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/*
********************************************************************************
* Copyright (C) 1997-2008, International Business Machines
* Corporation and others. All Rights Reserved.
********************************************************************************
*
* File CHOICFMT.H
*
* Modification History:
*
* Date Name Description
* 02/19/97 aliu Converted from java.
* 03/20/97 helena Finished first cut of implementation and got rid
* of nextDouble/previousDouble and replaced with
* boolean array.
* 4/10/97 aliu Clean up. Modified to work on AIX.
* 8/6/97 nos Removed overloaded constructor, member var 'buffer'.
* 07/22/98 stephen Removed operator!= (implemented in Format)
********************************************************************************
*/
#ifndef CHOICFMT_H
#define CHOICFMT_H
#include "unicode/utypes.h"
/**
* \file
* \brief C++ API: Choice Format.
*/
#if !UCONFIG_NO_FORMATTING
#include "unicode/unistr.h"
#include "unicode/numfmt.h"
#include "unicode/fieldpos.h"
#include "unicode/format.h"
U_NAMESPACE_BEGIN
class MessageFormat;
/**
* ChoiceFormat converts between ranges of numeric values
* and string names for those ranges. A <code>ChoiceFormat</code> splits
* the real number line <code>-Inf</code> to <code>+Inf</code> into two
* or more contiguous ranges. Each range is mapped to a
* string. <code>ChoiceFormat</code> is generally used in a
* <code>MessageFormat</code> for displaying grammatically correct
* plurals such as "There are 2 files."</p>
*
* <p>There are two methods of defining a <code>ChoiceFormat</code>; both
* are equivalent. The first is by using a string pattern. This is the
* preferred method in most cases. The second method is through direct
* specification of the arrays that make up the
* <code>ChoiceFormat</code>.</p>
*
* <p><strong>Patterns</strong></p>
*
* <p>In most cases, the preferred way to define a
* <code>ChoiceFormat</code> is with a pattern. Here is an example of a
* <code>ChoiceFormat</code> pattern:</p>
*
* \htmlonly<pre> 0≤are no files|1≤is one file|1<are many files</pre>\endhtmlonly
*
* <p>or equivalently,</p>
*
* \htmlonly<pre> 0#are no files|1#is one file|1<are many files</pre>\endhtmlonly
*
* <p>The pattern consists of a number or <em>range specifiers</em>
* separated by vertical bars '|' (U+007C). There is no
* vertical bar after the last range. Each range specifier is of the
* form:</p>
*
* \htmlonly<blockquote><em>Number Separator String</em></blockquote>\endhtmlonly
*
* <p><em>Number</em> is a floating point number that can be parsed by a
* default <code>NumberFormat</code> for the US locale. It gives the
* lower limit of this range. The lower limit is either inclusive or
* exclusive, depending on the <em>separator</em>. The upper limit is
* given by the lower limit of the next range. The Unicode infinity
* sign \htmlonly∞ \endhtmlonly (U+221E) is recognized for positive infinity. It may be preceded by
* '-' (U+002D) to indicate negative infinity.</p>
*
* <p><em>String</em> is the format string for this range, with special
* characters enclosed in single quotes (<code>'The #
* sign'</code>). Single quotes themselves are indicated by two single
* quotes in a row (<code>'o''clock'</code>).</p>
*
* <p><em>Separator</em> is one of the following single characters:
*
* <ul>
* <li>\htmlonly'≤' \endhtmlonly (U+2264) or '#' (U+0023)
* indicates that the lower limit given by <em>Number</em> is
* inclusive. (The two characters are equivalent to ChoiceFormat.)
* This means that the limit value <em>Number</em> belongs to this
* range. Another way of saying this is that the corresponding
* closure is <code>FALSE</code>.</li>
*
* <li>'<' (U+003C) indicates that the lower limit given by
* <em>Number</em> is exclusive. This means that the value
* <em>Number</em> belongs to the prior range.</li> Another way of
* saying this is that the corresponding closure is
* <code>TRUE</code>.
