de.undercouch.citeproc.helper.SmartQuotes Maven / Gradle / Ivy
package de.undercouch.citeproc.helper;
import java.util.Locale;
import java.util.regex.Pattern;
/**
* Replaces straight quotation marks and apostrophes by their typographically
* correct counterparts.
* The code is based on smartquotes.js (https://smartquotes.js.org/)
* written by Kelly Martin released under the MIT license. It has been
* translated to Java and extended to support multiple languages.
* @author Michel Kraemer
*/
public class SmartQuotes {
private static final String NUMBER = "\\p{N}";
private static final String NO_NUMBER = "[^" + NUMBER + "]";
private static final String LETTER = "\\p{L}";
private static final String WORD = "[" + LETTER + "_" + NUMBER + "]";
private static final String NO_WORD = "[^" + LETTER + "_" + NUMBER + "]";
private static final String LEFT_SINGLE_QUOTE = "‘";
private static final String RIGHT_SINGLE_QUOTE = "’";
private static final String LEFT_DOUBLE_QUOTE = "“";
private static final String RIGHT_DOUBLE_QUOTE = "”";
private static final String PRIME = "′";
private static final String DOUBLE_PRIME = "″";
private static final String TRIPLE_PRIME = "‴";
private final Pattern[] patterns;
private final String[] replacements;
/**
* Creates the smart-quotes parser
*/
public SmartQuotes() {
this(LEFT_SINGLE_QUOTE, RIGHT_SINGLE_QUOTE,
LEFT_DOUBLE_QUOTE, RIGHT_DOUBLE_QUOTE, Locale.ENGLISH);
}
/**
* Creates the smart-quotes parser with custom symbols
* @param leftSingleQuote custom left single quotation mark
* @param rightSingleQuote custom right singe quotation mark
* @param leftDoubleQuote custom left double quotation mark
* @param rightDoubleQuote custom right double quotation mark
* @param locale a locale object used to apply special rules and corner cases
*/
public SmartQuotes(String leftSingleQuote, String rightSingleQuote,
String leftDoubleQuote, String rightDoubleQuote, Locale locale) {
this(leftSingleQuote, rightSingleQuote, leftDoubleQuote, rightDoubleQuote,
RIGHT_SINGLE_QUOTE, PRIME, DOUBLE_PRIME, TRIPLE_PRIME, locale);
}
/**
* Creates the smart-quotes parser with custom symbols
* @param leftSingleQuote custom left single quotation mark
* @param rightSingleQuote custom right singe quotation mark
* @param leftDoubleQuote custom left double quotation mark
* @param rightDoubleQuote custom right double quotation mark
* @param apostrophe custom apostrophe
* @param prime custom prime
* @param doublePrime custom double prime
* @param triplePrime custom triple prime
* @param locale a locale object used to apply special rules and corner cases
*/
@SuppressWarnings({"RegExpUnexpectedAnchor"})
public SmartQuotes(String leftSingleQuote, String rightSingleQuote,
String leftDoubleQuote, String rightDoubleQuote, String apostrophe,
String prime, String doublePrime, String triplePrime, Locale locale) {
String[][] replacements = new String[][] {
// whitelist (works for English only, bummer)
new String[] { "'(em|cause|twas|tis|til)([^a-z])", (locale != null && locale.getLanguage().equalsIgnoreCase("en")) ? apostrophe + "$1$2" : "$0" },
// triple prime
new String[] { "'''", triplePrime },
// beginning "
new String[] { "(" + NO_WORD + "|^)\"(" + leftSingleQuote + "|'|" + WORD + ")", "$1" + leftDoubleQuote + "$2" },
// ending "
new String[] { "(" + leftDoubleQuote + "[^\"]*)\"([^\"]*$|[^" + leftDoubleQuote + "\"]*" + leftDoubleQuote + ")", "$1" + rightDoubleQuote + "$2" },
// remaining " at end of word
new String[] { "(" + NO_NUMBER + ")\"", "$1" + rightDoubleQuote },
// double prime as two single quotes
new String[] { "''", doublePrime },
// beginning '
new String[] { "(" + NO_WORD + "|^)'(\\S)", "$1" + leftSingleQuote + "$2" },
// conjunction's possession
new String[] { "(" + LETTER + "|" + NUMBER + ")'(" + LETTER + ")", "$1" + apostrophe + "$2" },
// abbrev. years like '93
new String[] { "(" + leftSingleQuote + ")([0-9]{2}[^" + rightSingleQuote + apostrophe + "]*)(" + leftSingleQuote + "(" + NO_NUMBER + "|$)|$|" + rightSingleQuote + apostrophe + LETTER + ")", apostrophe + "$2$3" },
// ending '
new String[] { "((" + leftSingleQuote + "[^']*)|" + LETTER + ")'(" + NO_NUMBER + "|$)", "$1" + rightSingleQuote + "$3" },
// backwards apostrophe
new String[] { "(\\B|^)" + leftSingleQuote + "(?=([^" + leftSingleQuote + rightSingleQuote + apostrophe + "]*[" + rightSingleQuote + apostrophe + "]\\b)*([^" + leftSingleQuote + rightSingleQuote + apostrophe + "]*\\B" + NO_WORD + "[" + leftSingleQuote + rightSingleQuote + apostrophe + "]\\b|[^" + leftSingleQuote + rightSingleQuote + apostrophe + "]*$))", "$1" + rightSingleQuote },
// double prime (not first character)
new String[] { "(.)\"", "$1" + doublePrime },
// left double quote at the beginning of string
new String[] { "^\"", leftDoubleQuote },
// prime
new String[] { "'", prime }
};
this.patterns = new Pattern[replacements.length];
this.replacements = new String[replacements.length];
for (int i = 0; i < replacements.length; ++i) {
this.patterns[i] = Pattern.compile(replacements[i][0]);
this.replacements[i] = replacements[i][1];
}
}
/**
* Replace straight quotation marks and apostrophes in the given string
* by their typographically correct counterparts.
* @param str the input string
* @return the processed string
*/
public String apply(String str) {
for (int i = 0; i < patterns.length; ++i) {
str = patterns[i].matcher(str).replaceAll(replacements[i]);
}
return str;
}
}