GoToSocial/vendor/github.com/tdewolff/parse/v2/css/parse.go

494 lines
13 KiB
Go

package css
import (
"bytes"
"fmt"
"strconv"
"github.com/tdewolff/parse/v2"
"github.com/tdewolff/parse/v2/buffer"
)
var wsBytes = []byte(" ")
var endBytes = []byte("}")
var emptyBytes = []byte("")
// GrammarType determines the type of grammar.
type GrammarType uint32
// GrammarType values.
const (
ErrorGrammar GrammarType = iota // extra token when errors occur
CommentGrammar
AtRuleGrammar
BeginAtRuleGrammar
EndAtRuleGrammar
QualifiedRuleGrammar
BeginRulesetGrammar
EndRulesetGrammar
DeclarationGrammar
TokenGrammar
CustomPropertyGrammar
)
// String returns the string representation of a GrammarType.
func (tt GrammarType) String() string {
switch tt {
case ErrorGrammar:
return "Error"
case CommentGrammar:
return "Comment"
case AtRuleGrammar:
return "AtRule"
case BeginAtRuleGrammar:
return "BeginAtRule"
case EndAtRuleGrammar:
return "EndAtRule"
case QualifiedRuleGrammar:
return "QualifiedRule"
case BeginRulesetGrammar:
return "BeginRuleset"
case EndRulesetGrammar:
return "EndRuleset"
case DeclarationGrammar:
return "Declaration"
case TokenGrammar:
return "Token"
case CustomPropertyGrammar:
return "CustomProperty"
}
return "Invalid(" + strconv.Itoa(int(tt)) + ")"
}
////////////////////////////////////////////////////////////////
// State is the state function the parser currently is in.
type State func(*Parser) GrammarType
// Token is a single TokenType and its associated data.
type Token struct {
TokenType
Data []byte
}
func (t Token) String() string {
return t.TokenType.String() + "('" + string(t.Data) + "')"
}
// Parser is the state for the parser.
type Parser struct {
l *Lexer
state []State
err string
errPos int
buf []Token
level int
data []byte
tt TokenType
keepWS bool
prevWS bool
prevEnd bool
prevComment bool
}
// NewParser returns a new CSS parser from an io.Reader. isInline specifies whether this is an inline style attribute.
func NewParser(r *parse.Input, isInline bool) *Parser {
l := NewLexer(r)
p := &Parser{
l: l,
state: make([]State, 0, 4),
}
if isInline {
p.state = append(p.state, (*Parser).parseDeclarationList)
} else {
p.state = append(p.state, (*Parser).parseStylesheet)
}
return p
}
// HasParseError returns true if there is a parse error (and not a read error).
func (p *Parser) HasParseError() bool {
return p.err != ""
}
// Err returns the error encountered during parsing, this is often io.EOF but also other errors can be returned.
func (p *Parser) Err() error {
if p.err != "" {
r := buffer.NewReader(p.l.r.Bytes())
return parse.NewError(r, p.errPos, p.err)
}
return p.l.Err()
}
// Next returns the next Grammar. It returns ErrorGrammar when an error was encountered. Using Err() one can retrieve the error message.
func (p *Parser) Next() (GrammarType, TokenType, []byte) {
p.err = ""
if p.prevEnd {
p.tt, p.data = RightBraceToken, endBytes
p.prevEnd = false
} else {
p.tt, p.data = p.popToken(true)
}
gt := p.state[len(p.state)-1](p)
return gt, p.tt, p.data
}
// Offset return offset for current Grammar
func (p *Parser) Offset() int {
return p.l.r.Offset()
}
// Values returns a slice of Tokens for the last Grammar. Only AtRuleGrammar, BeginAtRuleGrammar, BeginRulesetGrammar and Declaration will return the at-rule components, ruleset selector and declaration values respectively.
