datokenizer.go - KorAP/Datok - Gitiles

 package datokenizer

 /**
  * The file reader is basically a port of foma2js,
  * licensed under the Apache License, version 2,
  * and written by Mans Hulden.
  */

 import (
 	"bufio"
 	"compress/gzip"
 	"fmt"
 	"io"
 	"os"
 	"strconv"
 	"strings"
 	"unicode/utf8"
 )

 const (
 	PROPS  = 1
 	SIGMA  = 2
 	STATES = 3
 	NONE   = 4
 )

 // Special symbols in sigma
 var EPSILON, UNKNOWN, IDENTITY, FINAL int

 type mapping struct {
 	source int
 	target int
 }

 type edge struct {
 	in     int
 	out    int
 	target int
 }

 type Tokenizer struct {
 	sigma       map[rune]int
 	sigma_rev   map[int]rune
 	arccount    int
 	statecount  int
 	sigmacount  int
 	maxsize     int
 	array       []int
 	transitions []map[int]*edge
 }

 func parse_file(file string) *Tokenizer {
 	f, err := os.Open(file)
 	if err != nil {
 		panic(err)
 	}
 	defer f.Close()

 	gz, err := gzip.NewReader(f)
 	if err != nil {
 		panic(err)
 	}
 	defer gz.Close()

 	return parse(gz)
 }

 func parse(ior io.Reader) *Tokenizer {
 	r := bufio.NewReader(ior)

 	tok := &Tokenizer{
 		sigma:     make(map[rune]int),
 		sigma_rev: make(map[int]rune),
 	}

 	final := false

 	var arrstate, arrin, arrout, arrtarget, arrfinal int

 	mode := 0
 	var elem []string
 	var elemint [5]int

 	for {
 		line, err := r.ReadString('\n')
 		if err != nil {
 			if err == io.EOF {
 				break
 			}
 			panic(err)
 		}
 		if strings.HasPrefix(line, "##foma-net") {
 			continue
 		}
 		if strings.HasPrefix(line, "##props##") {
 			mode = PROPS
 			continue
 		}
 		if strings.HasPrefix(line, "##states##") {
 			mode = STATES

 			// Adds a final transition symbol to sigma
 			// written as '#' in Mizobuchi et al (2000)
 			tok.sigmacount++
 			FINAL = tok.sigmacount
 			continue
 		}
 		if strings.HasPrefix(line, "##sigma##") {
 			mode = SIGMA
 			continue
 		}
 		if strings.HasPrefix(line, "##end##") {
 			mode = NONE
 			continue
 		}

 		switch mode {
 		case PROPS:
 			{
 				elem = strings.Split(line, " ")
 				/*
 					fmt.Println("arity:            " + elem[0])
 					fmt.Println("arccount:         " + elem[1])
 					fmt.Println("statecount:       " + elem[2])
 					fmt.Println("linecount:        " + elem[3])
 					fmt.Println("finalcount:       " + elem[4])
 					fmt.Println("pathcount:        " + elem[5])
 					fmt.Println("is_deterministic: " + elem[6])
 					fmt.Println("is_pruned:        " + elem[7])
 					fmt.Println("is_minimized:     " + elem[8])
 					fmt.Println("is_epsilon_free:  " + elem[9])
 					fmt.Println("is_loop_free:     " + elem[10])
 					fmt.Println("extras:           " + elem[11])
 					fmt.Println("name:             " + elem[12])
 				*/
 				if elem[6] != "1" {
 					panic("The FST needs to be deterministic")
 				}
 				if elem[9] != "1" {
 					panic("The FST needs to be epsilon free")
 				}

 				elemint[0], err = strconv.Atoi(elem[1])
 				if err != nil {
 					panic("Can't read arccount")
 				}
 				tok.arccount = elemint[0]

