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-rw-r--r--src/urubu/grammar/lexical/compiler.go413
-rw-r--r--src/urubu/grammar/lexical/dfa/dfa.go173
-rw-r--r--src/urubu/grammar/lexical/dfa/symbol_position.go182
-rw-r--r--src/urubu/grammar/lexical/dfa/tree.go567
-rw-r--r--src/urubu/grammar/lexical/entry.go171
-rw-r--r--src/urubu/grammar/lexical/parser/error.go36
-rw-r--r--src/urubu/grammar/lexical/parser/fragment.go72
-rw-r--r--src/urubu/grammar/lexical/parser/lexer.go594
-rw-r--r--src/urubu/grammar/lexical/parser/parser.go531
-rw-r--r--src/urubu/grammar/lexical/parser/tree.go459
10 files changed, 3198 insertions, 0 deletions
diff --git a/src/urubu/grammar/lexical/compiler.go b/src/urubu/grammar/lexical/compiler.go
new file mode 100644
index 0000000..637018a
--- /dev/null
+++ b/src/urubu/grammar/lexical/compiler.go
@@ -0,0 +1,413 @@
+package lexical
+
+import (
+ "bytes"
+ "fmt"
+
+ "urubu/compressor"
+ "urubu/grammar/lexical/dfa"
+ psr "urubu/grammar/lexical/parser"
+ spec "urubu/spec/grammar"
+)
+
+type CompileError struct {
+ Kind spec.LexKindName
+ Fragment bool
+ Cause error
+ Detail string
+}
+
+func Compile(lexspec *LexSpec, compLv int) (*spec.LexicalSpec, error, []*CompileError) {
+ err := lexspec.Validate()
+ if err != nil {
+ return nil, fmt.Errorf("invalid lexical specification:\n%w", err), nil
+ }
+
+ modeEntries, modeNames, modeName2ID, fragmetns := groupEntriesByLexMode(lexspec.Entries)
+
+ modeSpecs := []*spec.CompiledLexModeSpec{
+ nil,
+ }
+ for i, es := range modeEntries[1:] {
+ modeName := modeNames[i+1]
+ modeSpec, err, cerrs := compile(es, modeName2ID, fragmetns, compLv)
+ if err != nil {
+ return nil, fmt.Errorf("failed to compile in %v mode: %w", modeName, err), cerrs
+ }
+ modeSpecs = append(modeSpecs, modeSpec)
+ }
+
+ var kindNames []spec.LexKindName
+ var name2ID map[spec.LexKindName]spec.LexKindID
+ {
+ name2ID = map[spec.LexKindName]spec.LexKindID{}
+ id := spec.LexKindIDMin
+ for _, modeSpec := range modeSpecs[1:] {
+ for _, name := range modeSpec.KindNames[1:] {
+ if _, ok := name2ID[name]; ok {
+ continue
+ }
+ name2ID[name] = id
+ id++
+ }
+ }
+
+ kindNames = make([]spec.LexKindName, len(name2ID)+1)
+ for name, id := range name2ID {
+ kindNames[id] = name
+ }
+ }
+
+ var kindIDs [][]spec.LexKindID
+ {
+ kindIDs = make([][]spec.LexKindID, len(modeSpecs))
+ for i, modeSpec := range modeSpecs[1:] {
+ ids := make([]spec.LexKindID, len(modeSpec.KindNames))
+ for modeID, name := range modeSpec.KindNames {
+ if modeID == 0 {
+ continue
+ }
+ ids[modeID] = name2ID[name]
+ }
+ kindIDs[i+1] = ids
+ }
+ }
+
+ return &spec.LexicalSpec{
+ InitialModeID: spec.LexModeIDDefault,
+ ModeNames: modeNames,
+ KindNames: kindNames,
+ KindIDs: kindIDs,
+ CompressionLevel: compLv,
+ Specs: modeSpecs,
+ }, nil, nil
+}
+
+func groupEntriesByLexMode(entries []*LexEntry) ([][]*LexEntry, []spec.LexModeName, map[spec.LexModeName]spec.LexModeID, map[spec.LexKindName]*LexEntry) {
+ modeNames := []spec.LexModeName{
+ spec.LexModeNameNil,
+ spec.LexModeNameDefault,
+ }
+ modeName2ID := map[spec.LexModeName]spec.LexModeID{
+ spec.LexModeNameNil: spec.LexModeIDNil,
+ spec.LexModeNameDefault: spec.LexModeIDDefault,
+ }
+ lastModeID := spec.LexModeIDDefault
+ modeEntries := [][]*LexEntry{
+ nil,
+ {},
+ }
+ fragments := map[spec.LexKindName]*LexEntry{}
+ for _, e := range entries {
+ if e.Fragment {
+ fragments[e.Kind] = e
+ continue
+ }
+ ms := e.Modes
+ if len(ms) == 0 {
+ ms = []spec.LexModeName{
+ spec.LexModeNameDefault,
+ }
+ }
+ for _, modeName := range ms {
+ modeID, ok := modeName2ID[modeName]
+ if !ok {
+ modeID = lastModeID + 1
+ lastModeID = modeID
+ modeName2ID[modeName] = modeID
+ modeNames = append(modeNames, modeName)
+ modeEntries = append(modeEntries, []*LexEntry{})
+ }
+ modeEntries[modeID] = append(modeEntries[modeID], e)
+ }
+ }
+ return modeEntries, modeNames, modeName2ID, fragments
+}
+
+func compile(
+ entries []*LexEntry,
+ modeName2ID map[spec.LexModeName]spec.LexModeID,
+ fragments map[spec.LexKindName]*LexEntry,
+ compLv int,
+) (*spec.CompiledLexModeSpec, error, []*CompileError) {
+ var kindNames []spec.LexKindName
+ kindIDToName := map[spec.LexModeKindID]spec.LexKindName{}
+ var patterns map[spec.LexModeKindID][]byte
+ {
+ kindNames = append(kindNames, spec.LexKindNameNil)
+ patterns = map[spec.LexModeKindID][]byte{}
+ for i, e := range entries {
+ kindID := spec.LexModeKindID(i + 1)
+
+ kindNames = append(kindNames, e.Kind)
+ kindIDToName[kindID] = e.Kind
+ patterns[kindID] = []byte(e.Pattern)
+ }
+ }
+
+ push := []spec.LexModeID{
+ spec.LexModeIDNil,
+ }
+ pop := []int{
+ 0,
+ }
+ for _, e := range entries {
+ pushV := spec.LexModeIDNil
+ if e.Push != "" {
+ pushV = modeName2ID[e.Push]
+ }
+ push = append(push, pushV)
+ popV := 0
+ if e.Pop {
+ popV = 1
+ }
+ pop = append(pop, popV)
+ }
+
+ fragmentPatterns := map[spec.LexKindName][]byte{}
+ for k, e := range fragments {
+ fragmentPatterns[k] = []byte(e.Pattern)
+ }
+
+ fragmentCPTrees := make(map[spec.LexKindName]psr.CPTree, len(fragmentPatterns))
+ {
+ var cerrs []*CompileError
+ for kind, pat := range fragmentPatterns {
+ p := psr.NewParser(kind, bytes.NewReader(pat))
+ t, err := p.Parse()
+ if err != nil {
+ if err == psr.ParseErr {
+ detail, cause := p.Error()
+ cerrs = append(cerrs, &CompileError{
+ Kind: kind,
+ Fragment: true,
+ Cause: cause,
+ Detail: detail,
+ })
+ } else {
+ cerrs = append(cerrs, &CompileError{
+ Kind: kind,
+ Fragment: true,
+ Cause: err,
+ })
+ }
+ continue
+ }
+ fragmentCPTrees[kind] = t
+ }
+ if len(cerrs) > 0 {
+ return nil, fmt.Errorf("compile error"), cerrs
+ }
+
+ err := psr.CompleteFragments(fragmentCPTrees)
+ if err != nil {
+ if err == psr.ParseErr {
+ for _, frag := range fragmentCPTrees {
+ kind, frags, err := frag.Describe()
+ if err != nil {
+ return nil, err, nil
+ }
+
+ cerrs = append(cerrs, &CompileError{
+ Kind: kind,
+ Fragment: true,
+ Cause: fmt.Errorf("fragment contains undefined fragments or cycles"),
+ Detail: fmt.Sprintf("%v", frags),
+ })
+ }
+
+ return nil, fmt.Errorf("compile error"), cerrs
+ }
+
+ return nil, err, nil
+ }
+ }
+
+ cpTrees := map[spec.LexModeKindID]psr.CPTree{}
+ {
+ pats := make([]*psr.PatternEntry, len(patterns)+1)
+ pats[spec.LexModeKindIDNil] = &psr.PatternEntry{
+ ID: spec.LexModeKindIDNil,
+ }
+ for id, pattern := range patterns {
+ pats[id] = &psr.PatternEntry{
+ ID: id,
+ Pattern: pattern,
+ }
+ }
+
+ var cerrs []*CompileError
+ for _, pat := range pats {
+ if pat.ID == spec.LexModeKindIDNil {
+ continue
+ }
+
+ p := psr.NewParser(kindIDToName[pat.ID], bytes.NewReader(pat.Pattern))
+ t, err := p.Parse()
+ if err != nil {
+ if err == psr.ParseErr {
+ detail, cause := p.Error()
+ cerrs = append(cerrs, &CompileError{
+ Kind: kindIDToName[pat.ID],
+ Fragment: false,
+ Cause: cause,
+ Detail: detail,
+ })
+ } else {
+ cerrs = append(cerrs, &CompileError{
+ Kind: kindIDToName[pat.ID],
+ Fragment: false,
+ Cause: err,
+ })
+ }
+ continue
+ }
+
+ complete, err := psr.ApplyFragments(t, fragmentCPTrees)
+ if err != nil {
+ return nil, err, nil
+ }
+ if !complete {
+ _, frags, err := t.Describe()
+ if err != nil {
+ return nil, err, nil
+ }
+
+ cerrs = append(cerrs, &CompileError{
+ Kind: kindIDToName[pat.ID],
+ Fragment: false,
+ Cause: fmt.Errorf("pattern contains undefined fragments"),
+ Detail: fmt.Sprintf("%v", frags),
+ })
+ continue
+ }
+
+ cpTrees[pat.ID] = t
+ }
+ if len(cerrs) > 0 {
+ return nil, fmt.Errorf("compile error"), cerrs
+ }
+ }
+
+ var tranTab *spec.TransitionTable
+ {
+ root, symTab, err := dfa.ConvertCPTreeToByteTree(cpTrees)
+ if err != nil {
+ return nil, err, nil
+ }
+ d := dfa.GenDFA(root, symTab)
+ tranTab, err = dfa.GenTransitionTable(d)
+ if err != nil {
+ return nil, err, nil
+ }
+ }
+
+ var err error
+ switch compLv {
+ case 2:
+ tranTab, err = compressTransitionTableLv2(tranTab)
+ if err != nil {
+ return nil, err, nil
+ }
+ case 1:
+ tranTab, err = compressTransitionTableLv1(tranTab)
+ if err != nil {
+ return nil, err, nil
+ }
+ }
+
+ return &spec.CompiledLexModeSpec{
+ KindNames: kindNames,
+ Push: push,
+ Pop: pop,
+ DFA: tranTab,
+ }, nil, nil
+}
+
+const (
+ CompressionLevelMin = 0
+ CompressionLevelMax = 2
+)
+
+func compressTransitionTableLv2(tranTab *spec.TransitionTable) (*spec.TransitionTable, error) {
+ ueTab := compressor.NewUniqueEntriesTable()
+ {
+ orig, err := compressor.NewOriginalTable(convertStateIDSliceToIntSlice(tranTab.UncompressedTransition), tranTab.ColCount)
+ if err != nil {
+ return nil, err
+ }
+ err = ueTab.Compress(orig)
+ if err != nil {
+ return nil, err
+ }
+ }
+
+ rdTab := compressor.NewRowDisplacementTable(0)
+ {
+ orig, err := compressor.NewOriginalTable(ueTab.UniqueEntries, ueTab.OriginalColCount)
+ if err != nil {
+ return nil, err
+ }
+ err = rdTab.Compress(orig)
+ if err != nil {
+ return nil, err
+ }
+ }
+
+ tranTab.Transition = &spec.UniqueEntriesTable{
+ UniqueEntries: &spec.RowDisplacementTable{
+ OriginalRowCount: rdTab.OriginalRowCount,
+ OriginalColCount: rdTab.OriginalColCount,
+ EmptyValue: spec.StateIDNil,
+ Entries: convertIntSliceToStateIDSlice(rdTab.Entries),
+ Bounds: rdTab.Bounds,
