transtab_latex_unicode.inc.php in Bibliography Module 7

Copyright: Matthias Steffens This code is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY. Please see the GNU General Public License for more details. File: ./includes/transtab_latex_unicode.inc.php Created: 10-Aug-06, 23:55 Modified: 13-Aug-06, 16:16 This is a translation table for best-effort conversion from LaTeX to Unicode entities. It contains a comprehensive list of substitution strings for LaTeX characters, which are used with the 'T1' font encoding. Uses commands from the 'textcomp' package. Unicode characters that can't be matched uniquely are commented out. Adopted from 'transtab' by Markus Kuhn (transtab.utf v1.8 2000-10-12 11:01:28+01 mgk25 Exp); see <http://www.cl.cam.ac.uk/~mgk25/unicode.html> for more info about Unicode and transtab.

Modified: 2013-08-23 Christian Spitzlay: made sure closing braces match only if there are corresponding opening braces migrated most regular expressions to config arrays; regexps are generated on the fly now (more readable). added decoding of some missing greek symbols.

File

modules/bibtexParse/transtab_latex_unicode.inc.php

<?php

/**
 * @file
 * Copyright:  Matthias Steffens
 *             This code is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY.
 *             Please see the GNU General Public License for more details.
 * File:       ./includes/transtab_latex_unicode.inc.php
 * Created:    10-Aug-06, 23:55
 * Modified:   13-Aug-06, 16:16
 * This is a translation table for best-effort conversion from LaTeX to Unicode entities. It contains a comprehensive list of substitution strings for LaTeX characters,
 * which are used with the 'T1' font encoding. Uses commands from the 'textcomp' package. Unicode characters that can't be matched uniquely are commented out.
 * Adopted from 'transtab' by Markus Kuhn
 * (transtab.utf v1.8 2000-10-12 11:01:28+01 mgk25 Exp); see <http://www.cl.cam.ac.uk/~mgk25/unicode.html> for more info about Unicode and transtab.
 *
 * Modified:   2013-08-23 Christian Spitzlay:
 *             made sure closing braces match only if there are corresponding opening braces
 *             migrated most regular expressions to config arrays; regexps are generated on the fly now (more readable).
 *             added decoding of some missing greek symbols.
 */

/**
 * Creates a translation table for decoding of TeX symbols in BibTeX input.
 *
 * @return array An array with substitutions (regexps as keys, characters as values)
 *
 * @throws Exception Indicates that an internal check failed. Should only be thrown if someone broke a config array.
 */
function get_transtab_latex_unicode() {
  $transtab = array(
    '\\$\\\\#\\$' => '#',
    '\\\\%' => '%',
    '\\\\&' => '&',
    '(?<!\\\\)~' => ' ',
    '\\{\\\\c\\\\ \\}' => '¸',
    '--' => '–',
    '---' => '—',
    '\\$\\^\\{0\\}\\$' => '⁰',
    '\\$\\^\\{4\\}\\$' => '⁴',
    '\\$\\^\\{5\\}\\$' => '⁵',
    '\\$\\^\\{6\\}\\$' => '⁶',
    '\\$\\^\\{7\\}\\$' => '⁷',
    '\\$\\^\\{8\\}\\$' => '⁸',
    '\\$\\^\\{9\\}\\$' => '⁹',
    '\\$\\^\\{+\\}\\$' => '⁺',
    '\\$\\^\\{-\\}\\$' => '⁻',
    '\\$\\^\\{=\\}\\$' => '⁼',
    '\\$\\^\\{n\\}\\$' => 'ⁿ',
    '\\$_\\{0\\}\\$' => '₀',
    '\\$_\\{1\\}\\$' => '₁',
    '\\$_\\{2\\}\\$' => '₂',
    '\\$_\\{3\\}\\$' => '₃',
    '\\$_\\{4\\}\\$' => '₄',
    '\\$_\\{5\\}\\$' => '₅',
    '\\$_\\{6\\}\\$' => '₆',
    '\\$_\\{7\\}\\$' => '₇',
    '\\$_\\{8\\}\\$' => '₈',
    '\\$_\\{9\\}\\$' => '₉',
    '\\$_\\{+\\}\\$' => '₊',
    '\\$_\\{-\\}\\$' => '₋',
    '\\$_\\{=\\}\\$' => '₌',
  );

