// Copyright 2009 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. // Package xml implements a simple XML 1.0 parser that // understands XML name spaces. package xml // References: // Annotated XML spec: http://www.xml.com/axml/testaxml.htm // XML name spaces: http://www.w3.org/TR/REC-xml-names/ // TODO(rsc): // Test error handling. import ( "bufio" "bytes" "errors" "fmt" "io" "strconv" "strings" "unicode" "unicode/utf8" ) // A SyntaxError represents a syntax error in the XML input stream. type SyntaxError struct { Msg string Line int } func (e *SyntaxError) Error() string { return "XML syntax error on line " + strconv.Itoa(e.Line) + ": " + e.Msg } // A Name represents an XML name (Local) annotated // with a name space identifier (Space). // In tokens returned by Decoder.Token, the Space identifier // is given as a canonical URL, not the short prefix used // in the document being parsed. type Name struct { Space, Local string } // An Attr represents an attribute in an XML element (Name=Value). type Attr struct { Name Name Value string } // A Token is an interface holding one of the token types: // StartElement, EndElement, CharData, Comment, ProcInst, or Directive. type Token interface{} // A StartElement represents an XML start element. type StartElement struct { Name Name Attr []Attr } func (e StartElement) Copy() StartElement { attrs := make([]Attr, len(e.Attr)) copy(attrs, e.Attr) e.Attr = attrs return e } // End returns the corresponding XML end element. func (e StartElement) End() EndElement { return EndElement{e.Name} } // An EndElement represents an XML end element. type EndElement struct { Name Name } // A CharData represents XML character data (raw text), // in which XML escape sequences have been replaced by // the characters they represent. type CharData []byte func makeCopy(b []byte) []byte { b1 := make([]byte, len(b)) copy(b1, b) return b1 } func (c CharData) Copy() CharData { return CharData(makeCopy(c)) } // A Comment represents an XML comment of the form <!--comment-->. // The bytes do not include the <!-- and --> comment markers. type Comment []byte func (c Comment) Copy() Comment { return Comment(makeCopy(c)) } // A ProcInst represents an XML processing instruction of the form <?target inst?> type ProcInst struct { Target string Inst []byte } func (p ProcInst) Copy() ProcInst { p.Inst = makeCopy(p.Inst) return p } // A Directive represents an XML directive of the form <!text>. // The bytes do not include the <! and > markers. type Directive []byte func (d Directive) Copy() Directive { return Directive(makeCopy(d)) } // CopyToken returns a copy of a Token. func CopyToken(t Token) Token { switch v := t.(type) { case CharData: return v.Copy() case Comment: return v.Copy() case Directive: return v.Copy() case ProcInst: return v.Copy() case StartElement: return v.Copy() } return t } // A Decoder represents an XML parser reading a particular input stream. // The parser assumes that its input is encoded in UTF-8. type Decoder struct { // Strict defaults to true, enforcing the requirements // of the XML specification. // If set to false, the parser allows input containing common // mistakes: // * If an element is missing an end tag, the parser invents // end tags as necessary to keep the return values from Token // properly balanced. // * In attribute values and character data, unknown or malformed // character entities (sequences beginning with &) are left alone. // // Setting: // // d.Strict = false; // d.AutoClose = HTMLAutoClose; // d.Entity = HTMLEntity // // creates a parser that can handle typical HTML. // // Strict mode does not enforce the requirements of the XML name spaces TR. // In particular it does not reject name space tags using undefined prefixes. // Such tags are recorded with the unknown prefix as the name space URL. Strict bool // When Strict == false, AutoClose indicates a set of elements to // consider closed immediately after they are opened, regardless // of whether an end element is present. AutoClose []string // Entity can be used to map non-standard entity names to string replacements. // The parser behaves as if these standard mappings are present in the map, // regardless of the actual map content: // // "lt": "<", // "gt": ">", // "amp": "&", // "apos": "'", // "quot": `"`, Entity map[string]string // CharsetReader, if non-nil, defines a function to generate // charset-conversion readers, converting from the provided // non-UTF-8 charset into UTF-8. If CharsetReader is nil or // returns an error, parsing stops with an error. One of the // the CharsetReader's result values must be non-nil. CharsetReader func(charset string, input io.Reader) (io.Reader, error) // DefaultSpace sets the default name space used for unadorned tags, // as if the entire XML stream were wrapped in an element containing // the attribute xmlns="DefaultSpace". DefaultSpace string r io.ByteReader buf bytes.Buffer saved *bytes.Buffer stk *stack free *stack needClose bool toClose Name nextToken Token nextByte int ns map[string]string err error line int offset