* </ul>
*
* <p>See below for more information about closures.</p>
*
* <p><strong>Arrays</strong></p>
*
* <p>A <code>ChoiceFormat</code> defining <code>n</code> intervals
* (<code>n</code> >= 2) is specified by three arrays of
* <code>n</code> items:
*
* <ul>
* <li><code>double limits[]</code> gives the start of each
* interval. This must be a non-decreasing list of values, none of
* which may be <code>NaN</code>.</li>
* <li><code>UBool closures[]</code> determines whether each limit
* value is contained in the interval below it or in the interval
* above it. If <code>closures[i]</code> is <code>FALSE</code>, then
* <code>limits[i]</code> is a member of interval
* <code>i</code>. Otherwise it is a member of interval
* <code>i+1</code>. If no closures array is specified, this is
* equivalent to having all closures be <code>FALSE</code>. Closures
* allow one to specify half-open, open, or closed intervals.</li>
* <li><code>UnicodeString formats[]</code> gives the string label
* associated with each interval.</li>
* </ul>
*
* <p><strong>Formatting and Parsing</strong></p>
*
* <p>During formatting, a number is converted to a
* string. <code>ChoiceFormat</code> accomplishes this by mapping the
* number to an interval using the following rule. Given a number
* <code>X</code> and and index value <code>j</code> in the range
* <code>0..n-1</code>, where <code>n</code> is the number of ranges:</p>
*
* \htmlonly<blockquote>\endhtmlonly<code>X</code> matches <code>j</code> if and only if
* <code>limit[j] <= X < limit[j+1]</code>
* \htmlonly</blockquote>\endhtmlonly
*
* <p>(This assumes that all closures are <code>FALSE</code>. If some
* closures are <code>TRUE</code> then the relations must be changed to
* <code><=</code> or <code><</code> as appropriate.) If there is
* no match, then either the first or last index is used, depending on
* whether the number is too low or too high. Once a number is mapped to
* an interval <code>j</code>, the string <code>formats[j]</code> is
* output.</p>
*
* <p>During parsing, a string is converted to a
* number. <code>ChoiceFormat</code> finds the element
* <code>formats[j]</code> equal to the string, and returns
* <code>limits[j]</code> as the parsed value.</p>
*
* <p><strong>Notes</strong></p>
*
* <p>The first limit value does not define a range boundary. For
* example, in the pattern \htmlonly"<code>1.0#a|2.0#b</code>"\endhtmlonly, the
* intervals are [-Inf, 2.0) and [2.0, +Inf]. It appears that the first
* interval should be [1.0, 2.0). However, since all values that are too
* small are mapped to range zero, the first interval is effectively
* [-Inf, 2.0). However, the first limit value <em>is</em> used during
* formatting. In this example, <code>parse("a")</code> returns
* 1.0.</p>
*
* <p>There are no gaps between intervals and the entire number line is
* covered. A <code>ChoiceFormat</code> maps <em>all</em> possible
* double values to a finite set of intervals.</p>
*
* <p>The non-number <code>NaN</code> is mapped to interval zero during
* formatting.</p>
*
* <p><strong>Examples</strong></p>
*
* <p>Here is an example of two arrays that map the number
* <code>1..7</code> to the English day of the week abbreviations
* <code>Sun..Sat</code>. No closures array is given; this is the same as
* specifying all closures to be <code>FALSE</code>.</p>
*
* <pre> {1,2,3,4,5,6,7},
* {"Sun","Mon","Tue","Wed","Thur","Fri","Sat"}</pre>
*
* <p>Here is an example that maps the ranges [-Inf, 1), [1, 1], and (1,
* +Inf] to three strings. That is, the number line is split into three
* ranges: x < 1.0, x = 1.0, and x > 1.0.</p>
*
* <pre> {0, 1, 1},
* {FALSE, FALSE, TRUE},
* {"no files", "one file", "many files"}</pre>
*
* <p>Here is a simple example that shows formatting and parsing: </p>
*
* \code
* #include <unicode/choicfmt.h>
* #include <unicode/unistr.h>
* #include <iostream.h>
*
* int main(int argc, char *argv[]) {
* double limits[] = {1,2,3,4,5,6,7};
* UnicodeString monthNames[] = {
