Issue #303 Part 1: Move basilisk files from /browser to /application/basilisk

1 files changed, 1086 insertions, 0 deletions

diff --git a/application/basilisk/components/translation/cld2/internal/getonescriptspan.cc b/application/basilisk/components/translation/cld2/internal/getonescriptspan.cc
new file mode 100644
index 000000000..6bdd4871b
--- /dev/null
+++ b/application/basilisk/components/translation/cld2/internal/getonescriptspan.cc
@@ -0,0 +1,1086 @@
+// Copyright 2013 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//
+// Author: dsites@google.com (Dick Sites)
+//
+
+
+#include "getonescriptspan.h"
+#include <string.h>
+
+#include "fixunicodevalue.h"
+#include "lang_script.h"
+#include "port.h"
+#include "utf8statetable.h"
+
+#include "utf8prop_lettermarkscriptnum.h"
+#include "utf8repl_lettermarklower.h"
+#include "utf8scannot_lettermarkspecial.h"
+
+
+namespace CLD2 {
+
+// Alphabetical order for binary search, from
+// generated_entities.cc
+extern const int kNameToEntitySize;
+extern const CharIntPair kNameToEntity[];
+
+static const int kMaxUpToWordBoundary = 50;       // span < this make longer,
+                                                  // else make shorter
+static const int kMaxAdvanceToWordBoundary = 10;  // +/- this many bytes
+                                                  // to round to word boundary,
+                                                  // direction above
+
+static const char kSpecialSymbol[256] = {       // true for < > &
+  0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
+  0,0,0,0,0,0,1,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,1,0,1,0,
+  0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
+  0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
+
+  0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
+  0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
+  0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
+  0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
+};
+
+
+
+#define LT 0      // <
+#define GT 1      // >
+#define EX 2      // !
+#define HY 3      // -
+#define QU 4      // "
+#define AP 5      // '
+#define SL 6      // /
+#define S_ 7
+#define C_ 8
+#define R_ 9
+#define I_ 10
+#define P_ 11
+#define T_ 12
+#define Y_ 13
+#define L_ 14
+#define E_ 15
+#define CR 16     // <cr> or <lf>
+#define NL 17     // non-letter: ASCII whitespace, digit, punctuation
+#define PL 18     // possible letter, incl. &
+#define xx 19     // <unused>
+
+// Map byte to one of ~20 interesting categories for cheap tag parsing
+static const uint8 kCharToSub[256] = {
+  NL,NL,NL,NL, NL,NL,NL,NL, NL,NL,CR,NL, NL,CR,NL,NL,
+  NL,NL,NL,NL, NL,NL,NL,NL, NL,NL,NL,NL, NL,NL,NL,NL,
+  NL,EX,QU,NL, NL,NL,PL,AP, NL,NL,NL,NL, NL,HY,NL,SL,
+  NL,NL,NL,NL, NL,NL,NL,NL, NL,NL,NL,NL, LT,NL,GT,NL,
+
+  PL,PL,PL,C_, PL,E_,PL,PL, PL,I_,PL,PL, L_,PL,PL,PL,
+  P_,PL,R_,S_, T_,PL,PL,PL, PL,Y_,PL,NL, NL,NL,NL,NL,
+  PL,PL,PL,C_, PL,E_,PL,PL, PL,I_,PL,PL, L_,PL,PL,PL,
+  P_,PL,R_,S_, T_,PL,PL,PL, PL,Y_,PL,NL, NL,NL,NL,NL,
+
+  NL,NL,NL,NL, NL,NL,NL,NL, NL,NL,NL,NL, NL,NL,NL,NL,
+  NL,NL,NL,NL, NL,NL,NL,NL, NL,NL,NL,NL, NL,NL,NL,NL,
+  NL,NL,NL,NL, NL,NL,NL,NL, NL,NL,NL,NL, NL,NL,NL,NL,
+  NL,NL,NL,NL, NL,NL,NL,NL, NL,NL,NL,NL, NL,NL,NL,NL,
+
+  PL,PL,PL,PL, PL,PL,PL,PL, PL,PL,PL,PL, PL,PL,PL,PL,
+  PL,PL,PL,PL, PL,PL,PL,PL, PL,PL,PL,PL, PL,PL,PL,PL,
+  PL,PL,PL,PL, PL,PL,PL,PL, PL,PL,PL,PL, PL,PL,PL,PL,
+  PL,PL,PL,PL, PL,PL,PL,PL, PL,PL,PL,PL, PL,PL,PL,PL,
+};
+
+#undef LT
+#undef GT
+#undef EX
+#undef HY
+#undef QU
+#undef AP
+#undef SL
+#undef S_
+#undef C_
+#undef R_
+#undef I_
+#undef P_
+#undef T_
+#undef Y_
+#undef L_
+#undef E_
+#undef CR
+#undef NL
+#undef PL
+#undef xx
+
+
+#define OK 0
+#define X_ 1
+
+
+static const int kMaxExitStateLettersMarksOnly = 1;
+static const int kMaxExitStateAllText = 2;
+
+
+// State machine to do cheap parse of non-letter strings incl. tags
+// advances <tag>
+//          |    |
+// advances <tag> ... </tag>  for <script> <style>
+//          |               |
+// advances <!-- ... <tag> ... -->
+//          |                     |
+// advances <tag
+//          ||  (0)
+// advances <tag <tag2>
+//          ||  (0)
+//
+// We start in state [0] at a non-letter and make at least one transition
+// When scanning for just letters, arriving back at state [0] or [1] exits
+//   the state machine.