int64 unmarshalDepth int } // NewDecoder creates a new XML parser reading from r. // If r does not implement io.ByteReader, NewDecoder will // do its own buffering. func NewDecoder(r io.Reader) *Decoder { d := &Decoder{ ns: make(map[string]string), nextByte: -1, line: 1, Strict: true, } d.switchToReader(r) return d } // Token returns the next XML token in the input stream. // At the end of the input stream, Token returns nil, io.EOF. // // Slices of bytes in the returned token data refer to the // parser's internal buffer and remain valid only until the next // call to Token. To acquire a copy of the bytes, call CopyToken // or the token's Copy method. // // Token expands self-closing elements such as <br/> // into separate start and end elements returned by successive calls. // // Token guarantees that the StartElement and EndElement // tokens it returns are properly nested and matched: // if Token encounters an unexpected end element, // it will return an error. // // Token implements XML name spaces as described by // http://www.w3.org/TR/REC-xml-names/. Each of the // Name structures contained in the Token has the Space // set to the URL identifying its name space when known. // If Token encounters an unrecognized name space prefix, // it uses the prefix as the Space rather than report an error. func (d *Decoder) Token() (t Token, err error) { if d.stk != nil && d.stk.kind == stkEOF { err = io.EOF return } if d.nextToken != nil { t = d.nextToken d.nextToken = nil } else if t, err = d.rawToken(); err != nil { return } if !d.Strict { if t1, ok := d.autoClose(t); ok { d.nextToken = t t = t1 } } switch t1 := t.(type) { case StartElement: // In XML name spaces, the translations listed in the // attributes apply to the element name and // to the other attribute names, so process // the translations first. for _, a := range t1.Attr { if a.Name.Space == "xmlns" { v, ok := d.ns[a.Name.Local] d.pushNs(a.Name.Local, v, ok) d.ns[a.Name.Local] = a.Value } if a.Name.Space == "" && a.Name.Local == "xmlns" { // Default space for untagged names v, ok := d.ns[""] d.pushNs("", v, ok) d.ns[""] = a.Value } } d.translate(&t1.Name, true) for i := range t1.Attr { d.translate(&t1.Attr[i].Name, false) } d.pushElement(t1.Name) t = t1 case EndElement: d.translate(&t1.Name, true) if !d.popElement(&t1) { return nil, d.err } t = t1 } return } const xmlURL = "http://www.w3.org/XML/1998/namespace" // Apply name space translation to name n. // The default name space (for Space=="") // applies only to element names, not to attribute names. func (d *Decoder) translate(n *Name, isElementName bool) { switch { case n.Space == "xmlns": return case n.Space == "" && !isElementName: return case n.Space == "xml": n.Space = xmlURL case n.Space == "" && n.Local == "xmlns": return } if v, ok := d.ns[n.Space]; ok { n.Space = v } else if n.Space == "" { n.Space = d.DefaultSpace } } func (d *Decoder) switchToReader(r io.Reader) { // Get efficient byte at a time reader. // Assume that if reader has its own // ReadByte, it's efficient enough. // Otherwise, use bufio. if rb, ok := r.(io.ByteReader); ok { d.r = rb } else { d.r = bufio.NewReader(r) } } // Parsing state - stack holds old name space translations // and the current set of open elements. The translations to pop when // ending a given tag are *below* it on the stack, which is // more work but forced on us by XML. type stack struct { next *stack kind int name Name ok bool } const ( stkStart = iota stkNs stkEOF ) func (d *Decoder) push(kind int) *stack { s := d.free if s != nil { d.free = s.next } else { s = new(stack) } s.next = d.stk s.kind = kind d.stk = s return s } func (d *Decoder) pop() *stack { s := d.stk if s != nil { d.stk = s.next s.next = d.free d.free = s } return s } // Record that after the current element is finished // (that element is already pushed on the stack) // Token should return EOF until popEOF is called. func (d *Decoder) pushEOF() { // Walk down stack to find Start. // It might not be the top, because there might be stkNs // entries above it. start := d.stk for start.kind != stkStart { start = start.next } // The stkNs entries below a start are associated with that // element too; skip over them. for start.next != nil && start.next.kind == stkNs { start = start.next } s := d.free if s != nil { d.free = s.next } else { s = new(stack) } s.kind = stkEOF s.next = start.next start.next = s } // Undo a pushEOF. // The element must have been finished, so the EOF should be at the top of the stack. func (d *Decoder) popEOF() bool { if d.stk == nil || d.stk.kind != stkEOF { return false } d.pop() return true } // Record that we are starting an element with the given name. func (d *Decoder) pushElement(name Name) { s := d.push(stkStart) s.name = name } // Record that we are changing the value of ns[local]. // The old value is url, ok. func (d *Decoder) pushNs(local string, url string, ok bool) { s := d.push(stkNs) s.name.Local = local s.name.Space = url s.ok = ok } // Creates a SyntaxError with the current line number. func (d *Decoder) syntaxError(msg