package cern.colt.matrix.impl;
/**
* Factory producing implementations of {@link cern.colt.matrix.impl.Former} via method create();
* Implementations of can use existing libraries such as corejava.PrintfFormat or corejava.Format or other.
* Serves to isolate the interface of String formatting from the actual implementation.
* If you want to plug in a different String formatting implementation, simply replace this class with your alternative.
*
* @author wolfgang.hoschek@cern.ch
* @version 1.0, 21/07/00
*/
public class FormerFactory {
/**
* Constructs and returns a new format instance.
* @param s the format string following printf conventions.
* The string has a prefix, a format code and a suffix. The prefix and suffix
* become part of the formatted output. The format code directs the
* formatting of the (single) parameter to be formatted. The code has the
* following structure
* <ul>
* <li> a % (required)
* <li> a modifier (optional)
* <dl>
* <dt> + <dd> forces display of + for positive numbers
* <dt> 0 <dd> show leading zeroes
* <dt> - <dd> align left in the field
* <dt> space <dd> prepend a space in front of positive numbers
* <dt> # <dd> use "alternate" format. Add 0 or 0x for octal or hexadecimal numbers. Don't suppress trailing zeroes in general floating point format.
* </dl>
* <li> an integer denoting field width (optional)
* <li> a period followed by an integer denoting precision (optional)
* <li> a format descriptor (required)
* <dl>
* <dt>f <dd> floating point number in fixed format
* <dt>e, E <dd> floating point number in exponential notation (scientific format). The E format results in an uppercase E for the exponent (1.14130E+003), the e format in a lowercase e.
* <dt>g, G <dd> floating point number in general format (fixed format for small numbers, exponential format for large numbers). Trailing zeroes are suppressed. The G format results in an uppercase E for the exponent (if any), the g format in a lowercase e.
* <dt>d, i <dd> integer in decimal
* <dt>x <dd> integer in hexadecimal
* <dt>o <dd> integer in octal
* <dt>s <dd> string
* <dt>c <dd> character
* </dl>
* </ul>
* @exception IllegalArgumentException if bad format
*/
public Former create(final String format) {
return new Former() {
//private FormatStringBuffer f = (format!=null ? new corejava.FormatStringBuffer(format) : null);
private corejava.Format f = (format!=null ? new corejava.Format(format) : null);
//private corejava.PrintfFormat f = (format!=null ? new corejava.PrintfFormat(format) : null);
public String form(double value) {
if (f==null || value == Double.POSITIVE_INFINITY || value == Double.NEGATIVE_INFINITY || value != value) {
// value != value <==> Double.isNaN(value)
// Work around bug in corejava.Format.form() for inf, -inf, NaN
return String.valueOf(value);
}
//return f.format(value).toString();
return f.format(value);
//return f.sprintf(value);
}
};
}
}