+// When scanning for any non-tag text, arriving at state [2] also exits
+static const uint8 kTagParseTbl_0[] = {
+// <  >  !  -   "  '  /  S   C  R  I  P   T  Y  L  E  CR NL PL xx
+   3, 2, 2, 2,  2, 2, 2,OK, OK,OK,OK,OK, OK,OK,OK,OK,  2, 2,OK,X_, // [0] OK    exit state
+  X_,X_,X_,X_, X_,X_,X_,X_, X_,X_,X_,X_, X_,X_,X_,X_, X_,X_,X_,X_, // [1] error exit state
+   3, 2, 2, 2,  2, 2, 2,OK, OK,OK,OK,OK, OK,OK,OK,OK,  2, 2,OK,X_, // [2] NL*   [exit state]
+  X_, 2, 4, 9, 10,11, 9,13,  9, 9, 9, 9,  9, 9, 9, 9,  9, 9, 9,X_, // [3] <
+  X_, 2, 9, 5, 10,11, 9, 9,  9, 9, 9, 9,  9, 9, 9, 9,  9, 9, 9,X_, // [4] <!
+  X_, 2, 9, 6, 10,11, 9, 9,  9, 9, 9, 9,  9, 9, 9, 9,  9, 9, 9,X_, // [5] <!-
+   6, 6, 6, 7,  6, 6, 6, 6,  6, 6, 6, 6,  6, 6, 6, 6,  6, 6, 6,X_, // [6] <!--.*
+   6, 6, 6, 8,  6, 6, 6, 6,  6, 6, 6, 6,  6, 6, 6, 6,  6, 6, 6,X_, // [7] <!--.*-
+   6, 2, 6, 8,  6, 6, 6, 6,  6, 6, 6, 6,  6, 6, 6, 6,  6, 6, 6,X_, // [8] <!--.*--
+  X_, 2, 9, 9, 10,11, 9, 9,  9, 9, 9, 9,  9, 9, 9, 9,  9, 9, 9,X_, // [9] <.*
+  10,10,10,10,  9,10,10,10, 10,10,10,10, 10,10,10,10, 12,10,10,X_, // [10] <.*"
+  11,11,11,11, 11, 9,11,11, 11,11,11,11, 11,11,11,11, 12,11,11,X_, // [11] <.*'
+  X_, 2,12,12, 12,12,12,12, 12,12,12,12, 12,12,12,12, 12,12,12,X_, // [12] <.* no " '
+
+// <  >  !  -   "  '  /  S   C  R  I  P   T  Y  L  E  CR NL PL xx
+  X_, 2, 9, 9, 10,11, 9, 9, 14, 9, 9, 9, 28, 9, 9, 9,  9, 9, 9,X_, // [13] <S
+  X_, 2, 9, 9, 10,11, 9, 9,  9,15, 9, 9,  9, 9, 9, 9,  9, 9, 9,X_, // [14] <SC
+  X_, 2, 9, 9, 10,11, 9, 9,  9, 9,16, 9,  9, 9, 9, 9,  9, 9, 9,X_, // [15] <SCR
+  X_, 2, 9, 9, 10,11, 9, 9,  9, 9, 9,17,  9, 9, 9, 9,  9, 9, 9,X_, // [16] <SCRI
+  X_, 2, 9, 9, 10,11, 9, 9,  9, 9, 9, 9, 18, 9, 9, 9,  9, 9, 9,X_, // [17] <SCRIP
+  X_,19, 9, 9, 10,11, 9, 9,  9, 9, 9, 9,  9, 9, 9, 9, 19,19, 9,X_, // [18] <SCRIPT
+  20,19,19,19, 19,19,19,19, 19,19,19,19, 19,19,19,19, 19,19,19,X_, // [19] <SCRIPT .*
+  19,19,19,19, 19,19,21,19, 19,19,19,19, 19,19,19,19, 19,19,19,X_, // [20] <SCRIPT .*<
+  19,19,19,19, 19,19,19,22, 19,19,19,19, 19,19,19,19, 21,21,19,X_, // [21] <SCRIPT .*</ allow SP CR LF
+  19,19,19,19, 19,19,19,19, 23,19,19,19, 19,19,19,19, 19,19,19,X_, // [22] <SCRIPT .*</S
+  19,19,19,19, 19,19,19,19, 19,24,19,19, 19,19,19,19, 19,19,19,X_, // [23] <SCRIPT .*</SC
+  19,19,19,19, 19,19,19,19, 19,19,25,19, 19,19,19,19, 19,19,19,X_, // [24] <SCRIPT .*</SCR
+  19,19,19,19, 19,19,19,19, 19,19,19,26, 19,19,19,19, 19,19,19,X_, // [25] <SCRIPT .*</SCRI
+  19,19,19,19, 19,19,19,19, 19,19,19,19, 27,19,19,19, 19,19,19,X_, // [26] <SCRIPT .*</SCRIP
+  19, 2,19,19, 19,19,19,19, 19,19,19,19, 19,19,19,19, 19,19,19,X_, // [27] <SCRIPT .*</SCRIPT
+
+// <  >  !  -   "  '  /  S   C  R  I  P   T  Y  L  E  CR NL PL xx
+  X_, 2, 9, 9, 10,11, 9, 9,  9, 9, 9, 9,  9,29, 9, 9,  9, 9, 9,X_, // [28] <ST
+  X_, 2, 9, 9, 10,11, 9, 9,  9, 9, 9, 9,  9, 9,30, 9,  9, 9, 9,X_, // [29] <STY
+  X_, 2, 9, 9, 10,11, 9, 9,  9, 9, 9, 9,  9, 9, 9,31,  9, 9, 9,X_, // [30] <STYL
+  X_,32, 9, 9, 10,11, 9, 9,  9, 9, 9, 9,  9, 9, 9, 9, 32,32, 9,X_, // [31] <STYLE
+  33,32,32,32, 32,32,32,32, 32,32,32,32, 32,32,32,32, 32,32,32,X_, // [32] <STYLE .*
+  32,32,32,32, 32,32,34,32, 32,32,32,32, 32,32,32,32, 32,32,32,X_, // [33] <STYLE .*<
+  32,32,32,32, 32,32,32,35, 32,32,32,32, 32,32,32,32, 34,34,32,X_, // [34] <STYLE .*</ allow SP CR LF
+  32,32,32,32, 32,32,32,32, 32,32,32,32, 36,32,32,32, 32,32,32,X_, // [35] <STYLE .*</S
+  32,32,32,32, 32,32,32,32, 32,32,32,32, 32,37,32,32, 32,32,32,X_, // [36] <STYLE .*</ST
+  32,32,32,32, 32,32,32,32, 32,32,32,32, 32,32,38,32, 32,32,32,X_, // [37] <STYLE .*</STY
+  32,32,32,32, 32,32,32,32, 32,32,32,32, 32,32,32,39, 32,32,32,X_, // [38] <STYLE .*</STYL
+  32, 2,32,32, 32,32,32,32, 32,32,32,32, 32,32,32,32, 32,32,32,X_, // [39] <STYLE .*</STYLE
+};
+
+#undef OK
+#undef X_
+
+enum
+{
+  UTFmax        = 4,            // maximum bytes per rune
+  Runesync      = 0x80,         // cannot represent part of a UTF sequence (<)
+  Runeself      = 0x80,         // rune and UTF sequences are the same (<)
+  Runeerror     = 0xFFFD,       // decoding error in UTF
+  Runemax       = 0x10FFFF,     // maximum rune value
+};
+
+// Debugging. Not thread safe.