+ RowDisplacement: rdTab.RowDisplacement,
+ },
+ RowNums: ueTab.RowNums,
+ OriginalRowCount: ueTab.OriginalRowCount,
+ OriginalColCount: ueTab.OriginalColCount,
+ }
+ tranTab.UncompressedTransition = nil
+
+ return tranTab, nil
+}
+
+func compressTransitionTableLv1(tranTab *spec.TransitionTable) (*spec.TransitionTable, error) {
+ ueTab := compressor.NewUniqueEntriesTable()
+ {
+ orig, err := compressor.NewOriginalTable(convertStateIDSliceToIntSlice(tranTab.UncompressedTransition), tranTab.ColCount)
+ if err != nil {
+ return nil, err
+ }
+ err = ueTab.Compress(orig)
+ if err != nil {
+ return nil, err
+ }
+ }
+
+ tranTab.Transition = &spec.UniqueEntriesTable{
+ UncompressedUniqueEntries: convertIntSliceToStateIDSlice(ueTab.UniqueEntries),
+ RowNums: ueTab.RowNums,
+ OriginalRowCount: ueTab.OriginalRowCount,
+ OriginalColCount: ueTab.OriginalColCount,
+ }
+ tranTab.UncompressedTransition = nil
+
+ return tranTab, nil
+}
+
+func convertStateIDSliceToIntSlice(s []spec.StateID) []int {
+ is := make([]int, len(s))
+ for i, v := range s {
+ is[i] = v.Int()
+ }
+ return is
+}
+
+func convertIntSliceToStateIDSlice(s []int) []spec.StateID {
+ ss := make([]spec.StateID, len(s))
+ for i, v := range s {
+ ss[i] = spec.StateID(v)
+ }
+ return ss
+}
diff --git a/src/urubu/grammar/lexical/dfa/dfa.go b/src/urubu/grammar/lexical/dfa/dfa.go
new file mode 100644
index 0000000..48bd8b4
--- /dev/null
+++ b/src/urubu/grammar/lexical/dfa/dfa.go
@@ -0,0 +1,173 @@
+package dfa
+
+import (
+ "sort"
+
+ spec "urubu/spec/grammar"
+)
+
+type symbolTable struct {
+ symPos2Byte map[symbolPosition]byteRange
+ endPos2ID map[symbolPosition]spec.LexModeKindID
+}
+
+func genSymbolTable(root byteTree) *symbolTable {
+ symTab := &symbolTable{
+ symPos2Byte: map[symbolPosition]byteRange{},
+ endPos2ID: map[symbolPosition]spec.LexModeKindID{},
+ }
+ return genSymTab(symTab, root)
+}
+
+func genSymTab(symTab *symbolTable, node byteTree) *symbolTable {
+ if node == nil {
+ return symTab
+ }
+
+ switch n := node.(type) {
+ case *symbolNode:
+ symTab.symPos2Byte[n.pos] = byteRange{
+ from: n.from,
+ to: n.to,
+ }
+ case *endMarkerNode:
+ symTab.endPos2ID[n.pos] = n.id
+ default:
+ left, right := node.children()
+ genSymTab(symTab, left)
+ genSymTab(symTab, right)
+ }
+ return symTab
+}
+
+type DFA struct {
+ States []string
+ InitialState string
+ AcceptingStatesTable map[string]spec.LexModeKindID
+ TransitionTable map[string][256]string
+}
+
+func GenDFA(root byteTree, symTab *symbolTable) *DFA {
+ initialState := root.first()
+ initialStateHash := initialState.hash()
+ stateMap := map[string]*symbolPositionSet{
+ initialStateHash: initialState,
+ }
+ tranTab := map[string][256]string{}
+ {
+ follow := genFollowTable(root)
+ unmarkedStates := map[string]*symbolPositionSet{
+ initialStateHash: initialState,
+ }
+ for len(unmarkedStates) > 0 {
+ nextUnmarkedStates := map[string]*symbolPositionSet{}
+ for hash, state := range unmarkedStates {
+ tranTabOfState := [256]*symbolPositionSet{}
+ for _, pos := range state.set() {
+ if pos.isEndMark() {
+ continue
+ }
+ valRange := symTab.symPos2Byte[pos]
+ for symVal := valRange.from; symVal <= valRange.to; symVal++ {
+ if tranTabOfState[symVal] == nil {
+ tranTabOfState[symVal] = newSymbolPositionSet()
+ }
+ tranTabOfState[symVal].merge(follow[pos])
+ }
+ }
+ for _, t := range tranTabOfState {
+ if t == nil {
+ continue
+ }
+ h := t.hash()
+ if _, ok := stateMap[h]; ok {
+ continue
+ }
+ stateMap[h] = t
+ nextUnmarkedStates[h] = t
+ }
+ tabOfState := [256]string{}
+ for v, t := range tranTabOfState {
+ if t == nil {
+ continue
+ }
+ tabOfState[v] = t.hash()
+ }
+ tranTab[hash] = tabOfState
+ }
+ unmarkedStates = nextUnmarkedStates
+ }
+ }
+
+ accTab := map[string]spec.LexModeKindID{}
+ {
+ for h, s := range stateMap {
+ for _, pos := range s.set() {
+ if !pos.isEndMark() {
+ continue
+ }
+ priorID, ok := accTab[h]
+ if !ok {
+ accTab[h] = symTab.endPos2ID[pos]
+ } else {
+ id := symTab.endPos2ID[pos]
+ if id < priorID {
+ accTab[h] = id
+ }
+ }
+ }
+ }
+ }
+
+ var states []string
+ {
+ for s := range stateMap {
+ states = append(states, s)
+ }
+ sort.Slice(states, func(i, j int) bool {
+ return states[i] < states[j]
+ })
+ }
+
+ return &DFA{
+ States: states,
+ InitialState: initialStateHash,
+ AcceptingStatesTable: accTab,
+ TransitionTable: tranTab,
+ }
+}
+
+func GenTransitionTable(dfa *DFA) (*spec.TransitionTable, error) {
+ stateHash2ID := map[string]spec.StateID{}
+ for i, s := range dfa.States {
+ // Since 0 represents an invalid value in a transition table,
+ // assign a number greater than or equal to 1 to states.
+ stateHash2ID[s] = spec.StateID(i + spec.StateIDMin.Int())
+ }
+
+ acc := make([]spec.LexModeKindID, len(dfa.States)+1)
+ for _, s := range dfa.States {
+ id, ok := dfa.AcceptingStatesTable[s]
+ if !ok {
+ continue
+ }
+ acc[stateHash2ID[s]] = id
+ }
+
+ rowCount := len(dfa.States) + 1
+ colCount := 256
+ tran := make([]spec.StateID, rowCount*colCount)
+ for s, tab := range dfa.TransitionTable {
+ for v, to := range tab {
+ tran[stateHash2ID[s].Int()*256+v] = stateHash2ID[to]
+ }
+ }
+
+ return &spec.TransitionTable{
+ InitialStateID: stateHash2ID[dfa.InitialState],
+ AcceptingStates: acc,
+ UncompressedTransition: tran,
+ RowCount: rowCount,
+ ColCount: colCount,
+ }, nil
+}
diff --git a/src/urubu/grammar/lexical/dfa/symbol_position.go b/src/urubu/grammar/lexical/dfa/symbol_position.go
new file mode 100644
index 0000000..f154251
--- /dev/null
+++ b/src/urubu/grammar/lexical/dfa/symbol_position.go
@@ -0,0 +1,182 @@
+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)
+}
diff --git a/src/urubu/grammar/lexical/dfa/tree.go b/src/urubu/grammar/lexical/dfa/tree.go
new file mode 100644
index 0000000..8a11aee
--- /dev/null
+++ b/src/urubu/grammar/lexical/dfa/tree.go
@@ -0,0 +1,567 @@
+package dfa
+
+import (
+ "fmt"
+ "io"
+ "sort"
+
+ "urubu/grammar/lexical/parser"
+ spec "urubu/spec/grammar"
+ "urubu/utf8"
+)
+
+type byteTree interface {
+ fmt.Stringer
+ children() (byteTree, byteTree)
+ nullable() bool
+ first() *symbolPositionSet
+ last() *symbolPositionSet
+ clone() byteTree
+}
+
+var (
+ _ byteTree = &symbolNode{}
+ _ byteTree = &endMarkerNode{}
+ _ byteTree = &concatNode{}
+ _ byteTree = &altNode{}
+ _ byteTree = &repeatNode{}
+ _ byteTree = &optionNode{}
+)
+
+type byteRange struct {
+ from byte
+ to byte
+}
+
+type symbolNode struct {
+ byteRange
+ pos symbolPosition
+ firstMemo *symbolPositionSet
+ lastMemo *symbolPositionSet
+}
+
+func newSymbolNode(value byte) *symbolNode {
+ return &symbolNode{
+ byteRange: byteRange{
+ from: value,
+ to: value,
+ },
+ pos: symbolPositionNil,
+ }
+}
+
+func newRangeSymbolNode(from, to byte) *symbolNode {
+ return &symbolNode{
+ byteRange: byteRange{
+ from: from,
+ to: to,
+ },
+ pos: symbolPositionNil,
+ }
+}
+
+func (n *symbolNode) String() string {
+ return fmt.Sprintf("symbol: value: %v-%v, pos: %v", n.from, n.to, n.pos)
+}
+
+func (n *symbolNode) children() (byteTree, byteTree) {
+ return nil, nil
+}
+
+func (n *symbolNode) nullable() bool {
+ return false
+}
+
+func (n *symbolNode) first() *symbolPositionSet {
+ if n.firstMemo == nil {
+ n.firstMemo = newSymbolPositionSet()
+ n.firstMemo.add(n.pos)
+ }
+ return n.firstMemo
+}
+
+func (n *symbolNode) last() *symbolPositionSet {
+ if n.lastMemo == nil {
+ n.lastMemo = newSymbolPositionSet()
+ n.lastMemo.add(n.pos)
+ }
+ return n.lastMemo
+}
+
+func (n *symbolNode) clone() byteTree {
+ return newRangeSymbolNode(n.from, n.to)
+}
+
+type endMarkerNode struct {
+ id spec.LexModeKindID
+ pos symbolPosition
+ firstMemo *symbolPositionSet
+ lastMemo *symbolPositionSet
+}
+
+func newEndMarkerNode(id spec.LexModeKindID) *endMarkerNode {
+ return &endMarkerNode{
+ id: id,
+ pos: symbolPositionNil,
+ }
+}
+
+func (n *endMarkerNode) String() string {
+ return fmt.Sprintf("end: pos: %v", n.pos)
+}
+
+func (n *endMarkerNode) children() (byteTree, byteTree) {
+ return nil, nil
+}
+
+func (n *endMarkerNode) nullable() bool {
+ return false
+}
+
+func (n *endMarkerNode) first() *symbolPositionSet {
+ if n.firstMemo == nil {
+ n.firstMemo = newSymbolPositionSet()
+ n.firstMemo.add(n.pos)
+ }
+ return n.firstMemo
+}
+
+func (n *endMarkerNode) last() *symbolPositionSet {
+ if n.lastMemo == nil {
+ n.lastMemo = newSymbolPositionSet()
+ n.lastMemo.add(n.pos)
+ }
+ return n.lastMemo
+}
+
+func (n *endMarkerNode) clone() byteTree {
+ return newEndMarkerNode(n.id)
+}
+
+type concatNode struct {
+ left byteTree
+ right byteTree
+ firstMemo *symbolPositionSet
+ lastMemo *symbolPositionSet
+}
+
+func newConcatNode(left, right byteTree) *concatNode {
+ return &concatNode{
+ left: left,
+ right: right,
+ }
+}
+
+func (n *concatNode) String() string {
+ return "concat"
+}
+
+func (n *concatNode) children() (byteTree, byteTree) {
+ return n.left, n.right
+}
+
+func (n *concatNode) nullable() bool {
+ return n.left.nullable() && n.right.nullable()
+}
+
+func (n *concatNode) first() *symbolPositionSet {
+ if n.firstMemo == nil {
+ n.firstMemo = newSymbolPositionSet()
+ n.firstMemo.merge(n.left.first())
+ if n.left.nullable() {
