• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 // © 2017 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 
4 // umutablecptrie.h (split out of ucptrie.h)
5 // created: 2018jan24 Markus W. Scherer
6 
7 #ifndef __UMUTABLECPTRIE_H__
8 #define __UMUTABLECPTRIE_H__
9 
10 #include "unicode/utypes.h"
11 
12 #ifndef U_HIDE_DRAFT_API
13 
14 #include "unicode/localpointer.h"
15 #include "unicode/ucpmap.h"
16 #include "unicode/ucptrie.h"
17 #include "unicode/utf8.h"
18 
19 U_CDECL_BEGIN
20 
21 /**
22  * \file
23  *
24  * This file defines a mutable Unicode code point trie.
25  *
26  * @see UCPTrie
27  * @see UMutableCPTrie
28  */
29 
30 /**
31  * Mutable Unicode code point trie.
32  * Fast map from Unicode code points (U+0000..U+10FFFF) to 32-bit integer values.
33  * For details see http://site.icu-project.org/design/struct/utrie
34  *
35  * Setting values (especially ranges) and lookup is fast.
36  * The mutable trie is only somewhat space-efficient.
37  * It builds a compacted, immutable UCPTrie.
38  *
39  * This trie can be modified while iterating over its contents.
40  * For example, it is possible to merge its values with those from another
41  * set of ranges (e.g., another mutable or immutable trie):
42  * Iterate over those source ranges; for each of them iterate over this trie;
43  * add the source value into the value of each trie range.
44  *
45  * @see UCPTrie
46  * @see umutablecptrie_buildImmutable
47  * @draft ICU 63
48  */
49 typedef struct UMutableCPTrie UMutableCPTrie;
50 
51 /**
52  * Creates a mutable trie that initially maps each Unicode code point to the same value.
53  * It uses 32-bit data values until umutablecptrie_buildImmutable() is called.
54  * umutablecptrie_buildImmutable() takes a valueWidth parameter which
55  * determines the number of bits in the data value in the resulting UCPTrie.
56  * You must umutablecptrie_close() the trie once you are done using it.
57  *
58  * @param initialValue the initial value that is set for all code points
59  * @param errorValue the value for out-of-range code points and ill-formed UTF-8/16
60  * @param pErrorCode an in/out ICU UErrorCode
61  * @return the trie
62  * @draft ICU 63
63  */
64 U_CAPI UMutableCPTrie * U_EXPORT2
65 umutablecptrie_open(uint32_t initialValue, uint32_t errorValue, UErrorCode *pErrorCode);
66 
67 /**
68  * Clones a mutable trie.
69  * You must umutablecptrie_close() the clone once you are done using it.
70  *
71  * @param other the trie to clone
72  * @param pErrorCode an in/out ICU UErrorCode
73  * @return the trie clone
74  * @draft ICU 63
75  */
76 U_CAPI UMutableCPTrie * U_EXPORT2
77 umutablecptrie_clone(const UMutableCPTrie *other, UErrorCode *pErrorCode);
78 
79 /**
80  * Closes a mutable trie and releases associated memory.
81  *
82  * @param trie the trie
83  * @draft ICU 63
84  */
85 U_CAPI void U_EXPORT2
86 umutablecptrie_close(UMutableCPTrie *trie);
87 
88 #if U_SHOW_CPLUSPLUS_API
89 
90 U_NAMESPACE_BEGIN
91 
92 /**
93  * \class LocalUMutableCPTriePointer
94  * "Smart pointer" class, closes a UMutableCPTrie via umutablecptrie_close().
95  * For most methods see the LocalPointerBase base class.
96  *
97  * @see LocalPointerBase
98  * @see LocalPointer
99  * @draft ICU 63
100  */
101 U_DEFINE_LOCAL_OPEN_POINTER(LocalUMutableCPTriePointer, UMutableCPTrie, umutablecptrie_close);
102 
103 U_NAMESPACE_END
104 
105 #endif
106 
107 /**
108  * Creates a mutable trie with the same contents as the UCPMap.
109  * You must umutablecptrie_close() the mutable trie once you are done using it.
110  *
111  * @param map the source map
112  * @param pErrorCode an in/out ICU UErrorCode
113  * @return the mutable trie
114  * @draft ICU 63
115  */
116 U_CAPI UMutableCPTrie * U_EXPORT2
117 umutablecptrie_fromUCPMap(const UCPMap *map, UErrorCode *pErrorCode);
118 
119 /**
120  * Creates a mutable trie with the same contents as the immutable one.
121  * You must umutablecptrie_close() the mutable trie once you are done using it.
122  *
123  * @param trie the immutable trie
124  * @param pErrorCode an in/out ICU UErrorCode
125  * @return the mutable trie
126  * @draft ICU 63
127  */
128 U_CAPI UMutableCPTrie * U_EXPORT2
129 umutablecptrie_fromUCPTrie(const UCPTrie *trie, UErrorCode *pErrorCode);
130 
131 /**
132  * Returns the value for a code point as stored in the trie.