+static char gDisplayPiece[32];
+const uint8 gCharlen[16] = {1,1,1,1, 1,1,1,1, 1,1,1,1, 2,2,3,4};
+char* DisplayPiece(const char* next_byte_, int byte_length_) {
+  // Copy up to 8 UTF-8 chars to buffer
+  int k = 0;    // byte count
+  int n = 0;    // character count
+  for (int i = 0; i < byte_length_; ++i) {
+    char c = next_byte_[i];
+    if ((c & 0xc0) != 0x80) {
+      // Beginning of a UTF-8 character
+      int charlen = gCharlen[static_cast<uint8>(c) >> 4];
+      if (i + charlen > byte_length_) {break;} // Not enough room for full char
+      if (k >= (32 - 7)) {break;}   // Not necessarily enough room
+      if (n >= 8) {break;}          // Enough characters already
+      ++n;
+    }
+    if (c == '<') {
+      memcpy(&gDisplayPiece[k], "&lt;", 4); k += 4;
+    } else if (c == '>') {
+      memcpy(&gDisplayPiece[k], "&gt;", 4); k += 4;
+    } else if (c == '&') {
+      memcpy(&gDisplayPiece[k], "&amp;", 5); k += 5;
+    } else if (c == '\'') {
+      memcpy(&gDisplayPiece[k], "&apos;", 6); k += 6;
+    } else if (c == '"') {
+      memcpy(&gDisplayPiece[k], "&quot;", 6); k += 6;
+    } else {
+      gDisplayPiece[k++] = c;
+    }
+  }
+  gDisplayPiece[k++] = '\0';
+  return gDisplayPiece;
+}
+
+
+
+// runetochar copies (encodes) one rune, pointed to by r, to at most
+// UTFmax bytes starting at s and returns the number of bytes generated.
+int runetochar(char *str, const char32 *rune) {
+  // Convert to unsigned for range check.
+  unsigned long c;
+
+  // 1 char 00-7F
+  c = *rune;
+  if(c <= 0x7F) {
+    str[0] = c;
+    return 1;
+  }
+
+  // 2 char 0080-07FF
+  if(c <= 0x07FF) {
+    str[0] = 0xC0 | (c >> 1*6);
+    str[1] = 0x80 | (c & 0x3F);
+    return 2;
+  }
+
+  // Range check
+  if (c > Runemax) {
+    c = Runeerror;
+  }
+
+  // 3 char 0800-FFFF
+  if (c <= 0xFFFF) {
+    str[0] = 0xE0 |  (c >> 2*6);
+    str[1] = 0x80 | ((c >> 1*6) & 0x3F);
+    str[2] = 0x80 |  (c & 0x3F);
+    return 3;
+  }
+
+  // 4 char 10000-1FFFFF
+  str[0] = 0xF0 | (c >> 3*6);
+  str[1] = 0x80 | ((c >> 2*6) & 0x3F);
+  str[2] = 0x80 | ((c >> 1*6) & 0x3F);
+  str[3] = 0x80 | (c & 0x3F);
+  return 4;
+}
+
+
+
+// Useful for converting an entity to an ascii value.
+// RETURNS unicode value, or -1 if entity isn't valid.  Don't include & or ;
+int LookupEntity(const char* entity_name, int entity_len) {
+  // Make a C string
+  if (entity_len >= 16) {return -1;}    // All real entities are shorter
+  char temp[16];
+  memcpy(temp, entity_name, entity_len);
+  temp[entity_len] = '\0';
+  int match = BinarySearch(temp, 0, kNameToEntitySize, kNameToEntity);
+  if (match >= 0) {return kNameToEntity[match].i;}
+  return -1;
+}
+
+bool ascii_isdigit(char c) {
+  return ('0' <= c) && (c <= '9');
+}
+bool ascii_isxdigit(char c) {
+  if (('0' <= c) && (c <= '9')) {return true;}
+  if (('a' <= c) && (c <= 'f')) {return true;}
+  if (('A' <= c) && (c <= 'F')) {return true;}
+  return false;
+}
+bool ascii_isalnum(char c) {
+  if (('0' <= c) && (c <= '9')) {return true;}
+  if (('a' <= c) && (c <= 'z')) {return true;}
+  if (('A' <= c) && (c <= 'Z')) {return true;}
+  return false;
+}
+int hex_digit_to_int(char c) {
+  if (('0' <= c) && (c <= '9')) {return c - '0';}
+  if (('a' <= c) && (c <= 'f')) {return c - 'a' + 10;}
+  if (('A' <= c) && (c <= 'F')) {return c - 'A' + 10;}
+  return 0;
+}
+
+static int32 strto32_base10(const char* nptr, const char* limit,
+                            const char **endptr) {
+  *endptr = nptr;
+  while (nptr < limit && *nptr == '0') {
+    ++nptr;
+  }
+  if (nptr == limit || !ascii_isdigit(*nptr))
+    return -1;
+  const char* end_digits_run = nptr;
+  while (end_digits_run < limit && ascii_isdigit(*end_digits_run)) {
+    ++end_digits_run;
+  }
+  *endptr = end_digits_run;
+  const int num_digits = end_digits_run - nptr;
+  // kint32max == 2147483647.