+ n.firstMemo.merge(n.right.first())
+ }
+ n.firstMemo.sortAndRemoveDuplicates()
+ }
+ return n.firstMemo
+}
+
+func (n *concatNode) last() *symbolPositionSet {
+ if n.lastMemo == nil {
+ n.lastMemo = newSymbolPositionSet()
+ n.lastMemo.merge(n.right.last())
+ if n.right.nullable() {
+ n.lastMemo.merge(n.left.last())
+ }
+ n.lastMemo.sortAndRemoveDuplicates()
+ }
+ return n.lastMemo
+}
+
+func (n *concatNode) clone() byteTree {
+ return newConcatNode(n.left.clone(), n.right.clone())
+}
+
+type altNode struct {
+ left byteTree
+ right byteTree
+ firstMemo *symbolPositionSet
+ lastMemo *symbolPositionSet
+}
+
+func newAltNode(left, right byteTree) *altNode {
+ return &altNode{
+ left: left,
+ right: right,
+ }
+}
+
+func (n *altNode) String() string {
+ return "alt"
+}
+
+func (n *altNode) children() (byteTree, byteTree) {
+ return n.left, n.right
+}
+
+func (n *altNode) nullable() bool {
+ return n.left.nullable() || n.right.nullable()
+}
+
+func (n *altNode) first() *symbolPositionSet {
+ if n.firstMemo == nil {
+ n.firstMemo = newSymbolPositionSet()
+ n.firstMemo.merge(n.left.first())
+ n.firstMemo.merge(n.right.first())
+ n.firstMemo.sortAndRemoveDuplicates()
+ }
+ return n.firstMemo
+}
+
+func (n *altNode) last() *symbolPositionSet {
+ if n.lastMemo == nil {
+ n.lastMemo = newSymbolPositionSet()
+ n.lastMemo.merge(n.left.last())
+ n.lastMemo.merge(n.right.last())
+ n.lastMemo.sortAndRemoveDuplicates()
+ }
+ return n.lastMemo
+}
+
+func (n *altNode) clone() byteTree {
+ return newAltNode(n.left.clone(), n.right.clone())
+}
+
+type repeatNode struct {
+ left byteTree
+ firstMemo *symbolPositionSet
+ lastMemo *symbolPositionSet
+}
+
+func newRepeatNode(left byteTree) *repeatNode {
+ return &repeatNode{
+ left: left,
+ }
+}
+
+func (n *repeatNode) String() string {
+ return "repeat"
+}
+
+func (n *repeatNode) children() (byteTree, byteTree) {
+ return n.left, nil
+}
+
+func (n *repeatNode) nullable() bool {
+ return true
+}
+
+func (n *repeatNode) first() *symbolPositionSet {
+ if n.firstMemo == nil {
+ n.firstMemo = newSymbolPositionSet()
+ n.firstMemo.merge(n.left.first())
+ n.firstMemo.sortAndRemoveDuplicates()
+ }
+ return n.firstMemo
+}
+
+func (n *repeatNode) last() *symbolPositionSet {
+ if n.lastMemo == nil {
+ n.lastMemo = newSymbolPositionSet()
+ n.lastMemo.merge(n.left.last())
+ n.lastMemo.sortAndRemoveDuplicates()
+ }
+ return n.lastMemo
+}
+
+func (n *repeatNode) clone() byteTree {
+ return newRepeatNode(n.left.clone())
+}
+
+type optionNode struct {
+ left byteTree
+ firstMemo *symbolPositionSet
+ lastMemo *symbolPositionSet
+}
+
+func newOptionNode(left byteTree) *optionNode {
+ return &optionNode{
+ left: left,
+ }
+}
+
+func (n *optionNode) String() string {
+ return "option"
+}
+
+func (n *optionNode) children() (byteTree, byteTree) {
+ return n.left, nil
+}
+
+func (n *optionNode) nullable() bool {
+ return true
+}
+
+func (n *optionNode) first() *symbolPositionSet {
+ if n.firstMemo == nil {
+ n.firstMemo = newSymbolPositionSet()
+ n.firstMemo.merge(n.left.first())
+ n.firstMemo.sortAndRemoveDuplicates()
+ }
+ return n.firstMemo
+}
+
+func (n *optionNode) last() *symbolPositionSet {
+ if n.lastMemo == nil {
+ n.lastMemo = newSymbolPositionSet()
+ n.lastMemo.merge(n.left.last())
+ n.lastMemo.sortAndRemoveDuplicates()
+ }
+ return n.lastMemo
+}
+
+func (n *optionNode) clone() byteTree {
+ return newOptionNode(n.left.clone())
+}
+
+type followTable map[symbolPosition]*symbolPositionSet
+
+func genFollowTable(root byteTree) followTable {
+ follow := followTable{}
+ calcFollow(follow, root)
+ return follow
+}
+
+func calcFollow(follow followTable, ast byteTree) {
+ if ast == nil {
+ return
+ }
+ left, right := ast.children()
+ calcFollow(follow, left)
+ calcFollow(follow, right)
+ switch n := ast.(type) {
+ case *concatNode:
+ l, r := n.children()
+ for _, p := range l.last().set() {
+ if _, ok := follow[p]; !ok {
+ follow[p] = newSymbolPositionSet()
+ }
+ follow[p].merge(r.first())
+ }
+ case *repeatNode:
+ for _, p := range n.last().set() {
+ if _, ok := follow[p]; !ok {
+ follow[p] = newSymbolPositionSet()
+ }
+ follow[p].merge(n.first())
+ }
+ }
+}
+
+func positionSymbols(node byteTree, n uint16) (uint16, error) {
+ if node == nil {
+ return n, nil
+ }
+
+ l, r := node.children()
+ p := n
+ p, err := positionSymbols(l, p)
+ if err != nil {
+ return p, err
+ }
+ p, err = positionSymbols(r, p)
+ if err != nil {
+ return p, err
+ }
+ switch n := node.(type) {
+ case *symbolNode:
+ n.pos, err = newSymbolPosition(p, false)
+ if err != nil {
+ return p, err
+ }
+ p++
+ case *endMarkerNode:
+ n.pos, err = newSymbolPosition(p, true)
+ if err != nil {
+ return p, err
+ }
+ p++
+ }
+ node.first()
+ node.last()
+ return p, nil
+}
+
+func concat(ts ...byteTree) byteTree {
+ nonNilNodes := []byteTree{}
+ for _, t := range ts {
+ if t == nil {
+ continue
+ }
+ nonNilNodes = append(nonNilNodes, t)
+ }
+ if len(nonNilNodes) <= 0 {
+ return nil
+ }
+ if len(nonNilNodes) == 1 {
+ return nonNilNodes[0]
+ }
+ concat := newConcatNode(nonNilNodes[0], nonNilNodes[1])
+ for _, t := range nonNilNodes[2:] {
+ concat = newConcatNode(concat, t)
+ }
+ return concat
+}
+
+func oneOf(ts ...byteTree) byteTree {
+ nonNilNodes := []byteTree{}
+ for _, t := range ts {
+ if t == nil {
+ continue
+ }
+ nonNilNodes = append(nonNilNodes, t)
+ }
+ if len(nonNilNodes) <= 0 {
+ return nil
+ }
+ if len(nonNilNodes) == 1 {
+ return nonNilNodes[0]
+ }
+ alt := newAltNode(nonNilNodes[0], nonNilNodes[1])
+ for _, t := range nonNilNodes[2:] {
+ alt = newAltNode(alt, t)
+ }
+ return alt
+}
+
+//nolint:unused
+func printByteTree(w io.Writer, t byteTree, ruledLine string, childRuledLinePrefix string, withAttrs bool) {
+ if t == nil {
+ return
+ }
+ fmt.Fprintf(w, "%v%v", ruledLine, t)
+ if withAttrs {
+ fmt.Fprintf(w, ", nullable: %v, first: %v, last: %v", t.nullable(), t.first(), t.last())
+ }
+ fmt.Fprintf(w, "\n")
+ left, right := t.children()
+ children := []byteTree{}
+ if left != nil {
+ children = append(children, left)
+ }
+ if right != nil {
+ children = append(children, right)
+ }
+ num := len(children)
+ for i, child := range children {
+ line := "└─ "
+ if num > 1 {
+ if i == 0 {
+ line = "├─ "
+ } else if i < num-1 {
+ line = "│ "
+ }
+ }
+ prefix := "│ "
+ if i >= num-1 {
+ prefix = " "
+ }
+ printByteTree(w, child, childRuledLinePrefix+line, childRuledLinePrefix+prefix, withAttrs)
+ }
+}
+
+func ConvertCPTreeToByteTree(cpTrees map[spec.LexModeKindID]parser.CPTree) (byteTree, *symbolTable, error) {
+ var ids []spec.LexModeKindID
+ for id := range cpTrees {
+ ids = append(ids, id)
+ }
+ sort.Slice(ids, func(i, j int) bool {
+ return ids[i] < ids[j]
+ })
+
+ var bt byteTree
+ for _, id := range ids {
+ cpTree := cpTrees[id]
+ t, err := convCPTreeToByteTree(cpTree)
+ if err != nil {
+ return nil, nil, err
+ }
+ bt = oneOf(bt, concat(t, newEndMarkerNode(id)))
+ }
+ _, err := positionSymbols(bt, symbolPositionMin)
+ if err != nil {
+ return nil, nil, err
+ }
+
+ return bt, genSymbolTable(bt), nil
+}
+
+func convCPTreeToByteTree(cpTree parser.CPTree) (byteTree, error) {
+ if from, to, ok := cpTree.Range(); ok {
+ bs, err := utf8.GenCharBlocks(from, to)
+ if err != nil {
+ return nil, err
+ }
+ var a byteTree
+ for _, b := range bs {
+ var c byteTree
+ for i := 0; i < len(b.From); i++ {
+ c = concat(c, newRangeSymbolNode(b.From[i], b.To[i]))
+ }
+ a = oneOf(a, c)
+ }
+ return a, nil
+ }
+
+ if tree, ok := cpTree.Repeatable(); ok {
+ t, err := convCPTreeToByteTree(tree)
+ if err != nil {
+ return nil, err
+ }
+ return newRepeatNode(t), nil
+ }
+
+ if tree, ok := cpTree.Optional(); ok {
+ t, err := convCPTreeToByteTree(tree)
+ if err != nil {
+ return nil, err
+ }
+ return newOptionNode(t), nil
+ }
+
+ if left, right, ok := cpTree.Concatenation(); ok {
+ l, err := convCPTreeToByteTree(left)
+ if err != nil {
+ return nil, err
+ }
+ r, err := convCPTreeToByteTree(right)
+ if err != nil {
+ return nil, err
+ }
+ return newConcatNode(l, r), nil
+ }
+
+ if left, right, ok := cpTree.Alternatives(); ok {
+ l, err := convCPTreeToByteTree(left)
+ if err != nil {
+ return nil, err
+ }
+ r, err := convCPTreeToByteTree(right)
+ if err != nil {
+ return nil, err
+ }
+ return newAltNode(l, r), nil
+ }
+
+ return nil, fmt.Errorf("invalid tree type: %T", cpTree)
+}
diff --git a/src/urubu/grammar/lexical/entry.go b/src/urubu/grammar/lexical/entry.go
new file mode 100644
index 0000000..44af8ea
--- /dev/null
+++ b/src/urubu/grammar/lexical/entry.go
@@ -0,0 +1,171 @@
+package lexical
+
+import (
+ "fmt"
+ "sort"
+ "strings"
+
+ spec "urubu/spec/grammar"
+)
+
+type LexEntry struct {
+ Kind spec.LexKindName
+ Pattern string
+ Modes []spec.LexModeName
+ Push spec.LexModeName
+ Pop bool
+ Fragment bool
+}
+
+type LexSpec struct {
+ Entries []*LexEntry
+}
+
+func (s *LexSpec) Validate() error {
+ if len(s.Entries) <= 0 {
+ return fmt.Errorf("the lexical specification must have at least one entry")
+ }
+ {
+ ks := map[string]struct{}{}
+ fks := map[string]struct{}{}
+ for _, e := range s.Entries {
+ // Allow duplicate names between fragments and non-fragments.