string) error { return &SyntaxError{Msg: msg, Line: d.line} } // Record that we are ending an element with the given name. // The name must match the record at the top of the stack, // which must be a pushElement record. // After popping the element, apply any undo records from // the stack to restore the name translations that existed // before we saw this element. func (d *Decoder) popElement(t *EndElement) bool { s := d.pop() name := t.Name switch { case s == nil || s.kind != stkStart: d.err = d.syntaxError("unexpected end element </" + name.Local + ">") return false case s.name.Local != name.Local: if !d.Strict { d.needClose = true d.toClose = t.Name t.Name = s.name return true } d.err = d.syntaxError("element <" + s.name.Local + "> closed by </" + name.Local + ">") return false case s.name.Space != name.Space: d.err = d.syntaxError("element <" + s.name.Local + "> in space " + s.name.Space + "closed by </" + name.Local + "> in space " + name.Space) return false } // Pop stack until a Start or EOF is on the top, undoing the // translations that were associated with the element we just closed. for d.stk != nil && d.stk.kind != stkStart && d.stk.kind != stkEOF { s := d.pop() if s.ok { d.ns[s.name.Local] = s.name.Space } else { delete(d.ns, s.name.Local) } } return true } // If the top element on the stack is autoclosing and // t is not the end tag, invent the end tag. func (d *Decoder) autoClose(t Token) (Token, bool) { if d.stk == nil || d.stk.kind != stkStart { return nil, false } name := strings.ToLower(d.stk.name.Local) for _, s := range d.AutoClose { if strings.ToLower(s) == name { // This one should be auto closed if t doesn't close it. et, ok := t.(EndElement) if !ok || et.Name.Local != name { return EndElement{d.stk.name}, true } break } } return nil, false } var errRawToken = errors.New("xml: cannot use RawToken from UnmarshalXML method") // RawToken is like Token but does not verify that // start and end elements match and does not translate // name space prefixes to their corresponding URLs. func (d *Decoder) RawToken() (Token, error) { if d.unmarshalDepth > 0 { return nil, errRawToken } return d.rawToken() } func (d *Decoder) rawToken() (Token, error) { if d.err != nil { return nil, d.err } if d.needClose { // The last element we read was self-closing and // we returned just the StartElement half. // Return the EndElement half now. d.needClose = false return EndElement{d.toClose}, nil } b, ok := d.getc() if !ok { return nil, d.err } if b != '<' { // Text section. d.ungetc(b) data := d.text(-1, false) if data == nil { return nil, d.err } return CharData(data), nil } if b, ok = d.mustgetc(); !ok { return nil, d.err } switch b { case '/': // </: End element var name Name if name, ok = d.nsname(); !ok { if d.err == nil { d.err = d.syntaxError("expected element name after </") } return nil, d.err } d.space() if b, ok = d.mustgetc(); !ok { return nil, d.err } if b != '>' { d.err = d.syntaxError("invalid characters between </" + name.Local + " and >") return nil, d.err } return EndElement{name}, nil case '?': // <?: Processing instruction. var target string if target, ok = d.name(); !ok { if d.err == nil { d.err = d.syntaxError("expected target name after <?") } return nil, d.err } d.space() d.buf.Reset() var b0 byte for { if b, ok = d.mustgetc(); !ok { return nil, d.err } d.buf.WriteByte(b) if b0 == '?' && b == '>' { break } b0 = b } data := d.buf.Bytes() data = data[0 : len(data)-2] // chop ?> if target == "xml" { content := string(data) ver := procInst("version", content) if ver != "" && ver != "1.0" { d.err = fmt.Errorf("xml: unsupported version %q; only version 1.0 is supported", ver) return nil, d.err } enc := procInst("encoding", content) if enc != "" && enc != "utf-8" && enc != "UTF-8" { if d.CharsetReader == nil { d.err = fmt.Errorf("xml: encoding %q declared but Decoder.CharsetReader is nil", enc) return nil, d.err } newr, err := d.CharsetReader(enc, d.r.(io.Reader)) if err != nil { d.err = fmt.Errorf("xml: opening charset %q: %v", enc, err) return nil, d.err } if newr == nil { panic("CharsetReader returned a nil Reader for charset " + enc) } d.switchToReader(newr) } } return ProcInst{target, data}, nil case '!': // <!: Maybe comment, maybe CDATA. if b, ok = d.mustgetc(); !ok { return nil, d.err } switch b { case '-': // <!- // Probably <!-- for a comment. if b, ok = d.mustgetc(); !ok { return nil, d.err } if b != '-' { d.err = d.syntaxError("invalid sequence <!- not part of <!--") return nil, d.err } // Look for terminator. d.buf.Reset() var b0, b1 byte for { if b, ok = d.mustgetc(); !ok { return nil, d.err } d.buf.WriteByte(b) if b0 == '-' && b1 == '-' && b == '>' { break } b0, b1 = b1, b } data := d.buf.Bytes() data = data[0 : len(data)-3] // chop --> return Comment(data), nil case '[': // <![ // Probably <![CDATA[. for i := 0; i < 6; i++ { if b, ok = d.mustgetc(); !ok { return nil, d.err } if b != "CDATA["[i] { d.err = d.syntaxError("invalid <![ sequence") return nil, d.err } } // Have <![CDATA[. Read text until ]]>. data := d.text(-1, true) if data == nil { return nil, d.err } return CharData(data), nil } // Probably a directive: <!DOCTYPE ...