refactor - build phase

choice.go

@@ -206,14 +206,17 @@ func (b *choiceBuilder) build(c *context) ([]*Node, bool) {
 		return nil, false
 	}
 
+	from := c.offset
+	parsed := to > from
+
+	if parsed {
+		c.results.dropMatchTo(c.offset, b.id, to)
+	} else {
 		if c.buildPending(c.offset, b.id, to) {
 			return nil, false
 		}
 
 		c.markBuildPending(c.offset, b.id, to)
-
-	if to-c.offset > 0 {
-		c.results.dropMatchTo(c.offset, b.id, to)
 	}
 
 	var option builder
@@ -228,14 +231,14 @@ func (b *choiceBuilder) build(c *context) ([]*Node, bool) {
 		panic("damaged parse result")
 	}
 
-	from := c.offset
-
 	n, ok := option.build(c)
 	if !ok {
 		panic("damaged parse result")
 	}
 
+	if !parsed {
 		c.unmarkBuildPending(from, b.id, to)
+	}
 
 	if b.commit&Alias != 0 {
 		return n, true

sequence.go

@@ -239,22 +239,11 @@ func (b *sequenceBuilder) build(c *context) ([]*Node, bool) {
 		return nil, false
 	}
 
-	if c.buildPending(c.offset, b.id, to) {
-		return nil, false
-	}
-
-	c.markBuildPending(c.offset, b.id, to)
-
-	if to-c.offset > 0 {
-		c.results.dropMatchTo(c.offset, b.id, to)
-	}
-
 	from := c.offset
+	parsed := to > from
 
 	if b.allChars {
 		c.offset = to
-		c.unmarkBuildPending(from, b.id, to)
-
 		if b.commit&Alias != 0 {
 			return nil, true
 		}
@@ -265,6 +254,14 @@ func (b *sequenceBuilder) build(c *context) ([]*Node, bool) {
 			To:     to,
 			tokens: c.tokens,
 		}}, true
+	} else if parsed {
+		c.results.dropMatchTo(c.offset, b.id, to)
+	} else {
+		if c.buildPending(c.offset, b.id, to) {
+			return nil, false
+		}
+
+		c.markBuildPending(c.offset, b.id, to)
 	}
 
 	var (
@@ -286,14 +283,18 @@ func (b *sequenceBuilder) build(c *context) ([]*Node, bool) {
 			continue
 		}
 
-		parsed := c.offset > itemFrom
+		if c.offset > itemFrom {
-
-		if parsed {
 			nodes = append(nodes, n...)
 			currentCount++
+
+			if b.ranges[itemIndex][1] >= 0 && currentCount == b.ranges[itemIndex][1] {
+				itemIndex++
+				currentCount = 0
+			}
+
+			continue
 		}
 
-		if !parsed {
 		if currentCount < b.ranges[itemIndex][0] {
 			for i := 0; i < b.ranges[itemIndex][0]-currentCount; i++ {
 				nodes = append(nodes, n...)
@@ -302,16 +303,11 @@ func (b *sequenceBuilder) build(c *context) ([]*Node, bool) {
 
 		itemIndex++
 		currentCount = 0
-			continue
-		}
-
-		if b.ranges[itemIndex][1] >= 0 && currentCount == b.ranges[itemIndex][1] {
-			itemIndex++
-			currentCount = 0
-		}
 	}
 
+	if !parsed {
 		c.unmarkBuildPending(from, b.id, to)
+	}
 
 	if b.commit&Alias != 0 {
 		return nodes, true