/*
$Id: entities.c,v 1.18 2004/03/09 20:13:24 whmoseley Exp $
**
** This program and library is free software; you can redistribute it and/or
** modify it under the terms of the GNU (Library) General Public License
** as published by the Free Software Foundation; either version 2
** of the License, or any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
** GNU (Library) General Public License for more details.
**
** You should have received a copy of the GNU (Library) General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
**
** (c) Rainer.Scherg
**
**
** HTML entity routines (encoding, etc.):
**
** internally we are working with int/wchar_t to support unicode-16 for future
** enhancements of swish (rasc - Rainer Scherg).
**
** 2001-05-05  rasc   
**
*/




#include <stdlib.h>
#include "swish.h"
#include "mem.h"
#include "swstring.h"
#include "parse_conffile.h"
#include "config.h"
#include "entities.h"


/*
** ----------------------------------------------
** 
**  Private Module Data
**
** ----------------------------------------------
*/

/* Prototypes */

static int is_EOE(int c);       /* is_EndOfEntity */




#define  MAX_ENTITY_LEN  16     /* max chars after where we have to see the EOE */

/*
  -- Entity encoding/decoding structure 
*/

/* #define IS_EOE(a)   ((a)==';')    -- be W3C compliant */
#define IS_EOE(a)   (is_EOE((int)(a))) /* tolerant routine */


typedef struct
{
    char   *name;
    int     code;
}
CEntity;


/*
  -- CEntity Quick Hash structure
  -- works like follow: Array of ASCII-7 start "positions" (1. char of entity name)
  -- each entry can have a chain of pointers
  -- e.g.  &quote; --> ['q']->ce(.name .code)
  --                        ->next (chains all &q...;)
  -- lots of slots in the array will be empty because only [A-Z] and [a-z]
  -- is needed. But this cost hardly any memory, and is convenient...  (rasc)
  -- The hash sequence list will be re-sequenced during(!) usage (dynamic re-chaining).
  -- This brings down compares to almost 1 strcmp on entity checks. 
  --
  -- Warning: don't change this (ce_hasharray,etc) unless you know how this really works!
  --
  --   2001-05-14  Rainer.Scherg@rexroth.de (rasc)
  --
 */

struct CEHE
{                               /* CharEntityHashEntry */
    CEntity *ce;
    struct CEHE *next;
};

static struct CEHE *ce_hasharray[128];
static int ce_hasharray_initialized = 0;


/*
 -- the following table is retrieved from HTML4.x / SGML definitions
 -- of the W3C  (did it automated 2001-05-05).
 --   http://www.w3.org/TR/html40/
 --   http://www.w3.org/TR/1999/REC-html401-19991224/sgml/entities.html
 -- 
 -- 2001-05-07 Rainer.Scherg
*/


static CEntity entity_table[] = {
    {"quot", 0x0022},           /* quotation mark = APL quote, U+0022 ISOnum */
    {"amp", 0x0026},            /* ampersand, U+0026 ISOnum */
    {"apos", 0x0027},           /* single quote */
    {"lt", 0x003C},             /* less-than sign, U+003C ISOnum */
    {"gt", 0x003E},             /* greater-than sign, U+003E ISOnum */

