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// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
******************************************************************************
* Copyright (C) 2014-2016, International Business Machines
* Corporation and others. All Rights Reserved.
******************************************************************************
* simpleformatter.h
*/
#ifndef __SIMPLEFORMATTER_H__
#define __SIMPLEFORMATTER_H__
/**
* \file
* \brief C++ API: Simple formatter, minimal subset of MessageFormat.
*/
#include "unicode/utypes.h"
#if U_SHOW_CPLUSPLUS_API
#include "unicode/unistr.h"
U_NAMESPACE_BEGIN
// Forward declaration:
namespace number {
namespace impl {
class SimpleModifier;
}
}
/**
* Formats simple patterns like "{1} was born in {0}".
* Minimal subset of MessageFormat; fast, simple, minimal dependencies.
* Supports only numbered arguments with no type nor style parameters,
* and formats only string values.
* Quoting via ASCII apostrophe compatible with ICU MessageFormat default behavior.
*
* Factory methods set error codes for syntax errors
* and for too few or too many arguments/placeholders.
*
* SimpleFormatter objects are thread-safe except for assignment and applying new patterns.
*
* Example:
* <pre>
* UErrorCode errorCode = U_ZERO_ERROR;
* SimpleFormatter fmt("{1} '{born}' in {0}", errorCode);
* UnicodeString result;
*
* // Output: "paul {born} in england"
* fmt.format("england", "paul", result, errorCode);
* </pre>
*
* This class is not intended for public subclassing.
*
* @see MessageFormat
* @see UMessagePatternApostropheMode
* @stable ICU 57
*/
class U_COMMON_API SimpleFormatter U_FINAL : public UMemory {
public:
/**
* Default constructor.
* @stable ICU 57
*/
SimpleFormatter() : compiledPattern((char16_t)0) {}
/**
* Constructs a formatter from the pattern string.
*
* @param pattern The pattern string.
* @param errorCode ICU error code in/out parameter.
* Must fulfill U_SUCCESS before the function call.
* Set to U_ILLEGAL_ARGUMENT_ERROR for bad argument syntax.
* @stable ICU 57
*/
SimpleFormatter(const UnicodeString& pattern, UErrorCode &errorCode) {
applyPattern(pattern, errorCode);
}
/**
* Constructs a formatter from the pattern string.
* The number of arguments checked against the given limits is the
* highest argument number plus one, not the number of occurrences of arguments.
*
* @param pattern The pattern string.
* @param min The pattern must have at least this many arguments.
* @param max The pattern must have at most this many arguments.
* @param errorCode ICU error code in/out parameter.
* Must fulfill U_SUCCESS before the function call.
* Set to U_ILLEGAL_ARGUMENT_ERROR for bad argument syntax and
* too few or too many arguments.
* @stable ICU 57
*/
SimpleFormatter(const UnicodeString& pattern, int32_t min, int32_t max,
UErrorCode &errorCode) {
applyPatternMinMaxArguments(pattern, min, max, errorCode);
}
/**
* Copy constructor.
* @stable ICU 57
*/
SimpleFormatter(const SimpleFormatter& other)
: compiledPattern(other.compiledPattern) {}
/**
* Assignment operator.
* @stable ICU 57
*/
SimpleFormatter &operator=(const SimpleFormatter& other);
/**
* Destructor.
* @stable ICU 57
*/
~SimpleFormatter();
/**
* Changes this object according to the new pattern.
*
* @param pattern The pattern string.
* @param errorCode ICU error code in/out parameter.
* Must fulfill U_SUCCESS before the function call.
* Set to U_ILLEGAL_ARGUMENT_ERROR for bad argument syntax.
* @return TRUE if U_SUCCESS(errorCode).
* @stable ICU 57
*/
UBool applyPattern(const UnicodeString &pattern, UErrorCode &errorCode) {
return applyPatternMinMaxArguments(pattern, 0, INT32_MAX, errorCode);
}
/**
* Changes this object according to the new pattern.
* The number of arguments checked against the given limits is the
* highest argument number plus one, not the number of occurrences of arguments.
*
* @param pattern The pattern string.
* @param min The pattern must have at least this many arguments.
* @param max The pattern must have at most this many arguments.
* @param errorCode ICU error code in/out parameter.
* Must fulfill U_SUCCESS before the function call.
* Set to U_ILLEGAL_ARGUMENT_ERROR for bad argument syntax and
* too few or too many arguments.
* @return TRUE if U_SUCCESS(errorCode).
* @stable ICU 57
*/
UBool applyPatternMinMaxArguments(const UnicodeString &pattern,
int32_t min, int32_t max, UErrorCode &errorCode);
/**
* @return The max argument number + 1.
* @stable ICU 57
*/
int32_t getArgumentLimit() const {
return getArgumentLimit(compiledPattern.getBuffer(), compiledPattern.length());
}
/**
* Formats the given value, appending to the appendTo builder.
* The argument value must not be the same object as appendTo.
* getArgumentLimit() must be at most 1.
*
* @param value0 Value for argument {0}.
* @param appendTo Gets the formatted pattern and value appended.
* @param errorCode ICU error code in/out parameter.
* Must fulfill U_SUCCESS before the function call.
* @return appendTo
* @stable ICU 57
*/
UnicodeString &format(
const UnicodeString &value0,
UnicodeString &appendTo, UErrorCode &errorCode) const;
/**
* Formats the given values, appending to the appendTo builder.
* An argument value must not be the same object as appendTo.
* getArgumentLimit() must be at most 2.
*
* @param value0 Value for argument {0}.
* @param value1 Value for argument {1}.
