| /* |
| ****************************************************************************** |
| * Copyright (C) 2014-2015, International Business Machines |
| * Corporation and others. All Rights Reserved. |
| ****************************************************************************** |
| * simplepatternformatter.h |
| */ |
| |
| #ifndef __SIMPLEPATTERNFORMATTER_H__ |
| #define __SIMPLEPATTERNFORMATTER_H__ |
| |
| #define EXPECTED_PLACEHOLDER_COUNT 3 |
| |
| #include "cmemory.h" |
| #include "unicode/utypes.h" |
| #include "unicode/unistr.h" |
| |
| U_NAMESPACE_BEGIN |
| |
| class SimplePatternFormatterPlaceholderValues; |
| |
| struct PlaceholderInfo { |
| int32_t id; |
| int32_t offset; |
| }; |
| |
| /** |
| * Compiled version of a pattern string such as "{1} was born in {0}". |
| * <p> |
| * Using SimplePatternFormatter is both faster and safer than adhoc replacement. |
| * They are faster because they are precompiled; they are safer because they |
| * account for curly braces escaped by apostrophe ('). |
| * |
| * Placeholders are of the form \{[0-9]+\}. If a curly brace is preceded |
| * by a single quote, it becomes a curly brace instead of the start of a |
| * placeholder. Two single quotes resolve to one single quote. |
| * <p> |
| * Example: |
| * <pre> |
| * SimplePatternFormatter fmt("{1} '{born} in {0}"); |
| * UnicodeString result; |
| * UErrorCode status = U_ZERO_ERROR; |
| * // Evaluates to: "paul {born} in england" |
| * fmt.format("england", "paul", result, status); |
| * </pre> |
| */ |
| class U_COMMON_API SimplePatternFormatter : public UMemory { |
| public: |
| /** |
| * Default constructor |
| */ |
| SimplePatternFormatter(); |
| |
| /** |
| * Constructs from a pattern. Will never fail if pattern has three or |
| * fewer placeholders in it. |
| */ |
| explicit SimplePatternFormatter(const UnicodeString& pattern); |
| |
| /** |
| * Constructs from a pattern. Will never fail if pattern has three or |
| * fewer placeholders in it. |
| * |
| * @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); |
| |
| /** |
| * Copy constructor. |
| */ |
| SimplePatternFormatter(const SimplePatternFormatter& other); |
| |
| /** |
| * Assignment operator |
| */ |
| SimplePatternFormatter &operator=(const SimplePatternFormatter& other); |
| |
| /** |
| * Destructor. |
| */ |
| ~SimplePatternFormatter(); |
| |
| /** |
| * Compiles pattern and makes this object represent pattern. |
| * |
| * Returns TRUE on success; FALSE on failure. Will not fail if |
| * there are three or fewer placeholders in pattern. May fail with |
| * U_MEMORY_ALLOCATION_ERROR if there are more than three placeholders. |
| */ |
| UBool compile(const UnicodeString &pattern, UErrorCode &status) { |
| return compileMinMaxPlaceholders(pattern, 0, INT32_MAX, status); |
| } |
| |
| /** |
| * Compiles pattern and makes this object represent pattern. |
| * |
| * Returns TRUE on success; FALSE on failure. Will not fail if |
| * there are three or fewer placeholders in pattern. May fail with |
| * U_MEMORY_ALLOCATION_ERROR if there are more than three placeholders. |
| * |
| * @param min The pattern must have at least this many placeholders. |
| * @param max The pattern must have at most this many placeholders. |
| */ |
| UBool compileMinMaxPlaceholders(const UnicodeString &pattern, |
| int32_t min, int32_t max, UErrorCode &status); |
| |
| /** |
| * Returns (maxPlaceholderId + 1). For example |
| * <code>SimplePatternFormatter("{0} {2}").getPlaceholderCount() |
| * evaluates to 3. |
| * Callers use this function to find out how many values this object |
| * expects when formatting. |
| */ |
| int32_t getPlaceholderCount() const { |
| return placeholderCount; |
| } |
| |
| /** |
| * Returns this pattern with none of the placeholders. |
| */ |
| const UnicodeString &getPatternWithNoPlaceholders() const { |
| return noPlaceholders; |
| } |
| |
| /** |
| * Formats given value. arg0 cannot be appendTo. |
| */ |
| UnicodeString &format( |
| const UnicodeString &args0, |
| UnicodeString &appendTo, |
| UErrorCode &status) const; |
| |
| /** |
| * Formats given values. Neither arg0 nor arg1 can be appendTo. |
| */ |
| UnicodeString &format( |
| const UnicodeString &args0, |
| const UnicodeString &args1, |
| UnicodeString &appendTo, |
| UErrorCode &status) const; |
| |
| /** |
| * Formats given values. Neither arg0, arg1, nor arg2 can be appendTo. |
| */ |
| UnicodeString &format( |
| const UnicodeString &args0, |
| const UnicodeString &args1, |
| const UnicodeString &args2, |
| UnicodeString &appendTo, |
| UErrorCode &status) const; |
| |
| /** |
| * Formats given values. |
| * |
| * The caller retains ownership of all pointers. |
| * @param placeholderValues 1st one corresponds to {0}; 2nd to {1}; |
| * 3rd to {2} etc. If any of these point to appendTo, this method |
| * sets status to U_ILLEGAL_ARGUMENT_ERROR. |
| * @param placeholderValueCount the number of placeholder values |
