/* ****************************************************************************** * Copyright (C) 2014-2016, International Business Machines * Corporation and others. All Rights Reserved. ****************************************************************************** * simplepatternformatter.h */ #ifndef __SIMPLEPATTERNFORMATTER_H__ #define __SIMPLEPATTERNFORMATTER_H__ #include "unicode/utypes.h" #include "unicode/unistr.h" U_NAMESPACE_BEGIN /** * 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 throw exceptions for syntax errors * and for too few or too many arguments/placeholders. * * SimplePatternFormatter objects are immutable and can be safely cached like strings. * * Example: * <pre> * UErrorCode errorCode = U_ZERO_ERROR; * SimplePatternFormatter fmt("{1} '{born}' in {0}", errorCode); * UnicodeString result; * * // Output: "paul {born} in england" * fmt.format("england", "paul", result, errorCode); * </pre> * * @see MessageFormat * @see UMessagePatternApostropheMode */ class U_COMMON_API SimplePatternFormatter : public UMemory { public: /** * Default constructor. */ SimplePatternFormatter() : compiledPattern((UChar)0) {} /** * Constructs a formatter from the pattern string. * * @param pattern The pattern string. */ explicit SimplePatternFormatter(const UnicodeString& pattern, UErrorCode &errorCode) { compile(pattern, errorCode); } /** * Constructs a formatter from the pattern string. * * @param pattern The pattern string. * @param min The pattern must have at least this many placeholders. * @param max The pattern must have at most this many placeholders. */ SimplePatternFormatter(const UnicodeString& pattern, int32_t min, int32_t max, UErrorCode &errorCode) { compileMinMaxPlaceholders(pattern, min, max, errorCode); } /** * Copy constructor. */ SimplePatternFormatter(const SimplePatternFormatter& other) : compiledPattern(other.compiledPattern) {} /** * Assignment operator. */ SimplePatternFormatter &operator=(const SimplePatternFormatter& other); /** * Destructor. */ ~SimplePatternFormatter(); /** * Changes this object according to the new pattern. * * @param pattern The pattern string. * @return TRUE if U_SUCCESS(errorCode). */ UBool compile(const UnicodeString &pattern, UErrorCode &errorCode) { return compileMinMaxPlaceholders(pattern, 0, INT32_MAX, errorCode); } /** * Changes this object according to the new pattern. * * @param pattern The pattern string. * @param min The pattern must have at least this many placeholders. * @param max The pattern must have at most this many placeholders. * @return TRUE if U_SUCCESS(errorCode). */ UBool compileMinMaxPlaceholders(const UnicodeString &pattern, int32_t min, int32_t max, UErrorCode &errorCode); /** * @return The max argument number/placeholder ID + 1. */ int32_t getPlaceholderCount() const { return getPlaceholderCount(compiledPattern.getBuffer(), compiledPattern.length()); } /** * Formats the given value, appending to the appendTo builder. * The placeholder value must not be the same object as appendTo. * getPlaceholderCount() 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 */ UnicodeString &format( const UnicodeString &value0, UnicodeString &appendTo, UErrorCode &errorCode) const; /** * Formats the given values, appending to the appendTo builder. * A placeholder value must not be the same object as appendTo. * getPlaceholderCount() 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 */ UnicodeString &format( const UnicodeString &value0, const UnicodeString &value1, UnicodeString &appendTo, UErrorCode &errorCode) const; /** * Formats the given values, appending to the appendTo builder. * A placeholder value must not be the same object as appendTo. * getPlaceholderCount() 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 */ 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 placeholder values. * A placeholder value must not be the same object as appendTo. * Can be NULL if valuesLength==getPlaceholderCount()==0. * @param valuesLength The length of the values array. * Must be at least getPlaceholderCount(). * @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 */ 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 initial argument's corresponding value. * * @param values The placeholder values. * A placeholder value may be the same object as result. * Can be NULL if valuesLength==getPlaceholderCount()==0. * @param valuesLength The length of the values array. * Must be at least getPlaceholderCount(). * @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 */ 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 placeholders. * Like formatting with all-empty string values. */ UnicodeString getTextWithNoPlaceholders() const { return getTextWithNoPlaceholders(compiledPattern.getBuffer(), compiledPattern.length()); } 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 getPlaceholderCount(const UChar *compiledPattern, int32_t compiledPatternLength) { return compiledPatternLength == 0 ? 0 : compiledPattern[0]; } static UnicodeString getTextWithNoPlaceholders(const UChar *compiledPattern, int32_t compiledPatternLength); static UnicodeString &format( const UChar *compiledPattern, int32_t compiledPatternLength, const UnicodeString *const *values, UnicodeString &result, const UnicodeString *resultCopy, UBool forbidResultAsValue, int32_t *offsets, int32_t offsetsLength, UErrorCode &errorCode); }; U_NAMESPACE_END #endif