>, <!ENTITY ...>, etc. // We don't care, but accumulate for caller. Quoted angle // brackets do not count for nesting. d.buf.Reset() d.buf.WriteByte(b) inquote := uint8(0) depth := 0 for { if b, ok = d.mustgetc(); !ok { return nil, d.err } if inquote == 0 && b == '>' && depth == 0 { break } HandleB: d.buf.WriteByte(b) switch { case b == inquote: inquote = 0 case inquote != 0: // in quotes, no special action case b == '\'' || b == '"': inquote = b case b == '>' && inquote == 0: depth-- case b == '<' && inquote == 0: // Look for <!-- to begin comment. s := "!--" for i := 0; i < len(s); i++ { if b, ok = d.mustgetc(); !ok { return nil, d.err } if b != s[i] { for j := 0; j < i; j++ { d.buf.WriteByte(s[j]) } depth++ goto HandleB } } // Remove < that was written above. d.buf.Truncate(d.buf.Len() - 1) // Look for terminator. var b0, b1 byte for { if b, ok = d.mustgetc(); !ok { return nil, d.err } if b0 == '-' && b1 == '-' && b == '>' { break } b0, b1 = b1, b } } } return Directive(d.buf.Bytes()), nil } // Must be an open element like <a href="foo"> d.ungetc(b) var ( name Name empty bool attr []Attr ) if name, ok = d.nsname(); !ok { if d.err == nil { d.err = d.syntaxError("expected element name after <") } return nil, d.err } attr = []Attr{} for { d.space() if b, ok = d.mustgetc(); !ok { return nil, d.err } if b == '/' { empty = true if b, ok = d.mustgetc(); !ok { return nil, d.err } if b != '>' { d.err = d.syntaxError("expected /> in element") return nil, d.err } break } if b == '>' { break } d.ungetc(b) n := len(attr) if n >= cap(attr) { nCap := 2 * cap(attr) if nCap == 0 { nCap = 4 } nattr := make([]Attr, n, nCap) copy(nattr, attr) attr = nattr } attr = attr[0 : n+1] a := &attr[n] if a.Name, ok = d.nsname(); !ok { if d.err == nil { d.err = d.syntaxError("expected attribute name in element") } return nil, d.err } d.space() if b, ok = d.mustgetc(); !ok { return nil, d.err } if b != '=' { if d.Strict { d.err = d.syntaxError("attribute name without = in element") return nil, d.err } else { d.ungetc(b) a.Value = a.Name.Local } } else { d.space() data := d.attrval() if data == nil { return nil, d.err } a.Value = string(data) } } if empty { d.needClose = true d.toClose = name } return StartElement{name, attr}, nil } func (d *Decoder) attrval() []byte { b, ok := d.mustgetc() if !ok { return nil } // Handle quoted attribute values if b == '"' || b == '\'' { return d.text(int(b), false) } // Handle unquoted attribute values for strict parsers if d.Strict { d.err = d.syntaxError("unquoted or missing attribute value in element") return nil } // Handle unquoted attribute values for unstrict parsers d.ungetc(b) d.buf.Reset() for { b, ok = d.mustgetc() if !ok { return nil } // http://www.w3.org/TR/REC-html40/intro/sgmltut.html#h-3.2.2 if 'a' <= b && b <= 'z' || 'A' <= b && b <= 'Z' || '0' <= b && b <= '9' || b == '_' || b == ':' || b == '-' { d.buf.WriteByte(b) } else { d.ungetc(b) break } } return d.buf.Bytes() } // Skip spaces if any func (d *Decoder) space() { for { b, ok := d.getc() if !ok { return } switch b { case ' ', '\r', '\n', '\t': default: d.ungetc(b) return } } } // Read a single byte. // If there is no byte to read, return ok==false // and leave the error in d.err. // Maintain line number. func (d *Decoder) getc() (b byte, ok bool) { if d.err != nil { return 0, false } if d.nextByte >= 0 { b = byte(d.nextByte) d.nextByte = -1 } else { b, d.err = d.r.ReadByte() if d.err != nil { return 0, false } if d.saved != nil { d.saved.WriteByte(b) } } if b == '\n' { d.line++ } d.offset++ return b, true } // InputOffset returns the input stream byte offset of the current decoder position. // The offset gives the location of the end of the most recently returned token // and the beginning of the next token. func (d *Decoder) InputOffset() int64 { return d.offset } // Return saved offset. // If we did ungetc (nextByte >= 0), have to back up one. func (d *Decoder) savedOffset() int { n := d.saved.Len() if d.nextByte >= 0 { n-- } return n } // Must read a single byte. // If there is no byte to read, // set d.err to SyntaxError("unexpected EOF") // and return ok==false func (d *Decoder) mustgetc() (b byte, ok bool) { if b, ok = d.getc(); !ok { if d.err == io.EOF { d.err = d.syntaxError("unexpected EOF") } } return } // Unread a single byte. func (d *Decoder) ungetc(b byte) { if b == '\n' { d.line-- } d.nextByte = int(b) d.offset-- } var entity = map[string]int{ "lt": '<', "gt": '>', "amp": '&', "apos": '\'', "quot": '"', } // Read plain text section (XML calls it character data). // If quote >= 0, we are in a quoted string and need to find the matching quote. // If cdata == true, we are in a <![CDATA[ section and need to find ]]>. // On failure return nil and leave the error in d.err. func (d *Decoder) text(quote int, cdata bool) []byte { var b0, b1 byte var trunc int d.buf.Reset() Input: for { b, ok := d.getc() if !ok { if cdata { if d.err == io.EOF { d.err = d.syntaxError("unexpected EOF in CDATA section") } return nil } break Input } // <![CDATA[ section ends with ]]>. // It is an error for ]]> to appear in ordinary text. if b0 == ']' && b1 == ']' && b == '>' { if cdata { trunc = 2 break Input } d.err = d.syntaxError("unescaped ]]> not in CDATA section") return nil } // Stop reading text if we see a <. if b == '<' && !cdata { if quote >= 0 { d.err = d.syntaxError("unescaped < inside quoted string") return nil } d.ungetc('<') break Input } if quote >= 0 && b == byte(quote) { break Input } if b == '&' && !cdata { // Read escaped character expression up to semicolon. // XML in all its glory allows a document to define and use // its own character names with <!ENTITY ...