* "Sun","Mon","Tue","Wed","Thu","Fri","Sat"};
* ChoiceFormat fmt(limits, monthNames, 7);
* UnicodeString str;
* char buf[256];
* for (double x = 1.0; x <= 8.0; x += 1.0) {
* fmt.format(x, str);
* str.extract(0, str.length(), buf, 256, "");
* str.truncate(0);
* cout << x << " -> "
* << buf << endl;
* }
* cout << endl;
* return 0;
* }
* \endcode
*
* <p>Here is a more complex example using a <code>ChoiceFormat</code>
* constructed from a pattern together with a
* <code>MessageFormat</code>.</p>
*
* \code
* #include <unicode/choicfmt.h>
* #include <unicode/msgfmt.h>
* #include <unicode/unistr.h>
* #include <iostream.h>
*
* int main(int argc, char *argv[]) {
* UErrorCode status = U_ZERO_ERROR;
* double filelimits[] = {0,1,2};
* UnicodeString filepart[] =
* {"are no files","is one file","are {0} files"};
* ChoiceFormat* fileform = new ChoiceFormat(filelimits, filepart, 3 );
* Format* testFormats[] =
* {fileform, NULL, NumberFormat::createInstance(status)};
* MessageFormat pattform("There {0} on {1}", status );
* pattform.adoptFormats(testFormats, 3);
* Formattable testArgs[] = {0L, "Disk A"};
* FieldPosition fp(0);
* UnicodeString str;
* char buf[256];
* for (int32_t i = 0; i < 4; ++i) {
* Formattable fInt(i);
* testArgs[0] = fInt;
* pattform.format(testArgs, 2, str, fp, status );
* str.extract(0, str.length(), buf, "");
* str.truncate(0);
* cout << "Output for i=" << i << " : " << buf << endl;
* }
* cout << endl;
* return 0;
* }
* \endcode
*
* <p><em>User subclasses are not supported.</em> While clients may write
* subclasses, such code will not necessarily work and will not be
* guaranteed to work stably from release to release.
*/
class U_I18N_API ChoiceFormat: public NumberFormat {
public:
/**
* Construct a new ChoiceFormat with the limits and the corresponding formats
* based on the pattern.
*
* @param pattern Pattern used to construct object.
* @param status Output param to receive success code. If the
* pattern cannot be parsed, set to failure code.
* @stable ICU 2.0
*/
ChoiceFormat(const UnicodeString& pattern,
UErrorCode& status);
/**
* Construct a new ChoiceFormat with the given limits and formats. Copy
* the limits and formats instead of adopting them.
*
* @param limits Array of limit values.
* @param formats Array of formats.
* @param count Size of 'limits' and 'formats' arrays.
* @stable ICU 2.0
*/
ChoiceFormat(const double* limits,
const UnicodeString* formats,
int32_t count );
/**
* Construct a new ChoiceFormat with the given limits and formats.
* Copy the limits and formats (instead of adopting them). By
* default, each limit in the array specifies the inclusive lower
* bound of its range, and the exclusive upper bound of the previous
* range. However, if the isLimitOpen element corresponding to a
* limit is TRUE, then the limit is the exclusive lower bound of its
* range, and the inclusive upper bound of the previous range.
* @param limits Array of limit values
* @param closures Array of booleans specifying whether each
* element of 'limits' is open or closed. If FALSE, then the
* corresponding limit is a member of the range above it. If TRUE,
* then the limit belongs to the range below it.
* @param formats Array of formats
* @param count Size of 'limits', 'closures', and 'formats' arrays
* @stable ICU 2.4
*/
ChoiceFormat(const double* limits,
const UBool* closures,
const UnicodeString* formats,
int32_t count);
/**
* Copy constructor.
*
* @param that ChoiceFormat object to be copied from
* @stable ICU 2.0
*/
ChoiceFormat(const ChoiceFormat& that);
/**
* Assignment operator.
*
* @param that ChoiceFormat object to be copied
* @stable ICU 2.0
*/
const ChoiceFormat& operator=(const ChoiceFormat& that);
/**
* Destructor.
* @stable ICU 2.0
*/
virtual ~ChoiceFormat();
/**
* Clone this Format object polymorphically. The caller owns the
* result and should delete it when done.
*
* @return a copy of this object
* @stable ICU 2.0
*/
virtual Format* clone(void) const;
/**
* Return true if the given Format objects are semantically equal.
