/**
* Lexes the tab character ("\t")
*
* Tab characters should be converted to "\tab" control words.
*
* @param Jstewmc\Stream\Stream $stream the character stream
* @return Jstewmc\Rtf\Token\Control\Word
* @throws InvalidArgumentException if the current character in $stream is not
* the tab character
* @since 0.2.0
*/
protected function lexTab(\Jstewmc\Stream\Stream $stream)
{
if ($stream->current() !== "\t") {
throw new \InvalidArgumentException(__METHOD__ . "() expects the current character in the stream to be a tab character");
}
return new Token\Control\Word('tab');
}
/**
* Creates a control symbol token from stream
*
* @param Jstewmc\Stream $stream a stream of characters (the current character
* must be the backslash character, and the next character should be non-
* alphanumeric)
* @return Jstewmc\Rtf\Token\Control\Symbol|false
* @throws InvalidArgumentException if the current character in $stream is
* not a backslash
* @throws InvalidArgumentException if the next character in $stream is not
* a non-alphanumeric character
* @since 0.1.0
* @since 0.2.0 renamed from createFromSource() to createFromStream; replaced
* argument $characters, an array of characters, with $stream, an instance
* of Jstewmc\STream
*/
public static function createFromStream(\Jstewmc\Stream\Stream $stream)
{
$symbol = false;
// if a current character exists
if ($stream->current()) {
// if the current character is a backslash
if ($stream->current() === '\\') {
// if the next character exists
if ($stream->next() !== false) {
// if the now current character is not alphanumeric
if (!ctype_alnum($stream->current())) {
// create a new control symbol
$symbol = new Symbol($stream->current());
// if the current character is an apostrophe, get the symbol's parameter
if ($stream->current() === '\'') {
$parameter = $stream->next() . $stream->next();
$symbol->setParameter($parameter);
}
// if the next character is a space, the control symbol is space-delimited,
// and we should set the flag; otherwise, it's not, and we should rollback
// to leave the pointer on the last character in the token (i.e., the
// symbol)
//
if ($stream->next() === ' ') {
$symbol->setIsSpaceDelimited(true);
} else {
$symbol->setIsSpaceDelimited(false);
$stream->previous();
}
} else {
throw new \InvalidArgumentException(__METHOD__ . "() expects the next element in parameter one, characters, to " . "be a non-alphanumeric character");
}
} else {
// hmm, do nothing?
}
} else {
throw new \InvalidArgumentException(__METHOD__ . "() expects the current element in parameter one, characters, to " . "be the backslash character");
}
}
return $symbol;
}
/**
* reset() should reset the internal chunk pointer
*/
public function testReset()
{
$chunker = new Chunker\Text('foo');
$stream = new Stream($chunker);
$stream->next();
// returns "o"
$stream->next();
// returns "o"
$this->assertEquals('o', $stream->current());
$stream->reset();
$this->assertEquals('f', $stream->current());
return;
}
/**
* Reads a control word's parameter from the characters stream
*
* @param Jstewmc\Stream $stream a stream of characters (the current character
* must be a digit or hyphen)
* @return int
* @throws InvalidArgumentException if the current character in $stream is
* not a digit or hyphen
* @since 0.1.0
* @since 0.2.0 replace argument $characters, an array of characters, with $stream
* an instance of Jstewmc\Stream
*/
protected static function readParameter(\Jstewmc\Stream\Stream $stream)
{
$parameter = '';
// if the current character is a digit or hyphen ("-")
if (ctype_digit($stream->current()) || $stream->current() == '-') {
// determine if the parameter is negative
$isNegative = $stream->current() == '-';
// if the number is negative, consume the hyphen
if ($isNegative) {
$stream->next();
}
// loop through the digits and append them to the parameter
while (ctype_digit($stream->current())) {
$parameter .= $stream->current();
$stream->next();
}
// evaluate the parameter's numeric value
$parameter = +$parameter;
// if the parameter is negative, negate it
if ($isNegative) {
$parameter = -$parameter;
}
} else {
throw new \InvalidArgumentException(__METHOD__ . "() expects the current element in parameter one, characters, " . "to be a digit or hyphen");
}
return $parameter;
}
/**
* Creates a new text token from a stream
*
* @param Jstewmc\Stream\Stream $stream a stream of characters
* @return Jstewmc\Rtf\Token\Text|false
* @since 0.1.0
* @since 0.2.0 renamed from createFromSource() to createFromStream();
* replaced argument $characters, an array of characters, with $stream, an
* instance of Jstewmc\Stream
*/
public static function createFromStream(\Jstewmc\Stream\Stream $stream)
{
$token = false;
// loop through the characters until a group-open, group-close, control word,
// or control symbol occurs and append the plain-text
//
$text = '';
while (false !== ($character = $stream->current())) {
// if the current characer isn't ignored
if (!in_array($character, ["\n", "\r", "\f", ""])) {
// if the current character is a backslash
if ($character == '\\') {
// if the next character exists
if (false !== ($next = $stream->next())) {
// if the next character is a control character
if (in_array($next, ['\\', '{', '}'])) {
// it's a literal control character
// ignore the backslash and append the character
//
$text .= $next;
} else {
// otherwise, the backslash is the start of a control word
// rollback two characters (i.e., put the pointer on the character before
// the control word's backslash)
//
$stream->previous();
$stream->previous();
break;
}
} else {
// hmmm, do nothing?
}
} elseif ($character == '{' || $character == '}') {
// otherwise, the current group is closing or a sub-group is opening
// rollback to the previous character (so it isn't consumed)
//
$stream->previous();
break;
} else {
// otherwise, it's text!
$text .= $character;
}
}
// advance to the next character
$stream->next();
}
// if $text is not empty, create a new token
// keep in mind, empty() will consider '0'to be empty, and it's a valid value
//
if (!empty($text) || $text === '0') {
$token = new Text($text);
}
return $token;
}