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authorRob Pike <r@golang.org>2009-06-09 09:53:44 -0700
committerRob Pike <r@golang.org>2009-06-09 09:53:44 -0700
commit7249ea4df2b4f12a4e7ed446f270cea87e4ffd34 (patch)
tree7032a11d0cac2ae4d3e90f7a189b575b5a50f848 /src/lib/xml/xml.go
parentacf6ef7a82b3fe61516a1bac4563706552bdf078 (diff)
downloadgolang-7249ea4df2b4f12a4e7ed446f270cea87e4ffd34.tar.gz
mv src/lib to src/pkg
tests: all.bash passes, gobuild still works, godoc still works. R=rsc OCL=30096 CL=30102
Diffstat (limited to 'src/lib/xml/xml.go')
-rw-r--r--src/lib/xml/xml.go426
1 files changed, 0 insertions, 426 deletions
diff --git a/src/lib/xml/xml.go b/src/lib/xml/xml.go
deleted file mode 100644
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--- a/src/lib/xml/xml.go
+++ /dev/null
@@ -1,426 +0,0 @@
-// 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.
-
-// NOTE(rsc): Actually, this package is just a description
-// of an implementation that hasn't been written yet.
-
-// This package implements an XML parser but relies on
-// clients to implement the parsing actions.
-
-// An XML document is a single XML element.
-//
-// An XML element is either a start tag and an end tag,
-// like <tag>...</tag>, or a combined start/end tag <tag/>.
-// The latter is identical in semantics to <tag></tag>,
-// and this parser does not distinguish them.
-//
-// The start (or combined start/end) tag can have
-// name="value" attributes inside the angle brackets after
-// the tag name, as in <img src="http://google.com/icon.png" alt="Google">.
-// Names are drawn from a fixed set of alphabetic letters;
-// Values are strings quoted with single or double quotes.
-//
-// An element made up of distinct start and end tags can
-// contain free-form text and other elements inside it,
-// as in <a href="http://www.google.com">Google</a>
-// or <b><a href="http://www.google.com">Google</a></b>.
-// The former is an <a> element with the text "Google" inside it.
-// The latter is a <b> element with that <a> element inside it.
-// In general, an element can contain a sequence of elements
-// and text inside it. In XML, white space inside an element is
-// always counted as text--it is never discarded by the parser.
-// XML parsers do translate \r and \r\n into \n in text.
-//
-// This parser reads an XML document and calls methods on a
-// Builder interface object in response to the text.
-// It calls the builder's StartElement, Text, and EndElement
-// methods, mimicking the structure of the text.
-// For example, the simple XML document:
-//
-// <a href="http://www.google.com">
-// <img src="http://www.google.com/icon.png" alt="Google" />
-// <br/></a>
-//
-// results in the following sequence of builder calls:
-//
-// StartElement("a", []Attr(Attr("href", "http://www.google.com")));
-// Text("\n\t");
-// StartElement("img", []Attr(Attr("src", "http://www.google.com/icon.png"),
-// Attr("alt", "Google")));
-// EndElement("img");
-// Text("\n");
-// StartElement("br", []Attr());
-// EndElement("br");
-// EndElement("a");
-//
-// There are, of course, a few more details, but the story so far
-// should be enough for the majority of uses. The details are:
-//
-// * XML documents typically begin with an XML declaration line like
-// <?xml version="1.0" encoding="UTF-8"?>.
-// This line is strongly recommended, but not strictly required.
-// It introduces the XML version and text encoding for the rest
-// of the file. XML parsers are required to recognize UTF-8 and
-// UTF-16. This parser only recognizes UTF-8 (for now?).
-//
-// * After the XML declaration comes an optional doctype declaration like
-// <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
-// "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-// The parser should pass this information on to the client in some
-// form, but does not. It discards such lines.