+ if e.Fragment {
+ if _, exist := fks[e.Kind.String()]; exist {
+ return fmt.Errorf("kinds `%v` are duplicates", e.Kind)
+ }
+ fks[e.Kind.String()] = struct{}{}
+ } else {
+ if _, exist := ks[e.Kind.String()]; exist {
+ return fmt.Errorf("kinds `%v` are duplicates", e.Kind)
+ }
+ ks[e.Kind.String()] = struct{}{}
+ }
+ }
+ }
+ {
+ kinds := []string{}
+ modes := []string{
+ spec.LexModeNameDefault.String(), // This is a predefined mode.
+ }
+ for _, e := range s.Entries {
+ if e.Fragment {
+ continue
+ }
+
+ kinds = append(kinds, e.Kind.String())
+
+ for _, m := range e.Modes {
+ modes = append(modes, m.String())
+ }
+ }
+
+ kindErrs := findSpellingInconsistenciesErrors(kinds, nil)
+ modeErrs := findSpellingInconsistenciesErrors(modes, func(ids []string) error {
+ if SnakeCaseToUpperCamelCase(ids[0]) == SnakeCaseToUpperCamelCase(spec.LexModeNameDefault.String()) {
+ var b strings.Builder
+ fmt.Fprintf(&b, "%+v", ids[0])
+ for _, id := range ids[1:] {
+ fmt.Fprintf(&b, ", %+v", id)
+ }
+ return fmt.Errorf("these identifiers are treated as the same. please use the same spelling as predefined '%v': %v", spec.LexModeNameDefault, b.String())
+ }
+ return nil
+ })
+ errs := append(kindErrs, modeErrs...)
+ if len(errs) > 0 {
+ var b strings.Builder
+ fmt.Fprintf(&b, "%v", errs[0])
+ for _, err := range errs[1:] {
+ fmt.Fprintf(&b, "\n%v", err)
+ }
+ return fmt.Errorf(b.String())
+ }
+ }
+
+ return nil
+}
+
+func findSpellingInconsistenciesErrors(ids []string, hook func(ids []string) error) []error {
+ duplicated := FindSpellingInconsistencies(ids)
+ if len(duplicated) == 0 {
+ return nil
+ }
+
+ var errs []error
+ for _, dup := range duplicated {
+ if hook != nil {
+ err := hook(dup)
+ if err != nil {
+ errs = append(errs, err)
+ continue
+ }
+ }
+
+ var b strings.Builder
+ fmt.Fprintf(&b, "%+v", dup[0])
+ for _, id := range dup[1:] {
+ fmt.Fprintf(&b, ", %+v", id)
+ }
+ err := fmt.Errorf("these identifiers are treated as the same. please use the same spelling: %v", b.String())
+ errs = append(errs, err)
+ }
+
+ return errs
+}
+
+// FindSpellingInconsistencies finds spelling inconsistencies in identifiers. The identifiers are considered to be the same
+// if they are spelled the same when expressed in UpperCamelCase. For example, `left_paren` and `LeftParen` are spelled the same
+// in UpperCamelCase. Thus they are considere to be spelling inconsistency.
+func FindSpellingInconsistencies(ids []string) [][]string {
+ m := map[string][]string{}
+ for _, id := range removeDuplicates(ids) {
+ c := SnakeCaseToUpperCamelCase(id)
+ m[c] = append(m[c], id)
+ }
+
+ var duplicated [][]string
+ for _, camels := range m {
+ if len(camels) == 1 {
+ continue
+ }
+ duplicated = append(duplicated, camels)
+ }
+
+ for _, dup := range duplicated {
+ sort.Slice(dup, func(i, j int) bool {
+ return dup[i] < dup[j]
+ })
+ }
+ sort.Slice(duplicated, func(i, j int) bool {
+ return duplicated[i][0] < duplicated[j][0]
+ })
+
+ return duplicated
+}
+
+func removeDuplicates(s []string) []string {
+ m := map[string]struct{}{}
+ for _, v := range s {
+ m[v] = struct{}{}
+ }
+
+ var unique []string
+ for v := range m {
+ unique = append(unique, v)
+ }
+
+ return unique
+}
+
+func SnakeCaseToUpperCamelCase(snake string) string {
+ elems := strings.Split(snake, "_")
+ for i, e := range elems {
+ if len(e) == 0 {
+ continue
+ }
+ elems[i] = strings.ToUpper(string(e[0])) + e[1:]
+ }
+
+ return strings.Join(elems, "")
+}
diff --git a/src/urubu/grammar/lexical/parser/error.go b/src/urubu/grammar/lexical/parser/error.go
new file mode 100644
index 0000000..be81da4
--- /dev/null
+++ b/src/urubu/grammar/lexical/parser/error.go
@@ -0,0 +1,36 @@
+package parser
+
+import "fmt"
+
+var (
+ ParseErr = fmt.Errorf("parse error")
+
+ // lexical errors
+ synErrIncompletedEscSeq = fmt.Errorf("incompleted escape sequence; unexpected EOF following \\")
+ synErrInvalidEscSeq = fmt.Errorf("invalid escape sequence")
+ synErrInvalidCodePoint = fmt.Errorf("code points must consist of just 4 or 6 hex digits")
+ synErrCharPropInvalidSymbol = fmt.Errorf("invalid character property symbol")
+ SynErrFragmentInvalidSymbol = fmt.Errorf("invalid fragment symbol")
+
+ // syntax errors
+ synErrUnexpectedToken = fmt.Errorf("unexpected token")
+ synErrNullPattern = fmt.Errorf("a pattern must be a non-empty byte sequence")
+ synErrUnmatchablePattern = fmt.Errorf("a pattern cannot match any characters")
+ synErrAltLackOfOperand = fmt.Errorf("an alternation expression must have operands")
+ synErrRepNoTarget = fmt.Errorf("a repeat expression must have an operand")
+ synErrGroupNoElem = fmt.Errorf("a grouping expression must include at least one character")
+ synErrGroupUnclosed = fmt.Errorf("unclosed grouping expression")
+ synErrGroupNoInitiator = fmt.Errorf(") needs preceding (")
+ synErrGroupInvalidForm = fmt.Errorf("invalid grouping expression")
+ synErrBExpNoElem = fmt.Errorf("a bracket expression must include at least one character")
+ synErrBExpUnclosed = fmt.Errorf("unclosed bracket expression")
+ synErrBExpInvalidForm = fmt.Errorf("invalid bracket expression")
+ synErrRangeInvalidOrder = fmt.Errorf("a range expression with invalid order")
+ synErrRangePropIsUnavailable = fmt.Errorf("a property expression is unavailable in a range expression")
+ synErrRangeInvalidForm = fmt.Errorf("invalid range expression")
+ synErrCPExpInvalidForm = fmt.Errorf("invalid code point expression")
+ synErrCPExpOutOfRange = fmt.Errorf("a code point must be between U+0000 to U+10FFFF")
+ synErrCharPropExpInvalidForm = fmt.Errorf("invalid character property expression")
+ synErrCharPropUnsupported = fmt.Errorf("unsupported character property")
+ synErrFragmentExpInvalidForm = fmt.Errorf("invalid fragment expression")
+)
diff --git a/src/urubu/grammar/lexical/parser/fragment.go b/src/urubu/grammar/lexical/parser/fragment.go
new file mode 100644
index 0000000..196c00b
--- /dev/null
+++ b/src/urubu/grammar/lexical/parser/fragment.go
@@ -0,0 +1,72 @@
+package parser
+
+import (
+ "fmt"
+
+ spec "urubu/spec/grammar"
+)
+
+type incompleteFragment struct {
+ kind spec.LexKindName
+ root *rootNode
+}
+
+func CompleteFragments(fragments map[spec.LexKindName]CPTree) error {
+ if len(fragments) == 0 {
+ return nil
+ }
+
+ completeFragments := map[spec.LexKindName]CPTree{}
+ incompleteFragments := []*incompleteFragment{}
+ for kind, tree := range fragments {
+ root, ok := tree.(*rootNode)
+ if !ok {
+ return fmt.Errorf("CompleteFragments can take only *rootNode: %T", tree)
+ }
+ if root.incomplete() {
+ incompleteFragments = append(incompleteFragments, &incompleteFragment{
+ kind: kind,
+ root: root,
+ })
+ } else {
+ completeFragments[kind] = root
+ }
+ }
+ for len(incompleteFragments) > 0 {
+ lastIncompCount := len(incompleteFragments)
+ remainingFragments := []*incompleteFragment{}
+ for _, e := range incompleteFragments {
+ complete, err := ApplyFragments(e.root, completeFragments)
+ if err != nil {
+ return err
+ }
+ if !complete {
+ remainingFragments = append(remainingFragments, e)
+ } else {
+ completeFragments[e.kind] = e.root
+ }
+ }
+ incompleteFragments = remainingFragments
+ if len(incompleteFragments) == lastIncompCount {
+ return ParseErr
+ }
+ }
+
+ return nil
+}
+
+func ApplyFragments(t CPTree, fragments map[spec.LexKindName]CPTree) (bool, error) {
+ root, ok := t.(*rootNode)
+ if !ok {
+ return false, fmt.Errorf("ApplyFragments can take only *rootNode type: %T", t)
+ }
+
+ for name, frag := range fragments {
+ err := root.applyFragment(name, frag)
+ if err != nil {
+ return false, err
+ }
+ }
+
+ return !root.incomplete(), nil
+}
diff --git a/src/urubu/grammar/lexical/parser/lexer.go b/src/urubu/grammar/lexical/parser/lexer.go
new file mode 100644
index 0000000..3861825
--- /dev/null
+++ b/src/urubu/grammar/lexical/parser/lexer.go
@@ -0,0 +1,594 @@
+package parser
+
+import (
+ "bufio"
+ "fmt"
+ "io"
+ "strings"
+)
+
+type tokenKind string
+
+const (
+ tokenKindChar tokenKind = "char"
+ tokenKindAnyChar tokenKind = "."