func (p *Parser) Values() []Token {
return p.buf
}
func (p *Parser) popToken(allowComment bool) (TokenType, []byte) {
p.prevWS = false
p.prevComment = false
tt, data := p.l.Next()
for !p.keepWS && tt == WhitespaceToken || tt == CommentToken {
if tt == WhitespaceToken {
p.prevWS = true
} else {
p.prevComment = true
if allowComment && len(p.state) == 1 {
break
}
}
tt, data = p.l.Next()
}
return tt, data
}
func (p *Parser) initBuf() {
p.buf = p.buf[:0]
}
func (p *Parser) pushBuf(tt TokenType, data []byte) {
p.buf = append(p.buf, Token{tt, data})
}
////////////////////////////////////////////////////////////////
func (p *Parser) parseStylesheet() GrammarType {
if p.tt == CDOToken || p.tt == CDCToken {
return TokenGrammar
} else if p.tt == AtKeywordToken {
return p.parseAtRule()
} else if p.tt == CommentToken {
return CommentGrammar
} else if p.tt == ErrorToken {
return ErrorGrammar
}
return p.parseQualifiedRule()
}
func (p *Parser) parseDeclarationList() GrammarType {
if p.tt == CommentToken {
p.tt, p.data = p.popToken(false)
}
for p.tt == SemicolonToken {
p.tt, p.data = p.popToken(false)
}
// IE hack: *color:red;
if p.tt == DelimToken && p.data[0] == '*' {
tt, data := p.popToken(false)
p.tt = tt
p.data = append(p.data, data...)
}
if p.tt == ErrorToken {
return ErrorGrammar
} else if p.tt == AtKeywordToken {
return p.parseAtRule()
} else if p.tt == IdentToken || p.tt == DelimToken {
return p.parseDeclaration()
} else if p.tt == CustomPropertyNameToken {
return p.parseCustomProperty()
}
// parse error
p.initBuf()
p.l.r.Move(-len(p.data))
p.err, p.errPos = fmt.Sprintf("unexpected token '%s' in declaration", string(p.data)), p.l.r.Offset()
p.l.r.Move(len(p.data))
if p.tt == RightBraceToken {
// right brace token will occur when we've had a decl error that ended in a right brace token
// as these are not handled by decl error, we handle it here explicitly. Normally its used to end eg. the qual rule.
p.pushBuf(p.tt, p.data)
return ErrorGrammar
}
return p.parseDeclarationError(p.tt, p.data)
}
////////////////////////////////////////////////////////////////
func (p *Parser) parseAtRule() GrammarType {
p.initBuf()
p.data = parse.ToLower(parse.Copy(p.data))
atRuleName := p.data
if len(atRuleName) > 0 && atRuleName[1] == '-' {
if i := bytes.IndexByte(atRuleName[2:], '-'); i != -1 {
atRuleName = atRuleName[i+2:] // skip vendor specific prefix
}
}
atRule := ToHash(atRuleName[1:])
first := true
skipWS := false
for {
tt, data := p.popToken(false)
if tt == LeftBraceToken && p.level == 0 {
if atRule == Font_Face || atRule == Page {
p.state = append(p.state, (*Parser).parseAtRuleDeclarationList)
} else if atRule == Document || atRule == Keyframes || atRule == Media || atRule == Supports {
p.state = append(p.state, (*Parser).parseAtRuleRuleList)
} else {
p.state = append(p.state, (*Parser).parseAtRuleUnknown)
}
return BeginAtRuleGrammar
} else if (tt == SemicolonToken || tt == RightBraceToken) && p.level == 0 || tt == ErrorToken {
p.prevEnd = (tt == RightBraceToken)
return AtRuleGrammar
} else if tt == LeftParenthesisToken || tt == LeftBraceToken || tt == LeftBracketToken || tt == FunctionToken {