-//
-// * The XML declaration line is an instance of a more general tag
-// called a processing instruction, XML's #pragma. The general form is
-// <?target text?>, where target is a name (like "xml") specifying
-// the intended recipient of the instruction, and text is the
-// instruction itself. This XML parser keeps the <?xml ...?> declaration
-// to itself but passes along other processing instructions using
-// the ProcInst method. Processing instructions can appear anywhere
-// in an XML document. Most clients will simply ignore them.
-//
-// * An XML comment can appear anywhere in an XML document.
-// Comments have the form <!--text-->. The XML parser passes
-// them along by calling the Comment method. Again, most clients
-// will simply ignore them.
-//
-// * Text inside an XML element must be escaped to avoid looking like
-// a start/end tag. Specifically, the characters < and & must be
-// written as &lt; and &amp;. An alternate quoting mechanism is to
-// use the construct <![CDATA[...]]>. The quoted text ... can contain
-// < characters, but not the sequence ]]>. Ampersands must still be
-// escaped. For some reason, the existence of the CDATA quoting mechanism
-// infects the processing of ordinary unquoted text, which is not allowed
-// to contain the literal sequence ]]>. Instead, it would be written
-// escaped, as in ]]&gt;. The parser hides all these considerations
-// from the library client -- it reports all text, regardless of original
-// form and already unescaped, using the Text method.
-//
-// * A revision to XML 1.0 introduced the concept of name spaces
-// for attribute and tag names. A start tag with an attribute
-// xmlns:prefix="URL" introduces `prefix' as a shorthand
-// for the name space whose identifier is URL. Inside the element
-// with that start tag, an element name or attribute prefix:foo
-// (as in <prefix:foo prefix:bar="baz">) is understood to refer
-// to name `foo' in the name space denoted by `URL'. Although
-// this is a shorthand, there is no canonical expansion. Thus:
-//
-// <tag xmlns:foo="http://google.com/foo" xmlns:bar="http://google.com/bar">
-// <foo:red bar:attr="value">text1</foo:red>
-// <bar:red>text2</bar:red>
-// </tag>
-//
-// and
-//
-// <tag xmlns:bar="http://google.com/foo" xmlns:foo="http://google.com/bar">
-// <bar:red foo:attr="value">text1</bar:red>
-// <foo:red>text2</foo:red>
-// </tag>
-//
-// are equivalent XML documents, and there is no canonical form.
-//
-// The special attribute xmlns="URL" sets the default name space
-// for unprefixed tags (but not attribute names) to URL.
-// Thus:
-//
-// <tag xmlns="http://google.com/foo" xmlns:bar="http://google.com/bar">
-// <red bar:attr="value">text1</red>
-// <bar:red>text2</bar:red>
-// </tag>
-//
-// is another XML document equivalent to the first two, and
-//
-// <tag xmlns:bar="http://google.com/foo" xmlns="http://google.com/bar">
-// <bar:red attr="value">text1</bar:red>
-// <red>text2</red>
-// </tag>
-//
-// would be equivalent, except that `attr' in attr="value" has no
-// associated name space, in contrast to the previous three where it
-// is in the http://google.com/bar name space.
-//
-// The XML parser hides these details from the client by passing
-// a Name struct (ns + name pair) for tag and attribute names.
-// Tags and attributes without a name space have ns == "".
-//
-// References:
-// Annotated XML spec: http://www.xml.com/axml/testaxml.htm
-// XML name spaces: http://www.w3.org/TR/REC-xml-names/
-
-package xml
-
-import (
- "io";
- "os";
-)
-
-// XML name, annotated with name space URL
-type Name struct {
- ns, name string;
-}
-
-// XML attribute (name=value).
-type Attr struct {
- name Name;
- value string;
-}
-
-// XML Builder - methods client provides to Parser.
-// Parser calls methods on builder as it reads and parses XML.
-// If a builder method returns an error, the parse stops.
-type Builder interface {
- // Called when an element starts.
- // Attr is list of attributes given in the tag.
- // <name attr.name=attr.value attr1.name=attr1.value ...>
- // <name attr.name=attr.value attr1.name=attr1.value ... />
- // xmlns and xmlns:foo attributes are handled internally
- // and not passed through to StartElement.
