/**
* Lex an expression into SassScript tokens.
* @param string $string expression to lex
* @param SassContext $context the context in which the expression is lexed
* @return array tokens
*/
public function lex($string, $context)
{
// if it's already lexed, just return it as-is
if (is_object($string)) {
return array($string);
}
if (is_array($string)) {
return $string;
}
$tokens = array();
// whilst the string is not empty, split it into it's tokens.
while ($string !== false) {
if (($match = $this->isWhitespace($string)) !== false) {
$tokens[] = null;
} elseif (($match = SassScriptFunction::isa($string)) !== false) {
preg_match(SassScriptFunction::MATCH_FUNC, $match, $matches);
$args = array();
foreach (SassScriptFunction::extractArgs($matches[SassScriptFunction::ARGS], false, $context) as $key => $expression) {
$args[$key] = $this->parser->evaluate($expression, $context);
}
$tokens[] = new SassScriptFunction($matches[SassScriptFunction::NAME], $args);
} elseif (($match = SassBoolean::isa($string)) !== false) {
$tokens[] = new SassBoolean($match);
} elseif (($match = SassColour::isa($string)) !== false) {
$tokens[] = new SassColour($match);
} elseif (($match = SassNumber::isa($string)) !== false) {
$tokens[] = new SassNumber($match);
} elseif (($match = SassString::isa($string)) !== false) {
$stringed = new SassString($match);
if (strlen($stringed->quote) == 0 && SassList::isa($string) !== false && !preg_match("/^\\-\\w+\\-\\w+\$/", $stringed->value)) {
$tokens[] = new SassList($string);
} else {
$tokens[] = $stringed;
}
} elseif ($string == '()') {
$match = $string;
$tokens[] = new SassList($match);
} elseif (($match = SassScriptOperation::isa($string)) !== false) {
$tokens[] = new SassScriptOperation($match);
} elseif (($match = SassScriptVariable::isa($string)) !== false) {
$tokens[] = new SassScriptVariable($match);
} else {
$_string = $string;
$match = '';
while (strlen($_string) && !$this->isWhitespace($_string)) {
foreach (SassScriptOperation::$inStrOperators as $operator) {
if (substr($_string, 0, strlen($operator)) == $operator) {
break 2;
}
}
$match .= $_string[0];
$_string = substr($_string, 1);
}
$tokens[] = new SassString($match);
}
$string = substr($string, strlen($match));
}
return $tokens;
}