133  *
134  * @param trie the trie
135  * @param c the code point
136  * @return the value
137  * @draft ICU 63
138  */
139 U_CAPI uint32_t U_EXPORT2
140 umutablecptrie_get(const UMutableCPTrie *trie, UChar32 c);
141 
142 /**
143  * Returns the last code point such that all those from start to there have the same value.
144  * Can be used to efficiently iterate over all same-value ranges in a trie.
145  * (This is normally faster than iterating over code points and get()ting each value,
146  * but much slower than a data structure that stores ranges directly.)
147  *
148  * The trie can be modified between calls to this function.
149  *
150  * If the UCPMapValueFilter function pointer is not NULL, then
151  * the value to be delivered is passed through that function, and the return value is the end
152  * of the range where all values are modified to the same actual value.
153  * The value is unchanged if that function pointer is NULL.
154  *
155  * See the same-signature ucptrie_getRange() for a code sample.
156  *
157  * @param trie the trie
158  * @param start range start
159  * @param option defines whether surrogates are treated normally,
160  *               or as having the surrogateValue; usually UCPMAP_RANGE_NORMAL
161  * @param surrogateValue value for surrogates; ignored if option==UCPMAP_RANGE_NORMAL
162  * @param filter a pointer to a function that may modify the trie data value,
163  *     or NULL if the values from the trie are to be used unmodified
164  * @param context an opaque pointer that is passed on to the filter function
165  * @param pValue if not NULL, receives the value that every code point start..end has;
166  *     may have been modified by filter(context, trie value)
167  *     if that function pointer is not NULL
168  * @return the range end code point, or -1 if start is not a valid code point
169  * @draft ICU 63
170  */
171 U_CAPI UChar32 U_EXPORT2
172 umutablecptrie_getRange(const UMutableCPTrie *trie, UChar32 start,
173                         UCPMapRangeOption option, uint32_t surrogateValue,
174                         UCPMapValueFilter *filter, const void *context, uint32_t *pValue);
175 
176 /**
177  * Sets a value for a code point.
178  *
179  * @param trie the trie
180  * @param c the code point
181  * @param value the value
182  * @param pErrorCode an in/out ICU UErrorCode
183  * @draft ICU 63
184  */
185 U_CAPI void U_EXPORT2
186 umutablecptrie_set(UMutableCPTrie *trie, UChar32 c, uint32_t value, UErrorCode *pErrorCode);
187 
188 /**
189  * Sets a value for each code point [start..end].
190  * Faster and more space-efficient than setting the value for each code point separately.
191  *
192  * @param trie the trie
193  * @param start the first code point to get the value
194  * @param end the last code point to get the value (inclusive)
195  * @param value the value
196  * @param pErrorCode an in/out ICU UErrorCode
197  * @draft ICU 63
198  */
199 U_CAPI void U_EXPORT2
200 umutablecptrie_setRange(UMutableCPTrie *trie,
201                         UChar32 start, UChar32 end,
202                         uint32_t value, UErrorCode *pErrorCode);
203 
204 /**
205  * Compacts the data and builds an immutable UCPTrie according to the parameters.
206  * After this, the mutable trie will be empty.
207  *
208  * The mutable trie stores 32-bit values until buildImmutable() is called.
209  * If values shorter than 32 bits are to be stored in the immutable trie,
210  * then the upper bits are discarded.
211  * For example, when the mutable trie contains values 0x81, -0x7f, and 0xa581,
212  * and the value width is 8 bits, then each of these is stored as 0x81
213  * and the immutable trie will return that as an unsigned value.
214  * (Some implementations may want to make productive temporary use of the upper bits
215  * until buildImmutable() discards them.)
216  *
217  * Not every possible set of mappings can be built into a UCPTrie,
218  * because of limitations resulting from speed and space optimizations.
219  * Every Unicode assigned character can be mapped to a unique value.
220  * Typical data yields data structures far smaller than the limitations.
221  *
222  * It is possible to construct extremely unusual mappings that exceed the data structure limits.
223  * In such a case this function will fail with a U_INDEX_OUTOFBOUNDS_ERROR.
224  *
225  * @param trie the trie trie
226  * @param type selects the trie type
227  * @param valueWidth selects the number of bits in a trie data value; if smaller than 32 bits,
228  *                   then the values stored in the trie will be truncated first
229  * @param pErrorCode an in/out ICU UErrorCode
230  *
231  * @see umutablecptrie_fromUCPTrie
232  * @draft ICU 63
233  */
234 U_CAPI UCPTrie * U_EXPORT2
235 umutablecptrie_buildImmutable(UMutableCPTrie *trie, UCPTrieType type, UCPTrieValueWidth valueWidth,
236                               UErrorCode *pErrorCode);
237 
238 U_CDECL_END
239 
240 #endif  // U_HIDE_DRAFT_API
241 #endif
242