    /*
     * A bunch still in the 128-255 range
     * Replacing them depend really on the charset used.
     */
    {"nbsp", 0x00A0},           /* no-break space = non-breaking space, U+00A0 ISOnum */
    {"iexcl", 0x00A1},          /* inverted exclamation mark, U+00A1 ISOnum */
    {"cent", 0x00A2},           /* cent sign, U+00A2 ISOnum */
    {"pound", 0x00A3},          /* pound sign, U+00A3 ISOnum */
    {"curren", 0x00A4},         /* currency sign, U+00A4 ISOnum */
    {"yen", 0x00A5},            /* yen sign = yuan sign, U+00A5 ISOnum */
    {"brvbar", 0x00A6},         /* broken bar = broken vertical bar, U+00A6 ISOnum */
    {"sect", 0x00A7},           /* section sign, U+00A7 ISOnum */
    {"uml", 0x00A8},            /* diaeresis = spacing diaeresis, U+00A8 ISOdia */
    {"copy", 0x00A9},           /* copyright sign, U+00A9 ISOnum */
    {"ordf", 0x00AA},           /* feminine ordinal indicator, U+00AA ISOnum */
    {"laquo", 0x00AB},          /* left-pointing double angle quotation mark = left pointing guillemet, U+00AB ISOnum */
    {"not", 0x00AC},            /* not sign, U+00AC ISOnum */
    {"shy", 0x00AD},            /* soft hyphen = discretionary hyphen, U+00AD ISOnum */
    {"reg", 0x00AE},            /* registered sign = registered trade mark sign, U+00AE ISOnum */
    {"macr", 0x00AF},           /* macron = spacing macron = overline = APL overbar, U+00AF ISOdia */
    {"deg", 0x00B0},            /* degree sign, U+00B0 ISOnum */
    {"plusmn", 0x00B1},         /* plus-minus sign = plus-or-minus sign, U+00B1 ISOnum */
    {"sup2", 0x00B2},           /* superscript two = superscript digit two = squared, U+00B2 ISOnum */
    {"sup3", 0x00B3},           /* superscript three = superscript digit three = cubed, U+00B3 ISOnum */
    {"acute", 0x00B4},          /* acute accent = spacing acute, U+00B4 ISOdia */
    {"micro", 0x00B5},          /* micro sign, U+00B5 ISOnum */
    {"para", 0x00B6},           /* pilcrow sign = paragraph sign, U+00B6 ISOnum */
    {"middot", 0x00B7},         /* middle dot = Georgian comma Greek middle dot, U+00B7 ISOnum */
    {"cedil", 0x00B8},          /* cedilla = spacing cedilla, U+00B8 ISOdia */
    {"sup1", 0x00B9},           /* superscript one = superscript digit one, U+00B9 ISOnum */
    {"ordm", 0x00BA},           /* masculine ordinal indicator, U+00BA ISOnum */
    {"raquo", 0x00BB},          /* right-pointing double angle quotation mark right pointing guillemet, U+00BB ISOnum */
    {"frac14", 0x00BC},         /* vulgar fraction one quarter = fraction one quarter, U+00BC ISOnum */
    {"frac12", 0x00BD},         /* vulgar fraction one half = fraction one half, U+00BD ISOnum */
    {"frac34", 0x00BE},         /* vulgar fraction three quarters = fraction three quarters, U+00BE ISOnum */
    {"iquest", 0x00BF},         /* inverted question mark = turned question mark, U+00BF ISOnum */
    {"Agrave", 0x00C0},         /* latin capital letter A with grave = latin capital letter A grave, U+00C0 ISOlat1 */
    {"Aacute", 0x00C1},         /* latin capital letter A with acute, U+00C1 ISOlat1 */
    {"Acirc", 0x00C2},          /* latin capital letter A with circumflex, U+00C2 ISOlat1 */
    {"Atilde", 0x00C3},         /* latin capital letter A with tilde, U+00C3 ISOlat1 */
    {"Auml", 0x00C4},           /* latin capital letter A with diaeresis, U+00C4 ISOlat1 */
    {"Aring", 0x00C5},          /* latin capital letter A with ring above = latin capital letter A ring, U+00C5 ISOlat1 */
    {"AElig", 0x00C6},          /* latin capital letter AE = latin capital ligature AE, U+00C6 ISOlat1 */
    {"Ccedil", 0x00C7},         /* latin capital letter C with cedilla, U+00C7 ISOlat1 */
    {"Egrave", 0x00C8},         /* latin capital letter E with grave, U+00C8 ISOlat1 */
    {"Eacute", 0x00C9},         /* latin capital letter E with acute, U+00C9 ISOlat1 */
    {"Ecirc", 0x00CA},          /* latin capital letter E with circumflex, U+00CA ISOlat1 */
    {"Euml", 0x00CB},           /* latin capital letter E with diaeresis, U+00CB ISOlat1 */
    {"Igrave", 0x00CC},         /* latin capital letter I with grave, U+00CC ISOlat1 */
    {"Iacute", 0x00CD},         /* latin capital letter I with acute, U+00CD ISOlat1 */
    {"Icirc", 0x00CE},          /* latin capital letter I with circumflex, U+00CE ISOlat1 */
    {"Iuml", 0x00CF},           /* latin capital letter I with diaeresis, U+00CF ISOlat1 */