 				// States start at 1 in Mizobuchi et al (2000),
 				// as the state 0 is associated with a fail.
 				// Initialize states and transitions
 				elemint[0], err = strconv.Atoi(elem[2])
 				if err != nil {
 					panic("Can't read statecount")
 				}
 				tok.statecount = elemint[0]
 				tok.transitions = make([]map[int]*edge, elemint[0]+1)
 				continue
 			}
 		case STATES:
 			{
 				elem = strings.Split(line[0:len(line)-1], " ")
 				if elem[0] == "-1" {
 					continue
 				}
 				elemint[0], err = strconv.Atoi(elem[0])

 				if len(elem) > 1 {
 					elemint[1], err = strconv.Atoi(elem[1])
 					if err != nil {
 						break
 					}
 					if len(elem) > 2 {
 						elemint[2], err = strconv.Atoi(elem[2])
 						if err != nil {
 							break
 						}
 						if len(elem) > 3 {
 							elemint[3], err = strconv.Atoi(elem[3])
 							if err != nil {
 								break
 							}
 							if len(elem) > 4 {
 								elemint[4], err = strconv.Atoi(elem[4])
 								if err != nil {
 									break
 								}
 							}
 						}
 					}
 				}

 				switch len(elem) {
 				case 5:
 					{
 						arrstate = elemint[0]
 						arrin = elemint[1]
 						arrout = elemint[2]
 						arrtarget = elemint[3]
 						arrfinal = elemint[4]
 					}
 				case 4:
 					{
 						if elemint[1] == -1 {
 							arrstate = elemint[0]
 							arrfinal = elemint[3]
 						} else {
 							arrstate = elemint[0]
 							arrin = elemint[1]
 							arrtarget = elemint[2]
 							arrfinal = elemint[3]
 							arrout = arrin
 						}
 					}
 				case 3:
 					{
 						arrin = elemint[0]
 						arrout = elemint[1]
 						arrtarget = elemint[2]
 					}
 				case 2:
 					{
 						arrin = elemint[0]
 						arrtarget = elemint[2]
 						arrout = arrin
 					}
 				}

 				// This collects all edges until arrstate changes
 				if arrfinal == 1 {
 					final = true
 				} else {
 					final = false
 				}

 				// While the states in foma start with 0, the states in the
 				// Mizobuchi FSA start with one - so we increase every state by 1.

 				if arrin != arrout && arrin != EPSILON && tok.sigma_rev[arrin] != '\n' {
 					panic("Problem: " + strconv.Itoa(arrstate) + " -> " + strconv.Itoa(arrtarget) + " (" + strconv.Itoa(arrin) + ":" + strconv.Itoa(arrout) + ") ")
 				}

 				// TODO:
 				//   if arrin == EPSILON && arrout == TOKENEND, mark state as newline
 				//   if the next transition is the same, remove TOKENEND and add SENTENCEEND
 				//   This requires to remove the transition alltogether and marks the state instead.

 				// TODO:
 				//   if arrout == EPSILON, mark the transition as NOTOKEN

 				targetObj := &edge{
 					in:     arrin,
 					out:    arrout,
 					target: arrtarget + 1,
 				}

 				// Initialize outgoing state
 				if tok.transitions[arrstate+1] == nil {
 					tok.transitions[arrstate+1] = make(map[int]*edge)
 				}

 				tok.transitions[arrstate+1][arrin] = targetObj

 				if final {
 					tok.transitions[arrstate+1][FINAL] = &edge{}
 				}

 				continue
 			}
 		case SIGMA:
 			{
 				elem = strings.SplitN(line[0:len(line)-1], " ", 2)

 				// Turn string into sigma id
 				number, err := strconv.Atoi(elem[0])

 				if err != nil {
 					panic(err)
 				}

 				tok.sigmacount = number

 				var symbol rune

 				// Read rune
 				if utf8.RuneCountInString(elem[1]) == 1 {
 					symbol = []rune(elem[1])[0]

