1 files changed, 0 insertions, 182 deletions
diff --git a/src/urubu/grammar/lexical/dfa/symbol_position.go b/src/urubu/grammar/lexical/dfa/symbol_position.go
deleted file mode 100644
index f154251..0000000
--- a/src/urubu/grammar/lexical/dfa/symbol_position.go
+++ /dev/null
@@ -1,182 +0,0 @@
-package dfa
-
-import (
-	"encoding/binary"
-	"fmt"
-	"strings"
-)
-
-type symbolPosition uint16
-
-const (
-	symbolPositionNil symbolPosition = 0x0000
-
-	symbolPositionMin uint16 = 0x0001
-	symbolPositionMax uint16 = 0x7fff
-
-	symbolPositionMaskSymbol  uint16 = 0x0000
-	symbolPositionMaskEndMark uint16 = 0x8000
-
-	symbolPositionMaskValue uint16 = 0x7fff
-)
-
-func newSymbolPosition(n uint16, endMark bool) (symbolPosition, error) {
-	if n < symbolPositionMin || n > symbolPositionMax {
-		return symbolPositionNil, fmt.Errorf("symbol position must be within %v to %v: n: %v, endMark: %v", symbolPositionMin, symbolPositionMax, n, endMark)
-	}
-	if endMark {
-		return symbolPosition(n | symbolPositionMaskEndMark), nil
-	}
-	return symbolPosition(n | symbolPositionMaskSymbol), nil
-}
-
-func (p symbolPosition) String() string {
-	if p.isEndMark() {
-		return fmt.Sprintf("end#%v", uint16(p)&symbolPositionMaskValue)
-	}
-	return fmt.Sprintf("sym#%v", uint16(p)&symbolPositionMaskValue)
-}
-
-func (p symbolPosition) isEndMark() bool {
-	return uint16(p)&symbolPositionMaskEndMark > 1
-}
-
-func (p symbolPosition) describe() (uint16, bool) {
-	v := uint16(p) & symbolPositionMaskValue
-	if p.isEndMark() {
-		return v, true
-	}
-	return v, false
-}
-
-type symbolPositionSet struct {
-	// `s` represents a set of symbol positions.
-	// However, immediately after adding a symbol position, the elements may be duplicated.
-	// When you need an aligned set with no duplicates, you can get such value via the set function.
-	s      []symbolPosition
-	sorted bool
-}
-
-func newSymbolPositionSet() *symbolPositionSet {
-	return &symbolPositionSet{
-		s:      []symbolPosition{},
-		sorted: false,
-	}
-}
-
-func (s *symbolPositionSet) String() string {
-	if len(s.s) <= 0 {
-		return "{}"
-	}
-	ps := s.sortAndRemoveDuplicates()
-	var b strings.Builder
-	fmt.Fprintf(&b, "{")
-	for i, p := range ps {
-		if i <= 0 {
-			fmt.Fprintf(&b, "%v", p)
-			continue
-		}
-		fmt.Fprintf(&b, ", %v", p)
-	}
-	fmt.Fprintf(&b, "}")
-	return b.String()
-}
-
-func (s *symbolPositionSet) set() []symbolPosition {
-	s.sortAndRemoveDuplicates()
-	return s.s
-}
-
-func (s *symbolPositionSet) add(pos symbolPosition) *symbolPositionSet {
-	s.s = append(s.s, pos)
-	s.sorted = false
-	return s
-}
-
-func (s *symbolPositionSet) merge(t *symbolPositionSet) *symbolPositionSet {
-	s.s = append(s.s, t.s...)
-	s.sorted = false
-	return s
-}
-
-func (s *symbolPositionSet) hash() string {
-	if len(s.s) <= 0 {
-		return ""
-	}
-	sorted := s.sortAndRemoveDuplicates()
-	var buf []byte
-	for _, p := range sorted {
-		b := make([]byte, 8)
-		binary.PutUvarint(b, uint64(p))
-		buf = append(buf, b...)
-	}
-	// Convert to a string to be able to use it as a key of a map.
-	// But note this byte sequence is made from values of symbol positions,
-	// so this is not a well-formed UTF-8 sequence.
-	return string(buf)
-}
-
-func (s *symbolPositionSet) sortAndRemoveDuplicates() []symbolPosition {
-	if s.sorted {
-		return s.s
-	}
-
-	sortSymbolPositions(s.s, 0, len(s.s)-1)
-
-	// Remove duplicates.
-	lastV := s.s[0]
-	nextIdx := 1
-	for _, v := range s.s[1:] {
-		if v == lastV {
-			continue
-		}
-		s.s[nextIdx] = v
-		nextIdx++
-		lastV = v
-	}
-	s.s = s.s[:nextIdx]
-	s.sorted = true
-
-	return s.s
-}
-
-// sortSymbolPositions sorts a slice of symbol positions as it uses quick sort.
-func sortSymbolPositions(ps []symbolPosition, left, right int) {
-	if left >= right {
-		return
-	}
-	var pivot symbolPosition
-	{
-		// Use a median as a pivot.
-		p1 := ps[left]
-		p2 := ps[(left+right)/2]
-		p3 := ps[right]
-		if p1 > p2 {
-			p1, p2 = p2, p1
-		}
-		if p2 > p3 {
-			p2 = p3
-			if p1 > p2 {
-				p2 = p1
-			}
-		}
-		pivot = p2
-	}
-	i := left
-	j := right
-	for i <= j {
-		for ps[i] < pivot {
-			i++
-		}
-		for ps[j] > pivot {
-			j--
-		}
-		if i <= j {
-			ps[i], ps[j] = ps[j], ps[i]
-			i++
-			j--
-		}
-	}
-	sortSymbolPositions(ps, left, j)
-	sortSymbolPositions(ps, i, right)
-}