RWWTokenizer Class Reference
[String Processing]

Breaks up a string into separate tokens, delimited by arbitrary whitespace. More...

#include <rw/wtoken.h>

List of all members.

Public Member Functions
	RWWTokenizer (const RWWString &s)
bool	done () const
RWWSubString	operator() (const wchar_t *s)
RWWSubString	operator() (const wchar_t *s, size_t num)
RWWSubString	operator() ()
RWWSubString	operator() (RWTRegex< wchar_t > &regex)
RWWSubString	nextToken (RWTRegex< wchar_t > &regex)

---

Detailed Description

Class RWWTokenizer is designed to break a string up into separate tokens, delimited by arbitrary whitespace. It can be thought of as an iterator for strings and as an alternative to the C Standard Library function wstok() which has the unfortunate side effect of changing the string being tokenized.

Synopsis

 #include <rw/wtoken.h>
 RWWString str("a string of tokens", RWWString::ascii);
 RWWTokenizer(str);  // Lex the above string

Persistence

None

Examples

 #include <rw/wtoken.h>
 
 int main ()
 {
     RWWString a(L"Something is rotten in the state of Denmark");
 
     RWWTokenizer next(a); // Tokenize the string a
     RWWString token; // Will receive each token
 
     // Advance until the null string is returned:
     while (!(token=next()).isNull())
         std::cout << token << "\n";
     return 0;
 }

* Program output (assuming your platform displays wide characters as US-ASCII if they are in the US-ASCII character set):

 Something
 is
 rotten
 in
 the
 state
 of
 Denmark

---

Constructor & Destructor Documentation

RWWTokenizer::RWWTokenizer

(

const RWWString &

s

)

Constructs a tokenizer to lex the string s.

---

Member Function Documentation

bool RWWTokenizer::done

(

)

const

Returns true if the last token from the search string has been extracted, otherwise false. When using the function call operator interface, this is the same as the last non-empty token having been returned.

RWWSubString RWWTokenizer::nextToken

(

RWTRegex< wchar_t > &

regex

)

Returns the next token using a delimiter pattern represented by a regular expression pattern.

Unlike the other nextToken() overloads, this method allows a single occurrence of a delimiter to span multiple characters.

For example, nextToken(RWWString("ab")) treats either a or b as a delimiter character. Conversely, nextToken(RWTRegex<wchar_t>("ab")) treats the two-character pattern ab as a single delimiter.

This method may return an empty token if there are consecutive occurrences of any delimiter character in the search string.

RWWSubString RWWTokenizer::operator()

(

RWTRegex< wchar_t > &

regex

)

Returns the next token using a delimiter pattern represented by the regular expression pattern regex.

This method, unlike the other operator() overloads, allows a single occurrence of a delimiter to span multiple characters.

For example, consider the RWWTokenizer instance tok. The statement tok(RWWString("ab")) treats either a or b as a delimiter character. On the other hand, tok(RWTRegex<char>("ab")) treats the two-character pattern, ab, as a single delimiter.

This method consumes consecutive occurrences of delimiters and skips over any empty fields that may be present in the string. To obtain empty fields as well as non-empty fields, use the nextToken() method.

RWWSubString RWWTokenizer::operator()

(

)

Advances to the next token and returns it as a substring. The tokens are delimited by any of the four wide characters in L, " \t\n\0" (space, tab, newline and null).

RWWSubString RWWTokenizer::operator()	(	const wchar_t *	s,
		size_t	num
	)

Advances to the next token and returns it as a substring. The tokens are delimited by any of the first num wide characters in s. Buffer s may contain embedded nulls, and must contain at least num wide characters. Tokens will not be delimited by nulls unless s contains nulls.

RWWSubString RWWTokenizer::operator()

(

const wchar_t *

s

)

Advances to the next token and returns it as a wide substring. The tokens are delimited by any wide character in s, or any embedded wide null.