 					// Probably a MCS
 				} else if utf8.RuneCountInString(elem[1]) > 1 {
 					switch elem[1] {
 					case "@_EPSILON_SYMBOL_@":
 						{
 							EPSILON = number
 							continue
 						}
 					case "@_UNKNOWN_SYMBOL_@":
 						{
 							UNKNOWN = number
 							continue
 						}

 					case "@_IDENTITY_SYMBOL_@":
 						{
 							IDENTITY = number
 							continue
 						}
 					default:
 						panic("MCS not supported: " + line)
 					}

 					// Probably a new line symbol
 				} else {
 					line, err = r.ReadString('\n')
 					if err != nil {
 						panic(err)
 					}
 					if len(line) != 1 {
 						panic("MCS not supported:" + line)
 					}
 					symbol = rune('\n')
 				}

 				tok.sigma[symbol] = number
 				tok.sigma_rev[number] = symbol
 			}
 		}
 	}

 	return tok
 }

 // Implementation of Mizobuchi et al (2000), p.128
 func (tok *Tokenizer) buildDA() *Tokenizer {

 	mark := 0
 	size := 0

 	// Create a mapping from s to t
 	table := make([]*mapping, tok.arccount+1)

 	table[size] = &mapping{source: 1, target: 1}
 	size++

 	A := make([]int, 0, 256)

 	for mark < size {
 		s := table[mark].source // This is a state in Ms
 		t := table[mark].target // This is a state in Mt
 		mark++
 		//		fmt.Println("Increase mark", mark)
 		// St := append(St, t)
 		A = A[:0]
 		tok.get_set(s, &A)

 		// fmt.Println("Outgoing arcs from t", t, A)

 		// tok.array[t].base = tok.x_check(A)
 		tok.set_base(t, tok.x_check(A))

 		for _, a := range A {

 			if a != FINAL {
 				s1 := tok.transitions[s][a].target // g(s, a)

 				// fmt.Println("Found", s, "to", s1, "via", a)

 				t1 := tok.get_base(t) + a
 				tok.set_check(t1, t)

 				r := in_table(s1, table, size)
 				if r == 0 {
 					// fmt.Println("Increase size", t1)
 					table[size] = &mapping{source: s1, target: t1}
 					size++
 				} else {
 					//fmt.Println("Rep is there", t1, r)
 					tok.set_base(t1, -1*r)
 					// tok.array[t1].base = -1 * r
 				}
 			} else {
 				fmt.Println("I set a final")
 				// t1 := tok.array[t].base + FINAL
 				t1 := tok.get_base(t) + FINAL
 				// tok.array[t1].check = t
 				tok.set_check(t1, t)
 			}
 		}
 	}

 	// Following Mizobuchi et al (2000) the size of the
 	// FSA should be stored in check(1).
 	tok.set_check(1, tok.maxsize+1)
 	tok.array = tok.array[:tok.maxsize+1]
 	return tok
 }

 func (tok *Tokenizer) resize(l int) {
 	if len(tok.array) < l {
 		tok.array = append(tok.array, make([]int, l)...)
 	}
 }

 func (tok *Tokenizer) set_base(p int, v int) {
 	l := p*2 + 1
 	tok.resize(l)
 	if tok.maxsize < l {
 		tok.maxsize = l
 	}
 	tok.array[p*2] = v
 }

 func (tok *Tokenizer) get_base(p int) int {
 	if p*2 >= len(tok.array) {
 		return 0
 	}
 	return tok.array[p*2]
 }

 func (tok *Tokenizer) set_check(p int, v int) {
 	l := p*2 + 1
 	tok.resize(l)
 	if tok.maxsize < l {
 		tok.maxsize = l
 	}
 	tok.array[(p*2)+1] = v
 }

 func (tok *Tokenizer) get_check(p int) int {
 	if (p*2)+1 >= len(tok.array) {
 		return 0
 	}
 	return tok.array[(p*2)+1]
 }

 // Check the table if a mapping of s
 // exists and return this as a representative
 func in_table(s int, table []*mapping, size int) int {
 	for x := 0; x < size; x++ {
 		if table[x].source == s {
 			return table[x].target
 		}
 	}
 	return 0
 }

