func GenerateNFA(ruleName string, regularRuleList *list.List) *automata.NFA {
rules := make(map[string]*abnf.Rule)
for e := regularRuleList.Front(); e != nil; e = e.Next() {
v := e.Value.(*abnf.Rule)
rules[v.GetRuleName().String()] = v
}
startState := automata.NewNFAState()
acceptingState := automata.NewNFAState()
rules[ruleName].GetElements().GetNFAStates(startState, acceptingState, rules)
return automata.NewNFA2(startState, acceptingState)
}
func (this *Concatenation) GetNFAStates(startState, acceptingState *automata.NFAState, rules map[string]*Rule) {
current := startState
e := this.repetitions.Front()
var next *automata.NFAState
for index := 0; index < this.repetitions.Len()-1; index++ {
next = automata.NewNFAState()
e.Value.(*Repetition).GetNFAStates(current, next, rules)
current = next
e = e.Next()
}
e.Value.(*Repetition).GetNFAStates(current, acceptingState, rules)
}
func (this *Concatenation) GetNFA(rules map[string]*Rule) *automata.NFA { //throws IllegalAbnfException {
startState := automata.NewNFAState()
acceptingState := automata.NewNFAState()
this.GetNFAStates(startState, acceptingState, rules)
return automata.NewNFA2(startState, acceptingState)
}
func (this *Repetition) GetNFAStates(startState, acceptingState *automata.NFAState, rules map[string]*Rule) {
if this.repeat == nil {
this.element.GetNFAStates(startState, acceptingState, rules)
return
}
min := this.repeat.GetMin()
max := this.repeat.GetMax()
if min < 0 /*|| max < 0*/ {
panic("Min value of a repeat element can not be less than zero.")
}
if max == -1 {
if min == 0 {
// min == 0 && max == -1
startState.AddTransitEpsilon(acceptingState)
this.element.GetNFAStates(acceptingState, acceptingState, rules)
return
} else {
// min > 0 && max == -1
current := startState
for j := 0; j < min-1; j++ {
next := automata.NewNFAState()
this.element.GetNFAStates(current, next, rules)
current = next
}
this.element.GetNFAStates(current, acceptingState, rules)
this.element.GetNFAStates(acceptingState, acceptingState, rules)
return
}
} else {
if min == 0 {
// min == 0 && max > 0
current := startState
for j := 0; j < max-1; j++ {
current.AddTransitEpsilon(acceptingState)
next := automata.NewNFAState()
this.element.GetNFAStates(current, next, rules)
current = next
}
current.AddTransitEpsilon(acceptingState)
this.element.GetNFAStates(current, acceptingState, rules)
return
} else if min == max {
// 0 < min == max
current := startState
for j := 0; j < max-1; j++ {
next := automata.NewNFAState()
this.element.GetNFAStates(current, next, rules)
current = next
}
this.element.GetNFAStates(current, acceptingState, rules)
return
} else if min < max {
// 0 < min < max
current := startState
for j := 0; j < min; j++ {
next := automata.NewNFAState()
this.element.GetNFAStates(current, next, rules)
current = next
}
for j := 0; j < max-min-1; j++ {
current.AddTransitEpsilon(acceptingState)
next := automata.NewNFAState()
this.element.GetNFAStates(current, next, rules)
current = next
}
current.AddTransitEpsilon(acceptingState)
this.element.GetNFAStates(current, acceptingState, rules)
return
} else {
panic("Max can not less than min")
}
}
}