    {"ETH", 0x00D0},            /* latin capital letter ETH, U+00D0 ISOlat1 */
    {"Ntilde", 0x00D1},         /* latin capital letter N with tilde, U+00D1 ISOlat1 */
    {"Ograve", 0x00D2},         /* latin capital letter O with grave, U+00D2 ISOlat1 */
    {"Oacute", 0x00D3},         /* latin capital letter O with acute, U+00D3 ISOlat1 */
    {"Ocirc", 0x00D4},          /* latin capital letter O with circumflex, U+00D4 ISOlat1 */
    {"Otilde", 0x00D5},         /* latin capital letter O with tilde, U+00D5 ISOlat1 */
    {"Ouml", 0x00D6},           /* latin capital letter O with diaeresis, U+00D6 ISOlat1 */
    {"times", 0x00D7},          /* multiplication sign, U+00D7 ISOnum */
    {"Oslash", 0x00D8},         /* latin capital letter O with stroke latin capital letter O slash, U+00D8 ISOlat1 */
    {"Ugrave", 0x00D9},         /* latin capital letter U with grave, U+00D9 ISOlat1 */
    {"Uacute", 0x00DA},         /* latin capital letter U with acute, U+00DA ISOlat1 */
    {"Ucirc", 0x00DB},          /* latin capital letter U with circumflex, U+00DB ISOlat1 */
    {"Uuml", 0x00DC},           /* latin capital letter U with diaeresis, U+00DC ISOlat1 */
    {"Yacute", 0x00DD},         /* latin capital letter Y with acute, U+00DD ISOlat1 */
    {"THORN", 0x00DE},          /* latin capital letter THORN, U+00DE ISOlat1 */
    {"szlig", 0x00DF},          /* latin small letter sharp s = ess-zed, U+00DF ISOlat1 */
    {"agrave", 0x00E0},         /* latin small letter a with grave = latin small letter a grave, U+00E0 ISOlat1 */
    {"aacute", 0x00E1},         /* latin small letter a with acute, U+00E1 ISOlat1 */
    {"acirc", 0x00E2},          /* latin small letter a with circumflex, U+00E2 ISOlat1 */
    {"atilde", 0x00E3},         /* latin small letter a with tilde, U+00E3 ISOlat1 */
    {"auml", 0x00E4},           /* latin small letter a with diaeresis, U+00E4 ISOlat1 */
    {"aring", 0x00E5},          /* latin small letter a with ring above = latin small letter a ring, U+00E5 ISOlat1 */
    {"aelig", 0x00E6},          /* latin small letter ae = latin small ligature ae, U+00E6 ISOlat1 */
    {"ccedil", 0x00E7},         /* latin small letter c with cedilla, U+00E7 ISOlat1 */
    {"egrave", 0x00E8},         /* latin small letter e with grave, U+00E8 ISOlat1 */
    {"eacute", 0x00E9},         /* latin small letter e with acute, U+00E9 ISOlat1 */
    {"ecirc", 0x00EA},          /* latin small letter e with circumflex, U+00EA ISOlat1 */
    {"euml", 0x00EB},           /* latin small letter e with diaeresis, U+00EB ISOlat1 */
    {"igrave", 0x00EC},         /* latin small letter i with grave, U+00EC ISOlat1 */
    {"iacute", 0x00ED},         /* latin small letter i with acute, U+00ED ISOlat1 */
    {"icirc", 0x00EE},          /* latin small letter i with circumflex, U+00EE ISOlat1 */
    {"iuml", 0x00EF},           /* latin small letter i with diaeresis, U+00EF ISOlat1 */
    {"eth", 0x00F0},            /* latin small letter eth, U+00F0 ISOlat1 */
    {"ntilde", 0x00F1},         /* latin small letter n with tilde, U+00F1 ISOlat1 */
    {"ograve", 0x00F2},         /* latin small letter o with grave, U+00F2 ISOlat1 */
    {"oacute", 0x00F3},         /* latin small letter o with acute, U+00F3 ISOlat1 */
    {"ocirc", 0x00F4},          /* latin small letter o with circumflex, U+00F4 ISOlat1 */
    {"otilde", 0x00F5},         /* latin small letter o with tilde, U+00F5 ISOlat1 */
    {"ouml", 0x00F6},           /* latin small letter o with diaeresis, U+00F6 ISOlat1 */
    {"divide", 0x00F7},         /* division sign, U+00F7 ISOnum */
    {"oslash", 0x00F8},         /* latin small letter o with stroke, = latin small letter o slash, U+00F8 ISOlat1 */
    {"ugrave", 0x00F9},         /* latin small letter u with grave, U+00F9 ISOlat1 */
    {"uacute", 0x00FA},         /* latin small letter u with acute, U+00FA ISOlat1 */
    {"ucirc", 0x00FB},          /* latin small letter u with circumflex, U+00FB ISOlat1 */
    {"uuml", 0x00FC},           /* latin small letter u with diaeresis, U+00FC ISOlat1 */
    {"yacute", 0x00FD},         /* latin small letter y with acute, U+00FD ISOlat1 */
    {"thorn", 0x00FE},          /* latin small letter thorn with, U+00FE ISOlat1 */
    {"yuml", 0x00FF},           /* latin small letter y with diaeresis, U+00FF ISOlat1 */

