// Read returns the next Source ScannerRune.
func (s *Source) Read() (r ScannerRune) {
for {
r.Position = s.Position()
r.Rune, r.Size, r.Err = s.tos.reader.ReadRune()
if r.Err == nil || !fileutil.IsEOF(r.Err) {
p := &s.tos.position
p.Offset += r.Size
if r.Rune != '\n' {
p.Column++
} else {
p.Line++
p.Column = 1
}
return
}
// err == os.EOF, try parent source
if sp := len(s.stack) - 1; sp >= 0 {
s.tos = s.stack[sp]
s.stack = s.stack[:sp]
} else {
r.Rune, r.Size = 0, 0
return
}
}
}
// NewL parses a .l source fname from src, returns L or an error if any.
// Currently it is not reentrant and not invokable more than once in an application
// (which is assumed tolerable for a "lex" tool).
// The unoptdfa argument allows to disable optimization of the produced DFA.
// The mode32 parameter is not yet supported and must be false.
func NewL(fname string, src io.RuneReader, unoptdfa, mode32 bool) (l *L, err error) {
if mode32 {
return nil, errors.New("lex.NewL: mode32 unsupported yet")
}
nodfaopt, bits32 = unoptdfa, mode32
l = &L{}
if !hook {
defer func() {
if e := recover(); e != nil {
l = nil
err = e.(error)
}
}()
}
// Support \r\n line separators too
in := []rune{}
loop:
for {
r, _, err := src.ReadRune()
switch {
case err == nil:
in = append(in, r)
case fileutil.IsEOF(err):
break loop
default:
return nil, err
}
}
src = bytes.NewBufferString(strings.Replace(string(in), "\r\n", "\n", -1))
scanner := lxr.Scanner(fname, src)
if y := yyParse(newTokenizer(scanner)); y != 0 || len(errors_) != 0 {
return nil, errors.New(strings.Join(errors_, "\n"))
}
computePartialDFAs()
if len(errors_) != 0 {
return nil, errors.New(strings.Join(errors_, "\n"))
}
computeAllNfa()
allDfa = allNfa.powerSet()
for _, irule := range allDfa.acceptRule {
delete(unreachableRules, irule)
}
for irule := range unreachableRules {
logErr(fmt.Sprintf("%s - pattern `%s` unreachable", rulePos[irule], rules[irule].pattern))
}
if len(errors_) != 0 {
return nil, errors.New(strings.Join(errors_, "\n"))
}
l.DefCode = defCode
l.UserCode = usrCode
l.StartConditions = iStarts
l.StartConditionsStates = make(map[int]*lexer.NfaState)
l.StartConditionsBolStates = make(map[int]*lexer.NfaState)
for _, edge0 := range allDfa.nfa.in.Consuming {
switch edge := edge0.(type) {
default:
panic(errors.New("internal error"))
case *lexer.RuneEdge:
if _, ok := l.StartConditionsStates[int(edge.Rune)]; ok {
panic(errors.New("internal error"))
}
if edge.Rune < 128 {
l.StartConditionsStates[int(edge.Rune)] = edge.Target()
} else {
l.StartConditionsBolStates[int(edge.Rune)-128] = edge.Target()
}
case *lexer.RangesEdge:
for _, rng := range edge.Ranges.R32 {
for arune := rng.Lo; arune <= rng.Hi; arune += rng.Stride {
if _, ok := l.StartConditionsStates[int(arune)]; ok {
panic(errors.New("internal error"))
}
if arune < 128 {
l.StartConditionsStates[int(arune)] = edge.Target()
} else {
l.StartConditionsBolStates[int(arune)-128] = edge.Target()
}
}
}
}
}
for _, rule := range rules {
l.Rules = append(l.Rules, Rule{Conds: rule.conds, Pattern: rule.pattern, RE: rule.re, Action: rule.action, BOL: rule.bol, EOL: rule.eol})
}
l.Dfa = allDfa.nfa.nfa[1:]
l.Accepts = map[*lexer.NfaState]int{}
for id, state := range allDfa.accept {
l.Accepts[state] = allDfa.acceptRule[id]
}
l.YYT = _yyt
l.YYB = _yyb
l.YYC = _yyc
l.YYN = _yyn
l.YYM = _yym
return
}