+  if (num_digits < 9 ||
+      (num_digits == 10 && memcmp(nptr, "2147483647", 10) <= 0)) {
+    int value = 0;
+    for (; nptr < end_digits_run; ++nptr) {
+      value *= 10;
+      value += *nptr - '0';
+    }
+    // Overflow past the last valid unicode codepoint
+    // (0x10ffff) is converted to U+FFFD by FixUnicodeValue().
+    return FixUnicodeValue(value);
+  } else {
+    // Overflow: can't fit in an int32;
+    // returns the replacement character 0xFFFD.
+    return 0xFFFD;
+  }
+}
+
+static int32 strto32_base16(const char* nptr, const char* limit,
+                            const char **endptr) {
+  *endptr = nptr;
+  while (nptr < limit && *nptr == '0') {
+    ++nptr;
+  }
+  if (nptr == limit || !ascii_isxdigit(*nptr)) {
+    return -1;
+  }
+  const char* end_xdigits_run = nptr;
+  while (end_xdigits_run < limit && ascii_isxdigit(*end_xdigits_run)) {
+    ++end_xdigits_run;
+  }
+  *endptr = end_xdigits_run;
+  const int num_xdigits = end_xdigits_run - nptr;
+  // kint32max == 0x7FFFFFFF.
+  if (num_xdigits < 8 || (num_xdigits == 8 && nptr[0] < '8')) {
+    int value = 0;
+    for (; nptr < end_xdigits_run; ++nptr) {
+      value <<= 4;
+      value += hex_digit_to_int(*nptr);
+    }
+    // Overflow past the last valid unicode codepoint
+    // (0x10ffff) is converted to U+FFFD by FixUnicodeValue().
+    return FixUnicodeValue(value);
+  } else {
+    // Overflow: can't fit in an int32;
+    // returns the replacement character 0xFFFD.
+    return 0xFFFD;
+  }
+}
+
+// Unescape the current character pointed to by src.  SETS the number
+// of chars read for the conversion (in UTF8).  If src isn't a valid entity,
+// just consume the & and RETURN -1.  If src doesn't point to & -- which it
+// should -- set src_consumed to 0 and RETURN -1.
+int ReadEntity(const char* src, int srcn, int* src_consumed) {
+  const char* const srcend = src + srcn;
+
+  if (srcn == 0 || *src != '&') {      // input should start with an ampersand
+    *src_consumed = 0;
+    return -1;
+  }
+  *src_consumed = 1;                   // we'll get the & at least
+
+  // The standards are a bit unclear on when an entity ends.  Certainly a ";"
+  // ends one, but spaces probably do too.  We follow the lead of both IE and
+  // Netscape, which as far as we can tell end numeric entities (1st case below)
+  // at any non-digit, and end character entities (2nd case) at any non-alnum.
+  const char* entstart, *entend;  // where the entity starts and ends
+  entstart = src + 1;             // read past the &
+  int entval;                     // UCS2 value of the entity
+  if ( *entstart == '#' ) {       // -- 1st case: numeric entity
+    if ( entstart + 2 >= srcend ) {
+      return -1;                  // no way a legitimate number could fit
+    } else if ( entstart[1] == 'x' || entstart[1] == 'X' ) {   // hex numeric
+      entval = strto32_base16(entstart + 2, srcend, &entend);
+    } else {                                  // decimal numeric entity
+      entval = strto32_base10(entstart+1, srcend, &entend);
+    }
+    if (entval == -1 || entend > srcend) {
+      return -1;                 // not entirely correct, but close enough
+    }
+  } else {                       // -- 2nd case: character entity
+    for (entend = entstart;
+         entend < srcend && ascii_isalnum(*entend);
+         ++entend ) {
+      // entity consists of alphanumeric chars
+    }
+    entval = LookupEntity(entstart, entend - entstart);
+    if (entval < 0) {
+      return -1;  // not a legal entity name
+    }
+    // Now we do a strange-seeming IE6-compatibility check: if entval is
+    // >= 256, it *must* be followed by a semicolon or it's not considered
+    // an entity.  The problem is lots of the newfangled entity names, like
+    // "lang", also occur in URL CGI arguments: "/search?q=test&lang=en".
+    // When these links are written in HTML, it would be really bad if the
+    // "&lang" were treated as an entity, which is what the spec says
+    // *should* happen (even when the HTML is inside an "A HREF" tag!)
+    // IE ignores the spec for these new, high-value entities, so we do too.