    {"OElig", 0x0152},          /* latin capital ligature OE, U+0152 ISOlat2 */
    {"oelig", 0x0153},          /* latin small ligature oe, U+0153 ISOlat2 */
    {"Scaron", 0x0160},         /* latin capital letter S with caron, U+0160 ISOlat2 */
    {"scaron", 0x0161},         /* latin small letter s with caron, U+0161 ISOlat2 */
    {"Yuml", 0x0178},           /* latin capital letter Y with diaeresis, U+0178 ISOlat2 */

    /*
     * Anything below should really be kept as entities references
     */

    /*
       -- Latin Extended-B
     */
    {"fnof", 0x0192},           /* latin small f with hook = function = florin, U+0192 ISOtech */

    {"circ", 0x02C6},           /* modifier letter circumflex accent, U+02C6 ISOpub */
    {"tilde", 0x02DC},          /* small tilde, U+02DC ISOdia */

    /*
       -- Greek symbols
     */
    {"Alpha", 0x0391},          /* greek capital letter alpha, U+0391 */
    {"Beta", 0x0392},           /* greek capital letter beta, U+0392 */
    {"Gamma", 0x0393},          /* greek capital letter gamma, U+0393 ISOgrk3 */
    {"Delta", 0x0394},          /* greek capital letter delta, U+0394 ISOgrk3 */
    {"Epsilon", 0x0395},        /* greek capital letter epsilon, U+0395 */
    {"Zeta", 0x0396},           /* greek capital letter zeta, U+0396 */
    {"Eta", 0x0397},            /* greek capital letter eta, U+0397 */
    {"Theta", 0x0398},          /* greek capital letter theta, U+0398 ISOgrk3 */
    {"Iota", 0x0399},           /* greek capital letter iota, U+0399 */
    {"Kappa", 0x039A},          /* greek capital letter kappa, U+039A */
    {"Lambda", 0x039B},         /* greek capital letter lambda, U+039B ISOgrk3 */
    {"Mu", 0x039C},             /* greek capital letter mu, U+039C */
    {"Nu", 0x039D},             /* greek capital letter nu, U+039D */
    {"Xi", 0x039E},             /* greek capital letter xi, U+039E ISOgrk3 */
    {"Omicron", 0x039F},        /* greek capital letter omicron, U+039F */
    {"Pi", 0x03A0},             /* greek capital letter pi, U+03A0 ISOgrk3 */
    {"Rho", 0x03A1},            /* greek capital letter rho, U+03A1 */
    /* -- there is no Sigmaf, and no U+03A2 character either */
    {"Sigma", 0x03A3},          /* greek capital letter sigma, U+03A3 ISOgrk3 */
    {"Tau", 0x03A4},            /* greek capital letter tau, U+03A4 */
    {"Upsilon", 0x03A5},        /* greek capital letter upsilon, U+03A5 ISOgrk3 */
    {"Phi", 0x03A6},            /* greek capital letter phi, U+03A6 ISOgrk3 */
    {"Chi", 0x03A7},            /* greek capital letter chi, U+03A7 */
    {"Psi", 0x03A8},            /* greek capital letter psi, U+03A8 ISOgrk3 */
    {"Omega", 0x03A9},          /* greek capital letter omega, U+03A9 ISOgrk3 */