 // Set alphabet A to the list of all symbols
 // outgoing from s
 func (tok *Tokenizer) get_set(s int, A *[]int) {
 	for a, _ := range tok.transitions[s] {
 		*A = append(*A, a)
 	}
 }

 // Based on Mizobuchi et al (2000), p. 124
 // This iterates for every state through the complete double array
 // structure until it finds a gap that fits all outgoing transitions
 // of the state. This is extremely slow, but is only necessary in the
 // construction phase of the tokenizer.
 func (tok *Tokenizer) x_check(symbols []int) int {
 	// see https://github.com/bramstein/datrie/blob/master/lib/trie.js
 	base := 1

 	// 	fmt.Println("Resize", len(tok.linarray), "<", ((base + FINAL + 1) * 2))

 OVERLAP:
 	tok.resize((base + FINAL) * 2)
 	for _, a := range symbols {
 		// if tok.array[base+a].check != 0 {
 		if tok.get_check(base+a) != 0 {
 			base++
 			goto OVERLAP
 		}
 	}
 	fmt.Println("Found a nice place at", base, "for", len(symbols))
 	return base
 }

 // Based on Mizobuchi et al (2000), p. 129
 func (tok *Tokenizer) match(input string) bool {
 	t := 1 // Start position
 	chars := []rune(input)
 	i := 0
 	for ; i < len(chars); i++ {
 		a := tok.sigma[chars[i]]
 		tu := t
 		t = tok.get_base(tu) + a
 		fmt.Println("Check", a, t, tok.get_check(1))
 		if t > tok.get_check(1) {
 			break
 		} else if tok.get_check(t) != tu {
 			break
 		} else if tok.get_base(t) < 0 {
 			t = -1 * tok.get_base(t)
 			// fmt.Println("Match is representative!")
 		} else {
 			// fmt.Println("Match is fine!")
 		}
 	}

 	if i == len(chars) {
 		fmt.Println("At the end")
 	} else {
 		return false
 	}

 	// fmt.Println("Hmm...", tok.get_check(tok.get_base(t)+FINAL), "-", t)

 	if tok.get_check(tok.get_base(t)+FINAL) == t {
 		fmt.Println("FINE")
 		return true
 	}
 	return false
 }

 // In the final realization, the states can only have 30 bits:
 // base[1] -> is final
 // base[2] -> is_separate
 // check[1] -> translates to epsilon
 // check[2] -> appends newine (Maybe)
 // If check[1] && check[2] is set, this translates to a sentence split (Maybe)
	package datokenizer

	/**
	* The file reader is basically a port of foma2js,
	* licensed under the Apache License, version 2,
	* and written by Mans Hulden.
	*/

	import (
	"bufio"
	"compress/gzip"
	"fmt"
	"io"
	"os"
	"strconv"
	"strings"
	"unicode/utf8"
	)

	const (
	PROPS = 1
	SIGMA = 2
	STATES = 3
	NONE = 4
	)

	// Special symbols in sigma
	var EPSILON, UNKNOWN, IDENTITY, FINAL int

	type mapping struct {
	source int
	target int
	}

	type edge struct {
	in int
	out int
	target int
	}

	type Tokenizer struct {
	sigma map[rune]int
	sigma_rev map[int]rune
	arccount int
	statecount int
	sigmacount int
	maxsize int
	array []int
	transitions []map[int]*edge
	}

	func parse_file(file string) *Tokenizer {
	f, err := os.Open(file)
	if err != nil {
	panic(err)
	}
	defer f.Close()

	gz, err := gzip.NewReader(f)
	if err != nil {
	panic(err)
	}
	defer gz.Close()

	return parse(gz)
	}

	func parse(ior io.Reader) *Tokenizer {
	r := bufio.NewReader(ior)

	tok := &Tokenizer{
	sigma: make(map[rune]int),
	sigma_rev: make(map[int]rune),
	}

	final := false

	var arrstate, arrin, arrout, arrtarget, arrfinal int

	mode := 0
	var elem []string
	var elemint [5]int

	for {
	line, err := r.ReadString('\n')
	if err != nil {
	if err == io.EOF {
	break
	}
	panic(err)
	}
	if strings.HasPrefix(line, "##foma-net") {
	continue
	}
	if strings.HasPrefix(line, "##props##") {
	mode = PROPS
	continue
	}
	if strings.HasPrefix(line, "##states##") {
	mode = STATES