+    if ( entval >= 256 && !(entend < srcend && *entend == ';') ) {
+      return -1;                 // make non-;-terminated entity illegal
+    }
+  }
+
+  // Finally, figure out how much src was consumed
+  if ( entend < srcend && *entend == ';' ) {
+    entend++;                    // standard says ; terminator is special
+  }
+  *src_consumed = entend - src;
+  return entval;
+}
+
+
+// Src points to '&'
+// Writes entity value to dst. Returns take(src), put(dst) byte counts
+void EntityToBuffer(const char* src, int len, char* dst,
+                    int* tlen, int* plen) {
+  char32 entval = ReadEntity(src, len, tlen);
+
+  // ReadEntity does this already: entval = FixUnicodeValue(entval);
+
+  // Convert UTF-32 to UTF-8
+  if (entval > 0) {
+    *plen = runetochar(dst, &entval);
+  } else {
+    // Illegal entity; ignore the '&'
+    *tlen = 1;
+    *plen = 0;
+  }
+}
+
+// Returns true if character is < > or &, none of which are letters
+bool inline IsSpecial(char c) {
+  if ((c & 0xe0) == 0x20) {
+    return kSpecialSymbol[static_cast<uint8>(c)];
+  }
+  return false;
+}
+
+// Quick Skip to next letter or < > & or to end of string (eos)
+// Always return is_letter for eos
+int ScanToLetterOrSpecial(const char* src, int len) {
+  int bytes_consumed;
+  StringPiece str(src, len);
+  UTF8GenericScan(&utf8scannot_lettermarkspecial_obj, str, &bytes_consumed);
+  return bytes_consumed;
+}
+
+
+
+
+// src points to non-letter, such as tag-opening '<'
+// Return length from here to next possible letter
+// On another < before >, return 1
+// advances <tag>
+//          |    |
+// advances <tag> ... </tag>  for <script> <style>
+//          |               |
+// advances <!-- ... <tag> ... -->
+//          |                     |
+// advances <tag
+//          |    | end of string
+// advances <tag <tag2>
+//          ||
+int ScanToPossibleLetter(const char* isrc, int len, int max_exit_state) {
+  const uint8* src = reinterpret_cast<const uint8*>(isrc);
+  const uint8* srclimit = src + len;
+  const uint8* tagParseTbl = kTagParseTbl_0;
+  int e = 0;
+  while (src < srclimit) {
+    e = tagParseTbl[kCharToSub[*src++]];
+    if (e <= max_exit_state) {
+      // We overshot by one byte
+      --src;
+      break;
+    }
+    tagParseTbl = &kTagParseTbl_0[e * 20];
+  }
+
+  if (src >= srclimit) {
+    // We fell off the end of the text.
+    // It looks like the most common case for this is a truncated file, not
+    // mismatched angle brackets. So we pretend that the last char was '>'
+    return len;
+  }
+
+  // OK to be in state 0 or state 2 at exit
+  if ((e != 0) && (e != 2)) {
+    // Error, '<' followed by '<'
+    // We want to back up to first <, then advance by one byte past it
+    int offset = src - reinterpret_cast<const uint8*>(isrc);
+
+    // Backscan to first '<' and return enough length to just get past it
+    --offset;   // back up over the second '<', which caused us to stop
+    while ((0 < offset) && (isrc[offset] != '<')) {
+      // Find the first '<', which is unmatched
+      --offset;
+    }
+    // skip to just beyond first '<'
+    return offset + 1;
+  }
+
+  return src - reinterpret_cast<const uint8*>(isrc);
+}
+
+
+ScriptScanner::ScriptScanner(const char* buffer,
+                             int buffer_length,
+                             bool is_plain_text)
+  : start_byte_(buffer),
+  next_byte_(buffer),
+  next_byte_limit_(buffer + buffer_length),
+  byte_length_(buffer_length),
+  is_plain_text_(is_plain_text),
+  letters_marks_only_(true),
+  one_script_only_(true),
+  exit_state_(kMaxExitStateLettersMarksOnly) {
+    script_buffer_ = new char[kMaxScriptBuffer];
+    script_buffer_lower_ = new char[kMaxScriptLowerBuffer];
+    map2original_.Clear();    // map from script_buffer_ to buffer
+    map2uplow_.Clear();       // map from script_buffer_lower_ to script_buffer_
+}
+
+// Extended version to allow spans of any non-tag text and spans of mixed script
+ScriptScanner::ScriptScanner(const char* buffer,
+                             int buffer_length,
+                             bool is_plain_text,
+                             bool any_text,
+                             bool any_script)
+  : start_byte_(buffer),
+  next_byte_(buffer),
+  next_byte_limit_(buffer + buffer_length),
+  byte_length_(buffer_length),
+  is_plain_text_(is_plain_text),
+  letters_marks_only_(!any_text),
+  one_script_only_(!any_script),
+  exit_state_(any_text ? kMaxExitStateAllText : kMaxExitStateLettersMarksOnly) {
+    script_buffer_ = new char[kMaxScriptBuffer];
+    script_buffer_lower_ = new char[kMaxScriptLowerBuffer];
+    map2original_.Clear();    // map from script_buffer_ to buffer
+    map2uplow_.Clear();       // map from script_buffer_lower_ to script_buffer_
+}
+
+
+ScriptScanner::~ScriptScanner() {
+  delete[] script_buffer_;
+  delete[] script_buffer_lower_;
+}
+
+
+
+
+// Get to the first real non-tag letter or entity that is a letter
+// Sets script of that letter
+// Return len if no more letters
+int ScriptScanner::SkipToFrontOfSpan(const char* src, int len, int* script) {
+  int sc = UNKNOWN_ULSCRIPT;
+  int skip = 0;
+  int tlen, plen;
+
+  // Do run of non-letters (tag | &NL | NL)*
+  tlen = 0;
+  while (skip < len) {
+    // Do fast scan to next interesting byte
+    // int oldskip = skip;
+    skip += ScanToLetterOrSpecial(src + skip, len - skip);
+
+    // Check for no more letters/specials
+    if (skip >= len) {
+      // All done
+      *script = sc;
+      return len;
+    }
+
+    // We are at a letter, nonletter, tag, or entity
+    if (IsSpecial(src[skip]) && !is_plain_text_) {
+      if (src[skip] == '<') {
+        // Begining of tag; skip to end and go around again
+        tlen = ScanToPossibleLetter(src + skip, len - skip,
+                                    exit_state_);
+        sc = 0;
+      } else if (src[skip] == '>') {
+        // Unexpected end of tag; skip it and go around again
+        tlen = 1;         // Over the >
+        sc = 0;
+      } else if (src[skip] == '&') {
+        // Expand entity, no advance
+        char temp[4];
+        EntityToBuffer(src + skip, len - skip,
+                       temp, &tlen, &plen);
+        sc = GetUTF8LetterScriptNum(temp);
+      }
+    } else {
+      // Update 1..4 bytes
+      tlen = UTF8OneCharLen(src + skip);
+      sc = GetUTF8LetterScriptNum(src + skip);
+    }
+    if (sc != 0) {break;}           // Letter found
+    skip += tlen;                   // Else advance
+  }
+
+  *script = sc;
+  return skip;
+}
+
+
+// These are for ASCII-only tag names
+// Compare one letter uplow to c, ignoring case of uplowp
+inline bool EqCase(char uplow, char c) {
+  return (uplow | 0x20) == c;
+}
+
+// These are for ASCII-only tag names
+// Return true for space / < > etc. all less than 0x40
+inline bool NeqLetter(char c) {
+  return c < 0x40;
+}
+
+// These are for ASCII-only tag names
+// Return true for space \n false for \r
+inline bool WS(char c) {
+  return (c == ' ') || (c == '\n');
+}
+
+// Canonical CR or LF
+static const char LF = '\n';
+
+
+// The naive loop scans from next_byte_ to script_buffer_ until full.
