| /* |
| ******************************************************************************* |
| * |
| * Copyright (C) 2000, International Business Machines |
| * Corporation and others. All Rights Reserved. |
| * |
| ******************************************************************************* |
| * file name: ustring.c |
| * encoding: US-ASCII |
| * tab size: 8 (not used) |
| * indentation:4 |
| * |
| * created on: 2000aug15 |
| * created by: Markus W. Scherer |
| * |
| * This file contains sample code that illustrates the use of Unicode strings |
| * with ICU. |
| */ |
| |
| #include <stdio.h> |
| #include "unicode/utypes.h" |
| #include "unicode/ustring.h" |
| #include "unicode/unistr.h" |
| |
| // helper function --------------------------------------------------------- *** |
| |
| static void |
| printUnicodeString(const UnicodeString &s) { |
| static char out[200]; |
| int32_t i, length; |
| |
| // output the string, converted to the platform encoding |
| out[s.extract(0, 99, out)]=0; |
| printf("%s {", out); |
| |
| // output the code units |
| length=s.length(); |
| for(i=0; i<length; ++i) { |
| printf(" %04x", s.charAt(i)); |
| } |
| printf(" }\n"); |
| } |
| |
| // sample code for storage models ------------------------------------------ *** |
| |
| #define LENGTHOF(array) (sizeof(array)/sizeof((array)[0])) |
| |
| static const UChar readonly[]={ |
| 0x61, 0x31, 0x20ac |
| }; |
| static UChar writeable[]={ |
| 0x62, 0x32, 0xdbc0, 0xdc01 |
| }; |
| static char out[100]; |
| |
| static void |
| demoStorage() { |
| // These sample code lines illustrate how to use UnicodeString, and the |
| // comments tell what happens internally. There are no APIs to observe |
| // most of this programmatically, except for stepping into the code |
| // with a debugger. |
| // This is by design to hide such details from the user. |
| |
| // * UnicodeString with internally stored contents |
| // instantiate a UnicodeString from a single code point |
| // the few (2) UChars will be stored in the object itself |
| UnicodeString one((UChar32)0x24001); |
| // this copies the few UChars into the "two" object |
| UnicodeString two=one; |
| printf("length of short string copy: %d\n", two.length()); |
| // set "one" to contain the 3 UChars from readonly |
| one.setTo(readonly, LENGTHOF(readonly)); |
| |
| // * UnicodeString with allocated contents |
| // build a longer string that will not fit into the object's buffer |
| one+=UnicodeString(writeable, LENGTHOF(writeable)); |
| one+=one; |
| one+=one; |
| printf("length of longer string: %d\n", one.length()); |
| // copying will use the same allocated buffer and increment the reference |
| // counter |
| two=one; |
| printf("length of longer string copy: %d\n", two.length()); |
| |
| // * UnicodeString using readonly-alias to a const UChar array |
| // construct a string that aliases a readonly buffer |
| UnicodeString three(FALSE, readonly, LENGTHOF(readonly)); |
| UTextOffset i; |
| for(i=0; i<three.length(); ++i) { |
| printf("readonly-alias string[%d]=0x%lx\n", i, three.charAt(i)); |
| } |
| // copy-on-write: any modification to the string results in |
| // a copy to either the internal buffer or to a newly allocated one |
| three.setCharAt(1, 0x39); |
| out[three.extract(0, 99, out)]=0; |
| printf("readonly-aliasing string after modification: %s\n", out); |
| // the aliased array is not modified |
| for(i=0; i<three.length(); ++i) { |
| printf("readonly buffer[%d] after modifying its string: 0x%lx\n", |
| i, readonly[i]); |
| } |
| // setTo() readonly alias |
| one.setTo(FALSE, writeable, LENGTHOF(writeable)); |
| // copying the readonly-alias object will readonly-alias the same buffer |
| two=one; |
| out[two.extract(0, 99, out)]=0; |
| printf("copy of readonly-alias string of \"writeable\" array: %s\n", out); |
| |
| // * UnicodeString using writeable-alias to a non-const UChar array |
| UnicodeString four(writeable, LENGTHOF(writeable), LENGTHOF(writeable)); |
| for(i=0; i<four.length(); ++i) { |
