NAME

VSTRING is C++ string manipulation and handling library with Unicode support.

SYNOPSIS

#include "vstring.h"
#include "vstrlib.h"

VString str = "Hello";
str += " World";    // str is 'Hello World' now
str_reverse( str ); // str is 'dlroW olleH' now
str_low( str );     // lower case

VArray va = str_split( " +", str ); // array has 'dlroW', 'olleH'
                                    // " +" is Regexp
str_reverse( va[0] );
str_reverse( va[1] );

str = str_join( va, " " );  // str is back to "Hello World"

VTrie tr = va;

// tr[ "Hello" ] contains "World"

DESCRIPTION

VSTRING provides dynamic strings and char* compatibility and also Perl-like arrays, hashes and regexp objects. It also offers wide char (wchar_t) support for ISO10646/Unicode strings.

The dynamic string object can be freely exchanged with standard char* (or wchar_t*) type, so there is no need to change function calls nor the implementation when you change from char* to String (and vice versa). The main difference from other similar libs is that the dynamic string class has no visible methods (except operators) so you will use it as a plain char* but it will expand/shrink as needed.

All classes (VString, VArray, Vtrie and their counterparts WString, WArray, WTrie) implementation provide shallow copy and copy-on-write functionality so assignment operators like:

str1  = str2
arr1  = arr2
trie1 = tri2

are cheap and fast!

REFERENCE

vstring.h and vstrlib.h files can be used as reference. This file contains brief introduction and some notes but for further API documentation check the .h files.

BASE char*/wchar_t* AND VString/WString FUNCTIONS NOTES

All functions for char*/wchar_t* handling may overflow! If you need safe strings, use the same functions but with VString instead of char* (and WString instead of wchar_t*).

Functions common for char* and VString:

str_set( str, "hello" );
str_mul( str, 4 );
str_replace( str, "o", " " );
str_left( dest_str, str, 4 );
str_up( dest_str );

In the examples above, str, dest_str and source_str may be either char* or VString.

VString CLASS NOTES

VString str = "hello";
str += " world";
if( str == "hello world") { ... }
int len = str_len( str );
str[3] = 'z'; // safe! even outside string boundaries

VArray CLASS NOTES

VArray va;

// append array elements
va.push( "element 1" );
va.push( str ); // i.e. VString
va.push( other_varray ); 
va.push( trie ); // see VTrie below

// take out the last element
VString str = va.pop()

// push elements at the beginning 
va.unshift( "element 1" );
va.unshift( str ); // i.e. VString
va.unshift( other_varray ); 
va.unshift( trie ); // see VTrie below

// take out the first element
VString str = va.shift();

va.reverse(); // reverse elements order
va.undef(); // remove all elements

VTrie CLASS NOTES

VTrie tr;

tr[ "hello"  ] = "world";
tr[ "number" ] = "12345";

VArray va = tr; // array is: hello world number 12345
                // however only key+value order is preserved!

tr.reverse(); // reverse keys <-> values
                
tr.undef(); // remove all keys

VRegexp CLASS NOTES

VRegexp re( "a([0-9]+)" ); // compiling new regexp

if( re.m( "tralala85." ) ) // match against compiled regexp
  res1 = re[1]; // re[1] returns '85'

if( re.m( "tralala85.", "(la)+" ) ) // match against new regexp pattern
  {
  str_all_matched   = re[0]; // 'lala'
  str_first_capture = re[1]; // 'la'
  }
  
re.comp( "^[a-z]+[0-9]*" ); // reuse/recompile new regexp in the same obj
re.study(); // takes extra time to speed multiple matchings with m()

W-CLASSES AND wchar_t* FUNCTIONS

All WString, WArray, WTrie classes and functions behave the same way as V-ones. The only difference is that they hold wider-data (wchar_t) and keys.

Conversions between the two are implicit:

VString str;
WString wide;

str  = "проста проба едно";
wide = str;
wide = L"две прости проби";
str  = wide;

int f1 = str_find( str,  "проб" ); // returns  7
int f2 = str_find( wide, "проб" ); // returns 11

VString always holds byte string, it has no knowledge if the string is UTF8 or not. It does not have functions to manage characers in UTF8-encoded string. To do so it is needed that VString be converted to WString, which always works on Unicode Level 1 characters.

Conversion from VString to WString is safe, i.e. if VString holds incorrectly encoded UTF8, all incorrect chars will be replaced by 0xFFFD (unknown char) symbol and the rest will be converted properly.

Conversion from WString to VString is always correct.

If it is needed to check the result of the conversion from VString to WString, there is explicit function "set_failsafe()" which returns the count of the incorrect chars in the string:

VString str;
WString wide;

str  = "ще се видим на славейков";
int err = wide.set_failsafe( str );
if( err )
  {
  // there were errors, reset string or whatever...
  // wide.undef();
  }

FEEDBACK

If you find bug or have comment on library API, code or documentation text, please, contact me.

AUTHOR

Vladi Belperchinov-Shabanski "Cade" 

<cade@noxrun.com> <cade@bis.bg> <cade@cpan.org>

http://cade.noxrun.bg/projects/vstring/

https://github.com/cade-vs/vstring

LICENSE

Distributed under the GPL license, see COPYING file for the full text.