+// But this can leave an awkward hard-to-identify short fragment at the
+// end of the input. We would prefer to make the next-to-last fragment
+// shorter and the last fragment longer.
+
+// Copy next run of non-tag characters to buffer [NUL terminated]
+// This just replaces tags with space or \n and removes entities.
+// Tags <br> <p> and <tr> are replaced with \n. Non-letter sequences
+// including \r or \n are replaced by \n. All other tags and skipped text
+// are replaced with ASCII space.
+//
+// Buffer ALWAYS has leading space and trailing space space space NUL
+bool ScriptScanner::GetOneTextSpan(LangSpan* span) {
+  span->text = script_buffer_;
+  span->text_bytes = 0;
+  span->offset = next_byte_ - start_byte_;
+  span->ulscript = UNKNOWN_ULSCRIPT;
+  span->lang = UNKNOWN_LANGUAGE;
+  span->truncated = false;
+
+  int put_soft_limit = kMaxScriptBytes - kWithinScriptTail;
+  if ((kMaxScriptBytes <= byte_length_) &&
+      (byte_length_ < (2 * kMaxScriptBytes))) {
+    // Try to split the last two fragments in half
+    put_soft_limit = byte_length_ / 2;
+  }
+
+  script_buffer_[0] = ' ';  // Always a space at front of output
+  script_buffer_[1] = '\0';
+  int take = 0;
+  int put = 1;              // Start after the initial space
+  int tlen, plen;
+
+  if (byte_length_ <= 0) {
+    return false;          // No more text to be found
+  }
+
+  // Go over alternating spans of text and tags,
+  // copying letters to buffer with single spaces for each run of non-letters
+  bool last_byte_was_space = false;
+  while (take < byte_length_) {
+    char c = next_byte_[take];
+    if (c == '\r') {c = LF;}      // Canonical CR or LF
+    if (c == '\n') {c = LF;}      // Canonical CR or LF
+
+    if (IsSpecial(c) && !is_plain_text_) {
+      if (c == '<') {
+        // Replace tag with space
+        c = ' ';                      // for almost-full test below
+        // or if <p> <br> <tr>, replace with \n
+        if (take < (byte_length_ - 3)) {
+          if (EqCase(next_byte_[take + 1], 'p') &&
+              NeqLetter(next_byte_[take + 2])) {
+            c = LF;
+          }
+          if (EqCase(next_byte_[take + 1], 'b') &&
+              EqCase(next_byte_[take + 2], 'r') &&
+              NeqLetter(next_byte_[take + 3])) {
+            c = LF;
+          }
+          if (EqCase(next_byte_[take + 1], 't') &&
+              EqCase(next_byte_[take + 2], 'r') &&
+              NeqLetter(next_byte_[take + 3])) {
+            c = LF;
+          }
+        }
+        // Begining of tag; skip to end and go around again
+        tlen = 1 + ScanToPossibleLetter(next_byte_ + take, byte_length_ - take,
+                                    exit_state_);
+        // Copy one byte, compressing spaces
+        if (!last_byte_was_space || !WS(c)) {
+          script_buffer_[put++] = c;      // Advance dest
+          last_byte_was_space = WS(c);
+        }
+      } else if (c == '>') {
+        // Unexpected end of tag; copy it and go around again
+        tlen = 1;         // Over the >
+        script_buffer_[put++] = c;    // Advance dest
+      } else if (c == '&') {
+        // Expand entity, no advance
+        EntityToBuffer(next_byte_ + take, byte_length_ - take,
+                       script_buffer_ + put, &tlen, &plen);
+        put += plen;                  // Advance dest
+      }
+      take += tlen;                   // Advance source
+    } else {
+      // Copy one byte, compressing spaces
+      if (!last_byte_was_space || !WS(c)) {
+        script_buffer_[put++] = c;      // Advance dest
+        last_byte_was_space = WS(c);
+      }
+      ++take;                         // Advance source
+    }
+
+    if (WS(c) &&
+        (put >= put_soft_limit)) {
+      // Buffer is almost full
+      span->truncated = true;
+      break;
+    }
+    if (put >= kMaxScriptBytes) {
+      // Buffer is completely full
+      span->truncated = true;
+      break;
+    }
+  }
+
+  // Almost done. Back up to a character boundary if needed
+  while ((0 < take) && ((next_byte_[take] & 0xc0) == 0x80)) {
+    // Back up over continuation byte
+    --take;
+    --put;
+  }
+
+  // Update input position
+  next_byte_ += take;
+  byte_length_ -= take;
+
+  // Put four more spaces/NUL. Worst case is abcd _ _ _ \0
+  //                          kMaxScriptBytes |   | put
+  script_buffer_[put + 0] = ' ';
+  script_buffer_[put + 1] = ' ';
+  script_buffer_[put + 2] = ' ';
+  script_buffer_[put + 3] = '\0';
+
+  span->text_bytes = put;       // Does not include the last four chars above
+  return true;
+}
+
+
+// Copy next run of same-script non-tag letters to buffer [NUL terminated]
+// Buffer ALWAYS has leading space and trailing space space space NUL
+bool ScriptScanner::GetOneScriptSpan(LangSpan* span) {
+  if (!letters_marks_only_) {
+    // Return non-tag text, including punctuation and digits
+    return GetOneTextSpan(span);
+  }
+
+  span->text = script_buffer_;
+  span->text_bytes = 0;
+  span->offset = next_byte_ - start_byte_;
+  span->ulscript = UNKNOWN_ULSCRIPT;
