in src/main/java/org/apache/commons/lang3/time/FastDatePrinter.java [337:386]
protected String parseToken(final String pattern, final int[] indexRef) {
final StringBuilder buf = new StringBuilder();
int i = indexRef[0];
final int length = pattern.length();
char c = pattern.charAt(i);
if (c >= 'A' && c <= 'Z' || c >= 'a' && c <= 'z') {
// Scan a run of the same character, which indicates a time
// pattern.
buf.append(c);
while (i + 1 < length) {
final char peek = pattern.charAt(i + 1);
if (peek != c) {
break;
}
buf.append(c);
i++;
}
} else {
// This will identify token as text.
buf.append('\'');
boolean inLiteral = false;
for (; i < length; i++) {
c = pattern.charAt(i);
if (c == '\'') {
if (i + 1 < length && pattern.charAt(i + 1) == '\'') {
// '' is treated as escaped '
i++;
buf.append(c);
} else {
inLiteral = !inLiteral;
}
} else if (!inLiteral &&
(c >= 'A' && c <= 'Z' || c >= 'a' && c <= 'z')) {
i--;
break;
} else {
buf.append(c);
}
}
}
indexRef[0] = i;
return buf.toString();
}