* Objects of different subclasses are considered unequal.
*
* @param other ChoiceFormat object to be compared
* @return true if other is the same as this.
* @stable ICU 2.0
*/
virtual UBool operator==(const Format& other) const;
/**
* Sets the pattern.
* @param pattern The pattern to be applied.
* @param status Output param set to success/failure code on
* exit. If the pattern is invalid, this will be
* set to a failure result.
* @stable ICU 2.0
*/
virtual void applyPattern(const UnicodeString& pattern,
UErrorCode& status);
/**
* Sets the pattern.
* @param pattern The pattern to be applied.
* @param parseError Struct to recieve information on position
* of error if an error is encountered
* @param status Output param set to success/failure code on
* exit. If the pattern is invalid, this will be
* set to a failure result.
* @stable ICU 2.0
*/
virtual void applyPattern(const UnicodeString& pattern,
UParseError& parseError,
UErrorCode& status);
/**
* Gets the pattern.
*
* @param pattern Output param which will recieve the pattern
* Previous contents are deleted.
* @return A reference to 'pattern'
* @stable ICU 2.0
*/
virtual UnicodeString& toPattern(UnicodeString &pattern) const;
/**
* Set the choices to be used in formatting.
*
* @param limitsToCopy Contains the top value that you want
* parsed with that format,and should be in
* ascending sorted order. When formatting X,
* the choice will be the i, where limit[i]
* <= X < limit[i+1].
* @param formatsToCopy The format strings you want to use for each limit.
* @param count The size of the above arrays.
* @stable ICU 2.0
*/
virtual void setChoices(const double* limitsToCopy,
const UnicodeString* formatsToCopy,
int32_t count );
/**
* Set the choices to be used in formatting. See class description
* for documenatation of the limits, closures, and formats arrays.
* @param limits Array of limits
* @param closures Array of limit booleans
* @param formats Array of format string
* @param count The size of the above arrays
* @stable ICU 2.4
*/
virtual void setChoices(const double* limits,
const UBool* closures,
const UnicodeString* formats,
int32_t count);
/**
* Get the limits passed in the constructor.
*
* @param count The size of the limits arrays
* @return the limits.
* @stable ICU 2.0
*/
virtual const double* getLimits(int32_t& count) const;
/**
* Get the limit booleans passed in the constructor. The caller
* must not delete the result.
*
* @param count The size of the arrays
* @return the closures
* @stable ICU 2.4
*/
virtual const UBool* getClosures(int32_t& count) const;
/**
* Get the formats passed in the constructor.
*
* @param count The size of the arrays
* @return the formats.
* @stable ICU 2.0
*/
virtual const UnicodeString* getFormats(int32_t& count) const;
/**
* Format a double or long number using this object's choices.
*
* @param number The value to be formatted.
* @param appendTo Output parameter to receive result.
* Result is appended to existing contents.
* @param pos On input: an alignment field, if desired.
* On output: the offsets of the alignment field.
* @return Reference to 'appendTo' parameter.
* @stable ICU 2.0
*/
virtual UnicodeString& format(double number,
UnicodeString& appendTo,
FieldPosition& pos) const;
/**
* Format a int_32t number using this object's choices.
*
* @param number The value to be formatted.
* @param appendTo Output parameter to receive result.
* Result is appended to existing contents.
* @param pos On input: an alignment field, if desired.
* On output: the offsets of the alignment field.
* @return Reference to 'appendTo' parameter.
* @stable ICU 2.0
*/
virtual UnicodeString& format(int32_t number,
UnicodeString& appendTo,
FieldPosition& pos) const;
/**
* Format an int64_t number using this object's choices.
*
* @param number The value to be formatted.
* @param appendTo Output parameter to receive result.
* Result is appended to existing contents.
* @param pos On input: an alignment field, if desired.
* On output: the offsets of the alignment field.
* @return Reference to 'appendTo' parameter.
* @stable ICU 2.8
*/
virtual UnicodeString& format(int64_t number,
UnicodeString& appendTo,
FieldPosition& pos) const;
/**
* Format an array of objects using this object's choices.
*
* @param objs The array of objects to be formatted.
