rulebrk.c

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#define TH_UNICODE

#include <stdlib.h>
#include <stdint.h>
#include <assert.h>
#include "th_char.h"
#define th_isalpha(c) (((c) >= 'a' && (c) <= 'z') || ((c) >= 'A' && (c) <= 'Z'))
#define th_isspace(c) ((c) == ' ' || (c) == '\t')

/*
/////////////////////////////////////////////////
// Thai character type array
*/

typedef unsigned short twb_t;
extern const twb_t _TwbType[0x100 - 0xa0];

/*
// bit definition
*/

#define VRS 0x0001
#define VRE 0x0002
#define VRX 0x0004

#define VRA 0x0008

#define VLA 0x0010
#define VLO 0x0020
#define VLI 0x0040

#define VC 0x0080

#define CC 0x0100
#define CS 0x0200

#define C2 0x0400
#define CHB 0x0800
#define CHE 0x1000

#define MT 0x2000
/*
//_#define me 0x2000
*/
#define M 0x4000

#define T 0x8000

#define VL (VLA | VLO | VLI)
#define VR (VRS | VRE | VRX)
#define NE (VL | VRS)
#define NB (VR | M)
#define V (VL | VR)
#define CX (CC | CS)
#define C (CX | VC)
#define A (C | V | M)

#define twbtype(c) (_TwbType[th_zcode(c)])

#ifndef TRUE
#  define TRUE 1
#  define FALSE 0
#endif
#define RETURN(b) return (b)

/*
/////////////////////////////////////////////////
*/

int TrbWordBreakPos(const th_char* pstr, int left, const th_char* rstr,
                    int right)
/*                 const ThBreakIterator *it, const th_char **p)*/
{
  /*
  //int left, right;
  //const th_char *s = *p;
  */
  const th_char* lstr = pstr + left;
  th_char _c[6];
  twb_t _t[6];
#define c(i) (_c[(i) + 3])
#define t(i) (_t[(i) + 3])
  int i, j;

  /*
  //left = s - it->begin;
  */
  if (left < 0) return -1;
  /*
  //right = (it->end == NULL) ? 4 : it->begin - s;
  */
  if (right < 1) return -1;

  /*
  // get c(0), t(0)
  */
  c(0) = rstr[0]; /* may be '\0' */
  if (!th_isthai(c(0))) return -1;
  t(0) = twbtype(c(0));
  if (!(t(0) & A)) return -1;

  /*
  // get c(-1), t(-1)
  */
  if (left >= 1) {
    c(-1) = lstr[-1];
    if (!th_isthai(c(-1))) return 0;
    t(-1) = twbtype(c(-1));
    if (!(t(-1) & A)) return 0; /* handle punctuation marks here */
  } else {
    c(-1) = 0;
    t(-1) = 0;
  }

  /*
  // get c(1..2), t(1..2)
  */
  for (i = 1; i <= 2; i++) {
    if (i >= right) {
      c(i) = 0;
      t(i) = 0;
    } else {
      c(i) = rstr[i]; /* may be '\0'; */
      if (!th_isthai(c(i)))
        right = i--;
      else {
        t(i) = twbtype(c(i));
        if (!(t(i) & A)) right = i--;
      }
    }
  }
  /*
  // get c(-2..-3), t(-2..-3)
  */
  for (i = -2, j = -2; i >= -3; j--) {
    if (j < -left) {
      c(i) = 0;
      t(i) = 0;
      i--;
    } else {
      c(i) = lstr[j];
      if (!th_isthai(c(i)))
        left = 0;
      else {
        t(i) = (twb_t)(th_isthai(c(i)) ? twbtype(c(i)) : 0);
        if (!(t(i) & A))
          left = 0;
        else {
          if ((t(i + 1) & MT) && ((t(i) & VR) || (t(i + 2) & VR))) {
            c(i + 1) = c(i);
            t(i + 1) = t(i);
          } else
            i--;
        }
      }
    }
  }

  /*
  // prohibit the unlikely
  */
  if ((t(-1) & C) && (t(0) & C)) {
    if ((t(-1) & CHE) || (t(0) & CHB)) return -1;
  }
  /*
  // special case : vlao, C/ sara_a|aa, !sara_a
  */
  if ((t(-3) & (VLA | VLO)) && (t(-2) & C) && (c(0) != TH_SARA_A) &&
      (c(-1) == TH_SARA_A || c(-0) == TH_SARA_AA))
    return 0;

