cssgrammar.y

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    variables_declaration ';' maybe_space {
        $$ = $1;
    }
    | variables_declaration invalid_block_list ';' maybe_space {
        $$ = false;
    }
    | error ';' maybe_space {
        $$ = false;
    }
    | error invalid_block_list error ';' maybe_space {
        $$ = false;
    }
    | variables_decl_list variables_declaration ';' maybe_space {
        $$ = $1;
        if ($2)
            $$ = $2;
    }
    | variables_decl_list error ';' maybe_space {
        $$ = $1;
    }
    | variables_decl_list error invalid_block_list error ';' maybe_space {
        $$ = $1;
    }
    ;

variables_declaration:
    variable_name ':' maybe_space expr {
        $$ = static_cast<CSSParser*>(parser)->addVariable($1, $4);
    }
    |
    variable_name maybe_space '{' maybe_space declaration_list '}' maybe_space {
        $$ = static_cast<CSSParser*>(parser)->addVariableDeclarationBlock($1);
    }
    |
    variable_name error {
        $$ = false;
    }
    |
    variable_name ':' maybe_space error expr {
        $$ = false;
    }
    |
    variable_name ':' maybe_space {
        /* @variables { varname: } Just reduce away this variable with no value. */
        $$ = false;
    }
    |
    variable_name ':' maybe_space error {
        /* if we come across rules with invalid values like this case: @variables { varname: *; }, just discard the property/value pair */
        $$ = false;
    }
    ;

variable_name:
    IDENT maybe_space {
        $$ = $1;
    }
    ;

namespace:
NAMESPACE_SYM maybe_space maybe_ns_prefix string_or_uri maybe_space ';' {
    CSSParser* p = static_cast<CSSParser*>(parser);
    if (p->m_styleSheet)
        p->m_styleSheet->addNamespace(p, $3, $4);
}
| NAMESPACE_SYM error invalid_block
| NAMESPACE_SYM error ';'
;

maybe_ns_prefix:
/* empty */ { $$.characters = 0; }
| IDENT WHITESPACE { $$ = $1; }
;

string_or_uri:
STRING
| URI
;

media_feature:
    IDENT maybe_space {
        $$ = $1;
    }
    ;

maybe_media_value:
    /*empty*/ {
        $$ = 0;
    }
    | ':' maybe_space expr maybe_space {
        $$ = $3;
    }
    ;

media_query_exp:
    '(' maybe_space media_feature maybe_space maybe_media_value ')' maybe_space {
        $3.lower();
        $$ = static_cast<CSSParser*>(parser)->createFloatingMediaQueryExp($3, $5);
    }
    ;

media_query_exp_list:
    media_query_exp {
        CSSParser* p = static_cast<CSSParser*>(parser);
        $$ = p->createFloatingMediaQueryExpList();
        $$->append(p->sinkFloatingMediaQueryExp($1));
    }
    | media_query_exp_list maybe_space MEDIA_AND maybe_space media_query_exp {
        $$ = $1;
        $$->append(static_cast<CSSParser*>(parser)->sinkFloatingMediaQueryExp($5));
    }
    ;

maybe_and_media_query_exp_list:
    /*empty*/ {
        $$ = static_cast<CSSParser*>(parser)->createFloatingMediaQueryExpList();
    }
    | MEDIA_AND maybe_space media_query_exp_list {
        $$ = $3;
    }
    ;

maybe_media_restrictor:
    /*empty*/ {
        $$ = MediaQuery::None;
    }
    | MEDIA_ONLY {
        $$ = MediaQuery::Only;
    }
    | MEDIA_NOT {
        $$ = MediaQuery::Not;
    }
    ;

media_query:
    media_query_exp_list {
        CSSParser* p = static_cast<CSSParser*>(parser);
        $$ = p->createFloatingMediaQuery(p->sinkFloatingMediaQueryExpList($1));
    }
    |
    maybe_media_restrictor maybe_space medium maybe_and_media_query_exp_list {
        CSSParser* p = static_cast<CSSParser*>(parser);
        $3.lower();
        $$ = p->createFloatingMediaQuery($1, $3, p->sinkFloatingMediaQueryExpList($4));
    }
    ;

maybe_media_list:
     /* empty */ {
        $$ = static_cast<CSSParser*>(parser)->createMediaList();
     }
     | media_list
     ;

media_list:
    media_query {
        CSSParser* p = static_cast<CSSParser*>(parser);
        $$ = p->createMediaList();
        $$->appendMediaQuery(p->sinkFloatingMediaQuery($1));
    }
    | media_list ',' maybe_space media_query {
        $$ = $1;
        if ($$)
            $$->appendMediaQuery(static_cast<CSSParser*>(parser)->sinkFloatingMediaQuery($4));
    }
    | media_list error {
        $$ = 0;
    }
    ;

media:
    MEDIA_SYM maybe_space media_list '{' maybe_space block_rule_list save_block {
        $$ = static_cast<CSSParser*>(parser)->createMediaRule($3, $6);
    }
    | MEDIA_SYM maybe_space '{' maybe_space block_rule_list save_block {
        $$ = static_cast<CSSParser*>(parser)->createMediaRule(0, $5);
    }
    ;