* @param cnt The size of objs.
* @param appendTo Output parameter to receive result.
* Result is appended to existing contents.
* @param pos On input: an alignment field, if desired.
* On output: the offsets of the alignment field.
* @param success Output param set to success/failure code on
* exit.
* @return Reference to 'appendTo' parameter.
* @stable ICU 2.0
*/
virtual UnicodeString& format(const Formattable* objs,
int32_t cnt,
UnicodeString& appendTo,
FieldPosition& pos,
UErrorCode& success) const;
/**
* Format an object using this object's choices.
*
*
* @param obj The object to be formatted.
* @param appendTo Output parameter to receive result.
* Result is appended to existing contents.
* @param pos On input: an alignment field, if desired.
* On output: the offsets of the alignment field.
* @param status Output param set to success/failure code on
* exit.
* @return Reference to 'appendTo' parameter.
* @stable ICU 2.0
*/
virtual UnicodeString& format(const Formattable& obj,
UnicodeString& appendTo,
FieldPosition& pos,
UErrorCode& status) const;
/**
* Redeclared NumberFormat method.
*
* @param obj The object to be formatted.
* @param appendTo Output parameter to receive result.
* Result is appended to existing contents.
* @param status Output param set to success/failure code on
* exit.
* @return Reference to 'appendTo' parameter.
* @stable ICU 2.0
*/
UnicodeString& format(const Formattable& obj,
UnicodeString& appendTo,
UErrorCode& status) const;
/**
* Redeclared NumberFormat method.
* Format a double number. These methods call the NumberFormat
* pure virtual format() methods with the default FieldPosition.
*
* @param number The value to be formatted.
* @param appendTo Output parameter to receive result.
* Result is appended to existing contents.
* @return Reference to 'appendTo' parameter.
* @stable ICU 2.0
*/
UnicodeString& format( double number,
UnicodeString& appendTo) const;
/**
* Redeclared NumberFormat method.
* Format a long number. These methods call the NumberFormat
* pure virtual format() methods with the default FieldPosition.
*
* @param number The value to be formatted.
* @param appendTo Output parameter to receive result.
* Result is appended to existing contents.
* @return Reference to 'appendTo' parameter.
* @stable ICU 2.0
*/
UnicodeString& format( int32_t number,
UnicodeString& appendTo) const;
/**
* Return a long if possible (e.g. within range LONG_MAX,
* LONG_MAX], and with no decimals), otherwise a double. If
* IntegerOnly is set, will stop at a decimal point (or equivalent;
* e.g. for rational numbers "1 2/3", will stop after the 1).
* <P>
* If no object can be parsed, parsePosition is unchanged, and NULL is
* returned.
*
* @param text The text to be parsed.
* @param result Formattable to be set to the parse result.
* If parse fails, return contents are undefined.
* @param parsePosition The position to start parsing at on input.
* On output, moved to after the last successfully
* parse character. On parse failure, does not change.
* @see NumberFormat::isParseIntegerOnly
* @stable ICU 2.0
*/
virtual void parse(const UnicodeString& text,
Formattable& result,
ParsePosition& parsePosition) const;
/**
* Return a long if possible (e.g. within range LONG_MAX,
* LONG_MAX], and with no decimals), otherwise a double. If
* IntegerOnly is set, will stop at a decimal point (or equivalent;
* e.g. for rational numbers "1 2/3", will stop after the 1).
* <P>
* If no object can be parsed, parsePosition is unchanged, and NULL is
* returned.
*
* @param text The text to be parsed.
* @param result Formattable to be set to the parse result.
* If parse fails, return contents are undefined.
* @param status Output param with the formatted string.
* @see NumberFormat::isParseIntegerOnly
* @stable ICU 2.0
*/
virtual void parse(const UnicodeString& text,
Formattable& result,
UErrorCode& status) const;
public:
/**
* Returns a unique class ID POLYMORPHICALLY. Pure virtual override.
* This method is to implement a simple version of RTTI, since not all
* C++ compilers support genuine RTTI. Polymorphic operator==() and
* clone() methods call this method.
*
* @return The class ID for this object. All objects of a
* given class have the same class ID. Objects of
* other classes have different class IDs.