+ tokenKindRepeat tokenKind = "*"
+ tokenKindRepeatOneOrMore tokenKind = "+"
+ tokenKindOption tokenKind = "?"
+ tokenKindAlt tokenKind = "|"
+ tokenKindGroupOpen tokenKind = "("
+ tokenKindGroupClose tokenKind = ")"
+ tokenKindBExpOpen tokenKind = "["
+ tokenKindInverseBExpOpen tokenKind = "[^"
+ tokenKindBExpClose tokenKind = "]"
+ tokenKindCharRange tokenKind = "-"
+ tokenKindCodePointLeader tokenKind = "\\u"
+ tokenKindCharPropLeader tokenKind = "\\p"
+ tokenKindFragmentLeader tokenKind = "\\f"
+ tokenKindLBrace tokenKind = "{"
+ tokenKindRBrace tokenKind = "}"
+ tokenKindEqual tokenKind = "="
+ tokenKindCodePoint tokenKind = "code point"
+ tokenKindCharPropSymbol tokenKind = "character property symbol"
+ tokenKindFragmentSymbol tokenKind = "fragment symbol"
+ tokenKindEOF tokenKind = "eof"
+)
+
+type token struct {
+ kind tokenKind
+ char rune
+ propSymbol string
+ codePoint string
+ fragmentSymbol string
+}
+
+const nullChar = '\u0000'
+
+func newToken(kind tokenKind, char rune) *token {
+ return &token{
+ kind: kind,
+ char: char,
+ }
+}
+
+func newCodePointToken(codePoint string) *token {
+ return &token{
+ kind: tokenKindCodePoint,
+ codePoint: codePoint,
+ }
+}
+
+func newCharPropSymbolToken(propSymbol string) *token {
+ return &token{
+ kind: tokenKindCharPropSymbol,
+ propSymbol: propSymbol,
+ }
+}
+
+func newFragmentSymbolToken(fragmentSymbol string) *token {
+ return &token{
+ kind: tokenKindFragmentSymbol,
+ fragmentSymbol: fragmentSymbol,
+ }
+}
+
+type lexerMode string
+
+const (
+ lexerModeDefault lexerMode = "default"
+ lexerModeBExp lexerMode = "bracket expression"
+ lexerModeCPExp lexerMode = "code point expression"
+ lexerModeCharPropExp lexerMode = "character property expression"
+ lexerModeFragmentExp lexerMode = "fragment expression"
+)
+
+type lexerModeStack struct {
+ stack []lexerMode
+}
+
+func newLexerModeStack() *lexerModeStack {
+ return &lexerModeStack{
+ stack: []lexerMode{
+ lexerModeDefault,
+ },
+ }
+}
+
+func (s *lexerModeStack) top() lexerMode {
+ return s.stack[len(s.stack)-1]
+}
+
+func (s *lexerModeStack) push(m lexerMode) {
+ s.stack = append(s.stack, m)
+}
+
+func (s *lexerModeStack) pop() {
+ s.stack = s.stack[:len(s.stack)-1]
+}
+
+type rangeState string
+
+// [a-z]
+// ^^^^
+// |||`-- ready
+// ||`-- expect range terminator
+// |`-- read range initiator
+// `-- ready
+const (
+ rangeStateReady rangeState = "ready"
+ rangeStateReadRangeInitiator rangeState = "read range initiator"
+ rangeStateExpectRangeTerminator rangeState = "expect range terminator"
+)
+
+type lexer struct {
+ src *bufio.Reader
+ peekChar2 rune
+ peekEOF2 bool
+ peekChar1 rune
+ peekEOF1 bool
+ lastChar rune
+ reachedEOF bool
+ prevChar1 rune
+ prevEOF1 bool
+ prevChar2 rune
+ pervEOF2 bool
+ modeStack *lexerModeStack
+ rangeState rangeState
+
+ errCause error
+ errDetail string
+}
+
+func newLexer(src io.Reader) *lexer {
+ return &lexer{
+ src: bufio.NewReader(src),
+ peekChar2: nullChar,
+ peekEOF2: false,
+ peekChar1: nullChar,
+ peekEOF1: false,
+ lastChar: nullChar,
+ reachedEOF: false,
+ prevChar1: nullChar,
+ prevEOF1: false,
+ prevChar2: nullChar,
+ pervEOF2: false,
+ modeStack: newLexerModeStack(),
+ rangeState: rangeStateReady,
+ }
+}
+
+func (l *lexer) error() (string, error) {
+ return l.errDetail, l.errCause
+}
+
+func (l *lexer) next() (*token, error) {
+ c, eof, err := l.read()
+ if err != nil {
+ return nil, err
+ }
+ if eof {
+ return newToken(tokenKindEOF, nullChar), nil
+ }
+
+ switch l.modeStack.top() {
+ case lexerModeBExp:
+ tok, err := l.nextInBExp(c)
+ if err != nil {
+ return nil, err
+ }
+ if tok.kind == tokenKindChar || tok.kind == tokenKindCodePointLeader || tok.kind == tokenKindCharPropLeader {
+ switch l.rangeState {
+ case rangeStateReady:
+ l.rangeState = rangeStateReadRangeInitiator
+ case rangeStateExpectRangeTerminator:
+ l.rangeState = rangeStateReady
+ }
+ }
+ switch tok.kind {
+ case tokenKindBExpClose:
+ l.modeStack.pop()
+ case tokenKindCharRange:
+ l.rangeState = rangeStateExpectRangeTerminator
+ case tokenKindCodePointLeader:
+ l.modeStack.push(lexerModeCPExp)
+ case tokenKindCharPropLeader:
+ l.modeStack.push(lexerModeCharPropExp)
+ }
+ return tok, nil
+ case lexerModeCPExp:
+ tok, err := l.nextInCodePoint(c)
+ if err != nil {
+ return nil, err
+ }
+ switch tok.kind {
+ case tokenKindRBrace:
+ l.modeStack.pop()
+ }
+ return tok, nil
+ case lexerModeCharPropExp:
+ tok, err := l.nextInCharProp(c)
+ if err != nil {
+ return nil, err
+ }
+ switch tok.kind {
+ case tokenKindRBrace:
+ l.modeStack.pop()
+ }
+ return tok, nil
+ case lexerModeFragmentExp:
+ tok, err := l.nextInFragment(c)
+ if err != nil {
+ return nil, err
+ }
+ switch tok.kind {
+ case tokenKindRBrace:
+ l.modeStack.pop()
+ }
+ return tok, nil
+ default:
+ tok, err := l.nextInDefault(c)
+ if err != nil {
+ return nil, err
+ }
+ switch tok.kind {
+ case tokenKindBExpOpen:
+ l.modeStack.push(lexerModeBExp)
+ l.rangeState = rangeStateReady
+ case tokenKindInverseBExpOpen:
+ l.modeStack.push(lexerModeBExp)
+ l.rangeState = rangeStateReady
+ case tokenKindCodePointLeader:
+ l.modeStack.push(lexerModeCPExp)
+ case tokenKindCharPropLeader:
+ l.modeStack.push(lexerModeCharPropExp)
+ case tokenKindFragmentLeader:
+ l.modeStack.push(lexerModeFragmentExp)
+ }
+ return tok, nil
+ }
+}
+
+func (l *lexer) nextInDefault(c rune) (*token, error) {
+ switch c {
+ case '*':
+ return newToken(tokenKindRepeat, nullChar), nil
+ case '+':
+ return newToken(tokenKindRepeatOneOrMore, nullChar), nil
+ case '?':
+ return newToken(tokenKindOption, nullChar), nil
+ case '.':
+ return newToken(tokenKindAnyChar, nullChar), nil
+ case '|':
+ return newToken(tokenKindAlt, nullChar), nil
+ case '(':
+ return newToken(tokenKindGroupOpen, nullChar), nil
+ case ')':
+ return newToken(tokenKindGroupClose, nullChar), nil
+ case '[':
+ c1, eof, err := l.read()
+ if err != nil {
+ return nil, err
+ }
+ if eof {
+ err := l.restore()
+ if err != nil {
+ return nil, err
+ }
+ return newToken(tokenKindBExpOpen, nullChar), nil
+ }
+ if c1 != '^' {
+ err := l.restore()
+ if err != nil {
+ return nil, err
+ }
+ return newToken(tokenKindBExpOpen, nullChar), nil
+ }
+ c2, eof, err := l.read()
+ if err != nil {
+ return nil, err
+ }
+ if eof {
+ err := l.restore()
+ if err != nil {
+ return nil, err
+ }
+ return newToken(tokenKindInverseBExpOpen, nullChar), nil
+ }
+ if c2 != ']' {
+ err := l.restore()
+ if err != nil {
+ return nil, err
+ }
+ return newToken(tokenKindInverseBExpOpen, nullChar), nil
+ }
+ err = l.restore()
+ if err != nil {
+ return nil, err
+ }
+ err = l.restore()
+ if err != nil {
+ return nil, err
+ }
+ return newToken(tokenKindBExpOpen, nullChar), nil
+ case '\\':
+ c, eof, err := l.read()
+ if err != nil {
+ return nil, err
+ }
+ if eof {
+ l.errCause = synErrIncompletedEscSeq
+ return nil, ParseErr
+ }
+ if c == 'u' {
+ return newToken(tokenKindCodePointLeader, nullChar), nil
+ }
+ if c == 'p' {
+ return newToken(tokenKindCharPropLeader, nullChar), nil
+ }
+ if c == 'f' {
+ return newToken(tokenKindFragmentLeader, nullChar), nil
+ }
+ if c == '\\' || c == '.' || c == '*' || c == '+' || c == '?' || c == '|' || c == '(' || c == ')' || c == '[' || c == ']' {
+ return newToken(tokenKindChar, c), nil
+ }
+ l.errCause = synErrInvalidEscSeq
+ l.errDetail = fmt.Sprintf("\\%v is not supported", string(c))
+ return nil, ParseErr
+ default:
+ return newToken(tokenKindChar, c), nil
+ }
+}
+
+func (l *lexer) nextInBExp(c rune) (*token, error) {
+ switch c {
+ case '-':
+ if l.rangeState != rangeStateReadRangeInitiator {
+ return newToken(tokenKindChar, c), nil
+ }
+ c1, eof, err := l.read()
+ if err != nil {
+ return nil, err
+ }
+ if eof {
+ err := l.restore()
+ if err != nil {
+ return nil, err
+ }
+ return newToken(tokenKindChar, c), nil
+ }
+ if c1 != ']' {
+ err := l.restore()
+ if err != nil {
+ return nil, err
+ }
+ return newToken(tokenKindCharRange, nullChar), nil
+ }
+ err = l.restore()
+ if err != nil {
+ return nil, err
+ }
+ return newToken(tokenKindChar, c), nil
+ case ']':
+ return newToken(tokenKindBExpClose, nullChar), nil
+ case '\\':
+ c, eof, err := l.read()
+ if err != nil {
+ return nil, err
+ }
+ if eof {
+ l.errCause = synErrIncompletedEscSeq
+ return nil, ParseErr
+ }
+ if c == 'u' {
+ return newToken(tokenKindCodePointLeader, nullChar), nil
+ }
+ if c == 'p' {
+ return newToken(tokenKindCharPropLeader, nullChar), nil
+ }
+ if c == '\\' || c == '^' || c == '-' || c == ']' {
+ return newToken(tokenKindChar, c), nil
+ }
+ l.errCause = synErrInvalidEscSeq
+ l.errDetail = fmt.Sprintf("\\%v is not supported in a bracket expression", string(c))
+ return nil, ParseErr
+ default:
+ return newToken(tokenKindChar, c), nil
+ }
+}
+
+func (l *lexer) nextInCodePoint(c rune) (*token, error) {