    {"alpha", 0x03B1},          /* greek small letter alpha, U+03B1 ISOgrk3 */
    {"beta", 0x03B2},           /* greek small letter beta, U+03B2 ISOgrk3 */
    {"gamma", 0x03B3},          /* greek small letter gamma, U+03B3 ISOgrk3 */
    {"delta", 0x03B4},          /* greek small letter delta, U+03B4 ISOgrk3 */
    {"epsilon", 0x03B5},        /* greek small letter epsilon, U+03B5 ISOgrk3 */
    {"zeta", 0x03B6},           /* greek small letter zeta, U+03B6 ISOgrk3 */
    {"eta", 0x03B7},            /* greek small letter eta, U+03B7 ISOgrk3 */
    {"theta", 0x03B8},          /* greek small letter theta, U+03B8 ISOgrk3 */
    {"iota", 0x03B9},           /* greek small letter iota, U+03B9 ISOgrk3 */
    {"kappa", 0x03BA},          /* greek small letter kappa, U+03BA ISOgrk3 */
    {"lambda", 0x03BB},         /* greek small letter lambda, U+03BB ISOgrk3 */
    {"mu", 0x03BC},             /* greek small letter mu, U+03BC ISOgrk3 */
    {"nu", 0x03BD},             /* greek small letter nu, U+03BD ISOgrk3 */
    {"xi", 0x03BE},             /* greek small letter xi, U+03BE ISOgrk3 */
    {"omicron", 0x03BF},        /* greek small letter omicron, U+03BF NEW */
    {"pi", 0x03C0},             /* greek small letter pi, U+03C0 ISOgrk3 */
    {"rho", 0x03C1},            /* greek small letter rho, U+03C1 ISOgrk3 */
    {"sigmaf", 0x03C2},         /* greek small letter final sigma, U+03C2 ISOgrk3 */
    {"sigma", 0x03C3},          /* greek small letter sigma, U+03C3 ISOgrk3 */
    {"tau", 0x03C4},            /* greek small letter tau, U+03C4 ISOgrk3 */
    {"upsilon", 0x03C5},        /* greek small letter upsilon, U+03C5 ISOgrk3 */
    {"phi", 0x03C6},            /* greek small letter phi, U+03C6 ISOgrk3 */
    {"chi", 0x03C7},            /* greek small letter chi, U+03C7 ISOgrk3 */
    {"psi", 0x03C8},            /* greek small letter psi, U+03C8 ISOgrk3 */
    {"omega", 0x03C9},          /* greek small letter omega, U+03C9 ISOgrk3 */
    {"thetasym", 0x03D1},       /* greek small letter theta symbol, U+03D1 NEW */
    {"upsih", 0x03D2},          /* greek upsilon with hook symbol, U+03D2 NEW */
    {"piv", 0x03D6},            /* greek pi symbol, U+03D6 ISOgrk3 */

    {"ensp", 0x2002},           /* en space, U+2002 ISOpub */
    {"emsp", 0x2003},           /* em space, U+2003 ISOpub */
    {"thinsp", 0x2009},         /* thin space, U+2009 ISOpub */
    {"zwnj", 0x200C},           /* zero width non-joiner, U+200C NEW RFC 2070 */
    {"zwj", 0x200D},            /* zero width joiner, U+200D NEW RFC 2070 */
    {"lrm", 0x200E},            /* left-to-right mark, U+200E NEW RFC 2070 */
    {"rlm", 0x200F},            /* right-to-left mark, U+200F NEW RFC 2070 */
    {"ndash", 0x2013},          /* en dash, U+2013 ISOpub */
    {"mdash", 0x2014},          /* em dash, U+2014 ISOpub */
    {"lsquo", 0x2018},          /* left single quotation mark, U+2018 ISOnum */
    {"rsquo", 0x2019},          /* right single quotation mark, U+2019 ISOnum */
    {"sbquo", 0x201A},          /* single low-9 quotation mark, U+201A NEW */
    {"ldquo", 0x201C},          /* left double quotation mark, U+201C ISOnum */
    {"rdquo", 0x201D},          /* right double quotation mark, U+201D ISOnum */
    {"bdquo", 0x201E},          /* double low-9 quotation mark, U+201E NEW */
    {"dagger", 0x2020},         /* dagger, U+2020 ISOpub */
    {"Dagger", 0x2021},         /* double dagger, U+2021 ISOpub */

    {"bull", 0x2022},           /* bullet = black small circle, U+2022 ISOpub */
    {"hellip", 0x2026},         /* horizontal ellipsis = three dot leader, U+2026 ISOpub */

    {"permil", 0x2030},         /* per mille sign, U+2030 ISOtech */

    {"prime", 0x2032},          /* prime = minutes = feet, U+2032 ISOtech */
    {"Prime", 0x2033},          /* double prime = seconds = inches, U+2033 ISOtech */

    {"lsaquo", 0x2039},         /* single left-pointing angle quotation mark, U+2039 ISO proposed */
    {"rsaquo", 0x203A},         /* single right-pointing angle quotation mark, U+203A ISO proposed */

    {"oline", 0x203E},          /* overline = spacing overscore, U+203E NEW */
    {"frasl", 0x2044},          /* fraction slash, U+2044 NEW */

    {"euro", 0x20AC},           /* euro sign, U+20AC NEW */

    /* -- Letterlike Symbols  */
    {"image", 0x2111},          /* blackletter capital I = imaginary part, U+2111 ISOamso */
    {"weierp", 0x2118},         /* script capital P = power set = Weierstrass p, U+2118 ISOamso */
    {"real", 0x211C},           /* blackletter capital R = real part symbol, U+211C ISOamso */
    {"trade", 0x2122},          /* trade mark sign, U+2122 ISOnum */