  /*
  // prohibit break
  */
  if (t(0) & NB) return -1;
  if (t(-1) & NE) return -1;

  /*
        // apply 100% rules
  */
  if (t(-1) & VRE) {
    if (c(-2) == TH_SARA_AA && c(-1) == TH_SARA_A) return 0;
    return -1; /* usually too short syllable, part of word */
  }

  if (t(-2) & VRE) return -1;

  if ((t(0) & C) && (t(1) & (VR | MT)) &&
      (c(2) != TH_THANTHAKHAT)) {                              /*?C, NB */
    if ((t(-1) & (VRS | VRX)) && c(1) == TH_SARA_I) return -1; /* exception */
    if (t(-1) & (V | M)) return 0;                             /* !C/ C, NB */
    if (t(-2) & VRS) return 0;               /* VRS, C / C, NB */
    if (!(t(0) & C2) && c(1) == TH_SARA_I) { /*	/ !C2 or /c, sara_i */
      if (t(-2) & VRX) return 0;             /* VRX, C / C, NB ? 100%? */
      if (t(-2) & VC) return 0;              /* VC, C / C, NB ? 100% */
    }
  }
  if ((t(-1) & VRX) && (t(0) & CC)) return 0; /* VRX/ CC */
  if ((t(-2) & VRS) && (t(-1) & C) && (t(0) & (V | M)))
    return 0; /* VRS, C/ !C */

  if ((t(0) & CX) && (t(1) & C2) && (c(2) != TH_THANTHAKHAT)) {
    if ((t(-2) & A) && (t(-1) & CX)) return 0;  /* A, CX / CX, C2 */
    if ((t(-2) & CX) && (t(-1) & MT)) return 0; /* CX, MT / CX, C2 */
  }
  /*
  // apply 90% rules
  */
  if (t(0) & VL) return 0;
  if (t(1) & VL) return -1;
  if (c(-1) == TH_THANTHAKHAT && c(-2) != TH_RORUA && c(-2) != TH_LOLING)
    return 0;

  /*
  //return -1;
  // apply 80% rules
  */
  if (t(0) & CHE) {
    if ((t(-2) & VRS) && (t(-1) & C)) return 0; /* VRS, C/ CHE */
    /*if(t(-1) & VRX) return 0;					// VRX/ CHE */
    if (t(-1) & VC) return 0; /* VC/ CHE */
  }
  if (t(-1) & CHB) {
    if ((t(0) & C) && (t(1) & VR)) return 0; /* CHB/ CC, VR */
    if (t(0) & VC) return 0;                 /* CHB/ VC */
  }

  if ((t(-2) & VL) && (t(1) & VR)) { /* VL, C? C, VR */
    if (t(-2) & VLI)
      return 0;                        /* VLI,C/C,VR .*/
    else {                             /* vlao, C ? C , VR */
      if (c(1) == TH_SARA_A) return 2; /* vlao, C, C, sara_a/ */
      if (t(-2) & VLO) return 0;       /* VLO, C/ C, !sara_a */
      if (!(t(1) & VRA)) return 0;     /* VLA, C/ C, !vca */
    }
  }
  /* C,MT,C */
  if ((t(-2) & C) && (t(-1) & MT) && (t(0) & CX)) return 1;

  return -1;
}

int TrbFollowing(const th_char* begin, int length, int offset)
/*
//(ThBreakIterator *this, int offset)
*/
{
  const th_char* w = begin + offset;
  const th_char* end = begin + length;
  while (w < end && *w && !th_isthai(*w) && th_isspace(*w)) w++;

  if (w < end && *w && !th_isthai(*w)) {
    int english = FALSE;
    while (w < end && *w && !th_isthai(*w) && !th_isspace(*w)) {
      if (th_isalpha(*w)) english = TRUE;
      w++;
    }
    if (english || w == end || (!th_isthai(*w) && th_isspace(*w)))
      return w - begin;
  }
  if (w == end || *w == 0 || !th_isthai(*w)) return w - begin;
  w++;
  if (w < end && *w && th_isthai(*w)) {
    int brk = TrbWordBreakPos(begin, w - begin, w, end - w);
    while (brk < 0) {
      w++;
      if (w == end || *w == 0 || !th_isthai(*w)) break;
      brk = TrbWordBreakPos(begin, w - begin, w, end - w);
    }
    if (brk > 0) w += brk;
  }
  if (w < end && *w && !th_isthai(*w)) {
    while (w < end && *w && !th_isthai(*w) && !th_isalpha(*w) &&
           !th_isspace(*w))
      w++;
  }
  return w - begin;
}