+ switch c {
+ case '{':
+ return newToken(tokenKindLBrace, nullChar), nil
+ case '}':
+ return newToken(tokenKindRBrace, nullChar), nil
+ default:
+ if !isHexDigit(c) {
+ l.errCause = synErrInvalidCodePoint
+ return nil, ParseErr
+ }
+ var b strings.Builder
+ fmt.Fprint(&b, string(c))
+ n := 1
+ for {
+ c, eof, err := l.read()
+ if err != nil {
+ return nil, err
+ }
+ if eof {
+ err := l.restore()
+ if err != nil {
+ return nil, err
+ }
+ break
+ }
+ if c == '}' {
+ err := l.restore()
+ if err != nil {
+ return nil, err
+ }
+ break
+ }
+ if !isHexDigit(c) || n >= 6 {
+ l.errCause = synErrInvalidCodePoint
+ return nil, ParseErr
+ }
+ fmt.Fprint(&b, string(c))
+ n++
+ }
+ cp := b.String()
+ cpLen := len(cp)
+ if !(cpLen == 4 || cpLen == 6) {
+ l.errCause = synErrInvalidCodePoint
+ return nil, ParseErr
+ }
+ return newCodePointToken(b.String()), nil
+ }
+}
+
+func isHexDigit(c rune) bool {
+ if c >= '0' && c <= '9' || c >= 'A' && c <= 'Z' || c >= 'a' && c <= 'z' {
+ return true
+ }
+ return false
+}
+
+func (l *lexer) nextInCharProp(c rune) (*token, error) {
+ switch c {
+ case '{':
+ return newToken(tokenKindLBrace, nullChar), nil
+ case '}':
+ return newToken(tokenKindRBrace, nullChar), nil
+ case '=':
+ return newToken(tokenKindEqual, nullChar), nil
+ default:
+ var b strings.Builder
+ fmt.Fprint(&b, string(c))
+ n := 1
+ for {
+ c, eof, err := l.read()
+ if err != nil {
+ return nil, err
+ }
+ if eof {
+ err := l.restore()
+ if err != nil {
+ return nil, err
+ }
+ break
+ }
+ if c == '}' || c == '=' {
+ err := l.restore()
+ if err != nil {
+ return nil, err
+ }
+ break
+ }
+ fmt.Fprint(&b, string(c))
+ n++
+ }
+ sym := strings.TrimSpace(b.String())
+ if len(sym) == 0 {
+ l.errCause = synErrCharPropInvalidSymbol
+ return nil, ParseErr
+ }
+ return newCharPropSymbolToken(sym), nil
+ }
+}
+
+func (l *lexer) nextInFragment(c rune) (*token, error) {
+ switch c {
+ case '{':
+ return newToken(tokenKindLBrace, nullChar), nil
+ case '}':
+ return newToken(tokenKindRBrace, nullChar), nil
+ default:
+ var b strings.Builder
+ fmt.Fprint(&b, string(c))
+ n := 1
+ for {
+ c, eof, err := l.read()
+ if err != nil {
+ return nil, err
+ }
+ if eof {
+ err := l.restore()
+ if err != nil {
+ return nil, err
+ }
+ break
+ }
+ if c == '}' {
+ err := l.restore()
+ if err != nil {
+ return nil, err
+ }
+ break
+ }
+ fmt.Fprint(&b, string(c))
+ n++
+ }
+ sym := strings.TrimSpace(b.String())
+ if len(sym) == 0 {
+ l.errCause = SynErrFragmentInvalidSymbol
+ return nil, ParseErr
+ }
+ return newFragmentSymbolToken(sym), nil
+ }
+}
+
+func (l *lexer) read() (rune, bool, error) {
+ if l.reachedEOF {
+ return l.lastChar, l.reachedEOF, nil
+ }
+ if l.peekChar1 != nullChar || l.peekEOF1 {
+ l.prevChar2 = l.prevChar1
+ l.pervEOF2 = l.prevEOF1
+ l.prevChar1 = l.lastChar
+ l.prevEOF1 = l.reachedEOF
+ l.lastChar = l.peekChar1
+ l.reachedEOF = l.peekEOF1
+ l.peekChar1 = l.peekChar2
+ l.peekEOF1 = l.peekEOF2
+ l.peekChar2 = nullChar
+ l.peekEOF2 = false
+ return l.lastChar, l.reachedEOF, nil
+ }
+ c, _, err := l.src.ReadRune()
+ if err != nil {
+ if err == io.EOF {
+ l.prevChar2 = l.prevChar1
+ l.pervEOF2 = l.prevEOF1
+ l.prevChar1 = l.lastChar
+ l.prevEOF1 = l.reachedEOF
+ l.lastChar = nullChar
+ l.reachedEOF = true
+ return l.lastChar, l.reachedEOF, nil
+ }
+ return nullChar, false, err
+ }
+ l.prevChar2 = l.prevChar1
+ l.pervEOF2 = l.prevEOF1
+ l.prevChar1 = l.lastChar
+ l.prevEOF1 = l.reachedEOF
+ l.lastChar = c
+ l.reachedEOF = false
+ return l.lastChar, l.reachedEOF, nil
+}
+
+func (l *lexer) restore() error {
+ if l.lastChar == nullChar && !l.reachedEOF {
+ return fmt.Errorf("failed to call restore() because the last character is null")
+ }
+ l.peekChar2 = l.peekChar1
+ l.peekEOF2 = l.peekEOF1
+ l.peekChar1 = l.lastChar
+ l.peekEOF1 = l.reachedEOF
+ l.lastChar = l.prevChar1
+ l.reachedEOF = l.prevEOF1
+ l.prevChar1 = l.prevChar2
+ l.prevEOF1 = l.pervEOF2
+ l.prevChar2 = nullChar
+ l.pervEOF2 = false
+ return nil
+}
diff --git a/src/urubu/grammar/lexical/parser/parser.go b/src/urubu/grammar/lexical/parser/parser.go
new file mode 100644
index 0000000..425b553
--- /dev/null
+++ b/src/urubu/grammar/lexical/parser/parser.go
@@ -0,0 +1,531 @@
+package parser
+
+import (
+ "bytes"
+ "fmt"
+ "io"
+ "strconv"
+
+ spec "urubu/spec/grammar"
+ "urubu/ucd"
+)
+
+type PatternEntry struct {
+ ID spec.LexModeKindID
+ Pattern []byte
+}
+
+type parser struct {
+ kind spec.LexKindName
+ lex *lexer
+ peekedTok *token
+ lastTok *token
+
+ // If and only if isContributoryPropertyExposed is true, the parser interprets contributory properties that
+ // appear in property expressions.
+ //
+ // The contributory properties are not exposed, and users cannot use those properties because the parser
+ // follows [UAX #44 5.13 Property APIs]. For instance, \p{Other_Alphabetic} is invalid.
+ //
+ // isContributoryPropertyExposed is set to true when the parser is generated recursively. The parser needs to
+ // interpret derived properties internally because the derived properties consist of other properties that
+ // may contain the contributory properties.
+ //
+ // [UAX #44 5.13 Property APIs] says:
+ // > The following subtypes of Unicode character properties should generally not be exposed in APIs,
+ // > except in limited circumstances. They may not be useful, particularly in public API collections,
+ // > and may instead prove misleading to the users of such API collections.
+ // > * Contributory properties are not recommended for public APIs.
+ // > ...
+ // https://unicode.org/reports/tr44/#Property_APIs
+ isContributoryPropertyExposed bool
+
+ errCause error
+ errDetail string
+}
+
+func NewParser(kind spec.LexKindName, src io.Reader) *parser {
+ return &parser{
+ kind: kind,
+ lex: newLexer(src),
+ isContributoryPropertyExposed: false,
+ }
+}
+
+func (p *parser) exposeContributoryProperty() {
+ p.isContributoryPropertyExposed = true
+}
+
+func (p *parser) Error() (string, error) {
+ return p.errDetail, p.errCause
+}
+
+func (p *parser) Parse() (root CPTree, retErr error) {
+ defer func() {
+ err := recover()
+ if err != nil {
+ var ok bool
+ retErr, ok = err.(error)
+ if !ok {
+ panic(err)
+ }
+ return
+ }
+ }()
+
+ return newRootNode(p.kind, p.parseRegexp()), nil
+}
+
+func (p *parser) parseRegexp() CPTree {
+ alt := p.parseAlt()
+ if alt == nil {
+ if p.consume(tokenKindGroupClose) {
+ p.raiseParseError(synErrGroupNoInitiator, "")
+ }
+ p.raiseParseError(synErrNullPattern, "")
+ }
+ if p.consume(tokenKindGroupClose) {
+ p.raiseParseError(synErrGroupNoInitiator, "")
+ }
+ p.expect(tokenKindEOF)
+ return alt
+}
+
+func (p *parser) parseAlt() CPTree {
+ left := p.parseConcat()
+ if left == nil {
+ if p.consume(tokenKindAlt) {
+ p.raiseParseError(synErrAltLackOfOperand, "")
+ }
+ return nil
+ }
+ for {
+ if !p.consume(tokenKindAlt) {
+ break
+ }
+ right := p.parseConcat()
+ if right == nil {
+ p.raiseParseError(synErrAltLackOfOperand, "")
+ }
+ left = newAltNode(left, right)
+ }
+ return left
+}
+
+func (p *parser) parseConcat() CPTree {
+ left := p.parseRepeat()
+ for {
+ right := p.parseRepeat()
+ if right == nil {
+ break
+ }
+ left = newConcatNode(left, right)
+ }
+ return left
+}
+
+func (p *parser) parseRepeat() CPTree {
+ group := p.parseGroup()
+ if group == nil {
+ if p.consume(tokenKindRepeat) {
+ p.raiseParseError(synErrRepNoTarget, "* needs an operand")
+ }
+ if p.consume(tokenKindRepeatOneOrMore) {
+ p.raiseParseError(synErrRepNoTarget, "+ needs an operand")
+ }
+ if p.consume(tokenKindOption) {
+ p.raiseParseError(synErrRepNoTarget, "? needs an operand")
+ }
+ return nil
+ }
+ if p.consume(tokenKindRepeat) {
+ return newRepeatNode(group)
+ }
+ if p.consume(tokenKindRepeatOneOrMore) {
+ return newRepeatOneOrMoreNode(group)
+ }
+ if p.consume(tokenKindOption) {
+ return newOptionNode(group)
+ }
+ return group
+}
+
+func (p *parser) parseGroup() CPTree {
+ if p.consume(tokenKindGroupOpen) {
+ alt := p.parseAlt()
+ if alt == nil {
+ if p.consume(tokenKindEOF) {
+ p.raiseParseError(synErrGroupUnclosed, "")
+ }
+ p.raiseParseError(synErrGroupNoElem, "")
+ }
+ if p.consume(tokenKindEOF) {
+ p.raiseParseError(synErrGroupUnclosed, "")
+ }
+ if !p.consume(tokenKindGroupClose) {
+ p.raiseParseError(synErrGroupInvalidForm, "")
+ }
+ return alt
+ }
+ return p.parseSingleChar()
+}
+
+func (p *parser) parseSingleChar() CPTree {
+ if p.consume(tokenKindAnyChar) {
+ return genAnyCharAST()
+ }
+ if p.consume(tokenKindBExpOpen) {
+ left := p.parseBExpElem()
+ if left == nil {
+ if p.consume(tokenKindEOF) {
+ p.raiseParseError(synErrBExpUnclosed, "")
+ }
+ p.raiseParseError(synErrBExpNoElem, "")
+ }
+ for {
+ right := p.parseBExpElem()
+ if right == nil {
+ break
+ }
+ left = newAltNode(left, right)
+ }
+ if p.consume(tokenKindEOF) {