    /* -- alef symbol is NOT the same as hebrew letter alef, U+05D0 */
    {"alefsym", 0x2135},        /* alef symbol = first transfinite cardinal, U+2135 NEW */

    /* -- Arrow Symbols  */
    {"larr", 0x2190},           /* leftwards arrow, U+2190 ISOnum */
    {"uarr", 0x2191},           /* upwards arrow, U+2191 ISOnum */
    {"rarr", 0x2192},           /* rightwards arrow, U+2192 ISOnum */
    {"darr", 0x2193},           /* downwards arrow, U+2193 ISOnum */
    {"harr", 0x2194},           /* left right arrow, U+2194 ISOamsa */
    {"crarr", 0x21B5},          /* downwards arrow with corner leftwards = carriage return, U+21B5 NEW */
    {"lArr", 0x21D0},           /* leftwards double arrow, U+21D0 ISOtech */
    {"uArr", 0x21D1},           /* upwards double arrow, U+21D1 ISOamsa */
    {"rArr", 0x21D2},           /* rightwards double arrow, U+21D2 ISOtech */
    {"dArr", 0x21D3},           /* downwards double arrow, U+21D3 ISOamsa */
    {"hArr", 0x21D4},           /* left right double arrow, U+21D4 ISOamsa */

    /* -- Mathematical Operators */
    {"forall", 0x2200},         /* for all, U+2200 ISOtech */
    {"part", 0x2202},           /* partial differential, U+2202 ISOtech */
    {"exist", 0x2203},          /* there exists, U+2203 ISOtech */
    {"empty", 0x2205},          /* empty set = null set = diameter, U+2205 ISOamso */
    {"nabla", 0x2207},          /* nabla = backward difference, U+2207 ISOtech */
    {"isin", 0x2208},           /* element of, U+2208 ISOtech */
    {"notin", 0x2209},          /* not an element of, U+2209 ISOtech */
    {"ni", 0x220B},             /* contains as member, U+220B ISOtech */
    {"prod", 0x220F},           /* n-ary product = product sign, U+220F ISOamsb */
    {"sum", 0x2211},            /* n-ary sumation, U+2211 ISOamsb */
    {"minus", 0x2212},          /* minus sign, U+2212 ISOtech */
    {"lowast", 0x2217},         /* asterisk operator, U+2217 ISOtech */
    {"radic", 0x221A},          /* square root = radical sign, U+221A ISOtech */
    {"prop", 0x221D},           /* proportional to, U+221D ISOtech */
    {"infin", 0x221E},          /* infinity, U+221E ISOtech */
    {"ang", 0x2220},            /* angle, U+2220 ISOamso */
    {"and", 0x2227},            /* logical and = wedge, U+2227 ISOtech */
    {"or", 0x2228},             /* logical or = vee, U+2228 ISOtech */
    {"cap", 0x2229},            /* intersection = cap, U+2229 ISOtech */
    {"cup", 0x222A},            /* union = cup, U+222A ISOtech */
    {"int", 0x222B},            /* integral, U+222B ISOtech */
    {"there4", 0x2234},         /* therefore, U+2234 ISOtech */
    {"sim", 0x223C},            /* tilde operator = varies with = similar to, U+223C ISOtech */
    {"cong", 0x2245},           /* approximately equal to, U+2245 ISOtech */
    {"asymp", 0x2248},          /* almost equal to = asymptotic to, U+2248 ISOamsr */
    {"ne", 0x2260},             /* not equal to, U+2260 ISOtech */
    {"equiv", 0x2261},          /* identical to, U+2261 ISOtech */
    {"le", 0x2264},             /* less-than or equal to, U+2264 ISOtech */
    {"ge", 0x2265},             /* greater-than or equal to, U+2265 ISOtech */
    {"sub", 0x2282},            /* subset of, U+2282 ISOtech */
    {"sup", 0x2283},            /* superset of, U+2283 ISOtech */
    {"nsub", 0x2284},           /* not a subset of, U+2284 ISOamsn */
    {"sube", 0x2286},           /* subset of or equal to, U+2286 ISOtech */
    {"supe", 0x2287},           /* superset of or equal to, U+2287 ISOtech */
    {"oplus", 0x2295},          /* circled plus = direct sum, U+2295 ISOamsb */
    {"otimes", 0x2297},         /* circled times = vector product, U+2297 ISOamsb */
    {"perp", 0x22A5},           /* up tack = orthogonal to = perpendicular, U+22A5 ISOtech */
    {"sdot", 0x22C5},           /* dot operator, U+22C5 ISOamsb */
    {"lceil", 0x2308},          /* left ceiling = apl upstile, U+2308 ISOamsc */
    {"rceil", 0x2309},          /* right ceiling, U+2309 ISOamsc */
    {"lfloor", 0x230A},         /* left floor = apl downstile, U+230A ISOamsc */
    {"rfloor", 0x230B},         /* right floor, U+230B ISOamsc */
    {"lang", 0x2329},           /* left-pointing angle bracket = bra, U+2329 ISOtech */
    {"rang", 0x232A},           /* right-pointing angle bracket = ket, U+232A ISOtech */
    {"loz", 0x25CA},            /* lozenge, U+25CA ISOpub */