- StartElement(name Name, attr []Attr) os.Error;
-
- // Called when an element ends.
- // </name>
- // <name ... />
- EndElement(name Name) os.Error;
-
- // Called for non-empty character data string inside element.
- // Can be called multiple times between elements.
- // text
- // <![CDATA[text]]>
- Text(text []byte) os.Error;
-
- // Called when a comment is found in the XML.
- // <!-- text -->
- Comment(text []byte) os.Error;
-
- // Called for a processing instruction
- // <?target text?>
- ProcInst(target string, text []byte) os.Error;
-}
-
-// Default builder. Implements no-op Builder methods.
-// Embed this in your own Builders to handle the calls
-// you don't care about (e.g., Comment, ProcInst).
-type BaseBuilder struct {
-}
-
-func (b *BaseBuilder) StartElement(name Name, attr []Attr) os.Error {
- return nil;
-}
-
-func (b *BaseBuilder) EndElement(name Name) os.Error {
- return nil;
-}
-
-func (b *BaseBuilder) Text(text []byte) os.Error {
- return nil;
-}
-
-func (b *BaseBuilder) Comment(text []byte) os.Error {
- return nil;
-}
-
-func (b *BaseBuilder) ProcInst(target string, text []byte) os.Error {
- return nil;
-}
-
-// XML Parser. Calls Builder methods as it parses.
-func Parse(r io.Read, b Builder) os.Error {
- return os.NewError("unimplemented");
-}
-
-// Channel interface to XML parser: create a new channel,
-// go ParseTokens(r, c), and then read from the channel
-// until TokenEnd. This variant has the benefit that
-// the process reading the channel can be a recursive
-// function instead of a set of callbacks, but it has the
-// drawback that the channel interface cannot signal an
-// error to cause the parser to stop early.
-
-// An XML parsing token.
-const (
- TokenStartElement = 1 + iota;
- TokenEndElement;
- TokenText;
- TokenComment;
- TokenProcInst;
- TokenEnd;
-)
-
-type Token struct {
- Kind int; // TokenStartElement, TokenEndElement, etc.
- Name Name; // name (TokenStartElement, TokenEndElement)
- Attr []Attr; // attributes (TokenStartElement)
- Target string; // target (TokenProcessingInstruction)
- Text []byte; // text (TokenCharData, TokenComment, etc.)
- Err os.Error; // error (TokenEnd)
-}
-
-type ChanBuilder chan Token;
-
-func (c ChanBuilder) StartElement(name Name, attr []Attr) os.Error {
- var t Token;
- t.Kind = TokenStartElement;
- t.Name = name;
- t.Attr = attr;
- c <- t;
- return nil;
-}
-
-func (c ChanBuilder) EndElement(name Name) os.Error {
- var t Token;
- t.Kind = TokenEndElement;
- t.Name = name;
- c <- t;
- return nil;
-}
-
-func (c ChanBuilder) Text(text []byte) os.Error {
- var t Token;
- t.Kind = TokenText;
- t.Text = text;
- c <- t;
- return nil;
-}
-
-func (c ChanBuilder) Comment(text []byte) os.Error {
- var t Token;
- t.Kind = TokenComment;
- t.Text = text;
- c <- t;
- return nil;
-}
-
-func (c ChanBuilder) ProcInst(target string, text []byte) os.Error {
- var t Token;
- t.Kind = TokenProcInst;
- t.Target = target;
- t.Text = text;
- c <- t;
- return nil;
-}
-
-func ParseToChan(r io.Read, c chan Token) {
- var t Token;
- t.Kind = TokenEnd;
- t.Err = Parse(r, ChanBuilder(c));
- c <- t;
-}
-
-
-// scribbled notes based on XML spec.
-
-// document is
-// xml decl?
-// doctype decl?
-// element
-//
-// if xml decl is present, must be first. after that,
-// can have comments and procinsts scattered throughout,
-// even after the element is done.