+ p.raiseParseError(synErrBExpUnclosed, "")
+ }
+ p.expect(tokenKindBExpClose)
+ return left
+ }
+ if p.consume(tokenKindInverseBExpOpen) {
+ elem := p.parseBExpElem()
+ if elem == nil {
+ if p.consume(tokenKindEOF) {
+ p.raiseParseError(synErrBExpUnclosed, "")
+ }
+ p.raiseParseError(synErrBExpNoElem, "")
+ }
+ inverse := exclude(elem, genAnyCharAST())
+ if inverse == nil {
+ p.raiseParseError(synErrUnmatchablePattern, "")
+ }
+ for {
+ elem := p.parseBExpElem()
+ if elem == nil {
+ break
+ }
+ inverse = exclude(elem, inverse)
+ if inverse == nil {
+ p.raiseParseError(synErrUnmatchablePattern, "")
+ }
+ }
+ if p.consume(tokenKindEOF) {
+ p.raiseParseError(synErrBExpUnclosed, "")
+ }
+ p.expect(tokenKindBExpClose)
+ return inverse
+ }
+ if p.consume(tokenKindCodePointLeader) {
+ return p.parseCodePoint()
+ }
+ if p.consume(tokenKindCharPropLeader) {
+ return p.parseCharProp()
+ }
+ if p.consume(tokenKindFragmentLeader) {
+ return p.parseFragment()
+ }
+ c := p.parseNormalChar()
+ if c == nil {
+ if p.consume(tokenKindBExpClose) {
+ p.raiseParseError(synErrBExpInvalidForm, "")
+ }
+ return nil
+ }
+ return c
+}
+
+func (p *parser) parseBExpElem() CPTree {
+ var left CPTree
+ switch {
+ case p.consume(tokenKindCodePointLeader):
+ left = p.parseCodePoint()
+ case p.consume(tokenKindCharPropLeader):
+ left = p.parseCharProp()
+ if p.consume(tokenKindCharRange) {
+ p.raiseParseError(synErrRangePropIsUnavailable, "")
+ }
+ default:
+ left = p.parseNormalChar()
+ }
+ if left == nil {
+ return nil
+ }
+ if !p.consume(tokenKindCharRange) {
+ return left
+ }
+ var right CPTree
+ switch {
+ case p.consume(tokenKindCodePointLeader):
+ right = p.parseCodePoint()
+ case p.consume(tokenKindCharPropLeader):
+ p.raiseParseError(synErrRangePropIsUnavailable, "")
+ default:
+ right = p.parseNormalChar()
+ }
+ if right == nil {
+ p.raiseParseError(synErrRangeInvalidForm, "")
+ }
+ from, _, _ := left.Range()
+ _, to, _ := right.Range()
+ if !isValidOrder(from, to) {
+ p.raiseParseError(synErrRangeInvalidOrder, fmt.Sprintf("%X..%X", from, to))
+ }
+ return newRangeSymbolNode(from, to)
+}
+
+func (p *parser) parseCodePoint() CPTree {
+ if !p.consume(tokenKindLBrace) {
+ p.raiseParseError(synErrCPExpInvalidForm, "")
+ }
+ if !p.consume(tokenKindCodePoint) {
+ p.raiseParseError(synErrCPExpInvalidForm, "")
+ }
+
+ n, err := strconv.ParseInt(p.lastTok.codePoint, 16, 64)
+ if err != nil {
+ panic(fmt.Errorf("failed to decode a code point (%v) into a int: %v", p.lastTok.codePoint, err))
+ }
+ if n < 0x0000 || n > 0x10FFFF {
+ p.raiseParseError(synErrCPExpOutOfRange, "")
+ }
+
+ sym := newSymbolNode(rune(n))
+
+ if !p.consume(tokenKindRBrace) {
+ p.raiseParseError(synErrCPExpInvalidForm, "")
+ }
+
+ return sym
+}
+
+func (p *parser) parseCharProp() CPTree {
+ if !p.consume(tokenKindLBrace) {
+ p.raiseParseError(synErrCharPropExpInvalidForm, "")
+ }
+ var sym1, sym2 string
+ if !p.consume(tokenKindCharPropSymbol) {
+ p.raiseParseError(synErrCharPropExpInvalidForm, "")
+ }
+ sym1 = p.lastTok.propSymbol
+ if p.consume(tokenKindEqual) {
+ if !p.consume(tokenKindCharPropSymbol) {
+ p.raiseParseError(synErrCharPropExpInvalidForm, "")
+ }
+ sym2 = p.lastTok.propSymbol
+ }
+
+ var alt CPTree
+ var propName, propVal string
+ if sym2 != "" {
+ propName = sym1
+ propVal = sym2
+ } else {
+ propName = ""
+ propVal = sym1
+ }
+ if !p.isContributoryPropertyExposed && ucd.IsContributoryProperty(propName) {
+ p.raiseParseError(synErrCharPropUnsupported, propName)
+ }
+ pat, err := ucd.NormalizeCharacterProperty(propName, propVal)
+ if err != nil {
+ p.raiseParseError(synErrCharPropUnsupported, err.Error())
+ }
+ if pat != "" {
+ p := NewParser(p.kind, bytes.NewReader([]byte(pat)))
+ p.exposeContributoryProperty()
+ ast, err := p.Parse()
+ if err != nil {
+ panic(err)
+ }
+ alt = ast
+ } else {
+ cpRanges, inverse, err := ucd.FindCodePointRanges(propName, propVal)
+ if err != nil {
+ p.raiseParseError(synErrCharPropUnsupported, err.Error())
+ }
+ if inverse {
+ r := cpRanges[0]
+ alt = exclude(newRangeSymbolNode(r.From, r.To), genAnyCharAST())
+ if alt == nil {
+ p.raiseParseError(synErrUnmatchablePattern, "")
+ }
+ for _, r := range cpRanges[1:] {
+ alt = exclude(newRangeSymbolNode(r.From, r.To), alt)
+ if alt == nil {
+ p.raiseParseError(synErrUnmatchablePattern, "")
+ }
+ }
+ } else {
+ for _, r := range cpRanges {
+ alt = genAltNode(
+ alt,
+ newRangeSymbolNode(r.From, r.To),
+ )
+ }
+ }
+ }
+
+ if !p.consume(tokenKindRBrace) {
+ p.raiseParseError(synErrCharPropExpInvalidForm, "")
+ }
+
+ return alt
+}
+
+func (p *parser) parseFragment() CPTree {
+ if !p.consume(tokenKindLBrace) {
+ p.raiseParseError(synErrFragmentExpInvalidForm, "")
+ }
+ if !p.consume(tokenKindFragmentSymbol) {
+ p.raiseParseError(synErrFragmentExpInvalidForm, "")
+ }
+ sym := p.lastTok.fragmentSymbol
+
+ if !p.consume(tokenKindRBrace) {
+ p.raiseParseError(synErrFragmentExpInvalidForm, "")
+ }
+
+ return newFragmentNode(spec.LexKindName(sym), nil)
+}
+
+func (p *parser) parseNormalChar() CPTree {
+ if !p.consume(tokenKindChar) {
+ return nil
+ }
+ return newSymbolNode(p.lastTok.char)
+}
+
+func exclude(symbol, base CPTree) CPTree {
+ if left, right, ok := symbol.Alternatives(); ok {
+ return exclude(right, exclude(left, base))
+ }
+
+ if left, right, ok := base.Alternatives(); ok {
+ return genAltNode(
+ exclude(symbol, left),
+ exclude(symbol, right),
+ )
+ }
+
+ if bFrom, bTo, ok := base.Range(); ok {
+ sFrom, sTo, ok := symbol.Range()
+ if !ok {
+ panic(fmt.Errorf("invalid symbol tree: %T", symbol))
+ }
+
+ switch {
+ case sFrom > bFrom && sTo < bTo:
+ return genAltNode(
+ newRangeSymbolNode(bFrom, sFrom-1),
+ newRangeSymbolNode(sTo+1, bTo),
+ )
+ case sFrom <= bFrom && sTo >= bFrom && sTo < bTo:
+ return newRangeSymbolNode(sTo+1, bTo)
+ case sFrom > bFrom && sFrom <= bTo && sTo >= bTo:
+ return newRangeSymbolNode(bFrom, sFrom-1)
+ case sFrom <= bFrom && sTo >= bTo:
+ return nil
+ default:
+ return base
+ }
+ }
+
+ panic(fmt.Errorf("invalid base tree: %T", base))
+}
+
+func genAnyCharAST() CPTree {
+ return newRangeSymbolNode(0x0, 0x10FFFF)
+}
+
+func isValidOrder(from, to rune) bool {
+ return from <= to
+}
+
+func genConcatNode(cs ...CPTree) CPTree {
+ nonNilNodes := []CPTree{}
+ for _, c := range cs {
+ if c == nil {
+ continue
+ }
+ nonNilNodes = append(nonNilNodes, c)
+ }
+ if len(nonNilNodes) <= 0 {
+ return nil
+ }
+ if len(nonNilNodes) == 1 {
+ return nonNilNodes[0]
+ }
+ concat := newConcatNode(nonNilNodes[0], nonNilNodes[1])
+ for _, c := range nonNilNodes[2:] {
+ concat = newConcatNode(concat, c)
+ }
+ return concat
+}
+
+func genAltNode(cs ...CPTree) CPTree {
+ nonNilNodes := []CPTree{}
+ for _, c := range cs {
+ if c == nil {
+ continue
+ }
+ nonNilNodes = append(nonNilNodes, c)
+ }
+ if len(nonNilNodes) <= 0 {
+ return nil
+ }
+ if len(nonNilNodes) == 1 {
+ return nonNilNodes[0]
+ }
+ alt := newAltNode(nonNilNodes[0], nonNilNodes[1])
+ for _, c := range nonNilNodes[2:] {
+ alt = newAltNode(alt, c)
+ }
+ return alt
+}
+
+func (p *parser) expect(expected tokenKind) {
+ if !p.consume(expected) {
+ tok := p.peekedTok
+ p.raiseParseError(synErrUnexpectedToken, fmt.Sprintf("expected: %v, actual: %v", expected, tok.kind))
+ }
+}
+
+func (p *parser) consume(expected tokenKind) bool {
+ var tok *token
+ var err error
+ if p.peekedTok != nil {
+ tok = p.peekedTok
+ p.peekedTok = nil
+ } else {
+ tok, err = p.lex.next()
+ if err != nil {
+ if err == ParseErr {
+ detail, cause := p.lex.error()
+ p.raiseParseError(cause, detail)
+ }
+ panic(err)
+ }
+ }
+ p.lastTok = tok
+ if tok.kind == expected {
+ return true
+ }
+ p.peekedTok = tok
+ p.lastTok = nil
+
+ return false
+}
+
+func (p *parser) raiseParseError(err error, detail string) {
+ p.errCause = err
+ p.errDetail = detail
+ panic(ParseErr)
+}
diff --git a/src/urubu/grammar/lexical/parser/tree.go b/src/urubu/grammar/lexical/parser/tree.go
new file mode 100644
index 0000000..df03d37
--- /dev/null
+++ b/src/urubu/grammar/lexical/parser/tree.go
@@ -0,0 +1,459 @@
+package parser
+
+import (
+ "fmt"
+ "io"
+ "sort"
+
+ spec "urubu/spec/grammar"
+)
+
+type CPRange struct {
+ From rune
+ To rune
+}
+
+type CPTree interface {
+ fmt.Stringer
+ Range() (rune, rune, bool)
+ Optional() (CPTree, bool)
+ Repeatable() (CPTree, bool)
+ Concatenation() (CPTree, CPTree, bool)
+ Alternatives() (CPTree, CPTree, bool)
+ Describe() (spec.LexKindName, []spec.LexKindName, error)
+
+ children() (CPTree, CPTree)
+ clone() CPTree
+}
+
+var (
+ _ CPTree = &rootNode{}
+ _ CPTree = &symbolNode{}
+ _ CPTree = &concatNode{}
+ _ CPTree = &altNode{}
+ _ CPTree = &quantifierNode{}
+ _ CPTree = &fragmentNode{}
+)
+
+type rootNode struct {
+ kind spec.LexKindName
+ tree CPTree
+ fragments map[spec.LexKindName][]*fragmentNode