medium:
  IDENT maybe_space {
      $$ = $1;
  }
  ;

keyframes:
    WEBKIT_KEYFRAMES_SYM maybe_space keyframe_name maybe_space '{' maybe_space keyframes_rule '}' {
        $$ = $7;
        $7->setNameInternal($3);
    }
    ;
  
keyframe_name:
    IDENT
    | STRING
    ;

keyframes_rule:
    /* empty */ { $$ = static_cast<CSSParser*>(parser)->createKeyframesRule(); }
    | keyframes_rule keyframe_rule maybe_space {
        $$ = $1;
        if ($2)
            $$->append($2);
    }
    ;

keyframe_rule:
    key_list maybe_space '{' maybe_space declaration_list '}' {
        $$ = static_cast<CSSParser*>(parser)->createKeyframeRule($1);
    }
    ;

key_list:
    key {
        CSSParser* p = static_cast<CSSParser*>(parser);
        $$ = p->createFloatingValueList();
        $$->addValue(p->sinkFloatingValue($1));
    }
    | key_list maybe_space ',' maybe_space key {
        CSSParser* p = static_cast<CSSParser*>(parser);
        $$ = $1;
        if ($$)
            $$->addValue(p->sinkFloatingValue($5));
    }
    ;

key:
    PERCENTAGE { $$.id = 0; $$.isInt = false; $$.fValue = $1; $$.unit = CSSPrimitiveValue::CSS_NUMBER; }
    | IDENT {
        $$.id = 0; $$.isInt = false; $$.unit = CSSPrimitiveValue::CSS_NUMBER;
        CSSParserString& str = $1;
        if (equalIgnoringCase(static_cast<const String&>(str), "from"))
            $$.fValue = 0;
        else if (equalIgnoringCase(static_cast<const String&>(str), "to"))
            $$.fValue = 100;
        else
            YYERROR;
    }
    ;

/*
page:
    PAGE_SYM maybe_space IDENT? pseudo_page? maybe_space
    '{' maybe_space declaration [ ';' maybe_space declaration ]* '}' maybe_space
  ;

pseudo_page
  : ':' IDENT
  ;
*/

page:
    PAGE_SYM error invalid_block {
      $$ = 0;
    }
  | PAGE_SYM error ';' {
      $$ = 0;
    }
    ;

font_face:
    FONT_FACE_SYM maybe_space
    '{' maybe_space declaration_list '}'  maybe_space {
        $$ = static_cast<CSSParser*>(parser)->createFontFaceRule();
    }
    | FONT_FACE_SYM error invalid_block {
      $$ = 0;
    }
    | FONT_FACE_SYM error ';' {
      $$ = 0;
    }
;

combinator:
    '+' maybe_space { $$ = CSSSelector::DirectAdjacent; }
  | '~' maybe_space { $$ = CSSSelector::IndirectAdjacent; }
  | '>' maybe_space { $$ = CSSSelector::Child; }
  ;

unary_operator:
    '-' { $$ = -1; }
  | '+' { $$ = 1; }
  ;

ruleset:
    selector_list '{' maybe_space declaration_list closing_brace {
        $$ = static_cast<CSSParser*>(parser)->createStyleRule($1);
    }
  ;

selector_list:
    selector %prec UNIMPORTANT_TOK {
        if ($1) {
            CSSParser* p = static_cast<CSSParser*>(parser);
            $$ = p->reusableSelectorVector();
            deleteAllValues(*$$);
            $$->shrink(0);
            $$->append(p->sinkFloatingSelector($1));
        }
    }
    | selector_list ',' maybe_space selector %prec UNIMPORTANT_TOK {
        if ($1 && $4) {
            CSSParser* p = static_cast<CSSParser*>(parser);
            $$ = $1;
            $$->append(p->sinkFloatingSelector($4));
        } else
            $$ = 0;
    }
  | selector_list error {
        $$ = 0;
    }
   ;

selector_with_trailing_whitespace:
    selector WHITESPACE {
        $$ = $1;
    }
    ;

selector:
    simple_selector {
        $$ = $1;
    }
    | selector_with_trailing_whitespace
    {
        $$ = $1;
    }
    | selector_with_trailing_whitespace simple_selector
    {
        $$ = $2;
        if (!$1)
            $$ = 0;
        else if ($$) {
            CSSParser* p = static_cast<CSSParser*>(parser);
            CSSSelector* end = $$;
            while (end->tagHistory())
                end = end->tagHistory();
            end->m_relation = CSSSelector::Descendant;
            end->setTagHistory(p->sinkFloatingSelector($1));
            if (Document* doc = p->document())
                doc->setUsesDescendantRules(true);
        }
    }
    | selector combinator simple_selector {
        $$ = $3;
        if (!$1)
            $$ = 0;
        else if ($$) {
            CSSParser* p = static_cast<CSSParser*>(parser);
            CSSSelector* end = $$;
            while (end->tagHistory())
                end = end->tagHistory();
            end->m_relation = $2;
            end->setTagHistory(p->sinkFloatingSelector($1));
            if ($2 == CSSSelector::Child) {
                if (Document* doc = p->document())
                    doc->setUsesDescendantRules(true);
            } else if ($2 == CSSSelector::DirectAdjacent || $2 == CSSSelector::IndirectAdjacent) {
                if (Document* doc = p->document())
                    doc->setUsesSiblingRules(true);
            }
        }
    }
    | selector error {
        $$ = 0;
    }
    ;