    /* -- Miscellaneous Symbols */
    {"spades", 0x2660},         /* black spade suit, U+2660 ISOpub */
    {"clubs", 0x2663},          /* black club suit = shamrock, U+2663 ISOpub */
    {"hearts", 0x2665},         /* black heart suit = valentine, U+2665 ISOpub */
    {"diams", 0x2666},          /* black diamond suit, U+2666 ISOpub */

};


/*
** ----------------------------------------------
** 
**  Module management code starts here
**
** ----------------------------------------------
*/

/* 
  -- init structures for Entities
*/

void    initModule_Entities(SWISH * sw)
{
    struct MOD_Entities *md;


    md = (struct MOD_Entities *) emalloc(sizeof(struct MOD_Entities));

    sw->Entities = md;

    md->convertEntities = CONVERTHTMLENTITIES;

    /* 
       -- init entity hash 
       -- this is module local only
     */

    if ( !ce_hasharray_initialized++ )
    {
        int     i,
                tab_len;
        CEntity *ce_p;
        struct CEHE **hash_pp,
               *tmp_p;

        /* empty positions */
        for (i = 0; i < sizeof(ce_hasharray) / sizeof(ce_hasharray[0]); i++)
            ce_hasharray[i] = (struct CEHE *) NULL;


        /* 
           -- fill entity table into hash
           --  process from end to start of entity_table, because most used
           --  entities are at the beginning (iso)
           --  this is due to "insert in hash sequence" behavior in hashtab (performance!)
           --  The improvement is minimal, because the hash table re-chains during usage.
         */

        tab_len = sizeof(entity_table) / sizeof(entity_table[0]);

        for (i = tab_len - 1; i >= 0; i--)
        {
            ce_p = &entity_table[i];
            hash_pp = &ce_hasharray[(int) *(ce_p->name) & 0x7F];
            /* insert entity-ptr at start of ptr sequence in hash */
            tmp_p = *hash_pp;
            *hash_pp = (struct CEHE *) emalloc(sizeof(struct CEHE));
            (*hash_pp)->ce = ce_p;
            (*hash_pp)->next = tmp_p;
        }

    }                           /* end init hash block */

}



/* 
  -- release structures for Entities
  -- release all wired memory
*/

void    freeModule_Entities(SWISH * sw)
{

    /* free module data structure */

    efree(sw->Entities);
    sw->Entities = NULL;


    /* 
       -- free local entity hash table 
     */
    {
        int     i;
        struct CEHE *hash_p,
               *tmp_p;
        /* free ptr "chains" in array */
        for (i = 0; i < sizeof(ce_hasharray) / sizeof(ce_hasharray[0]); i++)
        {
            hash_p = ce_hasharray[i];
            while (hash_p)
            {
                tmp_p = hash_p->next;
                efree(hash_p);
                hash_p = tmp_p;
            }
            ce_hasharray[i] = (struct CEHE *) NULL;
        }

    }                           /* end free hash block */

}


/*
** ----------------------------------------------
** 
**  Module config code starts here
**
** ----------------------------------------------
*/


/*
 -- Config Directives
 -- Configuration directives for this Module
 -- return: 0/1 = none/config applied
*/

int     configModule_Entities(SWISH * sw, StringList * sl)
{
    struct MOD_Entities *md = sw->Entities;
    char   *w0;
    int     retval;


    w0 = sl->word[0];
    retval = 1;


    if (strcasecmp(w0, "ConvertHTMLEntities") == 0)
    {
        md->convertEntities = getYesNoOrAbort(sl, 1, 1);
    }
    else
    {
        retval = 0;             /* not a Entities directive */
    }


    return retval;
}






/*
** ----------------------------------------------
** 
**  Module code starts here
**
** ----------------------------------------------
*/


