Method Prev

src/string.cpp:712–742

	}

	size_t Prev(IterType what) override
	{
		int32_t pos;
		switch (what) {
			case ITER_CHARACTER:
				pos = this->char_itr->previous();
				break;

			case ITER_WORD:
				pos = this->word_itr->preceding(this->char_itr->current());
				/* The ICU word iterator considers both the start and the end of a word a valid
				 * break point, but we only want word starts. Move to the previous location in
				 * case the new position points to whitespace. */
				while (pos != icu::BreakIterator::DONE &&
						IsWhitespace(Utf16DecodeChar((const uint16_t *)&this->utf16_str[pos]))) {
					int32_t new_pos = this->word_itr->previous();
					/* Don't set it to DONE if it was valid before. Otherwise we'll return END
					 * even though the iterator wasn't at the start of the string before. */
					if (new_pos == icu::BreakIterator::DONE) break;
					pos = new_pos;
				}

				this->char_itr->isBoundary(pos);
				break;

			default:
				NOT_REACHED();
		}

		return pos == icu::BreakIterator::DONE ? END : this->utf16_to_utf8[pos];
	}
};

/* static */ std::unique_ptr<StringIterator> StringIterator::Create()