| * must be at least large enough to provide values for all placeholders |
| * in this object. Otherwise status set to U_ILLEGAL_ARGUMENT_ERROR. |
| * @param appendTo resulting string appended here. |
| * @param offsetArray The offset of each placeholder value in appendTo |
| * stored here. The first value gets the offset of the value for {0}; |
| * the 2nd for {1}; the 3rd for {2} etc. -1 means that the corresponding |
| * placeholder does not exist in this object. If caller is not |
| * interested in offsets, it may pass NULL and 0 for the length. |
| * @param offsetArrayLength the size of offsetArray. If less than |
| * placeholderValueCount only the first offsets get recorded. If |
| * greater than placeholderValueCount, then extra values in offset |
| * array are set to -1. |
| * @param status any error stored here. |
| */ |
| UnicodeString &formatAndAppend( |
| const UnicodeString * const *placeholderValues, |
| int32_t placeholderValueCount, |
| UnicodeString &appendTo, |
| int32_t *offsetArray, |
| int32_t offsetArrayLength, |
| UErrorCode &status) const; |
| |
| /** |
| * Formats given values. |
| * |
| * The caller retains ownership of all pointers. |
| * @param placeholderValues 1st one corresponds to {0}; 2nd to {1}; |
| * 3rd to {2} etc. May include pointer to result in which case |
| * the previous value of result is used for the corresponding |
| * placeholder. |
| * @param placeholderValueCount the number of placeholder values |
| * must be at least large enough to provide values for all placeholders |
| * in this object. Otherwise status set to U_ILLEGAL_ARGUMENT_ERROR. |
| * @param result resulting string stored here overwriting any previous |
| * value. |
| * @param offsetArray The offset of each placeholder value in result |
| * stored here. The first value gets the offset of the value for {0}; |
| * the 2nd for {1}; the 3rd for {2} etc. -1 means that the corresponding |
| * placeholder does not exist in this object. If caller is not |
| * interested in offsets, it may pass NULL and 0 for the length. |
| * @param offsetArrayLength the size of offsetArray. If less than |
| * placeholderValueCount only the first offsets get recorded. If |
| * greater than placeholderValueCount, then extra values in offset |
| * array are set to -1. |
| * @param status any error stored here. |
| */ |
| UnicodeString &formatAndReplace( |
| const UnicodeString * const *placeholderValues, |
| int32_t placeholderValueCount, |
| UnicodeString &result, |
| int32_t *offsetArray, |
| int32_t offsetArrayLength, |
| UErrorCode &status) const; |
| private: |
| UnicodeString noPlaceholders; |
| MaybeStackArray<PlaceholderInfo, 3> placeholders; |
| int32_t placeholderSize; |
| int32_t placeholderCount; |
| UBool firstPlaceholderReused; |
| |
| // A Placeholder value that is the same as appendTo is treated as the |
| // empty string. |
| UnicodeString &formatAndAppend( |
| const SimplePatternFormatterPlaceholderValues &placeholderValues, |
| UnicodeString &appendTo, |
| int32_t *offsetArray, |
| int32_t offsetArrayLength) const; |
| |
| // Returns the placeholder at the beginning of this pattern |
| // (e.g 3 for placeholder {3}). Returns -1 if the beginning of pattern |
| // is text or if the placeholder at the beginning of this pattern |
| // is used again in the middle of the pattern. |
| int32_t getUniquePlaceholderAtStart() const; |
| |
| // ensureCapacity ensures that the capacity of the placeholders array |
| // is desiredCapacity. If ensureCapacity must resize the placeholders |
| // array, the first placeholderSize elements stay in the array. Note |
| // that ensureCapcity NEVER changes the value of placeholderSize only |
| // the capacity of the placeholders array. |
| // If there is no memory allocation error when resizing, this |
| // function returns desiredCapacity. If there is a memory allocation |
| // error, this function leaves the placeholders array unchanged and |
| // returns the smaller, old capacity. ensureCapacity resizes only if |
| // the current capacity of placeholders array is less than desiredCapacity. |
| // Otherwise, it leaves the placeholders array unchanged. If caller |
| // specifies an allocation size, then it must be at least as large as |
| // desiredCapacity. In that case, if ensureCapacity resizes, it will |
| // allocate allocationSize spots instead of desiredCapacity spots in |
| // the array. If caller is calling ensureCapacity in a loop while adding |
| // elements, it is recommended that it use an allocationSize of |
| // approximately twice desiredCapacity to avoid memory allocation with |
| // every call to ensureCapacity. |
| int32_t ensureCapacity(int32_t desiredCapacity, int32_t allocationSize=0); |
| |
| // Records the offset of an individual placeholder in the noPlaceholders |
| // string. |
| UBool addPlaceholder(int32_t id, int32_t offset); |
| }; |
| |
| U_NAMESPACE_END |
| |
| #endif |
