StringTokenizer Class Reference

Splits delimited string into tokens. More...

#include <tokenizer.h>

Collaboration diagram for StringTokenizer:

Data Structures
class	iterator
	The input forward iterator for tokens. More...
class	NoSuchElementException
	Exception thrown, if someone tried to read beyond the end of the tokens. More...

Public Member Functions
	StringTokenizer (const char *str, const char *delim, bool skipAllDelim=false, bool trim=false)
	creates a new StringTokenizer for a string and a given set of delimiters. More...
	StringTokenizer (const char *s)
	create a new StringTokenizer which splits the input string at whitespaces. More...
iterator	begin () const
	returns the begin iterator More...
void	setDelimiters (const char *d)
	changes the set of delimiters used in subsequent iterations. More...
iterator	begin (const char *d)
	returns a begin iterator with an alternate set of delimiters. More...
const iterator &	end () const
	the iterator marking the end. More...

Static Public Attributes
static const char *const	SPACE
	a delimiter string containing all usual whitespace delimiters. More...

Private Attributes
const char *	str
const char *	delim
bool	skipAll
bool	trim
iterator	itEnd

Friends
class	StringTokenizer::iterator

Detailed Description

Splits delimited string into tokens.

The StringTokenizer takes a pointer to a string and a pointer to a string containing a number of possible delimiters. The StringTokenizer provides an input forward iterator which allows to iterate through all tokens. An iterator behaves like a logical pointer to the tokens, i.e. to shift to the next token, you've to increment the iterator, you get the token by dereferencing the iterator.

Memory consumption: This class operates on the original string and only allocates memory for the individual tokens actually requested, so this class allocates at maximum the space required for the longest token in the given string. Since for each iteration, memory is reclaimed for the last token, you MAY NOT store pointers to them; if you need them afterwards, copy them. You may not modify the original string while you operate on it with the StringTokenizer; the behaviour is undefined in that case.

The iterator has one special method 'nextDelimiter()' which returns a character containing the next delimiter following this tokenization process or '\0', if there are no following delimiters. In case of skipAllDelim, it returns the FIRST delimiter.

With the method 'setDelimiters(const char*)' you may change the set of delimiters. It affects all running iterators.

Example:

 StringTokenizer st("mary had a little lamb;its fleece was..", " ;");
 StringTokenizer::iterator i;
 for (i = st.begin() ; i != st.end() ; ++i) {
       cout << "Token: '" << *i << "'\t";
       cout << " next Delim: '" << i.nextDelimiter() << "'" << endl;
 }
 

Author

Henner Zeller H.Zel.nosp@m.ler@.nosp@m.acm.o.nosp@m.rg LGPL

Definition at line 102 of file tokenizer.h.

Constructor & Destructor Documentation

StringTokenizer::StringTokenizer	(	const char *	str,
		const char *	delim,
		bool	skipAllDelim = false,
		bool	trim = false
	)

creates a new StringTokenizer for a string and a given set of delimiters.

Parameters

str	String to be split up. This string will not be modified by this StringTokenizer, but you may as well not modfiy this string while tokenizing is in process, which may lead to undefined behaviour.
delim	String containing the characters which should be regarded as delimiters.
skipAllDelim	OPTIONAL. true, if subsequent delimiters should be skipped at once or false, if empty tokens should be returned for two delimiters with no other text inbetween. The first behaviour may be desirable for whitespace skipping, the second for input with delimited entry e.g. /etc/passwd like files or CSV input. NOTE, that 'true' here resembles the ANSI-C strtok(char *s,char *d) behaviour. DEFAULT = false
trim	OPTIONAL. true, if the tokens returned should be trimmed, so that they don't have any whitespaces at the beginning or end. Whitespaces are any of the characters defined in StringTokenizer::SPACE. If delim itself is StringTokenizer::SPACE, this will result in a behaviour with skipAllDelim = true. DEFAULT = false

StringTokenizer::StringTokenizer

(

const char *

s

)

create a new StringTokenizer which splits the input string at whitespaces.

The tokens are stripped from whitespaces. This means, if you change the set of delimiters in either the 'begin(const char *delim)' method or in 'setDelimiters()', you then get whitespace trimmed tokens, delimited by the new set. Behaves like StringTokenizer(s, StringTokenizer::SPACE,false,true);

Member Function Documentation

iterator StringTokenizer::begin ( ) const

inline

returns the begin iterator

Definition at line 279 of file tokenizer.h.

iterator StringTokenizer::begin ( const char *  d )

inline

returns a begin iterator with an alternate set of delimiters.

Definition at line 293 of file tokenizer.h.

const iterator& StringTokenizer::end ( void  ) const

inline

the iterator marking the end.

Definition at line 302 of file tokenizer.h.

void StringTokenizer::setDelimiters ( const char *  d )

inline

changes the set of delimiters used in subsequent iterations.

Definition at line 286 of file tokenizer.h.

Friends And Related Function Documentation

friend class StringTokenizer::iterator

friend

Definition at line 215 of file tokenizer.h.

Field Documentation

const char* StringTokenizer::delim

private

Definition at line 217 of file tokenizer.h.

iterator StringTokenizer::itEnd

private

Definition at line 219 of file tokenizer.h.

bool StringTokenizer::skipAll

private

Definition at line 218 of file tokenizer.h.

const char* const StringTokenizer::SPACE

static

a delimiter string containing all usual whitespace delimiters.

These are space, tab, newline, carriage return, formfeed and vertical tab. (see isspace() manpage).

Definition at line 109 of file tokenizer.h.

const char* StringTokenizer::str

private

Definition at line 216 of file tokenizer.h.

bool StringTokenizer::trim

private

Definition at line 218 of file tokenizer.h.

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The documentation for this class was generated from the following file:

• tokenizer.h