+  span->lang = UNKNOWN_LANGUAGE;
+  span->truncated = false;
+
+  // struct timeval script_start, script_mid, script_end;
+
+  int put_soft_limit = kMaxScriptBytes - kWithinScriptTail;
+  if ((kMaxScriptBytes <= byte_length_) &&
+      (byte_length_ < (2 * kMaxScriptBytes))) {
+    // Try to split the last two fragments in half
+    put_soft_limit = byte_length_ / 2;
+  }
+
+
+  int spanscript;           // The script of this span
+  int sc = UNKNOWN_ULSCRIPT;  // The script of next character
+  int tlen = 0;
+  int plen = 0;
+
+  script_buffer_[0] = ' ';  // Always a space at front of output
+  script_buffer_[1] = '\0';
+  int take = 0;
+  int put = 1;              // Start after the initial space
+
+  // Build offsets from span->text back to start_byte_ + span->offset
+  // This mapping reflects deletion of non-letters, expansion of
+  // entities, etc.
+  map2original_.Clear();
+  map2original_.Delete(span->offset);   // So that MapBack(0) gives offset
+
+  // Get to the first real non-tag letter or entity that is a letter
+  int skip = SkipToFrontOfSpan(next_byte_, byte_length_, &spanscript);
+  next_byte_ += skip;
+  byte_length_ -= skip;
+
+  if (skip != 1) {
+    map2original_.Delete(skip);
+    map2original_.Insert(1);
+  } else {
+    map2original_.Copy(1);
+  }
+  if (byte_length_ <= 0) {
+    map2original_.Reset();
+    return false;               // No more letters to be found
+  }
+
+  // There is at least one letter, so we know the script for this span
+  span->ulscript = (ULScript)spanscript;
+
+
+  // Go over alternating spans of same-script letters and non-letters,
+  // copying letters to buffer with single spaces for each run of non-letters
+  while (take < byte_length_) {
+    // Copy run of letters in same script (&LS | LS)*
+    int letter_count = 0;              // Keep track of word length
+    bool need_break = false;
+
+    while (take < byte_length_) {
+      // We are at a letter, nonletter, tag, or entity
+      if (IsSpecial(next_byte_[take]) && !is_plain_text_) {
+        if (next_byte_[take] == '<') {
+          // Begining of tag
+          sc = 0;
+          break;
+        } else if (next_byte_[take] == '>') {
+          // Unexpected end of tag
+          sc = 0;
+          break;
+        } else if (next_byte_[take] == '&') {
+          // Copy entity, no advance
+          EntityToBuffer(next_byte_ + take, byte_length_ - take,
+                         script_buffer_ + put, &tlen, &plen);
+          sc = GetUTF8LetterScriptNum(script_buffer_ + put);
+        }
+      } else {
+        // Real letter, safely copy up to 4 bytes, increment by 1..4
+        // Will update by 1..4 bytes at Advance, below
+        tlen = plen = UTF8OneCharLen(next_byte_ + take);
+        if (take < (byte_length_ - 3)) {
+          // X86 fast case, does unaligned load/store
+          UNALIGNED_STORE32(script_buffer_ + put,
+                            UNALIGNED_LOAD32(next_byte_ + take));
+
+        } else {
+          // Slow case, happens 1-3 times per input document
+          memcpy(script_buffer_ + put, next_byte_ + take, plen);
+        }
+        sc = GetUTF8LetterScriptNum(next_byte_ + take);
+      }
+
+      // Allow continue across a single letter in a different script:
+      // A B D = three scripts, c = common script, i = inherited script,
+      // - = don't care, ( = take position before the += below
+      //  AAA(A-    continue
+      //
+      //  AAA(BA    continue
+      //  AAA(BB    break
+      //  AAA(Bc    continue (breaks after B)
+      //  AAA(BD    break
+      //  AAA(Bi    break
+      //
+      //  AAA(c-    break
+      //
+      //  AAA(i-    continue
+      //
+
+      if ((sc != spanscript) && (sc != ULScript_Inherited)) {
+        // Might need to break this script span
+        if (sc == ULScript_Common) {
+          need_break = true;
+        } else {
+          // Look at next following character, ignoring entity as Common
+          int sc2 = GetUTF8LetterScriptNum(next_byte_ + take + tlen);
+          if ((sc2 != ULScript_Common) && (sc2 != spanscript)) {
+            // We found a non-trivial change of script
+            if (one_script_only_) {
+              need_break = true;
+            }
+          }
+        }
+      }
+      if (need_break) {break;}  // Non-letter or letter in wrong script
+
+      take += tlen;                   // Advance
+      put += plen;                    // Advance
+
+      // Update the offset map to reflect take/put lengths
+      if (tlen == plen) {
+        map2original_.Copy(tlen);
+      } else if (tlen < plen) {
+        map2original_.Copy(tlen);
+        map2original_.Insert(plen - tlen);
+      } else {    // plen < tlen
+        map2original_.Copy(plen);
+        map2original_.Delete(tlen - plen);
+      }
+
+      ++letter_count;
+      if (put >= kMaxScriptBytes) {
+        // Buffer is full
+        span->truncated = true;
+        break;
+      }
+    }     // End while letters
+
+    // Do run of non-letters (tag | &NL | NL)*