	// Adds a final transition symbol to sigma
	// written as '#' in Mizobuchi et al (2000)
	tok.sigmacount++
	FINAL = tok.sigmacount
	continue
	}
	if strings.HasPrefix(line, "##sigma##") {
	mode = SIGMA
	continue
	}
	if strings.HasPrefix(line, "##end##") {
	mode = NONE
	continue
	}

	switch mode {
	case PROPS:
	{
	elem = strings.Split(line, " ")
	/*
	fmt.Println("arity: " + elem[0])
	fmt.Println("arccount: " + elem[1])
	fmt.Println("statecount: " + elem[2])
	fmt.Println("linecount: " + elem[3])
	fmt.Println("finalcount: " + elem[4])
	fmt.Println("pathcount: " + elem[5])
	fmt.Println("is_deterministic: " + elem[6])
	fmt.Println("is_pruned: " + elem[7])
	fmt.Println("is_minimized: " + elem[8])
	fmt.Println("is_epsilon_free: " + elem[9])
	fmt.Println("is_loop_free: " + elem[10])
	fmt.Println("extras: " + elem[11])
	fmt.Println("name: " + elem[12])
	*/
	if elem[6] != "1" {
	panic("The FST needs to be deterministic")
	}
	if elem[9] != "1" {
	panic("The FST needs to be epsilon free")
	}

	elemint[0], err = strconv.Atoi(elem[1])
	if err != nil {
	panic("Can't read arccount")
	}
	tok.arccount = elemint[0]

	// States start at 1 in Mizobuchi et al (2000),
	// as the state 0 is associated with a fail.
	// Initialize states and transitions
	elemint[0], err = strconv.Atoi(elem[2])
	if err != nil {
	panic("Can't read statecount")
	}
	tok.statecount = elemint[0]
	tok.transitions = make([]map[int]*edge, elemint[0]+1)
	continue
	}
	case STATES:
	{
	elem = strings.Split(line[0:len(line)-1], " ")
	if elem[0] == "-1" {
	continue
	}
	elemint[0], err = strconv.Atoi(elem[0])

	if len(elem) > 1 {
	elemint[1], err = strconv.Atoi(elem[1])
	if err != nil {
	break
	}
	if len(elem) > 2 {
	elemint[2], err = strconv.Atoi(elem[2])
	if err != nil {
	break
	}
	if len(elem) > 3 {
	elemint[3], err = strconv.Atoi(elem[3])
	if err != nil {
	break
	}
	if len(elem) > 4 {
	elemint[4], err = strconv.Atoi(elem[4])
	if err != nil {
	break
	}
	}
	}
	}
	}

	switch len(elem) {
	case 5:
	{
	arrstate = elemint[0]
	arrin = elemint[1]
	arrout = elemint[2]
	arrtarget = elemint[3]
	arrfinal = elemint[4]
	}
	case 4:
	{
	if elemint[1] == -1 {
	arrstate = elemint[0]
	arrfinal = elemint[3]
	} else {
	arrstate = elemint[0]
	arrin = elemint[1]
	arrtarget = elemint[2]
	arrfinal = elemint[3]
	arrout = arrin
	}
	}
	case 3:
	{
	arrin = elemint[0]
	arrout = elemint[1]
	arrtarget = elemint[2]
	}
	case 2:
	{
	arrin = elemint[0]
	arrtarget = elemint[2]
	arrout = arrin
	}
	}

	// This collects all edges until arrstate changes
	if arrfinal == 1 {
	final = true
	} else {
	final = false
	}