p.level++
} else if tt == RightParenthesisToken || tt == RightBraceToken || tt == RightBracketToken {
if p.level == 0 {
// TODO: buggy
p.pushBuf(tt, data)
if 1 < len(p.state) {
p.state = p.state[:len(p.state)-1]
}
p.err, p.errPos = "unexpected ending in at rule", p.l.r.Offset()
return ErrorGrammar
}
p.level--
}
if first {
if tt == LeftParenthesisToken || tt == LeftBracketToken {
p.prevWS = false
}
first = false
}
if len(data) == 1 && (data[0] == ',' || data[0] == ':') {
skipWS = true
} else if p.prevWS && !skipWS && tt != RightParenthesisToken {
p.pushBuf(WhitespaceToken, wsBytes)
} else {
skipWS = false
}
if tt == LeftParenthesisToken {
skipWS = true
}
p.pushBuf(tt, data)
}
}
func (p *Parser) parseAtRuleRuleList() GrammarType {
if p.tt == RightBraceToken || p.tt == ErrorToken {
p.state = p.state[:len(p.state)-1]
return EndAtRuleGrammar
} else if p.tt == AtKeywordToken {
return p.parseAtRule()
} else {
return p.parseQualifiedRule()
}
}
func (p *Parser) parseAtRuleDeclarationList() GrammarType {
for p.tt == SemicolonToken {
p.tt, p.data = p.popToken(false)
}
if p.tt == RightBraceToken || p.tt == ErrorToken {
p.state = p.state[:len(p.state)-1]
return EndAtRuleGrammar
}
return p.parseDeclarationList()
}
func (p *Parser) parseAtRuleUnknown() GrammarType {
p.keepWS = true
if p.tt == RightBraceToken && p.level == 0 || p.tt == ErrorToken {
p.state = p.state[:len(p.state)-1]
p.keepWS = false
return EndAtRuleGrammar
}
if p.tt == LeftParenthesisToken || p.tt == LeftBraceToken || p.tt == LeftBracketToken || p.tt == FunctionToken {
p.level++
} else if p.tt == RightParenthesisToken || p.tt == RightBraceToken || p.tt == RightBracketToken {
p.level--
}
return TokenGrammar
}
func (p *Parser) parseQualifiedRule() GrammarType {
p.initBuf()
first := true
inAttrSel := false
skipWS := true
var tt TokenType
var data []byte
for {
if first {
tt, data = p.tt, p.data
p.tt = WhitespaceToken
p.data = emptyBytes
first = false
} else {
tt, data = p.popToken(false)
}
if tt == LeftBraceToken && p.level == 0 {
p.state = append(p.state, (*Parser).parseQualifiedRuleDeclarationList)
return BeginRulesetGrammar
} else if tt == ErrorToken {
p.err, p.errPos = "unexpected ending in qualified rule", p.l.r.Offset()
return ErrorGrammar
} else if tt == LeftParenthesisToken || tt == LeftBraceToken || tt == LeftBracketToken || tt == FunctionToken {
p.level++
} else if tt == RightParenthesisToken || tt == RightBraceToken || tt == RightBracketToken {
if p.level == 0 {
// TODO: buggy
p.pushBuf(tt, data)
if 1 < len(p.state) {
p.state = p.state[:len(p.state)-1]
}
p.err, p.errPos = "unexpected ending in qualified rule", p.l.r.Offset()
return ErrorGrammar
}
p.level--
}
if len(data) == 1 && (data[0] == ',' || data[0] == '>' || data[0] == '+' || data[0] == '~') {
if data[0] == ',' {
return QualifiedRuleGrammar
}
skipWS = true
} else if p.prevWS && !skipWS && !inAttrSel {
p.pushBuf(WhitespaceToken, wsBytes)
} else {
skipWS = false
}
if tt == LeftBracketToken {
inAttrSel = true
} else if tt == RightBracketToken {
inAttrSel = false
}
p.pushBuf(tt, data)
}
}
func (p *Parser) parseQualifiedRuleDeclarationList() GrammarType {