/*
/////////////////////////////////////////////////
*/
const twb_t _TwbType[0x100 - 0xa0] = {
#if 0
/* 80 € */	T,
/* 81-8f */	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
/* 90  */	T,
/* 91-9f */	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
#endif
    /* a0   */ 0,
    /* a1 ¡ */ CS,
    /* a2 ¢ */ CS | CHE,
    /* a3 £ */ CC | CHE,
    /* a4 € */ CS | CHE,
    /* a5 ¥ */ CC | CHE,
    /* a6 Š */ CS,
    /* a7 § */ CS | CHB,
    /* a8 š */ CS,
    /* a9 © */ CC | CHE,
    /* aa ª */ CS,
    /* ab « */ CC | CHE,
    /* ac ¬ */ CC | CHB | CHE,
    /* ad ­ */ CS | CHB,
    /* ae ® */ CS | CHB,
    /* af ¯ */ CS | CHB,
    /* b0 ° */ CS,
    /* b1 ± */ CS | CHB | CHE,
    /* b2 ² */ CS | CHB | CHE,
    /* b3 ³ */ CS | CHB,
    /* b4 Ž */ CS,
    /* b5 µ */ CS,
    /* b6 ¶ */ CS,
    /* b7 · */ CS,
    /* b8 ž */ CS,
    /* b9 ¹ */ CS,
    /* ba º */ CS,
    /* bb » */ CS,
    /* bc Π*/ CC | CHE,
    /* bd œ */ CC | CHE,
    /* be Ÿ */ CS,
    /* bf ¿ */ CS,
    /* c0 À */ CS | CHE,
    /* c1 Á */ CS,
    /* c2 Â */ CS,
    /* c3 Ã */ CS | C2 | CHE, /* ? add CHE  */
    /* c4 Ä */ VC | CHE,
    /* c5 Å */ CS | C2,
    /* c6 Æ */ VC | CHE,
    /* c7 Ç */ VC | C2,
    /* c8 È */ CS,
    /* c9 É */ CS | CHB,
    /* ca Ê */ CS | CHE,
    /* cb Ë */ CC | CHE,
    /* CC Ì */ CS | CHB | CHE,
    /* cd Í */ VC,
    /* ce Î */ CC | CHE,
    /* cf Ï */ T,
    /* d0 Ð */ VRE | VRA,
    /* d1  Ñ */ VRS,
    /* d2 Ò */ VRX | VRA,
    /* d3  Ó */ VRE,
    /* d4  Ô */ VRX | VRA,
    /* d5  Õ */ VRX | VRA,
    /* d6  Ö */ VRS,
    /* d7  × */ VRS | VRA,
    /* d8  Ø */ VRX,
    /* d9  Ù */ VRX,
    /* da  Ú */ T,
    /* db Û */ 0,
    /* dc Ü */ 0,
    /* dd Ý */ 0,
    /* de Þ */ 0,
    /* df ß */ T,
    /* e0 à */ VLA,
    /* e1 á */ VLO,
    /* e2 â */ VLO,
    /* e3 ã */ VLI,
    /* e4 ä */ VLI,
    /* e5 å */ VRE,
    /* e6 æ */ M,
    /* e7  ç */ M,
    /* e8  è */ M | MT,
    /* e9  é */ M | MT,
    /* ea  ê */ M | MT,
    /* eb  ë */ M | MT,
    /* ec  ì */ M,
    /* ed  í */ T,
    /* ee  î */ T,
    /* ef ï */ T,
    /* f0 ð */ T,
    /* f1 ñ */ T,
    /* f2 ò */ T,
    /* f3 ó */ T,
    /* f4 ô */ T,
    /* f5 õ */ T,
    /* f6 ö */ T,
    /* f7 ÷ */ T,
    /* f8 ø */ T,
    /* f9 ù */ T,
    /* fa ú */ T,
    /* fb û */ T,
    /* fc ü */ 0,
    /* fd ý */ 0,
    /* fe þ */ 0,
    /* ff ’ */ 0};