Qore::InputStreamLineIterator Class Reference

This class defines a line iterator for input streams. More...

Inheritance diagram for Qore::InputStreamLineIterator:

Public Member Methods
	constructor (Qore::InputStream is, *string encoding, *string eol, bool trim=True, int bufsize=DefaultStreamBufferSize)
	Creates the InputStreamLineIterator for iterating over the given InputStream. More...
	constructor (Qore::StreamReader sr, *string eol, bool trim=True)
	Creates the InputStreamLineIterator for iterating data from the given StreamReader. More...
string	getEncoding ()
	Returns the character encoding for the InputStreamLineIterator. More...
string	getLine ()
	Returns the current line in the data or throws an ITERATOR-ERROR exception if the iterator is invalid. More...
StreamReader	getStreamReader ()
	Returns the StreamReader object used internally. More...
string	getValue ()
	Returns the current line in the data or throws an ITERATOR-ERROR exception if the iterator is invalid. More...
int	index ()
	Returns the current iterator line number in the data (the first line is line 1) or 0 if not pointing at a valid element. More...
bool	next ()
	Moves the current position to the next line in the data; returns False if there are no more lines to read; if the iterator is not pointing at a valid element before this call, the iterator will be positioned to the beginning of the data. More...
bool	valid ()
	Returns True if the iterator is currently pointing at a valid element, False if not. More...

Detailed Description

This class defines a line iterator for input streams.

Since

Qore 0.8.13

Example: InputStreamLineIterator basic usage

FileInputStream fis("log.txt");
InputStreamLineIterator it(fis, "\n");
while (it.next()) {
    printf("line %d = %n\n", it.index(), it.getLine());
}

See also

Qore::DataLineIterator

Qore::FileLineIterator

Member Function Documentation

constructor() [1/2]

Qore::InputStreamLineIterator::constructor	(	Qore::InputStream	is,
		*string	encoding,
		*string	eol,
		bool	trim = True,
		int	bufsize = DefaultStreamBufferSize
	)

Creates the InputStreamLineIterator for iterating over the given InputStream.

Parameters

is	the InputStream to iterate over
encoding	character encoding of the data from input stream; if not ASCII-compatible, all data will be converted to UTF-8; if not present, the default character encoding is assumed
eol	the optional end of line character(s) to use to detect lines in the data; if this string is not passed, then if the character-encoding is ASCII-compatible, the end of line character(s) are detected automatically from "\n", "\r", or "\r\n"; if the stream uses a non-ASCII-compatible character encoding, then "\n" is assumed
trim	if True the string return values for the lines iterated will be trimmed of the eol bytes
bufsize	the size of the buffer for the internal Constants in bytes; must be a positive integer

Exceptions

STREAM-BUFFER-ERROR	an invalid stream buffer size was specified; the buffer size must be a positive integer
ENCODING-CONVERSION-ERROR	this exception could be thrown if the eol argument has a different character encoding from the data's and an error occurs during encoding conversion

Note

this variant of the InputStreamLineIterator::constructor creates a Constants to read the input data

constructor() [2/2]

Qore::InputStreamLineIterator::constructor	(	Qore::StreamReader	sr,
		*string	eol,
		bool	trim = True
	)

Creates the InputStreamLineIterator for iterating data from the given StreamReader.

Parameters

sr	the StreamReader used as a source of data to iterate over
eol	the optional end of line character(s) to use to detect lines in the data; if this string is not passed, then if the character-encoding is ASCII-compatible, the end of line character(s) are detected automatically from "\n", "\r", or "\r\n"; if the stream uses a non-ASCII-compatible character encoding, then "\n" is assumed
trim	if True the string return values for the lines iterated will be trimmed of the eol bytes

Exceptions

ENCODING-CONVERSION-ERROR

this exception could be thrown if the eol argument has a different character encoding from the data's and an error occurs during encoding conversion

getEncoding()

string Qore::InputStreamLineIterator::getEncoding

(

)

Returns the character encoding for the InputStreamLineIterator.

Code Flags:

CONSTANT

Example:

string encoding = i.getEncoding();

Returns

the character encoding for the InputStreamLineIterator

getLine()

string Qore::InputStreamLineIterator::getLine ( )

virtual

Returns the current line in the data or throws an ITERATOR-ERROR exception if the iterator is invalid.

Returns

the current line in the data or throws an ITERATOR-ERROR exception if the iterator is invalid

Code Flags:

RET_VALUE_ONLY

Example:

while (i.next()) {
    printf("+ %y\n", i.getLine());
}

Exceptions

ITERATOR-ERROR	the iterator is not pointing at a valid element
ITERATOR-THREAD-ERROR	this exception is thrown if this method is called from any thread other than the thread that created the object

See also

InputStreamLineIterator::getValue()

Implements Qore::AbstractLineIterator.

getStreamReader()

StreamReader Qore::InputStreamLineIterator::getStreamReader

(

)

Returns the StreamReader object used internally.

Example:

StreamReader sr = i.getStreamReader();

Returns

the StreamReader object used internally

getValue()

string Qore::InputStreamLineIterator::getValue ( )

virtual

Returns the current line in the data or throws an ITERATOR-ERROR exception if the iterator is invalid.

Returns

the current line in the data or throws an ITERATOR-ERROR exception if the iterator is invalid

Code Flags:

RET_VALUE_ONLY

Example:

while (i.next()) {
    printf("+ %y\n", i.getValue());
}

Exceptions

ITERATOR-ERROR	the iterator is not pointing at a valid element
ITERATOR-THREAD-ERROR	this exception is thrown if this method is called from any thread other than the thread that created the object

See also

InputStreamLineIterator::getLine()

Implements Qore::AbstractLineIterator.

index()

int Qore::InputStreamLineIterator::index ( )

virtual

Returns the current iterator line number in the data (the first line is line 1) or 0 if not pointing at a valid element.

Returns

the current iterator line number in the data (the first line is line 1) or 0 if not pointing at a valid element

Code Flags:

CONSTANT

Example:

while (i.next()) {
    printf("+ %d: %y\n", i.index(), i.getValue());
}

Implements Qore::AbstractLineIterator.

next()

bool Qore::InputStreamLineIterator::next ( )

virtual

Moves the current position to the next line in the data; returns False if there are no more lines to read; if the iterator is not pointing at a valid element before this call, the iterator will be positioned to the beginning of the data.

The iterator object should not be used after this method returns False.

Returns

False if there are no more lines in the data (in which case the iterator object is invalid and should not be used); True if successful (meaning that the iterator object is valid)

Example:

while (i.next()) {
    printf("line: %y\n", i.getValue());
}

Exceptions

ITERATOR-THREAD-ERROR

this exception is thrown if this method is called from any thread other than the thread that created the object

Implements Qore::AbstractLineIterator.

valid()

bool Qore::InputStreamLineIterator::valid ( )

virtual

Returns True if the iterator is currently pointing at a valid element, False if not.

Returns

True if the iterator is currently pointing at a valid element, False if not

Code Flags:

CONSTANT

Example:

if (i.valid())
    printf("current value: %y\n", i.getValue());

Implements Qore::AbstractLineIterator.