* @param appendTo Gets the formatted pattern and values appended.
* @param errorCode ICU error code in/out parameter.
* Must fulfill U_SUCCESS before the function call.
* @return appendTo
* @stable ICU 57
*/
UnicodeString &format(
const UnicodeString &value0,
const UnicodeString &value1,
UnicodeString &appendTo, UErrorCode &errorCode) const;
/**
* Formats the given values, appending to the appendTo builder.
* An argument value must not be the same object as appendTo.
* getArgumentLimit() must be at most 3.
*
* @param value0 Value for argument {0}.
* @param value1 Value for argument {1}.
* @param value2 Value for argument {2}.
* @param appendTo Gets the formatted pattern and values appended.
* @param errorCode ICU error code in/out parameter.
* Must fulfill U_SUCCESS before the function call.
* @return appendTo
* @stable ICU 57
*/
UnicodeString &format(
const UnicodeString &value0,
const UnicodeString &value1,
const UnicodeString &value2,
UnicodeString &appendTo, UErrorCode &errorCode) const;
/**
* Formats the given values, appending to the appendTo string.
*
* @param values The argument values.
* An argument value must not be the same object as appendTo.
* Can be NULL if valuesLength==getArgumentLimit()==0.
* @param valuesLength The length of the values array.
* Must be at least getArgumentLimit().
* @param appendTo Gets the formatted pattern and values appended.
* @param offsets offsets[i] receives the offset of where
* values[i] replaced pattern argument {i}.
* Can be shorter or longer than values. Can be NULL if offsetsLength==0.
* If there is no {i} in the pattern, then offsets[i] is set to -1.
* @param offsetsLength The length of the offsets array.
* @param errorCode ICU error code in/out parameter.
* Must fulfill U_SUCCESS before the function call.
* @return appendTo
* @stable ICU 57
*/
UnicodeString &formatAndAppend(
const UnicodeString *const *values, int32_t valuesLength,
UnicodeString &appendTo,
int32_t *offsets, int32_t offsetsLength, UErrorCode &errorCode) const;
/**
* Formats the given values, replacing the contents of the result string.
* May optimize by actually appending to the result if it is the same object
* as the value corresponding to the initial argument in the pattern.
*
* @param values The argument values.
* An argument value may be the same object as result.
* Can be NULL if valuesLength==getArgumentLimit()==0.
* @param valuesLength The length of the values array.
* Must be at least getArgumentLimit().
* @param result Gets its contents replaced by the formatted pattern and values.
* @param offsets offsets[i] receives the offset of where
* values[i] replaced pattern argument {i}.
* Can be shorter or longer than values. Can be NULL if offsetsLength==0.
* If there is no {i} in the pattern, then offsets[i] is set to -1.
* @param offsetsLength The length of the offsets array.
* @param errorCode ICU error code in/out parameter.
* Must fulfill U_SUCCESS before the function call.
* @return result
* @stable ICU 57
*/
UnicodeString &formatAndReplace(
const UnicodeString *const *values, int32_t valuesLength,
UnicodeString &result,
int32_t *offsets, int32_t offsetsLength, UErrorCode &errorCode) const;
/**
* Returns the pattern text with none of the arguments.
* Like formatting with all-empty string values.
* @stable ICU 57
*/
UnicodeString getTextWithNoArguments() const {
return getTextWithNoArguments(
compiledPattern.getBuffer(),
compiledPattern.length(),
nullptr,
0);
}
#ifndef U_HIDE_INTERNAL_API
/**
* Returns the pattern text with none of the arguments.
* Like formatting with all-empty string values.
*
* TODO(ICU-20406): Replace this with an Iterator interface.
*
* @param offsets offsets[i] receives the offset of where {i} was located
* before it was replaced by an empty string.
* For example, "a{0}b{1}" produces offset 1 for i=0 and 2 for i=1.
* Can be nullptr if offsetsLength==0.
* If there is no {i} in the pattern, then offsets[i] is set to -1.
* @param offsetsLength The length of the offsets array.
*
* @internal
*/
UnicodeString getTextWithNoArguments(int32_t *offsets, int32_t offsetsLength) const {
return getTextWithNoArguments(
compiledPattern.getBuffer(),
compiledPattern.length(),
offsets,
offsetsLength);
}
#endif // U_HIDE_INTERNAL_API
private:
/**
* Binary representation of the compiled pattern.
* Index 0: One more than the highest argument number.
* Followed by zero or more arguments or literal-text segments.
*
* An argument is stored as its number, less than ARG_NUM_LIMIT.
* A literal-text segment is stored as its length (at least 1) offset by ARG_NUM_LIMIT,
* followed by that many chars.
*/
UnicodeString compiledPattern;
static inline int32_t getArgumentLimit(const char16_t *compiledPattern,
int32_t compiledPatternLength) {
return compiledPatternLength == 0 ? 0 : compiledPattern[0];
}
static UnicodeString getTextWithNoArguments(
const char16_t *compiledPattern,
int32_t compiledPatternLength,
int32_t *offsets,
int32_t offsetsLength);
static UnicodeString &format(
const char16_t *compiledPattern, int32_t compiledPatternLength,
const UnicodeString *const *values,
UnicodeString &result, const UnicodeString *resultCopy, UBool forbidResultAsValue,
int32_t *offsets, int32_t offsetsLength,
UErrorCode &errorCode);
// Give access to internals to SimpleModifier for number formatting
friend class number::impl::SimpleModifier;
};
U_NAMESPACE_END
#endif /* U_SHOW_CPLUSPLUS_API */
#endif // __SIMPLEFORMATTER_H__