> directives. // Parsers are required to recognize lt, gt, amp, apos, and quot // even if they have not been declared. before := d.buf.Len() d.buf.WriteByte('&') var ok bool var text string var haveText bool if b, ok = d.mustgetc(); !ok { return nil } if b == '#' { d.buf.WriteByte(b) if b, ok = d.mustgetc(); !ok { return nil } base := 10 if b == 'x' { base = 16 d.buf.WriteByte(b) if b, ok = d.mustgetc(); !ok { return nil } } start := d.buf.Len() for '0' <= b && b <= '9' || base == 16 && 'a' <= b && b <= 'f' || base == 16 && 'A' <= b && b <= 'F' { d.buf.WriteByte(b) if b, ok = d.mustgetc(); !ok { return nil } } if b != ';' { d.ungetc(b) } else { s := string(d.buf.Bytes()[start:]) d.buf.WriteByte(';') n, err := strconv.ParseUint(s, base, 64) if err == nil && n <= unicode.MaxRune { text = string(n) haveText = true } } } else { d.ungetc(b) if !d.readName() { if d.err != nil { return nil } ok = false } if b, ok = d.mustgetc(); !ok { return nil } if b != ';' { d.ungetc(b) } else { name := d.buf.Bytes()[before+1:] d.buf.WriteByte(';') if isName(name) { s := string(name) if r, ok := entity[s]; ok { text = string(r) haveText = true } else if d.Entity != nil { text, haveText = d.Entity[s] } } } } if haveText { d.buf.Truncate(before) d.buf.Write([]byte(text)) b0, b1 = 0, 0 continue Input } if !d.Strict { b0, b1 = 0, 0 continue Input } ent := string(d.buf.Bytes()[before:]) if ent[len(ent)-1] != ';' { ent += " (no semicolon)" } d.err = d.syntaxError("invalid character entity " + ent) return nil } // We must rewrite unescaped \r and \r\n into \n. if b == '\r' { d.buf.WriteByte('\n') } else if b1 == '\r' && b == '\n' { // Skip \r\n--we already wrote \n. } else { d.buf.WriteByte(b) } b0, b1 = b1, b } data := d.buf.Bytes() data = data[0 : len(data)-trunc] // Inspect each rune for being a disallowed character. buf := data for len(buf) > 0 { r, size := utf8.DecodeRune(buf) if r == utf8.RuneError && size == 1 { d.err = d.syntaxError("invalid UTF-8") return nil } buf = buf[size:] if !isInCharacterRange(r) { d.err = d.syntaxError(fmt.Sprintf("illegal character code %U", r)) return nil } } return data } // Decide whether the given rune is in the XML Character Range, per // the Char production of http://www.xml.com/axml/testaxml.htm, // Section 2.2 Characters. func isInCharacterRange(r rune) (inrange bool) { return r == 0x09 || r == 0x0A || r == 0x0D || r >= 0x20 && r <= 0xDF77 || r >= 0xE000 && r <= 0xFFFD || r >= 0x10000 && r <= 0x10FFFF } // Get name space name: name with a : stuck in the middle. // The part before the : is the name space identifier. func (d *Decoder) nsname() (name Name, ok bool) { s, ok := d.name() if !ok { return } i := strings.Index(s, ":") if i < 0 { name.Local = s } else { name.Space = s[0:i] name.Local = s[i+1:] } return name, true } // Get name: /first(first|second)*/ // Do not set d.err if the name is missing (unless unexpected EOF is received): // let the caller provide better context. func (d *Decoder) name() (s string, ok bool) { d.buf.Reset() if !d.readName() { return "", false } // Now we check the characters. b := d.buf.Bytes() if !isName(b) { d.err = d.syntaxError("invalid XML name: " + string(b)) return "", false } return string(b), true } // Read a name and append its bytes to d.buf. // The name is delimited by any single-byte character not valid in names. // All multi-byte characters are accepted; the caller must check their validity. func (d *Decoder) readName() (ok bool) { var b byte if b, ok = d.mustgetc(); !ok { return } if b < utf8.RuneSelf && !isNameByte(b) { d.ungetc(b) return false } d.buf.WriteByte(b) for { if b, ok = d.mustgetc(); !ok { return } if b < utf8.RuneSelf && !isNameByte(b) { d.ungetc(b) break } d.buf.WriteByte(b) } return true } func isNameByte(c byte) bool { return 'A' <= c && c <= 'Z' || 'a' <= c && c <= 'z' || '0' <= c && c <= '9' || c == '_' || c == ':' || c == '.' || c == '-' } func isName(s []byte) bool { if len(s) == 0 { return false } c, n := utf8.DecodeRune(s) if c == utf8.RuneError && n == 1 { return false } if !unicode.Is(first, c) { return false } for n < len(s) { s = s[n:] c, n = utf8.DecodeRune(s) if c == utf8.RuneError && n == 1 { return false } if !unicode.Is(first, c) && !unicode.Is(second, c) { return false } } return true } func isNameString(s string) bool { if len(s) == 0 { return false } c, n := utf8.DecodeRuneInString(s) if c == utf8.RuneError && n == 1 { return false } if !unicode.Is(first, c) { return false } for n < len(s) { s = s[n:] c, n = utf8.DecodeRuneInString(s) if c == utf8.RuneError && n == 1 { return false } if !unicode.Is(first, c) && !unicode.Is(second, c) { return false } } return true } // These tables were generated by cut and paste from Appendix B of // the XML spec at http://www.xml.com/axml/testaxml.htm // and then reformatting. First corresponds to (Letter | '_' | ':') // and second corresponds to NameChar. var first = &unicode.RangeTable{ R16: []unicode.Range16{ {0x003A, 0x003A, 1}, {0x0041, 0x005A, 1}, {0x005F, 0x005F, 1}, {0x0061, 0x007A, 1}, {0x00C0, 0x00D6, 1}, {0x00D8, 0x00F6, 1}, {0x00F8, 0x00FF, 1}, {0x0100, 0x0131, 1}, {0x0134, 0x013E, 1}, {0x0141, 0x0148, 1}, {0x014A, 0x017E, 1}, {0x0180, 0x01C3, 1}, {0x01CD, 0x01F0, 1}, {0x01F4, 0x01F5, 1}, {0x01FA, 0x0217, 1}, {0x0250, 0x02A8, 1}, {0x02BB, 0x02C1, 1}, {0x0386, 0x0386, 1}, {0x0388, 0x038A, 1}, {0x038C, 0x038C, 1}, {0x038E, 0x03A1, 1}, {0x03A3, 0x03CE, 1}, {0x03D0, 0x03D6, 1}, {0x03DA, 0x03E0, 2}, {0x03E2, 0x03F3, 1}, {0x0401, 0x040C, 1}, {0x040E, 0x044F, 1}, {0x0451, 0x045C, 1}, {0x045E, 0x0481, 1}, {0x0490, 0x04C4, 1}, {0x04C7, 0x04C8, 1}, {0x04CB, 0x04CC, 1}, {0x04D0, 0x04EB, 1}, {0x04EE, 0x04F5, 1}, {0x04F8, 0x04F9, 1}, {0x0531, 0x0556, 1}, {0x0559, 0x0559, 1}, {0x0561, 0x0586, 1}, {0x05D0, 0x05EA, 1}, {0x05F0, 0x05F2, 1}, {0x0621, 0x063A, 1}, {0x0641, 0x064A, 1}, {0x0671, 0x06B7, 1}, {0x06BA, 0x06BE, 1}, {0x06C0, 0x06CE, 1}, {0x06D0, 0x06D3, 1}, {0x06D5, 0x06D5, 1}, {0x06E5, 0x06E6, 1}, {0x0905, 0x0939, 1}, {0x093D, 0x093D, 1}, {0x0958, 0x0961, 1}, {0x0985, 0x098C, 1}, {0x098F, 0x0990, 1}, {0x0993, 0x09A8, 1}, {0x09AA, 0x09B0, 1}, {0x09B2, 0x09B2, 1}, {0x09B6, 0x09B9, 1}, {0x09DC, 0x09DD, 1}, {0x09DF, 0x09E1, 1}, {0x09F0, 0x09F1, 1}, {0x0A05, 0x0A0A, 1}, {0x0A0F, 0x0A10, 1}, {0x0A13, 0x0A28, 1}, {0x0A2A, 0x0A30, 1}, {0x0A32, 0x0A33, 1}, {0x0A35, 0x0A36, 1}, {0x0A38, 0x0A39, 1}, {0x0A59, 0x0A5C, 1}, {0x0A5E, 0x0A5E, 1}, {0x0A72, 0x0A74, 1}, {0x0A85, 0x0A8B, 1}, {0x0A8D, 0x0A8D, 1}, {0x0A8F, 0x0A91, 1}, {0x0A93, 0x0AA8, 1}, {0x0AAA, 0x0AB0, 1}, {0x0AB2, 0x0AB3, 1}, {0x0AB5, 0x0AB9, 1}, {0x0ABD, 0x0AE0, 0x23}, {0x0B05, 0x0B0C, 1}, {0x0B0F, 0x0B10, 1}, {0x0B13, 0x0B28, 1}, {0x0B2A, 0x0B30, 1}, {0x0B32, 0x0B33, 1}, {0x0B36, 0x0B39, 1}, {0x0B3D, 0x0B3D, 1}, {0x0B5C, 0x0B5D, 1}, {0x0B5F, 0x0B61, 1}, {0x0B85, 0x0B8A, 1}, {0x0B8E, 0x0B90, 1}, {0x0B92, 0x0B95, 1}, {0x0B99, 0x0B9A, 1}, {0x0B9C, 0x0B9C, 1}, {0x0B9E, 0x0B9F, 1}, {0x0BA3, 0x0BA4, 1}, {0x0BA8, 0x0BAA, 1}, {0x0BAE, 0x0BB5, 1}, {0x0BB7, 0x0BB9, 1}, {0x0C05, 0x0C0C, 1}, {0x0C0E, 0x0C10, 1}, {0x0C12, 0x0C28, 1}, {0x0C2A, 0x0C33, 1}, {0x0C35, 0x0C39, 1}, {0x0C60, 0x0C61, 1}, {0x0C85, 0x0C8C, 1}, {0x0C8E, 0x0C90, 1}, {0x0C92, 0x0CA8, 1}, {0x0CAA, 0x0CB3, 1}, {0x0CB5, 0x0CB9, 1}, {0x0CDE, 0x0CDE, 1}, {0x0CE0, 0x0CE1, 1}, {0x0D05, 0x0D0C, 1}, {0x0D0E, 0x0D10, 1}, {0x0D12, 0x0D28, 1}, {0x0D2A, 0x0D39, 1}, {0x0D60, 0x0D61, 1}, {0x0E01, 0x0E2E, 1}, {0x0E30, 0x0E30, 1}, {0x0E32, 0x0E33, 1}, {0x0E40, 0x0E45, 1}, {0x0E81, 0x0E82, 1}, {0x0E84, 0x0E84, 1}, {0x0E87, 0x0E88, 1}, {0x0E8A, 0x0E8D, 3}, {0x0E94, 0x0E97, 1}, {0x0E99, 0x0E9F, 1}, {0x0EA1, 0x0EA3, 1}, {0x0EA5, 0x0EA7, 2}, {0x0EAA, 0x0EAB, 1}, {0x0EAD, 0x0EAE, 1}, {0x0EB0, 0x0EB0, 1}, {0x0EB2, 0x0EB3, 1}, {0x0EBD, 0x0EBD, 1}, {0x0EC0, 0x0EC4, 1}, {0x0F40, 0x0F47, 1}, {0x0F49, 0x0F69, 1}, {0x10A0, 0x10C5, 1}, {0x10D0, 0x10F6, 1}, {0x1100, 0x1100, 1}, {0x1102, 0x1103, 1}, {0x1105, 0x1107, 1}, {0x1109, 0x1109, 1}, {0x110B, 0x110C, 1}, {0x110E, 0x1112, 1}, {0x113C, 0x1140, 2}, {0x114C, 0x1150, 2}, {0x1154, 0x1155, 1}, {0x1159, 0x1159, 1}, {0x115F, 0x1161, 1}, {0x1163, 0x1169, 2}, {0x116D, 0x116E, 1}, {0x1172, 0x1173, 1}, {0x1175, 0x119E, 0x119E - 0x1175}, {0x11A8, 0x11AB, 0x11AB - 0x11A8}, {0x11AE, 0x11AF, 1}, {0x11B7, 0x11B8, 1}, {0x11BA, 0x11BA, 1}, {0x11BC, 0x11C2, 1}, {0x11EB, 0x11F0, 0x11F0 - 0x11EB}, {0x11F9, 0x11F9, 1}, {0x1E00, 0x1E9B, 1}, {0x1EA0, 0x1EF9, 1}, {0x1F00, 0x1F15, 1}, {0x1F18, 0x1F1D, 1}, {0x1F20, 0x1F45, 1}, {0x1F48, 0x1F4D, 1}, {0x1F50, 0x1F57, 1}, {0x1F59, 0x1F5B, 0x1F5B - 0x1F59}, {0x1F5D, 0x1F5D, 1}, {0x1F5F, 0x1F7D, 1}, {0x1F80, 0x1FB4, 1}, {0x1FB6, 0x1FBC, 1}, {0x1FBE, 0x1FBE, 1}, {0x1FC2, 0x1FC4, 1}, {0x1FC6, 0x1FCC, 1}, {0x1FD0, 0x1FD3, 1}, {0x1FD6, 0x1FDB, 1}, {0x1FE0, 0x1FEC, 1}, {0x1FF2, 0x1FF4, 1}, {0x1FF6, 0x1FFC, 1}, {0x2126, 0x2126, 1}, {0x212A, 0x212B, 1}, {0x212E, 0x212E, 1}, {0x2180, 0x2182, 1}, {0x3007, 0x3007, 1}, {0x3021, 0x3029, 1}, {0x3041, 0x3094, 1}, {0x30A1, 0x30FA, 1}, {0x3105, 0x312C, 1}, {0x4E00, 0x9FA5, 1}, {0xAC00, 0xD7A3, 1}, }, } var second = &unicode.RangeTable{ R16: []unicode.Range16{ {0x002D, 0x002E, 1}, {0x0030, 0x0039, 1}, {0x00B7, 0x00B7, 1}, {0x02D0, 0x02D1, 1}, {0x0300, 0x0345, 1}, {0x0360, 0x0361, 1}, {0x0387, 0x0387, 1}, {0x0483, 0x0486, 1}, {0x0591, 0x05A1, 1}, {0x05A3, 0x05B9, 1}, {0x05BB, 0x05BD, 1}, {0x05BF, 0x05BF, 1}, {0x05C1, 0x05C2, 1}, {0x05C4, 0x0640, 0x0640 - 0x05C4}, {0x064B, 0x0652, 1}, {0x0660, 0x0669, 1}, {0x0670, 0x0670, 1}, {0x06D6, 0x06DC, 1}, {0x06DD, 