namespace_selector:
    /* empty */ '|' { $$.characters = 0; $$.length = 0; }
    | '*' '|' { static UChar star = '*'; $$.characters = &star; $$.length = 1; }
    | IDENT '|' { $$ = $1; }
;
    
simple_selector:
    element_name {
        CSSParser* p = static_cast<CSSParser*>(parser);
        $$ = p->createFloatingSelector();
        $$->m_tag = QualifiedName(nullAtom, $1, p->m_defaultNamespace);
    }
    | element_name specifier_list {
        $$ = $2;
        if ($$) {
            CSSParser* p = static_cast<CSSParser*>(parser);
            $$->m_tag = QualifiedName(nullAtom, $1, p->m_defaultNamespace);
        }
    }
    | specifier_list {
        $$ = $1;
        CSSParser* p = static_cast<CSSParser*>(parser);
        if ($$ && p->m_defaultNamespace != starAtom)
            $$->m_tag = QualifiedName(nullAtom, starAtom, p->m_defaultNamespace);
    }
    | namespace_selector element_name {
        AtomicString namespacePrefix = $1;
        CSSParser* p = static_cast<CSSParser*>(parser);
        $$ = p->createFloatingSelector();
        if (p->m_styleSheet)
            $$->m_tag = QualifiedName(namespacePrefix, $2,
                                      p->m_styleSheet->determineNamespace(namespacePrefix));
        else // FIXME: Shouldn't this case be an error?
            $$->m_tag = QualifiedName(nullAtom, $2, p->m_defaultNamespace);
    }
    | namespace_selector element_name specifier_list {
        $$ = $3;
        if ($$) {
            AtomicString namespacePrefix = $1;
            CSSParser* p = static_cast<CSSParser*>(parser);
            if (p->m_styleSheet)
                $$->m_tag = QualifiedName(namespacePrefix, $2,
                                          p->m_styleSheet->determineNamespace(namespacePrefix));
            else // FIXME: Shouldn't this case be an error?
                $$->m_tag = QualifiedName(nullAtom, $2, p->m_defaultNamespace);
        }
    }
    | namespace_selector specifier_list {
        $$ = $2;
        if ($$) {
            AtomicString namespacePrefix = $1;
            CSSParser* p = static_cast<CSSParser*>(parser);
            if (p->m_styleSheet)
                $$->m_tag = QualifiedName(namespacePrefix, starAtom,
                                          p->m_styleSheet->determineNamespace(namespacePrefix));
        }
    }
  ;

element_name:
    IDENT {
        CSSParserString& str = $1;
        CSSParser* p = static_cast<CSSParser*>(parser);
        Document* doc = p->document();
        if (doc && doc->isHTMLDocument())
            str.lower();
        $$ = str;
    }
    | '*' {
        static UChar star = '*';
        $$.characters = &star;
        $$.length = 1;
    }
  ;

specifier_list:
    specifier {
        $$ = $1;
    }
    | specifier_list specifier {
        if (!$2)
            $$ = 0;
        else if ($1) {
            $$ = $1;
            CSSParser* p = static_cast<CSSParser*>(parser);
            CSSSelector* end = $1;
            while (end->tagHistory())
                end = end->tagHistory();
            end->m_relation = CSSSelector::SubSelector;
            end->setTagHistory(p->sinkFloatingSelector($2));
        }
    }
    | specifier_list error {
        $$ = 0;
    }
;

specifier:
    IDSEL {
        CSSParser* p = static_cast<CSSParser*>(parser);
        $$ = p->createFloatingSelector();
        $$->m_match = CSSSelector::Id;
        if (!p->m_strict)
            $1.lower();
        $$->m_value = $1;
    }
  | HEX {
        if ($1.characters[0] >= '0' && $1.characters[0] <= '9') {
            $$ = 0;
        } else {
            CSSParser* p = static_cast<CSSParser*>(parser);
            $$ = p->createFloatingSelector();
            $$->m_match = CSSSelector::Id;
            if (!p->m_strict)
                $1.lower();
            $$->m_value = $1;
        }
    }
  | class
  | attrib
  | pseudo
    ;

class:
    '.' IDENT {
        CSSParser* p = static_cast<CSSParser*>(parser);
        $$ = p->createFloatingSelector();
        $$->m_match = CSSSelector::Class;
        if (!p->m_strict)
            $2.lower();
        $$->m_value = $2;
    }
  ;

attr_name:
    IDENT maybe_space {
        CSSParserString& str = $1;