-//
-// xml decl is:
-//
-// <\?xml version='[a-zA-Z0-9_.:\-]+'( encoding='[A-Za-z][A-Za-z0-9._\-]*')?
-// ( standalone='(yes|no)')? ?\?>
-//
-// spaces denote [ \r\t\n]+.
-// written with '' above but can use "" too.
-//
-// doctype decl might as well be <!DOCTYPE[^>]*>
-//
-// procinst is <\?name( .*?)\?>. name cannot be [Xx][Mm][Ll].
-//
-// comment is <!--(.*?)-->.
-//
-// tags are:
-// <name( attrib)* ?> start tag
-// <name( attrib)* ?/> combined start/end tag
-// </name ?> end tag
-// (the " ?" is an optional space, not a literal question mark.)
-//
-// plain text is [^<&]* except cannot contain "]]>".
-// can also have escaped characters:
-// &#[0-9]+;
-// &#x[0-9A-Fa-f]+;
-// &name;
-//
-// can use <![CDATA[.*?]]> to avoid escaping < characters.
-//
-// must rewrite \r and \r\n into \n in text.
-//
-// names are Unicode. valid chars listed below.
-//
-// attrib is name="value" or name='value'.
-// can have spaces around =.
-// attribute value text is [^<&"]* for appropriate ".
-// can also use the &...; escape sequences above.
-// cannot use <![CDATA[...]]>.
-//
-// xmlns attributes are name=value where name has form xmlns:name
-// (i.e., xmlns:123 is not okay, because 123 is not a name; xmlns:a123 is ok).
-// sub-name must not start with : either.
-//
-// name is first(second)*.
-//
-// first is
-//
-// 003A 04D0-04EB 0A59-0A5C 0C35-0C39 0F49-0F69 1E00-1E9B
-// 0041-005A 04EE-04F5 0A5E 0C60-0C61 10A0-10C5 1EA0-1EF9
-// 005F 04F8-04F9 0A72-0A74 0C85-0C8C 10D0-10F6 1F00-1F15
-// 0061-007A 0531-0556 0A85-0A8B 0C8E-0C90 1100 1F18-1F1D
-// 00C0-00D6 0559 0A8D 0C92-0CA8 1102-1103 1F20-1F45
-// 00D8-00F6 0561-0586 0A8F-0A91 0CAA-0CB3 1105-1107 1F48-1F4D
-// 00F8-00FF 05D0-05EA 0A93-0AA8 0CB5-0CB9 1109 1F50-1F57
-// 0100-0131 05F0-05F2 0AAA-0AB0 0CDE 110B-110C 1F59
-// 0134-013E 0621-063A 0AB2-0AB3 0CE0-0CE1 110E-1112 1F5B
-// 0141-0148 0641-064A 0AB5-0AB9 0D05-0D0C 113C 1F5D
-// 014A-017E 0671-06B7 0ABD 0D0E-0D10 113E 1F5F-1F7D
-// 0180-01C3 06BA-06BE 0AE0 0D12-0D28 1140 1F80-1FB4
-// 01CD-01F0 06C0-06CE 0B05-0B0C 0D2A-0D39 114C 1FB6-1FBC
-// 01F4-01F5 06D0-06D3 0B0F-0B10 0D60-0D61 114E 1FBE
-// 01FA-0217 06D5 0B13-0B28 0E01-0E2E 1150 1FC2-1FC4