0x06DF, 1}, {0x06E0, 0x06E4, 1}, {0x06E7, 0x06E8, 1}, {0x06EA, 0x06ED, 1}, {0x06F0, 0x06F9, 1}, {0x0901, 0x0903, 1}, {0x093C, 0x093C, 1}, {0x093E, 0x094C, 1}, {0x094D, 0x094D, 1}, {0x0951, 0x0954, 1}, {0x0962, 0x0963, 1}, {0x0966, 0x096F, 1}, {0x0981, 0x0983, 1}, {0x09BC, 0x09BC, 1}, {0x09BE, 0x09BF, 1}, {0x09C0, 0x09C4, 1}, {0x09C7, 0x09C8, 1}, {0x09CB, 0x09CD, 1}, {0x09D7, 0x09D7, 1}, {0x09E2, 0x09E3, 1}, {0x09E6, 0x09EF, 1}, {0x0A02, 0x0A3C, 0x3A}, {0x0A3E, 0x0A3F, 1}, {0x0A40, 0x0A42, 1}, {0x0A47, 0x0A48, 1}, {0x0A4B, 0x0A4D, 1}, {0x0A66, 0x0A6F, 1}, {0x0A70, 0x0A71, 1}, {0x0A81, 0x0A83, 1}, {0x0ABC, 0x0ABC, 1}, {0x0ABE, 0x0AC5, 1}, {0x0AC7, 0x0AC9, 1}, {0x0ACB, 0x0ACD, 1}, {0x0AE6, 0x0AEF, 1}, {0x0B01, 0x0B03, 1}, {0x0B3C, 0x0B3C, 1}, {0x0B3E, 0x0B43, 1}, {0x0B47, 0x0B48, 1}, {0x0B4B, 0x0B4D, 1}, {0x0B56, 0x0B57, 1}, {0x0B66, 0x0B6F, 1}, {0x0B82, 0x0B83, 1}, {0x0BBE, 0x0BC2, 1}, {0x0BC6, 0x0BC8, 1}, {0x0BCA, 0x0BCD, 1}, {0x0BD7, 0x0BD7, 1}, {0x0BE7, 0x0BEF, 1}, {0x0C01, 0x0C03, 1}, {0x0C3E, 0x0C44, 1}, {0x0C46, 0x0C48, 1}, {0x0C4A, 0x0C4D, 1}, {0x0C55, 0x0C56, 1}, {0x0C66, 0x0C6F, 1}, {0x0C82, 0x0C83, 1}, {0x0CBE, 0x0CC4, 1}, {0x0CC6, 0x0CC8, 1}, {0x0CCA, 0x0CCD, 1}, {0x0CD5, 0x0CD6, 1}, {0x0CE6, 0x0CEF, 1}, {0x0D02, 0x0D03, 1}, {0x0D3E, 0x0D43, 1}, {0x0D46, 0x0D48, 1}, {0x0D4A, 0x0D4D, 1}, {0x0D57, 0x0D57, 1}, {0x0D66, 0x0D6F, 1}, {0x0E31, 0x0E31, 1}, {0x0E34, 0x0E3A, 1}, {0x0E46, 0x0E46, 1}, {0x0E47, 0x0E4E, 1}, {0x0E50, 0x0E59, 1}, {0x0EB1, 0x0EB1, 1}, {0x0EB4, 0x0EB9, 1}, {0x0EBB, 0x0EBC, 1}, {0x0EC6, 0x0EC6, 1}, {0x0EC8, 0x0ECD, 1}, {0x0ED0, 0x0ED9, 1}, {0x0F18, 0x0F19, 1}, {0x0F20, 0x0F29, 1}, {0x0F35, 0x0F39, 2}, {0x0F3E, 0x0F3F, 1}, {0x0F71, 0x0F84, 1}, {0x0F86, 0x0F8B, 1}, {0x0F90, 0x0F95, 1}, {0x0F97, 0x0F97, 1}, {0x0F99, 0x0FAD, 1}, {0x0FB1, 0x0FB7, 1}, {0x0FB9, 0x0FB9, 1}, {0x20D0, 0x20DC, 1}, {0x20E1, 0x3005, 0x3005 - 0x20E1}, {0x302A, 0x302F, 1}, {0x3031, 0x3035, 1}, {0x3099, 0x309A, 1}, {0x309D, 0x309E, 1}, {0x30FC, 0x30FE, 1}, }, } // HTMLEntity is an entity map containing translations for the // standard HTML entity characters. var HTMLEntity = htmlEntity var htmlEntity = map[string]string{ /* hget http://www.w3.org/TR/html4/sgml/entities.html | ssam ' ,y /\>/ x/\<(.|\n)+/ s/\n/ /g ,x v/^\<!ENTITY/d ,s/\<!ENTITY ([^ ]+) .*U\+([0-9A-F][0-9A-F][0-9A-F][0-9A-F]) .+/ "\1": "\\u\2",/g ' */ "nbsp": "\u00A0", "iexcl": "\u00A1", "cent": "\u00A2", "pound": "\u00A3", "curren": "\u00A4", "yen": "\u00A5", "brvbar": "\u00A6", "sect": "\u00A7", "uml": "\u00A8", "copy": "\u00A9", "ordf": "\u00AA", "laquo": "\u00AB", "not": "\u00AC", "shy": "\u00AD", "reg": "\u00AE", "macr": "\u00AF", "deg": "\u00B0", "plusmn": "\u00B1", "sup2": "\u00B2", "sup3": "\u00B3", "acute": "\u00B4", "micro": "\u00B5", "para": "\u00B6", "middot": "\u00B7", "cedil": "\u00B8", "sup1": "\u00B9", "ordm": "\u00BA", "raquo": "\u00BB", "frac14": "\u00BC", "frac12": "\u00BD", "frac34": "\u00BE", "iquest": "\u00BF", "Agrave": "\u00C0", "Aacute": "\u00C1", "Acirc": "\u00C2", "Atilde": "\u00C3", "Auml": "\u00C4", "Aring": "\u00C5", "AElig": "\u00C6", "Ccedil": "\u00C7", "Egrave": "\u00C8", "Eacute": "\u00C9", "Ecirc": "\u00CA", "Euml": "\u00CB", "Igrave": "\u00CC", "Iacute": "\u00CD", "Icirc": "\u00CE", "Iuml": "\u00CF", "ETH": "\u00D0", "Ntilde": "\u00D1", "Ograve": "\u00D2", "Oacute": "\u00D3", "Ocirc": "\u00D4", "Otilde": "\u00D5", "Ouml": "\u00D6", "times": "\u00D7", "Oslash": "\u00D8", "Ugrave": "\u00D9", "Uacute": "\u00DA", "Ucirc": "\u00DB", "Uuml": "\u00DC", "Yacute": "\u00DD", "THORN": "\u00DE", "szlig": "\u00DF", "agrave": "\u00E0", "aacute": "\u00E1", "acirc": "\u00E2", "atilde": "\u00E3", "auml": "\u00E4", "aring": "\u00E5", "aelig": "\u00E6", "ccedil": "\u00E7", "egrave": "\u00E8", "eacute": "\u00E9", "ecirc": "\u00EA", "euml": "\u00EB", "igrave": "\u00EC", "iacute": "\u00ED", "icirc": "\u00EE", "iuml": "\u00EF", "eth": "\u00F0", "ntilde": "\u00F1", "ograve": "\u00F2", "oacute": "\u00F3", "ocirc": "\u00F4", "otilde": "\u00F5", "ouml": "\u00F6", "divide": "\u00F7", "oslash": "\u00F8", "ugrave": "\u00F9", "uacute": "\u00FA", "ucirc": "\u00FB", "uuml": "\u00FC", "yacute": "\u00FD", "thorn": "\u00FE", "yuml": "\u00FF", "fnof": "\u0192", "Alpha": "\u0391", "Beta": "\u0392", "Gamma": "\u0393", "Delta": "\u0394", "Epsilon": "\u0395", "Zeta": "\u0396", "Eta": "\u0397", "Theta": "\u0398", "Iota": "\u0399", "Kappa": "\u039A", "Lambda": "\u039B", "Mu": "\u039C", "Nu": "\u039D", "Xi": "\u039E", "Omicron": "\u039F", "Pi": "\u03A0", "Rho": "\u03A1", "Sigma": "\u03A3", "Tau": "\u03A4", "Upsilon": "\u03A5", "Phi": "\u03A6", "Chi": "\u03A7", "Psi": "\u03A8", "Omega": "\u03A9", "alpha": "\u03B1", "beta": "\u03B2", "gamma": "\u03B3", "delta": "\u03B4", "epsilon": "\u03B5", "zeta": "\u03B6", "eta": "\u03B7", "theta": "\u03B8", "iota": "\u03B9", "kappa": "\u03BA", "lambda": "\u03BB", "mu": "\u03BC", "nu": "\u03BD", "xi": "\u03BE", "omicron": "\u03BF", "pi": "\u03C0", "rho": "\u03C1", "sigmaf": "\u03C2", "sigma": "\u03C3", "tau": "\u03C4", "upsilon": "\u03C5", "phi": "\u03C6", "chi": "\u03C7", "psi": "\u03