name : simpleformatter.h // © 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 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 nullptr 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 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. * @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 nullptr 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 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. * @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__