-// 0250-02A8 06E5-06E6 0B2A-0B30 0E30 1154-1155 1FC6-1FCC
-// 02BB-02C1 0905-0939 0B32-0B33 0E32-0E33 1159 1FD0-1FD3
-// 0386 093D 0B36-0B39 0E40-0E45 115F-1161 1FD6-1FDB
-// 0388-038A 0958-0961 0B3D 0E81-0E82 1163 1FE0-1FEC
-// 038C 0985-098C 0B5C-0B5D 0E84 1165 1FF2-1FF4
-// 038E-03A1 098F-0990 0B5F-0B61 0E87-0E88 1167 1FF6-1FFC
-// 03A3-03CE 0993-09A8 0B85-0B8A 0E8A 1169 2126
-// 03D0-03D6 09AA-09B0 0B8E-0B90 0E8D 116D-116E 212A-212B
-// 03DA 09B2 0B92-0B95 0E94-0E97 1172-1173 212E
-// 03DC 09B6-09B9 0B99-0B9A 0E99-0E9F 1175 2180-2182
-// 03DE 09DC-09DD 0B9C 0EA1-0EA3 119E 3007
-// 03E0 09DF-09E1 0B9E-0B9F 0EA5 11A8 3021-3029
-// 03E2-03F3 09F0-09F1 0BA3-0BA4 0EA7 11AB 3041-3094
-// 0401-040C 0A05-0A0A 0BA8-0BAA 0EAA-0EAB 11AE-11AF 30A1-30FA
-// 040E-044F 0A0F-0A10 0BAE-0BB5 0EAD-0EAE 11B7-11B8 3105-312C
-// 0451-045C 0A13-0A28 0BB7-0BB9 0EB0 11BA 4E00-9FA5
-// 045E-0481 0A2A-0A30 0C05-0C0C 0EB2-0EB3 11BC-11C2 AC00-D7A3
-// 0490-04C4 0A32-0A33 0C0E-0C10 0EBD 11EB
-// 04C7-04C8 0A35-0A36 0C12-0C28 0EC0-0EC4 11F0
-// 04CB-04CC 0A38-0A39 0C2A-0C33 0F40-0F47 11F9
-//
-// second is first plus
-//
-// 002D 06DD-06DF 09E6-09EF 0B56-0B57 0D3E-0D43 0F3E
-// 002E 06E0-06E4 0A02 0B66-0B6F 0D46-0D48 0F3F
-// 0030-0039 06E7-06E8 0A3C 0B82-0B83 0D4A-0D4D 0F71-0F84
-// 00B7 06EA-06ED 0A3E 0BBE-0BC2 0D57 0F86-0F8B
-// 02D0 06F0-06F9 0A3F 0BC6-0BC8 0D66-0D6F 0F90-0F95
-// 02D1 0901-0903 0A40-0A42 0BCA-0BCD 0E31 0F97
-// 0300-0345 093C 0A47-0A48 0BD7 0E34-0E3A 0F99-0FAD
-// 0360-0361 093E-094C 0A4B-0A4D 0BE7-0BEF 0E46 0FB1-0FB7
-// 0387 094D 0A66-0A6F 0C01-0C03 0E47-0E4E 0FB9
-// 0483-0486 0951-0954 0A70-0A71 0C3E-0C44 0E50-0E59 20D0-20DC
-// 0591-05A1 0962-0963 0A81-0A83 0C46-0C48 0EB1 20E1
-// 05A3-05B9 0966-096F 0ABC 0C4A-0C4D 0EB4-0EB9 3005
-// 05BB-05BD 0981-0983 0ABE-0AC5 0C55-0C56 0EBB-0EBC 302A-302F
-// 05BF 09BC 0AC7-0AC9 0C66-0C6F 0EC6 3031-3035
-// 05C1-05C2 09BE 0ACB-0ACD 0C82-0C83 0EC8-0ECD 3099
-// 05C4 09BF 0AE6-0AEF 0CBE-0CC4 0ED0-0ED9 309A
-// 0640 09C0-09C4 0B01-0B03 0CC6-0CC8 0F18-0F19 309D-309E
-// 064B-0652 09C7-09C8 0B3C 0CCA-0CCD 0F20-0F29 30FC-30FE
-// 0660-0669 09CB-09CD 0B3E-0B43 0CD5-0CD6 0F35
-// 0670 09D7 0B47-0B48 0CE6-0CEF 0F37
-// 06D6-06DC 09E2-09E3 0B4B-0B4D 0D02-0D03 0F39
-