/**
* This method optionally parses an expression node and returns it. When no
* expression was found this method will return <b>null</b>.
*
* @return \PDepend\Source\AST\ASTNode
* @throws \PDepend\Source\Parser\ParserException
* @since 0.9.6
*/
protected function parseOptionalExpression()
{
$expressions = array();
while (($tokenType = $this->tokenizer->peek()) != Tokenizer::T_EOF) {
$expr = null;
switch ($tokenType) {
case Tokens::T_COMMA:
case Tokens::T_AS:
case Tokens::T_BREAK:
case Tokens::T_CLOSE_TAG:
case Tokens::T_COLON:
case Tokens::T_CONTINUE:
case Tokens::T_CURLY_BRACE_CLOSE:
case Tokens::T_DECLARE:
case Tokens::T_DO:
case Tokens::T_DOUBLE_ARROW:
case Tokens::T_ECHO:
case Tokens::T_END_HEREDOC:
case Tokens::T_ENDFOREACH:
case Tokens::T_FOR:
case Tokens::T_FOREACH:
case Tokens::T_GLOBAL:
case Tokens::T_GOTO:
case Tokens::T_IF:
case Tokens::T_PARENTHESIS_CLOSE:
case Tokens::T_RETURN:
case Tokens::T_SEMICOLON:
case Tokens::T_SQUARED_BRACKET_CLOSE:
case Tokens::T_SWITCH:
case Tokens::T_THROW:
case Tokens::T_TRY:
case Tokens::T_UNSET:
case Tokens::T_WHILE:
break 2;
case Tokens::T_SELF:
case Tokens::T_STRING:
case Tokens::T_PARENT:
case Tokens::T_STATIC:
case Tokens::T_DOLLAR:
case Tokens::T_VARIABLE:
case Tokens::T_BACKSLASH:
case Tokens::T_NAMESPACE:
$expressions[] = $this->parseVariableOrConstantOrPrimaryPrefix();
break;
case $this->isArrayStartDelimiter():
$expressions[] = $this->doParseArray();
break;
case Tokens::T_NULL:
case Tokens::T_TRUE:
case Tokens::T_FALSE:
case Tokens::T_LNUMBER:
case Tokens::T_DNUMBER:
case Tokens::T_BACKTICK:
case Tokens::T_DOUBLE_QUOTE:
case Tokens::T_CONSTANT_ENCAPSED_STRING:
$expressions[] = $this->parseLiteralOrString();
break;
case Tokens::T_NEW:
$expressions[] = $this->parseAllocationExpression();
break;
case Tokens::T_EVAL:
$expressions[] = $this->parseEvalExpression();
break;
case Tokens::T_CLONE:
$expressions[] = $this->parseCloneExpression();
break;
case Tokens::T_INSTANCEOF:
$expressions[] = $this->parseInstanceOfExpression();
break;
case Tokens::T_ISSET:
$expressions[] = $this->parseIssetExpression();
break;
case Tokens::T_LIST:
$expressions[] = $this->parseListExpression();
break;
case Tokens::T_QUESTION_MARK:
$expressions[] = $this->parseConditionalExpression();
break;
case Tokens::T_BOOLEAN_AND:
$expressions[] = $this->parseBooleanAndExpression();
break;
case Tokens::T_BOOLEAN_OR:
$expressions[] = $this->parseBooleanOrExpression();
break;
case Tokens::T_LOGICAL_AND:
$expressions[] = $this->parseLogicalAndExpression();
break;
case Tokens::T_LOGICAL_OR:
$expressions[] = $this->parseLogicalOrExpression();
break;
case Tokens::T_LOGICAL_XOR:
$expressions[] = $this->parseLogicalXorExpression();
break;
case Tokens::T_FUNCTION:
$expressions[] = $this->parseClosureDeclaration();
break;
case Tokens::T_PARENTHESIS_OPEN:
$expressions[] = $this->parseParenthesisExpressionOrPrimaryPrefix();
break;
case Tokens::T_EXIT:
$expressions[] = $this->parseExitExpression();
break;
case Tokens::T_START_HEREDOC:
$expressions[] = $this->parseHeredoc();
break;
case Tokens::T_CURLY_BRACE_OPEN:
$expressions[] = $this->parseBraceExpression($this->builder->buildAstExpression(), $this->consumeToken(Tokens::T_CURLY_BRACE_OPEN), Tokens::T_CURLY_BRACE_CLOSE);
break;
case Tokens::T_INCLUDE:
$expressions[] = $this->parseIncludeExpression();
break;
case Tokens::T_INCLUDE_ONCE:
$expressions[] = $this->parseIncludeOnceExpression();
break;
case Tokens::T_REQUIRE:
$expressions[] = $this->parseRequireExpression();
break;
case Tokens::T_REQUIRE_ONCE:
$expressions[] = $this->parseRequireOnceExpression();