  // Map for diacritics that do *not* require whitespace in the absence of curly braces around the letter;
  // diacritic code and letter are separated by a pipe symbol.
  $quoty_mapping = array(
    '`|A' => 'À',
    '\'|A' => 'Á',
    '^|A' => 'Â',
    '~|A' => 'Ã',
    '"|A' => 'Ä',
    '`|E' => 'È',
    '\'|E' => 'É',
    '^|E' => 'Ê',
    '"|E' => 'Ë',
    '`|I' => 'Ì',
    '\'|I' => 'Í',
    '^|I' => 'Î',
    '"|I' => 'Ï',
    '~|N' => 'Ñ',
    '\'|N' => 'Ń',
    '\'|n' => 'ń',
    '`|O' => 'Ò',
    '\'|O' => 'Ó',
    '^|O' => 'Ô',
    '~|O' => 'Õ',
    '"|O' => 'Ö',
    '`|U' => 'Ù',
    '\'|U' => 'Ú',
    '^|U' => 'Û',
    '"|U' => 'Ü',
    '\'|Y' => 'Ý',
    '`|a' => 'à',
    '\'|a' => 'á',
    '^|a' => 'â',
    '~|a' => 'ã',
    '"|a' => 'ä',
    '`|e' => 'è',
    '\'|e' => 'é',
    '^|e' => 'ê',
    '"|e' => 'ë',
    '`|i' => 'ì',
    '\'|i' => 'í',
    '^|i' => 'î',
    '"|i' => 'ï',
    '"|\\i' => 'ï',
    '~|n' => 'ñ',
    '`|o' => 'ò',
    '\'|o' => 'ó',
    '^|o' => 'ô',
    '~|o' => 'õ',
    '"|o' => 'ö',
    '=|o' => 'ō',
    '`|u' => 'ù',
    '\'|u' => 'ú',
    '^|u' => 'û',
    '"|u' => 'ü',
    '\'|y' => 'ý',
    '"|y' => 'ÿ',
    '\'|C' => 'Ć',
    '\'|c' => 'ć',
    '.|g' => 'ġ',
    '.|I' => 'İ',
    '\'|\\i' => 'í',
    '\'|L' => 'Ĺ',
    '\'|l' => 'ĺ',
    '\'|R' => 'Ŕ',
    '\'|r' => 'ŕ',
    '\'|S' => 'Ś',
    '\'|s' => 'ś',
    '"|Y' => 'Ÿ',
    '\'|Z' => 'Ź',
    '\'|z' => 'ź',
    '.|Z' => 'Ż',
    '.|z' => 'ż',
  );
  foreach ($quoty_mapping as $sequence => $character) {

    // Split sequence at the pipe symbol.
    $key = explode('|', $sequence);
    if (count($key) != 2) {
      throw new Exception('Internal error: Invalid sequence ' . check_plain($sequence) . ' for character ' . check_plain($character));
    }
    $pattern = '(\\{)?\\\\' . preg_quote($key[0], '/') . '(\\s*\\{)?' . preg_quote($key[1], '/') . '(?(2)\\}|)(?(1)\\}|)';
    $transtab[$pattern] = $character;
  }

  // Map for diacritics that *require* whitespace in the absence of curly braces around the letter;
  // diacritic code and letter are separated by a pipe symbol.
  $lettery_mapping = array(
    'v|L' => 'Ľ',
    'v|l' => 'ľ',
    'r|A' => 'Å',
    'c|C' => 'Ç',
    'r|a' => 'å',
    'c|c' => 'ç',
    'u|A' => 'Ă',
    'u|a' => 'ă',
    'k|A' => 'Ą',
    'k|a' => 'ą',
    'v|C' => 'Č',
    'v|c' => 'č',
    'v|D' => 'Ď',
    'v|d' => 'ď',
    'k|E' => 'Ę',
    'k|e' => 'ę',
    'v|E' => 'Ě',
    'v|e' => 'ě',
    'u|e' => 'ĕ',
    'u|G' => 'Ğ',
    'u|g' => 'ğ',
    'v|N' => 'Ň',
    'v|n' => 'ň',
    'H|O' => 'Ő',
    'H|o' => 'ő',
    'v|R' => 'Ř',
    'v|r' => 'ř',
    'c|S' => 'Ş',
    'c|s' => 'ş',
    'v|S' => 'Š',
    'v|s' => 'š',
    'c|T' => 'Ţ',
    'c|t' => 'ţ',
    'v|T' => 'Ť',
    'v|t' => 'ť',
    'r|U' => 'Ů',
    'r|u' => 'ů',
    'H|U' => 'Ű',
    'H|u' => 'ű',
    'v|Z' => 'Ž',
    'v|z' => 'ž',
  );
  foreach ($lettery_mapping as $sequence => $character) {

    // Split sequence at the pipe symbol.
    $key = explode('|', $sequence);
    if (count($key) != 2) {
      throw new Exception('Internal error: Invalid sequence ' . check_plain($sequence) . ' for character ' . check_plain($character));
    }

    // Letter escapes require whitespace or quotes, or both.
    $pattern = '(\\{)?\\\\' . preg_quote($key[0], '/') . '((\\s*\\{)?|\\s+)' . preg_quote($key[1], '/') . '(?(3)\\}|)(?(1)\\}|)';
    $transtab[$pattern] = $character;
  }