C8", "omega": "\u03C9", "thetasym": "\u03D1", "upsih": "\u03D2", "piv": "\u03D6", "bull": "\u2022", "hellip": "\u2026", "prime": "\u2032", "Prime": "\u2033", "oline": "\u203E", "frasl": "\u2044", "weierp": "\u2118", "image": "\u2111", "real": "\u211C", "trade": "\u2122", "alefsym": "\u2135", "larr": "\u2190", "uarr": "\u2191", "rarr": "\u2192", "darr": "\u2193", "harr": "\u2194", "crarr": "\u21B5", "lArr": "\u21D0", "uArr": "\u21D1", "rArr": "\u21D2", "dArr": "\u21D3", "hArr": "\u21D4", "forall": "\u2200", "part": "\u2202", "exist": "\u2203", "empty": "\u2205", "nabla": "\u2207", "isin": "\u2208", "notin": "\u2209", "ni": "\u220B", "prod": "\u220F", "sum": "\u2211", "minus": "\u2212", "lowast": "\u2217", "radic": "\u221A", "prop": "\u221D", "infin": "\u221E", "ang": "\u2220", "and": "\u2227", "or": "\u2228", "cap": "\u2229", "cup": "\u222A", "int": "\u222B", "there4": "\u2234", "sim": "\u223C", "cong": "\u2245", "asymp": "\u2248", "ne": "\u2260", "equiv": "\u2261", "le": "\u2264", "ge": "\u2265", "sub": "\u2282", "sup": "\u2283", "nsub": "\u2284", "sube": "\u2286", "supe": "\u2287", "oplus": "\u2295", "otimes": "\u2297", "perp": "\u22A5", "sdot": "\u22C5", "lceil": "\u2308", "rceil": "\u2309", "lfloor": "\u230A", "rfloor": "\u230B", "lang": "\u2329", "rang": "\u232A", "loz": "\u25CA", "spades": "\u2660", "clubs": "\u2663", "hearts": "\u2665", "diams": "\u2666", "quot": "\u0022", "amp": "\u0026", "lt": "\u003C", "gt": "\u003E", "OElig": "\u0152", "oelig": "\u0153", "Scaron": "\u0160", "scaron": "\u0161", "Yuml": "\u0178", "circ": "\u02C6", "tilde": "\u02DC", "ensp": "\u2002", "emsp": "\u2003", "thinsp": "\u2009", "zwnj": "\u200C", "zwj": "\u200D", "lrm": "\u200E", "rlm": "\u200F", "ndash": "\u2013", "mdash": "\u2014", "lsquo": "\u2018", "rsquo": "\u2019", "sbquo": "\u201A", "ldquo": "\u201C", "rdquo": "\u201D", "bdquo": "\u201E", "dagger": "\u2020", "Dagger": "\u2021", "permil": "\u2030", "lsaquo": "\u2039", "rsaquo": "\u203A", "euro": "\u20AC", } // HTMLAutoClose is the set of HTML elements that // should be considered to close automatically. var HTMLAutoClose = htmlAutoClose var htmlAutoClose = []string{ /* hget http://www.w3.org/TR/html4/loose.dtd | 9 sed -n 's/<!ELEMENT ([^ ]*) +- O EMPTY.+/ "\1",/p' | tr A-Z a-z */ "basefont", "br", "area", "link", "img", "param", "hr", "input", "col", "frame", "isindex", "base", "meta", } var ( esc_quot = []byte(""") // shorter than """ esc_apos = []byte("'") // shorter than "'" esc_amp = []byte("&") esc_lt = []byte("<") esc_gt = []byte(">") esc_tab = []byte("	") esc_nl = []byte("
") esc_cr = []byte("
") esc_fffd = []byte("\uFFFD") // Unicode replacement character ) // EscapeText writes to w the properly escaped XML equivalent // of the plain text data s. func EscapeText(w io.Writer, s []byte) error { return escapeText(w, s, true) } // escapeText writes to w the properly escaped XML equivalent // of the plain text data s. If escapeNewline is true, newline // characters will be escaped. func escapeText(w io.Writer, s []byte, escapeNewline bool) error { var esc []byte last := 0 for i := 0; i < len(s); { r, width := utf8.DecodeRune(s[i:]) i += width switch r { case '"': esc = esc_quot case '\'': esc = esc_apos case '&': esc = esc_amp case '<': esc = esc_lt case '>': esc = esc_gt case '\t': esc = esc_tab case '\n': if !escapeNewline { continue } esc = esc_nl case '\r': esc = esc_cr default: if !isInCharacterRange(r) || (r == 0xFFFD && width == 1) { esc = esc_fffd break } continue } if _, err := w.Write(s[last : i-width]); err != nil { return err } if _, err := w.Write(esc); err != nil { return err } last = i } if _, err := w.Write(s[last:]); err != nil { return err } return nil } // EscapeString writes to p the properly escaped XML equivalent // of the plain text data s. func (p *printer) EscapeString(s string) { var esc []byte last := 0 for i := 0; i < len(s); { r, width := utf8.DecodeRuneInString(s[i:]) i += width switch r { case '"': esc = esc_quot case '\'': esc = esc_apos case '&': esc = esc_amp case '<': esc = esc_lt case '>': esc = esc_gt case '\t': esc = esc_tab case '\n': esc = esc_nl case '\r': esc = esc_cr default: if !isInCharacterRange(r) || (r == 0xFFFD && width == 1) { esc = esc_fffd break } continue } p.WriteString(s[last : i-width]) p.Write(esc) last = i } p.WriteString(s[last:]) } // Escape is like EscapeText but omits the error return value. // It is provided for backwards compatibility with Go 1.0. // Code targeting Go 1.1 or later should use EscapeText. func Escape(w io.Writer, s []byte) { EscapeText(w, s) } // procInst parses the `param="..."` or `param='...'` // value out of the provided string, returning "" if not found. func procInst(param, s string) string { // TODO: this parsing is somewhat lame and not exact. // It works for all actual cases, though. param = param + "=" idx := strings.Index(s, param) if idx == -1 { return "" } v := s[idx+len(param):] if v == "" { return "" } if v[0] != '\'' && v[0] != '"' { return "" } idx = strings.IndexRune(v[1:], rune(v[0])) if idx == -1 { return "" } return v[1 : idx+1] }