition(target ATNState, intervalSet int) *AtomTransition {
t := new(AtomTransition)
t.BaseTransition = NewBaseTransition(target)
t.label = intervalSet // The token type or character value or, signifies special intervalSet.
t.intervalSet = t.makeLabel()
t.serializationType = TransitionATOM
return t
}
func (t *AtomTransition) makeLabel() *IntervalSet {
s := NewIntervalSet()
s.addOne(t.label)
return s
}
func (t *AtomTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool {
return t.label == symbol
}
func (t *AtomTransition) String() string {
return strconv.Itoa(t.label)
}
type RuleTransition struct {
*BaseTransition
followState ATNState
ruleIndex, precedence int
}
func NewRuleTransition(ruleStart ATNState, ruleIndex, precedence int, followState ATNState) *RuleTransition {
t := new(RuleTransition)
t.BaseTransition = NewBaseTransition(ruleStart)
t.ruleIndex = ruleIndex
t.precedence = precedence
t.followState = followState
t.serializationType = TransitionRULE
t.isEpsilon = true
return t
}
func (t *RuleTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool {
return false
}
type EpsilonTransition struct {
*BaseTransition
outermostPrecedenceReturn int
}
func NewEpsilonTransition(target ATNState, outermostPrecedenceReturn int) *EpsilonTransition {
t := new(EpsilonTransition)
t.BaseTransition = NewBaseTransition(target)
t.serializationType = TransitionEPSILON
t.isEpsilon = true
t.outermostPrecedenceReturn = outermostPrecedenceReturn
return t
}
func (t *EpsilonTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool {
return false
}
func (t *EpsilonTransition) String() string {
return "epsilon"
}
type RangeTransition struct {
*BaseTransition
start, stop int
}
func NewRangeTransition(target ATNState, start, stop int) *RangeTransition {
t := new(RangeTransition)
t.BaseTransition = NewBaseTransition(target)
t.serializationType = TransitionRANGE
t.start = start
t.stop = stop
t.intervalSet = t.makeLabel()
return t
}
func (t *RangeTransition) makeLabel() *IntervalSet {
s := NewIntervalSet()
s.addRange(t.start, t.stop)
return s
}
func (t *RangeTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool {
return symbol >= t.start && symbol <= t.stop
}
func (t *RangeTransition) String() string {
return "'" + string(t.start) + "'..'" + string(t.stop) + "'"
}
type AbstractPredicateTransition interface {
Transition
IAbstractPredicateTransitionFoo()
}
type BaseAbstractPredicateTransition struct {
*BaseTransition
}
func NewBasePredicateTransition(target ATNState) *BaseAbstractPredicateTransition {
t := new(BaseAbstractPredicateTransition)
t.BaseTransition = NewBaseTransition(target)
return t
}
func (a *BaseAbstractPredicateTransition) IAbstractPredicateTransitionFoo() {}
type PredicateTransition struct {
*BaseAbstractPredicateTransition
isCtxDependent bool
ruleIndex, predIndex int
}
func NewPredicateTransition(target ATNState, ruleIndex, predIndex int, isCtxDependent bool) *PredicateTransition {
t := new(PredicateTransition)
t.BaseAbstractPredicateTransition = NewBasePredicateTransition(target)
t.serializationType = TransitionPREDICATE
t.ruleIndex = ruleIndex
t.predIndex = predIndex
t.isCtxDependent = isCtxDependent // e.g., $i ref in pred
t.isEpsilon = true
return t
}
func (t *PredicateTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool {
return false
}
func (t *PredicateTransition) getPredicate() *Predicate {
return NewPredicate(t.ruleIndex, t.predIndex, t.isCtxDependent)
}
func (t *PredicateTransition) String() string {
return "pred_" + strconv.Itoa(t.ruleIndex) + ":" + strconv.Itoa(t.predIndex)
}
type ActionTransition struct {
*BaseTransition
isCtxDependent bool
ruleIndex, actionIndex, predIndex int
}
func NewActionTransition(target ATNState, ruleIndex, actionIndex int, isCtxDependent bool) *ActionTransition {
t := new(ActionTransition)
t.BaseTransition = NewBaseTransition(target)
t.serializationType = TransitionACTION
t.ruleIndex = ruleIndex
t.actionIndex = actionIndex
t.isCtxDependent = isCtxDependent // e.g., $i ref in pred
t.isEpsilon = true
return t
}
func (t *ActionTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool {
return false
}
func (t *ActionTransition) String() string {
return "action_" + strconv.Itoa(t.ruleIndex) + ":" + strconv.Itoa(t.actionIndex)
}
type SetTransition struct {
*BaseTransition
}
func NewSetTransition(target ATNState, set *IntervalSet) *SetTransition {
t := new(SetTransition)
t.BaseTransition = NewBaseTransition(target)
t.serializationType = TransitionSET
if set != nil {
t.intervalSet = set
} else {
t.intervalSet = NewIntervalSet()
t.intervalSet.addOne(TokenInvalidType)
}
return t
}
func (t *SetTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool {
return t.intervalSet.contains(symbol)
}
func (t *SetTransition) String() string {
return t.intervalSet.String()
}
type NotSetTransition struct {
*SetTransition
}
func NewNotSetTransition(target ATNState, set *IntervalSet) *NotSetTransition {
t := new(NotSetTransition)
t.SetTransition = NewSetTransition(target, set)
t.serializationType = TransitionNOTSET
return t
}
func (t *NotSetTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool {
return symbol >= minVocabSymbol && symbol <= maxVocabSymbol && !t.intervalSet.contains(symbol)
}
func (t *NotSetTransition) String() string {
return "~" + t.intervalSet.String()
}
type WildcardTransition struct {
*BaseTransition
}
func NewWildcardTransition(target ATNState) *WildcardTransition {
t := new(WildcardTransition)
t.BaseTransition = NewBaseTransition(target)
t.serializationType = TransitionWILDCARD
return t
}
func (t *WildcardTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool {
return symbol >= minVocabSymbol && symbol <= maxVocabSymbol
}
func (t *WildcardTransition) String() string {
return "."
}
type PrecedencePredicateTransition struct {
*BaseAbstractPredicateTransition
precedence int
}
func NewPrecedencePredicateTransition(target ATNState, precedence int) *PrecedencePredicateTransition {
t := new(PrecedencePredicateTransition)
t.BaseAbstractPredicateTransition = NewBasePredicateTransition(target)
t.serializationType = TransitionPRECEDENCE
t.precedence = precedence
t.isEpsilon = true
return t
}
func (t *PrecedencePredicateTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool {
return false
}
func (t *PrecedencePredicateTransition) getPredicate() *PrecedencePredicate {
return NewPrecedencePredicate(t.precedence)
}
func (t *PrecedencePredicateTransition) String() string {
return fmt.Sprint(t.precedence) + " >= _p"
}
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