for p.tt == SemicolonToken {
p.tt, p.data = p.popToken(false)
}
if p.tt == RightBraceToken || p.tt == ErrorToken {
p.state = p.state[:len(p.state)-1]
return EndRulesetGrammar
}
return p.parseDeclarationList()
}
func (p *Parser) parseDeclaration() GrammarType {
p.initBuf()
p.data = parse.ToLower(parse.Copy(p.data))
ttName, dataName := p.tt, p.data
tt, data := p.popToken(false)
if tt != ColonToken {
p.l.r.Move(-len(data))
p.err, p.errPos = "expected colon in declaration", p.l.r.Offset()
p.l.r.Move(len(data))
p.pushBuf(ttName, dataName)
return p.parseDeclarationError(tt, data)
}
skipWS := true
for {
tt, data := p.popToken(false)
if (tt == SemicolonToken || tt == RightBraceToken) && p.level == 0 || tt == ErrorToken {
p.prevEnd = (tt == RightBraceToken)
return DeclarationGrammar
} else if tt == LeftParenthesisToken || tt == LeftBraceToken || tt == LeftBracketToken || tt == FunctionToken {
p.level++
} else if tt == RightParenthesisToken || tt == RightBraceToken || tt == RightBracketToken {
if p.level == 0 {
// TODO: buggy
p.err, p.errPos = "unexpected ending in declaration", p.l.r.Offset()
p.pushBuf(ttName, dataName)
p.pushBuf(ColonToken, []byte{':'})
return p.parseDeclarationError(tt, data)
}
p.level--
}
if len(data) == 1 && (data[0] == ',' || data[0] == '/' || data[0] == ':' || data[0] == '!' || data[0] == '=') {
skipWS = true
} else if (p.prevWS || p.prevComment) && !skipWS {
p.pushBuf(WhitespaceToken, wsBytes)
} else {
skipWS = false
}
p.pushBuf(tt, data)
}
}
func (p *Parser) parseDeclarationError(tt TokenType, data []byte) GrammarType {
// we're on the offending (tt,data), keep popping tokens till we reach ;, }, or EOF
p.tt, p.data = tt, data
for {
if (tt == SemicolonToken || tt == RightBraceToken) && p.level == 0 || tt == ErrorToken {
p.prevEnd = (tt == RightBraceToken)
if tt == SemicolonToken {
p.pushBuf(tt, data)
}
return ErrorGrammar
} else if tt == LeftParenthesisToken || tt == LeftBraceToken || tt == LeftBracketToken || tt == FunctionToken {
p.level++
} else if tt == RightParenthesisToken || tt == RightBraceToken || tt == RightBracketToken {
p.level--
}
if p.prevWS {
p.pushBuf(WhitespaceToken, wsBytes)
}
p.pushBuf(tt, data)
tt, data = p.popToken(false)
}
}
func (p *Parser) parseCustomProperty() GrammarType {
p.initBuf()
if tt, data := p.popToken(false); tt != ColonToken {
p.l.r.Move(-len(data))
p.err, p.errPos = "expected colon in custom property", p.l.r.Offset()
p.l.r.Move(len(data))
return ErrorGrammar
}
val := []byte{}
for {
tt, data := p.l.Next()
if (tt == SemicolonToken || tt == RightBraceToken) && p.level == 0 || tt == ErrorToken {
p.prevEnd = (tt == RightBraceToken)
p.pushBuf(CustomPropertyValueToken, val)
return CustomPropertyGrammar
} else if tt == LeftParenthesisToken || tt == LeftBraceToken || tt == LeftBracketToken || tt == FunctionToken {
p.level++
} else if tt == RightParenthesisToken || tt == RightBraceToken || tt == RightBracketToken {
if p.level == 0 {
// TODO: buggy
p.pushBuf(tt, data)
p.err, p.errPos = "unexpected ending in custom property", p.l.r.Offset()
return ErrorGrammar
}
p.level--
}
val = append(val, data...)
}
}