	// While the states in foma start with 0, the states in the
	// Mizobuchi FSA start with one - so we increase every state by 1.

	if arrin != arrout && arrin != EPSILON && tok.sigma_rev[arrin] != '\n' {
	panic("Problem: " + strconv.Itoa(arrstate) + " -> " + strconv.Itoa(arrtarget) + " (" + strconv.Itoa(arrin) + ":" + strconv.Itoa(arrout) + ") ")
	}

	// TODO:
	// if arrin == EPSILON && arrout == TOKENEND, mark state as newline
	// if the next transition is the same, remove TOKENEND and add SENTENCEEND
	// This requires to remove the transition alltogether and marks the state instead.

	// TODO:
	// if arrout == EPSILON, mark the transition as NOTOKEN

	targetObj := &edge{
	in: arrin,
	out: arrout,
	target: arrtarget + 1,
	}

	// Initialize outgoing state
	if tok.transitions[arrstate+1] == nil {
	tok.transitions[arrstate+1] = make(map[int]*edge)
	}

	tok.transitions[arrstate+1][arrin] = targetObj

	if final {
	tok.transitions[arrstate+1][FINAL] = &edge{}
	}

	continue
	}
	case SIGMA:
	{
	elem = strings.SplitN(line[0:len(line)-1], " ", 2)

	// Turn string into sigma id
	number, err := strconv.Atoi(elem[0])

	if err != nil {
	panic(err)
	}

	tok.sigmacount = number

	var symbol rune

	// Read rune
	if utf8.RuneCountInString(elem[1]) == 1 {
	symbol = []rune(elem[1])[0]

	// Probably a MCS
	} else if utf8.RuneCountInString(elem[1]) > 1 {
	switch elem[1] {
	case "@_EPSILON_SYMBOL_@":
	{
	EPSILON = number
	continue
	}
	case "@_UNKNOWN_SYMBOL_@":
	{
	UNKNOWN = number
	continue
	}

	case "@_IDENTITY_SYMBOL_@":
	{
	IDENTITY = number
	continue
	}
	default:
	panic("MCS not supported: " + line)
	}

	// Probably a new line symbol
	} else {
	line, err = r.ReadString('\n')
	if err != nil {
	panic(err)
	}
	if len(line) != 1 {
	panic("MCS not supported:" + line)
	}
	symbol = rune('\n')
	}

	tok.sigma[symbol] = number
	tok.sigma_rev[number] = symbol
	}
	}
	}

	return tok
	}

	// Implementation of Mizobuchi et al (2000), p.128
	func (tok Tokenizer) buildDA() Tokenizer {

	mark := 0
	size := 0

	// Create a mapping from s to t
	table := make([]*mapping, tok.arccount+1)

	table[size] = &mapping{source: 1, target: 1}
	size++

	A := make([]int, 0, 256)

	for mark < size {
	s := table[mark].source // This is a state in Ms
	t := table[mark].target // This is a state in Mt
	mark++
	// fmt.Println("Increase mark", mark)
	// St := append(St, t)
	A = A[:0]
	tok.get_set(s, &A)

	// fmt.Println("Outgoing arcs from t", t, A)

	// tok.array[t].base = tok.x_check(A)
	tok.set_base(t, tok.x_check(A))

	for _, a := range A {

	if a != FINAL {
	s1 := tok.transitions[s][a].target // g(s, a)

	// fmt.Println("Found", s, "to", s1, "via", a)

	t1 := tok.get_base(t) + a
	tok.set_check(t1, t)

	r := in_table(s1, table, size)
	if r == 0 {
	// fmt.Println("Increase size", t1)
	table[size] = &mapping{source: s1, target: t1}
	size++
	} else {
	//fmt.Println("Rep is there", t1, r)
	tok.set_base(t1, -1*r)
	// tok.array[t1].base = -1 * r
	}
	} else {
	fmt.Println("I set a final")
	// t1 := tok.array[t].base + FINAL
	t1 := tok.get_base(t) + FINAL
	// tok.array[t1].check = t
	tok.set_check(t1, t)
	}
	}
	}

