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// © 2017 and later: Unicode, Inc. and others.
// License & terms of use:
#include "unicode/utypes.h"
#include <cstdint>
#include "number_types.h"
#include "unicode/stringpiece.h"
#include "unicode/unistr.h"
#include "formatted_string_builder.h"
#include "unicode/uniset.h"
U_NAMESPACE_BEGIN namespace number {
namespace impl {
enum AffixPatternState {
// enum AffixPatternType defined in internals.h
struct AffixTag {
int32_t offset;
UChar32 codePoint;
AffixPatternState state;
AffixPatternType type;
: offset(0), state(STATE_BASE) {}
AffixTag(int32_t offset)
: offset(offset) {}
AffixTag(int32_t offset, UChar32 codePoint, AffixPatternState state, AffixPatternType type)
: offset(offset), codePoint(codePoint), state(state), type(type) {}
class TokenConsumer {
virtual ~TokenConsumer();
virtual void consumeToken(AffixPatternType type, UChar32 cp, UErrorCode& status) = 0;
// Exported as U_I18N_API because it is a base class for other exported types
class U_I18N_API SymbolProvider {
virtual ~SymbolProvider();
// TODO: Could this be more efficient if it returned by reference?
virtual UnicodeString getSymbol(AffixPatternType type) const = 0;
* Performs manipulations on affix patterns: the prefix and suffix strings associated with a decimal
* format pattern. For example:
* <table>
* <tr><th>Affix Pattern</th><th>Example Unescaped (Formatted) String</th></tr>
* <tr><td>abc</td><td>abc</td></tr>
* <tr><td>ab-</td><td>ab−</td></tr>
* <tr><td>ab'-'</td><td>ab-</td></tr>
* <tr><td>ab''</td><td>ab'</td></tr>
* </table>
* To manually iterate over tokens in a literal string, use the following pattern, which is designed
* to be efficient.
* <pre>
* long tag = 0L;
* while (AffixPatternUtils.hasNext(tag, patternString)) {
* tag = AffixPatternUtils.nextToken(tag, patternString);
* int typeOrCp = AffixPatternUtils.getTypeOrCp(tag);
* switch (typeOrCp) {
* case AffixPatternUtils.TYPE_MINUS_SIGN:
* // Current token is a minus sign.
* break;
* case AffixPatternUtils.TYPE_PLUS_SIGN:
* // Current token is a plus sign.
* break;
* case AffixPatternUtils.TYPE_PERCENT:
* // Current token is a percent sign.
* break;
* // ... other types ...
* default:
* // Current token is an arbitrary code point.
* // The variable typeOrCp is the code point.
* break;
* }
* }
* </pre>
class U_I18N_API AffixUtils {
* Estimates the number of code points present in an unescaped version of the affix pattern string
* (one that would be returned by {@link #unescape}), assuming that all interpolated symbols
* consume one code point and that currencies consume as many code points as their symbol width.
* Used for computing padding width.
* @param patternString The original string whose width will be estimated.
* @return The length of the unescaped string.
static int32_t estimateLength(const UnicodeString& patternString, UErrorCode& status);
* Takes a string and escapes (quotes) characters that have special meaning in the affix pattern
* syntax. This function does not reverse-lookup symbols.
* <p>Example input: "-$x"; example output: "'-'$x"
* @param input The string to be escaped.
* @return The resulting UnicodeString.
static UnicodeString escape(const UnicodeString& input);
static Field getFieldForType(AffixPatternType type);
* Executes the unescape state machine. Replaces the unquoted characters "-", "+", "%", "‰", and
* "¤" with the corresponding symbols provided by the {@link SymbolProvider}, and inserts the
* result into the FormattedStringBuilder at the requested location.
* <p>Example input: "'-'¤x"; example output: "-$x"
* @param affixPattern The original string to be unescaped.
* @param output The FormattedStringBuilder to mutate with the result.
* @param position The index into the FormattedStringBuilder to insert the string.
* @param provider An object to generate locale symbols.
static int32_t unescape(const UnicodeString& affixPattern, FormattedStringBuilder& output,
int32_t position, const SymbolProvider& provider, Field field,
UErrorCode& status);
* Sames as {@link #unescape}, but only calculates the code point count. More efficient than {@link #unescape}
* if you only need the length but not the string itself.
* @param affixPattern The original string to be unescaped.
* @param provider An object to generate locale symbols.
* @return The same return value as if you called {@link #unescape}.
static int32_t unescapedCodePointCount(const UnicodeString& affixPattern,
const SymbolProvider& provider, UErrorCode& status);
* Checks whether the given affix pattern contains at least one token of the given type, which is
* one of the constants "TYPE_" in {@link AffixPatternUtils}.
* @param affixPattern The affix pattern to check.
* @param type The token type.
* @return true if the affix pattern contains the given token type; false otherwise.
static bool containsType(const UnicodeString& affixPattern, AffixPatternType type, UErrorCode& status);
* Checks whether the specified affix pattern has any unquoted currency symbols ("¤").
* @param affixPattern The string to check for currency symbols.
* @return true if the literal has at least one unquoted currency symbol; false otherwise.
static bool hasCurrencySymbols(const UnicodeString& affixPattern, UErrorCode& status);
* Replaces all occurrences of tokens with the given type with the given replacement char.
* @param affixPattern The source affix pattern (does not get modified).
* @param type The token type.
* @param replacementChar The char to substitute in place of chars of the given token type.
* @return A string containing the new affix pattern.
static UnicodeString replaceType(const UnicodeString& affixPattern, AffixPatternType type,
char16_t replacementChar, UErrorCode& status);
* Returns whether the given affix pattern contains only symbols and ignorables as defined by the
* given ignorables set.
static bool containsOnlySymbolsAndIgnorables(const UnicodeString& affixPattern,
const UnicodeSet& ignorables, UErrorCode& status);
* Iterates over the affix pattern, calling the TokenConsumer for each token.
static void iterateWithConsumer(const UnicodeString& affixPattern, TokenConsumer& consumer,
UErrorCode& status);
* Returns the next token from the affix pattern.
* @param tag A bitmask used for keeping track of state from token to token. The initial value
* should be 0L.
* @param patternString The affix pattern.
* @return The bitmask tag to pass to the next call of this method to retrieve the following token
* (never negative), or -1 if there were no more tokens in the affix pattern.
* @see #hasNext
static AffixTag nextToken(AffixTag tag, const UnicodeString& patternString, UErrorCode& status);
* Returns whether the affix pattern string has any more tokens to be retrieved from a call to
* {@link #nextToken}.
* @param tag The bitmask tag of the previous token, as returned by {@link #nextToken}.
* @param string The affix pattern.
* @return true if there are more tokens to consume; false otherwise.
static bool hasNext(const AffixTag& tag, const UnicodeString& string);
* Encodes the given values into a tag struct.
* The order of the arguments is consistent with Java, but the order of the stored
* fields is not necessarily the same.
static inline AffixTag makeTag(int32_t offset, AffixPatternType type, AffixPatternState state,
UChar32 cp) {
return {offset, cp, state, type};
} // namespace impl
} // namespace number
#endif /* #if !UCONFIG_NO_FORMATTING */