break;
case Tokens::T_DEC:
$expressions[] = $this->parseDecrementExpression($expressions);
break;
case Tokens::T_INC:
$expressions[] = $this->parseIncrementExpression($expressions);
break;
case Tokens::T_SL:
$expressions[] = $this->parseShiftLeftExpression();
break;
case Tokens::T_SR:
$expressions[] = $this->parseShiftRightExpression();
break;
case Tokens::T_DIR:
case Tokens::T_FILE:
case Tokens::T_LINE:
case Tokens::T_NS_C:
case Tokens::T_FUNC_C:
case Tokens::T_CLASS_C:
case Tokens::T_METHOD_C:
$expressions[] = $this->parseConstant();
break;
case Tokens::T_INT_CAST:
case Tokens::T_BOOL_CAST:
case Tokens::T_ARRAY_CAST:
case Tokens::T_UNSET_CAST:
case Tokens::T_OBJECT_CAST:
case Tokens::T_DOUBLE_CAST:
case Tokens::T_STRING_CAST:
$expressions[] = $this->parseCastExpression();
break;
case Tokens::T_EQUAL:
case Tokens::T_OR_EQUAL:
case Tokens::T_SL_EQUAL:
case Tokens::T_SR_EQUAL:
case Tokens::T_AND_EQUAL:
case Tokens::T_DIV_EQUAL:
case Tokens::T_MOD_EQUAL:
case Tokens::T_MUL_EQUAL:
case Tokens::T_XOR_EQUAL:
case Tokens::T_PLUS_EQUAL:
case Tokens::T_MINUS_EQUAL:
case Tokens::T_CONCAT_EQUAL:
$expressions[] = $this->parseAssignmentExpression(array_pop($expressions));
break;
// TODO: Handle comments here
// TODO: Handle comments here
case Tokens::T_COMMENT:
case Tokens::T_DOC_COMMENT:
$this->consumeToken($tokenType);
break;
case Tokens::T_PRINT:
// TODO: Implement print expression
$token = $this->consumeToken($tokenType);
$expr = $this->builder->buildAstPrintExpression();
$expr->configureLinesAndColumns($token->startLine, $token->endLine, $token->startColumn, $token->endColumn);
$expressions[] = $expr;
break;
case Tokens::T_STRING_VARNAME:
// TODO: Implement this
// TODO: Implement this
case Tokens::T_PLUS:
// TODO: Make this a arithmetic expression
// TODO: Make this a arithmetic expression
case Tokens::T_MINUS:
case Tokens::T_MUL:
case Tokens::T_DIV:
case Tokens::T_MOD:
case Tokens::T_IS_EQUAL:
// TODO: Implement compare expressions
// TODO: Implement compare expressions
case Tokens::T_IS_NOT_EQUAL:
case Tokens::T_IS_IDENTICAL:
case Tokens::T_IS_NOT_IDENTICAL:
case Tokens::T_IS_GREATER_OR_EQUAL:
case Tokens::T_IS_SMALLER_OR_EQUAL:
case Tokens::T_ANGLE_BRACKET_OPEN:
case Tokens::T_ANGLE_BRACKET_CLOSE:
case Tokens::T_EMPTY:
case Tokens::T_CONCAT:
case Tokens::T_BITWISE_OR:
case Tokens::T_BITWISE_AND:
case Tokens::T_BITWISE_NOT:
case Tokens::T_BITWISE_XOR:
$token = $this->consumeToken($tokenType);
$expr = $this->builder->buildAstExpression($token->image);
$expr->configureLinesAndColumns($token->startLine, $token->endLine, $token->startColumn, $token->endColumn);
$expressions[] = $expr;
break;
case Tokens::T_AT:
case Tokens::T_EXCLAMATION_MARK:
$token = $this->consumeToken($tokenType);
$expr = $this->builder->buildAstUnaryExpression($token->image);
$expr->configureLinesAndColumns($token->startLine, $token->endLine, $token->startColumn, $token->endColumn);
$expressions[] = $expr;
break;
case Tokens::T_YIELD:
$expressions[] = $this->parseYield();
break;
default:
$expressions[] = $this->parseOptionalExpressionForVersion();
break;
}
}
$expressions = $this->reduce($expressions);
$count = count($expressions);
if ($count == 0) {
return null;
} elseif ($count == 1) {
return $expressions[0];
}
$expr = $this->builder->buildAstExpression();
foreach ($expressions as $node) {
$expr->addChild($node);
}
$expr->configureLinesAndColumns($expressions[0]->getStartLine(), $expressions[$count - 1]->getEndLine(), $expressions[0]->getStartColumn(), $expressions[$count - 1]->getEndColumn());
return $expr;
}