+    while (take < byte_length_) {
+      // Do fast scan to next interesting byte
+      tlen = ScanToLetterOrSpecial(next_byte_ + take, byte_length_ - take);
+      take += tlen;
+      map2original_.Delete(tlen);
+      if (take >= byte_length_) {break;}    // Might have scanned to end
+
+      // We are at a letter, nonletter, tag, or entity
+      if (IsSpecial(next_byte_[take]) && !is_plain_text_) {
+        if (next_byte_[take] == '<') {
+          // Begining of tag; skip to end and go around again
+          tlen = ScanToPossibleLetter(next_byte_ + take, byte_length_ - take,
+                                      exit_state_);
+          sc = 0;
+        } else if (next_byte_[take] == '>') {
+          // Unexpected end of tag; skip it and go around again
+          tlen = 1;         // Over the >
+          sc = 0;
+        } else if (next_byte_[take] == '&') {
+          // Expand entity, no advance
+          EntityToBuffer(next_byte_ + take, byte_length_ - take,
+                         script_buffer_ + put, &tlen, &plen);
+          sc = GetUTF8LetterScriptNum(script_buffer_ + put);
+        }
+      } else {
+        // Update 1..4
+        tlen = UTF8OneCharLen(next_byte_ + take);
+        sc = GetUTF8LetterScriptNum(next_byte_ + take);
+      }
+      if (sc != 0) {break;}           // Letter found
+      take += tlen;                   // Else advance
+      map2original_.Delete(tlen);
+    }     // End while not-letters
+
+    script_buffer_[put++] = ' ';
+    map2original_.Insert(1);
+
+    // Letter in wrong script ?
+    if ((sc != spanscript) && (sc != ULScript_Inherited)) {break;}
+    if (put >= put_soft_limit) {
+      // Buffer is almost full
+      span->truncated = true;
+      break;
+    }
+  }
+
+  // Almost done. Back up to a character boundary if needed
+  while ((0 < take) && (take < byte_length_) &&
+         ((next_byte_[take] & 0xc0) == 0x80)) {
+    // Back up over continuation byte
+    --take;
+    --put;
+  }
+
+  // Update input position
+  next_byte_ += take;
+  byte_length_ -= take;
+
+  // Put four more spaces/NUL. Worst case is abcd _ _ _ \0
+  //                          kMaxScriptBytes |   | put
+  script_buffer_[put + 0] = ' ';
+  script_buffer_[put + 1] = ' ';
+  script_buffer_[put + 2] = ' ';
+  script_buffer_[put + 3] = '\0';
+  map2original_.Insert(4);
+  map2original_.Reset();
+
+  span->text_bytes = put;       // Does not include the last four chars above
+  return true;
+}
+
+// Force Latin, Cyrillic, Armenian, Greek scripts to be lowercase
+// List changes with each version of Unicode, so just always lowercase
+// Unicode 6.2.0:
+//   ARMENIAN COPTIC CYRILLIC DESERET GEORGIAN GLAGOLITIC GREEK LATIN
+void ScriptScanner::LowerScriptSpan(LangSpan* span) {
+  // If needed, lowercase all the text. If we do it sooner, might miss
+  // lowercasing an entity such as &Aacute;
+  // We only need to do this for Latn and Cyrl scripts
+  map2uplow_.Clear();
+  // Full Unicode lowercase of the entire buffer, including
+  // four pad bytes off the end.
+  // Ahhh. But the last byte 0x00 is not interchange-valid, so we do 3 pad
+  // bytes and put the 0x00 in explicitly.
+  // Build an offset map from script_buffer_lower_ back to script_buffer_
+  int consumed, filled, changed;
+  StringPiece istr(span->text, span->text_bytes + 3);
+  StringPiece ostr(script_buffer_lower_, kMaxScriptLowerBuffer);
+
+  UTF8GenericReplace(&utf8repl_lettermarklower_obj,
+                            istr, ostr, is_plain_text_,
+                            &consumed, &filled, &changed, &map2uplow_);
+  script_buffer_lower_[filled] = '\0';
+  span->text = script_buffer_lower_;
+  span->text_bytes = filled - 3;
+  map2uplow_.Reset();
+}
+
+// Copy next run of same-script non-tag letters to buffer [NUL terminated]
+// Force Latin, Cyrillic, Greek scripts to be lowercase
+// Buffer ALWAYS has leading space and trailing space space space NUL
+bool ScriptScanner::GetOneScriptSpanLower(LangSpan* span) {
+  bool ok = GetOneScriptSpan(span);
+  LowerScriptSpan(span);
+  return ok;
+}
+
+
+// Maps byte offset in most recent GetOneScriptSpan/Lower
+// span->text [0..text_bytes] into an additional byte offset from
+// span->offset, to get back to corresponding text in the original
+// input buffer.
+// text_offset must be the first byte
+// of a UTF-8 character, or just beyond the last character. Normally this
+// routine is called with the first byte of an interesting range and
+// again with the first byte of the following range.
+int ScriptScanner::MapBack(int text_offset) {
+  return map2original_.MapBack(map2uplow_.MapBack(text_offset));
+}
+
+
+// Gets lscript number for letters; always returns
+//   0 (common script) for non-letters
+int GetUTF8LetterScriptNum(const char* src) {
+  int srclen = UTF8OneCharLen(src);
+  const uint8* usrc = reinterpret_cast<const uint8*>(src);
+  return UTF8GenericPropertyTwoByte(&utf8prop_lettermarkscriptnum_obj,
+                                    &usrc, &srclen);
+}
+
+}  // namespace CLD2
+
+