+}
+
+func newRootNode(kind spec.LexKindName, t CPTree) *rootNode {
+ fragments := map[spec.LexKindName][]*fragmentNode{}
+ collectFragments(t, fragments)
+
+ return &rootNode{
+ kind: kind,
+ tree: t,
+ fragments: fragments,
+ }
+}
+
+func collectFragments(n CPTree, fragments map[spec.LexKindName][]*fragmentNode) {
+ if n == nil {
+ return
+ }
+
+ if f, ok := n.(*fragmentNode); ok {
+ fragments[f.kind] = append(fragments[f.kind], f)
+ return
+ }
+
+ l, r := n.children()
+ collectFragments(l, fragments)
+ collectFragments(r, fragments)
+}
+
+func (n *rootNode) String() string {
+ return fmt.Sprintf("root: %v: %v fragments", n.kind, len(n.fragments))
+}
+
+func (n *rootNode) Range() (rune, rune, bool) {
+ return n.tree.Range()
+}
+
+func (n *rootNode) Optional() (CPTree, bool) {
+ return n.tree.Optional()
+}
+
+func (n *rootNode) Repeatable() (CPTree, bool) {
+ return n.tree.Repeatable()
+}
+
+func (n *rootNode) Concatenation() (CPTree, CPTree, bool) {
+ return n.tree.Concatenation()
+}
+
+func (n *rootNode) Alternatives() (CPTree, CPTree, bool) {
+ return n.tree.Alternatives()
+}
+
+func (n *rootNode) Describe() (spec.LexKindName, []spec.LexKindName, error) {
+ var frags []spec.LexKindName
+ for f := range n.fragments {
+ frags = append(frags, spec.LexKindName(f))
+ }
+ sort.Slice(frags, func(i, j int) bool {
+ return frags[i] < frags[j]
+ })
+
+ return n.kind, frags, nil
+}
+
+func (n *rootNode) children() (CPTree, CPTree) {
+ return n.tree.children()
+}
+
+func (n *rootNode) clone() CPTree {
+ return n.tree.clone()
+}
+
+func (n *rootNode) incomplete() bool {
+ return len(n.fragments) > 0
+}
+
+func (n *rootNode) applyFragment(kind spec.LexKindName, fragment CPTree) error {
+ root, ok := fragment.(*rootNode)
+ if !ok {
+ return fmt.Errorf("applyFragment can take only *rootNode: %T", fragment)
+ }
+ if root.incomplete() {
+ return fmt.Errorf("fragment is incomplete")
+ }
+
+ fs, ok := n.fragments[kind]
+ if !ok {
+ return nil
+ }
+ for _, f := range fs {
+ f.tree = root.clone()
+ }
+ delete(n.fragments, kind)
+
+ return nil
+}
+
+type symbolNode struct {
+ CPRange
+}
+
+func newSymbolNode(cp rune) *symbolNode {
+ return &symbolNode{
+ CPRange: CPRange{
+ From: cp,
+ To: cp,
+ },
+ }
+}
+
+func newRangeSymbolNode(from, to rune) *symbolNode {
+ return &symbolNode{
+ CPRange: CPRange{
+ From: from,
+ To: to,
+ },
+ }
+}
+
+func (n *symbolNode) String() string {
+ return fmt.Sprintf("symbol: %X..%X", n.From, n.To)
+}
+
+func (n *symbolNode) Range() (rune, rune, bool) {
+ return n.From, n.To, true
+}
+
+func (n *symbolNode) Optional() (CPTree, bool) {
+ return nil, false
+}
+
+func (n *symbolNode) Repeatable() (CPTree, bool) {
+ return nil, false
+}
+
+func (n *symbolNode) Concatenation() (CPTree, CPTree, bool) {
+ return nil, nil, false
+}
+
+func (n *symbolNode) Alternatives() (CPTree, CPTree, bool) {
+ return nil, nil, false
+}
+
+func (n *symbolNode) Describe() (spec.LexKindName, []spec.LexKindName, error) {
+ return spec.LexKindNameNil, nil, fmt.Errorf("%T cannot describe", n)
+}
+
+func (n *symbolNode) children() (CPTree, CPTree) {
+ return nil, nil
+}
+
+func (n *symbolNode) clone() CPTree {
+ return newRangeSymbolNode(n.From, n.To)
+}
+
+type concatNode struct {
+ left CPTree
+ right CPTree
+}
+
+func newConcatNode(left, right CPTree) *concatNode {
+ return &concatNode{
+ left: left,
+ right: right,
+ }
+}
+
+func (n *concatNode) String() string {
+ return "concat"
+}
+
+func (n *concatNode) Range() (rune, rune, bool) {
+ return 0, 0, false
+}
+
+func (n *concatNode) Optional() (CPTree, bool) {
+ return nil, false
+}
+
+func (n *concatNode) Repeatable() (CPTree, bool) {
+ return nil, false
+}
+
+func (n *concatNode) Concatenation() (CPTree, CPTree, bool) {
+ return n.left, n.right, true
+}
+
+func (n *concatNode) Alternatives() (CPTree, CPTree, bool) {
+ return nil, nil, false
+}
+
+func (n *concatNode) Describe() (spec.LexKindName, []spec.LexKindName, error) {
+ return spec.LexKindNameNil, nil, fmt.Errorf("%T cannot describe", n)
+}
+
+func (n *concatNode) children() (CPTree, CPTree) {
+ return n.left, n.right
+}
+
+func (n *concatNode) clone() CPTree {
+ if n == nil {
+ return nil
+ }
+ return newConcatNode(n.left.clone(), n.right.clone())
+}
+
+type altNode struct {
+ left CPTree
+ right CPTree
+}
+
+func newAltNode(left, right CPTree) *altNode {
+ return &altNode{
+ left: left,
+ right: right,
+ }
+}
+
+func (n *altNode) String() string {
+ return "alt"
+}
+
+func (n *altNode) Range() (rune, rune, bool) {
+ return 0, 0, false
+}
+
+func (n *altNode) Optional() (CPTree, bool) {
+ return nil, false
+}
+
+func (n *altNode) Repeatable() (CPTree, bool) {
+ return nil, false
+}
+
+func (n *altNode) Concatenation() (CPTree, CPTree, bool) {
+ return nil, nil, false
+}
+
+func (n *altNode) Alternatives() (CPTree, CPTree, bool) {
+ return n.left, n.right, true
+}
+
+func (n *altNode) Describe() (spec.LexKindName, []spec.LexKindName, error) {
+ return spec.LexKindNameNil, nil, fmt.Errorf("%T cannot describe", n)
+}
+
+func (n *altNode) children() (CPTree, CPTree) {
+ return n.left, n.right
+}
+
+func (n *altNode) clone() CPTree {
+ return newAltNode(n.left.clone(), n.right.clone())
+}
+
+type quantifierNode struct {
+ optional bool
+ repeatable bool
+ tree CPTree
+}
+
+func (n *quantifierNode) String() string {
+ switch {
+ case n.repeatable:
+ return "repeatable (>= 0 times)"
+ case n.optional:
+ return "optional (0 or 1 times)"
+ default:
+ return "invalid quantifier"
+ }
+}
+
+func newRepeatNode(t CPTree) *quantifierNode {
+ return &quantifierNode{
+ repeatable: true,
+ tree: t,
+ }
+}
+
+func newRepeatOneOrMoreNode(t CPTree) *concatNode {
+ return newConcatNode(
+ t,
+ &quantifierNode{
+ repeatable: true,
+ tree: t.clone(),
+ })
+}
+
+func newOptionNode(t CPTree) *quantifierNode {
+ return &quantifierNode{
+ optional: true,
+ tree: t,
+ }
+}
+
+func (n *quantifierNode) Range() (rune, rune, bool) {
+ return 0, 0, false
+}
+
+func (n *quantifierNode) Optional() (CPTree, bool) {
+ return n.tree, n.optional
+}
+
+func (n *quantifierNode) Repeatable() (CPTree, bool) {
+ return n.tree, n.repeatable
+}
+
+func (n *quantifierNode) Concatenation() (CPTree, CPTree, bool) {
+ return nil, nil, false
+}
+
+func (n *quantifierNode) Alternatives() (CPTree, CPTree, bool) {
+ return nil, nil, false
+}
+
+func (n *quantifierNode) Describe() (spec.LexKindName, []spec.LexKindName, error) {
+ return spec.LexKindNameNil, nil, fmt.Errorf("%T cannot describe", n)
+}
+
+func (n *quantifierNode) children() (CPTree, CPTree) {
+ return n.tree, nil
+}
+
+func (n *quantifierNode) clone() CPTree {
+ if n.repeatable {
+ return newRepeatNode(n.tree.clone())
+ }
+ return newOptionNode(n.tree.clone())
+}
+
+type fragmentNode struct {
+ kind spec.LexKindName
+ tree CPTree
+}
+
+func newFragmentNode(kind spec.LexKindName, t CPTree) *fragmentNode {
+ return &fragmentNode{
+ kind: kind,
+ tree: t,
+ }
+}
+
+func (n *fragmentNode) String() string {
+ return fmt.Sprintf("fragment: %v", n.kind)
+}
+
+func (n *fragmentNode) Range() (rune, rune, bool) {
+ return n.tree.Range()
+}
+
+func (n *fragmentNode) Optional() (CPTree, bool) {
+ return n.tree.Optional()
+}
+
+func (n *fragmentNode) Repeatable() (CPTree, bool) {
+ return n.tree.Repeatable()
+}
+
+func (n *fragmentNode) Concatenation() (CPTree, CPTree, bool) {
+ return n.tree.Concatenation()
+}
+
+func (n *fragmentNode) Alternatives() (CPTree, CPTree, bool) {
+ return n.tree.Alternatives()
+}
+
+func (n *fragmentNode) Describe() (spec.LexKindName, []spec.LexKindName, error) {
+ return spec.LexKindNameNil, nil, fmt.Errorf("%T cannot describe", n)
+}
+
+func (n *fragmentNode) children() (CPTree, CPTree) {
+ return n.tree.children()
+}
+
+func (n *fragmentNode) clone() CPTree {
+ if n.tree == nil {
+ return newFragmentNode(n.kind, nil)
+ }
+ return newFragmentNode(n.kind, n.tree.clone())
+}
+
+//nolint:unused
+func printCPTree(w io.Writer, t CPTree, ruledLine string, childRuledLinePrefix string) {
+ if t == nil {
+ return
+ }
+ fmt.Fprintf(w, "%v%v\n", ruledLine, t)
+ children := []CPTree{}
+ switch n := t.(type) {
+ case *rootNode:
+ children = append(children, n.tree)
+ case *fragmentNode:
+ children = append(children, n.tree)
+ default:
+ left, right := t.children()
+ if left != nil {
+ children = append(children, left)
+ }
+ if right != nil {
+ children = append(children, right)
+ }
+ }
+ num := len(children)
+ for i, child := range children {
+ line := "└─ "
+ if num > 1 {
+ if i == 0 {
+ line = "├─ "
+ } else if i < num-1 {
+ line = "│ "
+ }
+ }
+ prefix := "│ "
+ if i >= num-1 {
+ prefix = " "
+ }
+ printCPTree(w, child, childRuledLinePrefix+line, childRuledLinePrefix+prefix)
+ }
+}
generated by cgit v1.2.3 (git 2.50.1) at 2025-07-24 20:38:34 +0000