| printf("writeable-alias string[%d]=0x%lx\n", i, four.charAt(i)); |
| } |
| // a modification writes through to the buffer |
| four.setCharAt(1, 0x39); |
| for(i=0; i<four.length(); ++i) { |
| printf("writeable-alias backing buffer[%d]=0x%lx " |
| "after modification\n", i, writeable[i]); |
| } |
| // a copy will not alias any more; |
| // instead, it will get a copy of the contents into allocated memory |
| two=four; |
| two.setCharAt(1, 0x21); |
| for(i=0; i<two.length(); ++i) { |
| printf("writeable-alias backing buffer[%d]=0x%lx after " |
| "modification of string copy\n", i, writeable[i]); |
| } |
| // setTo() writeable alias |
| one.setTo(writeable, LENGTHOF(writeable), LENGTHOF(writeable)); |
| // grow the string - it will not fit into the backing buffer any more |
| // and will get copied before modification |
| one.append((UChar)0x40); |
| // shrink it back so it would fit |
| one.truncate(one.length()-1); |
| // we still operate on the copy |
| one.setCharAt(1, 0x25); |
| printf("string after growing too much and then shrinking[1]=0x%lx\n" |
| " backing store for this[1]=0x%lx\n", |
| one.charAt(1), writeable[1]); |
| // if we need it in the original buffer, then extract() to it |
| // extract() does not do anything if the string aliases that same buffer |
| // i=min(one.length(), length of array) |
| if(one.length()<LENGTHOF(writeable)) { |
| i=one.length(); |
| } else { |
| i=LENGTHOF(writeable); |
| } |
| one.extract(0, i, writeable); |
| for(i=0; i<LENGTHOF(writeable); ++i) { |
| printf("writeable-alias backing buffer[%d]=0x%lx after re-extract\n", |
| i, writeable[i]); |
| } |
| } |
| |
| // sample code for instantiating Unicode strings --------------------------- *** |
| |
| static void |
| initString() { |
| // the string literal is 32 chars long - this must be counted for the macro |
| UnicodeString invariantOnly=UNICODE_STRING("such characters are safe 123 %-.", 32); |
| |
| /* |
| * In C, we need two macros: one to declare the UChar[] array, and |
| * one to populate it; the second one is a noop on platforms where |
| * wchar_t is compatible with UChar and ASCII-based. |
| * The length of the string literal must be counted for both macros. |
| */ |
| /* declare the invString array for the string */ |
| U_STRING_DECL(invString, "such characters are safe 123 %-.", 32); |
| /* populate it with the characters */ |
| U_STRING_INIT(invString, "such characters are safe 123 %-.", 32); |
| |
| // compare the C and C++ strings |
| printf("C and C++ Unicode strings are equal: %d\n", invariantOnly==UnicodeString(TRUE, invString, 32)); |
| |
| /* |
| * convert between char * and UChar * strings that |
| * contain only invariant characters |
| */ |
| static const char *cs1="such characters are safe 123 %-."; |
| static UChar us1[40]; |
| static char cs2[40]; |
| u_charsToUChars(cs1, us1, 33); /* include the terminating NUL */ |
| u_UCharsToChars(us1, cs2, 33); |
| printf("char * -> UChar * -> char * with only " |
| "invariant characters: \"%s\"\n", |
| cs2); |
| |
| // initialize a UnicodeString from a string literal that contains |
| // escape sequences written with invariant characters |
| // do not forget to duplicate the backslashes for ICU to see them |
| // then, count each double backslash only once! |
| UnicodeString german=UNICODE_STRING( |
| "Sch\\u00f6nes Auto: \\u20ac 11240.\\fPrivates Zeichen: \\U00102345\\n", 64). |
| unescape(); |
| printf("german UnicodeString from unescaping:\n "); |
| printUnicodeString(german); |
| |
| /* |
| * C: convert and unescape a char * string with only invariant |
| * characters to fill a UChar * string |
| */ |
| UChar buffer[200]; |
| int32_t length; |
| length=u_unescape( |
| "Sch\\u00f6nes Auto: \\u20ac 11240.\\fPrivates Zeichen: \\U00102345\\n", |
| buffer, LENGTHOF(buffer)); |
| printf("german C Unicode string from char * unescaping: (length %d)\n ", length); |
| printUnicodeString(UnicodeString(buffer)); |
| } |
| |
| extern int |
| main(int argc, const char *argv[]) { |
| demoStorage(); |
| initString(); |
| |
| return 0; |
| } |