refactor - ranges

char.go

@@ -29,6 +29,7 @@ func (p *charParser) nodeID() int                 { return p.id }
 func (p *charParser) setID(id int)                { p.id = id }
 func (p *charParser) commitType() CommitType      { return Alias }
 func (p *charParser) setCommitType(ct CommitType) {}
+func (p *charParser) preinit()                    {}
 func (p *charParser) validate(*registry) error    { return nil }
 func (p *charParser) init(*registry)              {}
 

choice.go

@@ -42,6 +42,7 @@ func (d *choiceDefinition) nodeID() int                 { return d.id }
 func (d *choiceDefinition) setID(id int)                { d.id = id }
 func (d *choiceDefinition) commitType() CommitType      { return d.commit }
 func (d *choiceDefinition) setCommitType(ct CommitType) { d.commit = ct }
+func (d *choiceDefinition) preinit()                    {}
 
 func (d *choiceDefinition) validate(r *registry) error {
 	if d.validated {

sequence.go

@@ -49,6 +49,29 @@ func (d *sequenceDefinition) setID(id int)                { d.id = id }
 func (d *sequenceDefinition) commitType() CommitType      { return d.commit }
 func (d *sequenceDefinition) setCommitType(ct CommitType) { d.commit = ct }
 
+func (d *sequenceDefinition) initRanges() {
+	for i, item := range d.items {
+		if item.Min == 0 && item.Max == 0 {
+			item.Min, item.Max = 1, 1
+		} else {
+			if item.Min <= 0 {
+				item.Min = 0
+			}
+
+			if item.Max <= 0 {
+				item.Max = -1
+			}
+		}
+
+		d.items[i] = item
+		d.ranges = append(d.ranges, []int{item.Min, item.Max})
+	}
+}
+
+func (d *sequenceDefinition) preinit() {
+	d.initRanges()
+}
+
 func (d *sequenceDefinition) validate(r *registry) error {
 	if d.validated {
 		return nil
@@ -82,18 +105,6 @@ func (d *sequenceDefinition) createBuilder() {
 	}
 }
 
-func (d *sequenceDefinition) initRanges() {
-	for _, item := range d.items {
-		if item.Min == 0 && item.Max == 0 {
-			item.Min, item.Max = 1, 1
-		} else if item.Max == 0 {
-			item.Max = -1
-		}
-
-		d.ranges = append(d.ranges, []int{item.Min, item.Max})
-	}
-}
-
 func (d *sequenceDefinition) initItems(r *registry) {
 	allChars := true
 	for _, item := range d.items {
@@ -181,10 +192,6 @@ func (p *sequenceParser) parse(c *context) {
 	var parsed bool
 
 	for itemIndex < len(p.items) {
-		// TODO:
-		// - is it ok to parse before max range check? what if max=0
-		// - validate, normalize and document max=0
-
 		// TODO: test this f(g())
 		p.items[itemIndex].parse(c)
 		if !c.matchLast {
@@ -210,8 +217,7 @@ func (p *sequenceParser) parse(c *context) {
 
 		to = c.offset
 
-		// TODO: max cannot be 0
-		if !parsed || p.ranges[itemIndex][1] >= 0 && currentCount == p.ranges[itemIndex][1] {
+		if !parsed || p.ranges[itemIndex][1] > 0 && currentCount == p.ranges[itemIndex][1] {
 			itemIndex++
 			currentCount = 0
 		}
@@ -287,7 +293,7 @@ func (b *sequenceBuilder) build(c *context) ([]*Node, bool) {
 			nodes = append(nodes, n...)
 			currentCount++
 
-			if b.ranges[itemIndex][1] >= 0 && currentCount == b.ranges[itemIndex][1] {
+			if b.ranges[itemIndex][1] > 0 && currentCount == b.ranges[itemIndex][1] {
 				itemIndex++
 				currentCount = 0
 			}

syntax.go

@@ -18,9 +18,12 @@ const (
 	Root
 )
 
+// if min=0&&max=0, it means min=1,max=1
+// else if max<=0, it means no max
+// else if min<=0, it means no min
 type SequenceItem struct {
 	Name     string
-	Min, Max int // 0,0 considered as 1,1, x,0 considered as x,-1
+	Min, Max int
 }
 
 type Syntax struct {
@@ -40,6 +43,7 @@ type definition interface {
 	commitType() CommitType
 	setCommitType(CommitType)
 	setID(int)
+	preinit()
 	validate(*registry) error
 	init(*registry)
 	addGeneralization(int)
@@ -220,6 +224,8 @@ func (s *Syntax) CharSequence(name string, ct CommitType, chars []rune) error {
 }
 
 func (s *Syntax) sequence(name string, ct CommitType, items ...SequenceItem) error {
+	citems := make([]SequenceItem, len(items))
+	copy(citems, items)
 	return s.register(newSequence(name, ct, items))
 }
 
@@ -251,8 +257,6 @@ func (s *Syntax) Read(r io.Reader) error {
 	return ErrNotImplemented
 }
 
-// TODO: why normalization failed?
-
 func (s *Syntax) Init() error {
 	if s.initFailed {
 		return ErrInitFailed
@@ -275,6 +279,9 @@ func (s *Syntax) Init() error {
 	}
 
 	defs := s.registry.getDefinitions()
+	for i := range defs {
+		defs[i].preinit()
+	}
 
 	if hasWhitespace(defs) {
 		defs, s.root = applyWhitespace(defs)

whitespace.go

@@ -66,8 +66,7 @@ func applyWhitespaceToSeq(s *sequenceDefinition) []definition {
 
 	whitespace := SequenceItem{Name: whitespaceName, Min: 0, Max: -1}
 	for i, item := range s.items {
-		// TODO: there should not be max=0
-		if item.Max >= 0 && item.Max <= 1 {
+		if item.Max == 1 {
 			if i > 0 {
 				items = append(items, whitespace)
 			}