	// Following Mizobuchi et al (2000) the size of the
	// FSA should be stored in check(1).
	tok.set_check(1, tok.maxsize+1)
	tok.array = tok.array[:tok.maxsize+1]
	return tok
	}

	func (tok *Tokenizer) resize(l int) {
	if len(tok.array) < l {
	tok.array = append(tok.array, make([]int, l)...)
	}
	}

	func (tok *Tokenizer) set_base(p int, v int) {
	l := p*2 + 1
	tok.resize(l)
	if tok.maxsize < l {
	tok.maxsize = l
	}
	tok.array[p*2] = v
	}

	func (tok *Tokenizer) get_base(p int) int {
	if p*2 >= len(tok.array) {
	return 0
	}
	return tok.array[p*2]
	}

	func (tok *Tokenizer) set_check(p int, v int) {
	l := p*2 + 1
	tok.resize(l)
	if tok.maxsize < l {
	tok.maxsize = l
	}
	tok.array[(p*2)+1] = v
	}

	func (tok *Tokenizer) get_check(p int) int {
	if (p*2)+1 >= len(tok.array) {
	return 0
	}
	return tok.array[(p*2)+1]
	}

	// Check the table if a mapping of s
	// exists and return this as a representative
	func in_table(s int, table []*mapping, size int) int {
	for x := 0; x < size; x++ {
	if table[x].source == s {
	return table[x].target
	}
	}
	return 0
	}

	// Set alphabet A to the list of all symbols
	// outgoing from s
	func (tok Tokenizer) get_set(s int, A []int) {
	for a, _ := range tok.transitions[s] {
	A = append(A, a)
	}
	}

	// Based on Mizobuchi et al (2000), p. 124
	// This iterates for every state through the complete double array
	// structure until it finds a gap that fits all outgoing transitions
	// of the state. This is extremely slow, but is only necessary in the
	// construction phase of the tokenizer.
	func (tok *Tokenizer) x_check(symbols []int) int {
	// see https://github.com/bramstein/datrie/blob/master/lib/trie.js
	base := 1

	// fmt.Println("Resize", len(tok.linarray), "<", ((base + FINAL + 1) * 2))

	OVERLAP:
	tok.resize((base + FINAL) * 2)
	for _, a := range symbols {
	// if tok.array[base+a].check != 0 {
	if tok.get_check(base+a) != 0 {
	base++
	goto OVERLAP
	}
	}
	fmt.Println("Found a nice place at", base, "for", len(symbols))
	return base
	}

	// Based on Mizobuchi et al (2000), p. 129
	func (tok *Tokenizer) match(input string) bool {
	t := 1 // Start position
	chars := []rune(input)
	i := 0
	for ; i < len(chars); i++ {
	a := tok.sigma[chars[i]]
	tu := t
	t = tok.get_base(tu) + a
	fmt.Println("Check", a, t, tok.get_check(1))
	if t > tok.get_check(1) {
	break
	} else if tok.get_check(t) != tu {
	break
	} else if tok.get_base(t) < 0 {
	t = -1 * tok.get_base(t)
	// fmt.Println("Match is representative!")
	} else {
	// fmt.Println("Match is fine!")
	}
	}

	if i == len(chars) {
	fmt.Println("At the end")
	} else {
	return false
	}

	// fmt.Println("Hmm...", tok.get_check(tok.get_base(t)+FINAL), "-", t)

	if tok.get_check(tok.get_base(t)+FINAL) == t {
	fmt.Println("FINE")
	return true
	}
	return false
	}

	// In the final realization, the states can only have 30 bits:
	// base[1] -> is final
	// base[2] -> is_separate
	// check[1] -> translates to epsilon
	// check[2] -> appends newine (Maybe)
	// If check[1] && check[2] is set, this translates to a sentence split (Maybe)