* @stable ICU 2.0
*/
virtual UClassID getDynamicClassID(void) const;
/**
* Return the class ID for this class. This is useful only for
* comparing to a return value from getDynamicClassID(). For example:
* <pre>
* . Base* polymorphic_pointer = createPolymorphicObject();
* . if (polymorphic_pointer->getDynamicClassID() ==
* . Derived::getStaticClassID()) ...
* </pre>
* @return The class ID for all objects of this class.
* @stable ICU 2.0
*/
static UClassID U_EXPORT2 getStaticClassID(void);
private:
// static cache management (thread-safe)
// static NumberFormat* getNumberFormat(UErrorCode &status); // call this function to 'check out' a numberformat from the cache.
// static void releaseNumberFormat(NumberFormat *adopt); // call this function to 'return' the number format to the cache.
/**
* Converts a string to a double value using a default NumberFormat object
* which is static (shared by all ChoiceFormat instances).
* @param string the string to be converted with.
* @return the converted double number.
*/
static double stod(const UnicodeString& string);
/**
* Converts a double value to a string using a default NumberFormat object
* which is static (shared by all ChoiceFormat instances).
* @param value the double number to be converted with.
* @param string the result string.
* @return the converted string.
*/
static UnicodeString& dtos(double value, UnicodeString& string);
ChoiceFormat(); // default constructor not implemented
/**
* Construct a new ChoiceFormat with the limits and the corresponding formats
* based on the pattern.
*
* @param newPattern Pattern used to construct object.
* @param parseError Struct to recieve information on position
* of error if an error is encountered.
* @param status Output param to receive success code. If the
* pattern cannot be parsed, set to failure code.
* @stable ICU 2.0
*/
ChoiceFormat(const UnicodeString& newPattern,
UParseError& parseError,
UErrorCode& status);
friend class MessageFormat;
/**
* Each ChoiceFormat divides the range -Inf..+Inf into fCount
* intervals. The intervals are:
*
* 0: fChoiceLimits[0]..fChoiceLimits[1]
* 1: fChoiceLimits[1]..fChoiceLimits[2]
* ...
* fCount-2: fChoiceLimits[fCount-2]..fChoiceLimits[fCount-1]
* fCount-1: fChoiceLimits[fCount-1]..+Inf
*
* Interval 0 is special; during formatting (mapping numbers to
* strings), it also contains all numbers less than
* fChoiceLimits[0], as well as NaN values.
*
* Interval i maps to and from string fChoiceFormats[i]. When
* parsing (mapping strings to numbers), then intervals map to
* their lower limit, that is, interval i maps to fChoiceLimit[i].
*
* The intervals may be closed, half open, or open. This affects
* formatting but does not affect parsing. Interval i is affected
* by fClosures[i] and fClosures[i+1]. If fClosures[i]
* is FALSE, then the value fChoiceLimits[i] is in interval i.
* That is, intervals i and i are:
*
* i-1: ... x < fChoiceLimits[i]
* i: fChoiceLimits[i] <= x ...
*
* If fClosures[i] is TRUE, then the value fChoiceLimits[i] is
* in interval i-1. That is, intervals i-1 and i are:
*
* i-1: ... x <= fChoiceLimits[i]
* i: fChoiceLimits[i] < x ...
*
* Because of the nature of interval 0, fClosures[0] has no
* effect.
*/
double* fChoiceLimits;
UBool* fClosures;
UnicodeString* fChoiceFormats;
int32_t fCount;
};
inline UnicodeString&
ChoiceFormat::format(const Formattable& obj,
UnicodeString& appendTo,
UErrorCode& status) const {
// Don't use Format:: - use immediate base class only,
// in case immediate base modifies behavior later.
return NumberFormat::format(obj, appendTo, status);
}
inline UnicodeString&
ChoiceFormat::format(double number,
UnicodeString& appendTo) const {
return NumberFormat::format(number, appendTo);
}
inline UnicodeString&
ChoiceFormat::format(int32_t number,
UnicodeString& appendTo) const {
return NumberFormat::format(number, appendTo);
}
U_NAMESPACE_END
#endif /* #if !UCONFIG_NO_FORMATTING */
#endif // _CHOICFMT
//eof