/*
  -- convert a string containing HTML/XML entities
  -- conversion is done on the string itsself.
  -- conversion is only done, if config directive is set to "YES"
  -- return ptr to converted string.
*/

unsigned char *sw_ConvHTMLEntities2ISO(SWISH * sw, unsigned char *s)
{
    return (sw->Entities->convertEntities) ? strConvHTMLEntities2ISO(s) : s;
}



/*
  -- convert a string containing HTML/XML entities
  -- conversion is done on the string itsself.
  -- return ptr to converted string.
*/

unsigned char *strConvHTMLEntities2ISO(unsigned char *buf)
{
    unsigned char *s,
           *t;
    unsigned char *d;
    int     code;


    s = d = buf;

    while (*s)
    {

        /* if not entity start, next */
        if (*s != '&')
        {
            *d++ = *s++;
        }
        else
        {
            /* entity found, identify and decode */
            /* ignore zero entities and UNICODE ! */
            code = charEntityDecode(s, &t);
            if (code && (code < 256))
                *d++ = (unsigned char) code;
            s = t;
        }
    }
    *d = '\0';

    return buf;
}



/* 
 -- decode entity string to character code:
 --  &#dec;   &#xhex;   &#Xhex;   &named;
 -- Decoding is hash optimized with dynamic re-chaining for
 -- performance improvement...
 -- return: entity character (decoded)
 --    position "end" (if != NULL) past "entity" or behind ret. char
 --    on illegal entities, just return the char...
*/

int     charEntityDecode(unsigned char *s, unsigned char **end)
{
    unsigned char *s1,
           *t;
    char *e_end;
    unsigned char s_cmp[MAX_ENTITY_LEN + 1];
    int     len;
    int     code;


    /*
       -- no entity ctrl start char?, err: return char 
     */
    if (*s != '&')
    {
        if (end)
            *end = s + 1;
        return (int) *s;
    }



    /* ok, seems valid entity starting char */
    code = 0;
    e_end = NULL;

    if (*(s + 1) == '#')
    {                           /* numeric entity  "&#" */

        s += 2;                 /* after "&#" */
        switch (*s)
        {
        case 'x':
        case 'X':
            ++s;                /* skip x */
            code = (int) strtoul((char *)s, (char **) &e_end, (int) 16);
            break;
        default:
            code = (int) strtoul((char *)s, (char **) &e_end, (int) 10);
            break;
        }

    }
    else
    {

        /* 
           -- ok, seems to be a named entity, find terminating char 
           -- t = NULL if  not found...
           -- if no char found: return '&' (illegal entity) 
         */

        len = 0;
        t = NULL;
        s1 = s;
        while (len < MAX_ENTITY_LEN)
        {
            s_cmp[len] = *(++s1);
            if (IS_EOE(*s1))
            {
                t = s1;         /* End of named entity */
                break;
            }
            if (!*s1)
                break;          /* maybe this is also checked by is_EOE! */
            len++;
        }
        s_cmp[len] = '\0';

        /*
           -- hash search block
           -- case sensitiv search  (hashvalue = 1 entity name char)
           -- (& 0x7F to prevent hashtable mem coredumps by illegal chars)
           -- improve performance, by rechaining found elements
         */

        if (t)
        {
            struct CEHE *hash_p;
            struct CEHE **hash_pp,
                   *last_p;

            hash_pp = &ce_hasharray[*(s + 1) & 0x7F];
            last_p = NULL;
            hash_p = *hash_pp;
            while (hash_p)
            {
                if (!strcmp( (char *)hash_p->ce->name, (char *)s_cmp))
                {
                    code = hash_p->ce->code;
                    if (last_p)
                    {           /* rechain hash sequence list (last found = first) */
                        last_p->next = hash_p->next; /* take elem out of seq */
                        hash_p->next = *hash_pp; /* old 1. = 2.          */
                        *hash_pp = hash_p; /* found = 1st          */
                    }
                    e_end = t;  /* found -> set end     */
                    break;
                }
                last_p = hash_p;
                hash_p = hash_p->next;
            }

        }
    }                           /* end if */


    if (!e_end)
    {
        code = *s;
        e_end = s + 1;
    }
    else
    {
        if (*e_end == ';')
            e_end++;            /* W3C  EndOfEntity */
    }


    if (end)
        *end = e_end;
    return code;
}


/*
  -- check if a char is the end of a html entity.
  -- behavior can be W3C pedantic or tolerant.
  -- mapped via macro to avoid function calls on strict ==';' behavior
  -- return: cmp value
*/

static int is_EOE(int c)
{
/* be tolerant ! */
    return ((!isprint(c)) || ispunct(c) || isspace(c)) ? 1 : 0;
}