  // Simple named sequences like greek letters
  // tex name without the backslash => unicode.
  $mapping = array(
    'alpha' => 'α',
    'beta' => 'β',
    'gamma' => 'γ',
    'delta' => 'δ',
    'epsilon' => 'ε',
    'zeta' => 'ζ',
    'eta' => 'η',
    'theta' => 'θ',
    'iota' => 'ι',
    'kappa' => 'κ',
    'lambda' => 'λ',
    'mu' => 'μ',
    'nu' => 'ν',
    // AFAICT there is no omicron sequence in TeX,
    // but the previous version had this replacement.
    'omicron' => 'o',
    'xi' => 'ξ',
    'pi' => 'π',
    'rho' => 'ρ',
    'varsigma' => 'ς',
    'sigma' => 'σ',
    'tau' => 'τ',
    'upsilon' => 'υ',
    'phi' => 'φ',
    'chi' => 'χ',
    'psi' => 'ψ',
    'omega' => 'ω',
    'Gamma' => 'Γ',
    'Delta' => 'Δ',
    'Theta' => 'Θ',
    'Lambda' => 'Λ',
    'Xi' => 'Ξ',
    'Pi' => 'Π',
    'Sigma' => 'Σ',
    'Upsilon' => 'Υ',
    'Phi' => 'Φ',
    'Psi' => 'Ψ',
    'Omega' => 'Ω',
    'AA' => 'Å',
    'aa' => 'å',
    'AE' => 'Æ',
    'ae' => 'æ',
    'DH' => 'Ð',
    'dh' => 'ð',
    'DJ' => 'Đ',
    'dj' => 'đ',
    'i' => 'ı',
    'L' => 'Ł',
    'l' => 'ł',
    'NG' => 'Ŋ',
    'ng' => 'ŋ',
    'O' => 'Ø',
    'o' => 'ø',
    'OE' => 'Œ',
    'oe' => 'œ',
    'TH' => 'Þ',
    'th' => 'þ',
    'ss' => 'ß',
    'texteuro' => '€',
    'textcelsius' => '℃',
    'textnumero' => '№',
    'textcircledP' => '℗',
    'textservicemark' => '℠',
    'texttrademark' => '™',
    'textohm' => 'Ω',
    'textestimated' => '℮',
    'textleftarrow' => '←',
    'textuparrow' => '↑',
    'textrightarrow' => '→',
    'textdownarrow' => '↓',
    'infty' => '∞',
    'textlangle' => '〈',
    'textrangle' => '〉',
    'textvisiblespace' => '␣',
    'textopenbullet' => '◦',
    'textflorin' => 'ƒ',
    'textasciicircum' => 'ˆ',
    'textacutedbl' => '˝',
    'textendash' => '–',
    'textemdash' => '—',
    'textbardbl' => '‖',
    'textunderscore' => '‗',
    'textquoteleft' => '‘',
    'textquoteright' => '’',
    'quotesinglbase' => '‚',
    'textquotedblleft' => '“',
    'textquotedblright' => '”',
    'quotedblbase' => '„',
    'textdagger' => '†',
    'textdaggerdbl' => '‡',
    'textbullet' => '•',
    'textellipsis' => '…',
    'textperthousand' => '‰',
    'guilsinglleft' => '‹',
    'guilsinglright' => '›',
    'textfractionsolidus' => '⁄',
    'textdiv' => '÷',
    'textexclamdown' => '¡',
    'textcent' => '¢',
    'textsterling' => '£',
    'textyen' => '¥',
    'textbrokenbar' => '¦',
    'textsection' => '§',
    'textasciidieresis' => '¨',
    'textcopyright' => '©',
    'textordfeminine' => 'ª',
    'guillemotleft' => '«',
    'textlnot' => '¬',
    'textregistered' => '®',
    'textasciimacron' => '¯',
    'textdegree' => '°',
    'textpm' => '±',
    'texttwosuperior' => '²',
    'textthreesuperior' => '³',
    'textasciiacute' => '´',
    'textmu' => 'µ',
    'textparagraph' => '¶',
    'textperiodcentered' => '·',
    'textonesuperior' => '¹',
    'textordmasculine' => 'º',
    'guillemotright' => '»',
    'textonequarter' => '¼',
    'textonehalf' => '½',
    'textthreequarters' => '¾',
    'textquestiondown' => '¿',
    'texttimes' => '×',
    'textgreater' => '>',
    'textless' => '<',
  );
  foreach ($mapping as $name => $character) {

    // Consume pairs of $ signs and curly braces, if any;
    // if neither brace nor $ is present then whitespace or a backslash is required to end a sequence.
    $pattern = '(\\$)?(\\{)?\\\\' . $name . '(?(2)\\}|(\\s+|(?=\\$)|(?=\\\\)))(?(1)\\s*\\$|)';
    $transtab[$pattern] = $character;
  }

  // Decode escaped underscores.
  $transtab['\\\\_'] = '_';

  // finally, handle escaped space.
  $transtab['\\\\ '] = ' ';

  // drupal_set_message('<pre>'.check_plain(print_r($transtab, TRUE)).'</pre>');.
  return $transtab;
}

Functions

Name	Description
get_transtab_latex_unicode	Creates a translation table for decoding of TeX symbols in BibTeX input.