scuffed-code/icu4c/source/tools/toolutil/uchartrieiterator.h

122 lines
4.1 KiB
C++

/*
*******************************************************************************
* Copyright (C) 2010, International Business Machines
* Corporation and others. All Rights Reserved.
*******************************************************************************
* file name: uchartrieiterator.h
* encoding: US-ASCII
* tab size: 8 (not used)
* indentation:4
*
* created on: 2010nov15
* created by: Markus W. Scherer
*/
#ifndef __UCHARTRIEITERATOR_H__
#define __UCHARTRIEITERATOR_H__
/**
* \file
* \brief C++ API: UCharTrie iterator for all of its (string, value) pairs.
*/
#include "unicode/utypes.h"
#include "unicode/unistr.h"
#include "uchartrie.h"
#include "uvectr32.h"
U_NAMESPACE_BEGIN
/**
* Iterator for all of the (string, value) pairs in a UCharTrie.
*/
class U_TOOLUTIL_API UCharTrieIterator : public UMemory {
public:
/**
* Iterates from the root of a UChar-serialized UCharTrie.
* @param trieUChars The trie UChars.
* @param maxStringLength If 0, the iterator returns full strings.
* Otherwise, the iterator returns strings with this maximum length.
* @param errorCode Standard ICU error code. Its input value must
* pass the U_SUCCESS() test, or else the function returns
* immediately. Check for U_FAILURE() on output or use with
* function chaining. (See User Guide for details.)
*/
UCharTrieIterator(const UChar *trieUChars, int32_t maxStringLength, UErrorCode &errorCode);
/**
* Iterates from the current state of the specified UCharTrie.
* @param trie The trie whose state will be copied for iteration.
* @param maxStringLength If 0, the iterator returns full strings.
* Otherwise, the iterator returns strings with this maximum length.
* @param errorCode Standard ICU error code. Its input value must
* pass the U_SUCCESS() test, or else the function returns
* immediately. Check for U_FAILURE() on output or use with
* function chaining. (See User Guide for details.)
*/
UCharTrieIterator(const UCharTrie &trie, int32_t maxStringLength, UErrorCode &errorCode);
/**
* Resets this iterator to its initial state.
*/
UCharTrieIterator &reset();
/**
* Finds the next (string, value) pair if there is one.
*
* If the string is truncated to the maximum length and does not
* have a real value, then the value is set to -1.
* In this case, this "not a real value" is indistinguishable from
* a real value of -1.
* @return TRUE if there is another element.
*/
UBool next(UErrorCode &errorCode);
/**
* @return TRUE if there are more elements.
*/
UBool hasNext() const { return pos_!=NULL || !stack_.isEmpty(); }
/**
* @return the NUL-terminated string for the last successful next()
*/
const UnicodeString &getString() const { return str_; }
/**
* @return the value for the last successful next()
*/
int32_t getValue() const { return value_; }
private:
UBool truncateAndStop() {
pos_=NULL;
value_=-1; // no real value for str
return TRUE;
}
const UChar *branchNext(const UChar *pos, int32_t length, UErrorCode &errorCode);
const UChar *uchars_;
const UChar *pos_;
const UChar *initialPos_;
int32_t remainingMatchLength_;
int32_t initialRemainingMatchLength_;
UBool skipValue_; // Skip intermediate value which was already delivered.
UnicodeString str_;
int32_t maxLength_;
int32_t value_;
// The stack stores pairs of integers for backtracking to another
// outbound edge of a branch node.
// The first integer is an offset from ByteTrie.bytes.
// The second integer has the str.length() from before the node in bits 15..0,
// and the remaining branch length in bits 31..16.
// (We could store the remaining branch length minus 1 in bits 30..16 and not use the sign bit,
// but the code looks more confusing that way.)
UVector32 stack_;
};
U_NAMESPACE_END
#endif // __UCHARTRIEITERATOR_H__