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comparison src/goodjava/xml/XmlParser.java @ 1466:670b7d089699

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xml support
author Franklin Schmidt <fschmidt@gmail.com>
date Mon, 13 Apr 2020 22:00:40 -0600
parents
children 35f3bfd4f51d
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1465:5e3870618377 1466:670b7d089699
1 package goodjava.xml;
2
3 import java.util.Map;
4 import java.util.AbstractMap;
5 import java.util.LinkedHashMap;
6 import java.util.List;
7 import java.util.ArrayList;
8 import goodjava.parser.Parser;
9 import goodjava.parser.ParseException;
10
11
12 public final class XmlParser {
13
14 public static XmlElement parse(String text) throws ParseException {
15 return new XmlParser(text).parse();
16 }
17
18 private final Parser parser;
19
20 private XmlParser(String text) {
21 this.parser = new Parser(text);
22 }
23
24 private ParseException exception(String msg) {
25 return new ParseException(parser,msg);
26 }
27
28 private XmlElement parse() throws ParseException {
29 spaces();
30 prolog();
31 spaces();
32 XmlElement element = element();
33 spaces();
34 if( !parser.endOfInput() )
35 throw exception("unexpected text");
36 return element;
37 }
38
39 private void prolog() throws ParseException {
40 if( !parser.match("<?xml") )
41 return;
42 while( attribute() != null );
43 spaces();
44 required("?>");
45 }
46
47 private XmlElement element() throws ParseException {
48 parser.begin();
49 if( !parser.match('<') || parser.test('/') )
50 return parser.failure(null);
51 //spaces();
52 String name = name();
53 if( name==null )
54 throw exception("element name not found");
55 Map<String,String> attributes = new LinkedHashMap<String,String>();
56 Map.Entry<String,String> attribute;
57 while( (attribute=attribute()) != null ) {
58 attributes.put(attribute.getKey(),attribute.getValue());
59 }
60 spaces();
61 required(">");
62 String s = string(name);
63 if( s != null ) {
64 XmlElement element = new XmlElement(name,attributes,s);
65 return parser.success(element);
66 }
67 List<XmlElement> elements = elements(name);
68 if( elements != null ) {
69 XmlElement element = new XmlElement(name,attributes,elements.toArray(new XmlElement[0]));
70 return parser.success(element);
71 }
72 throw exception("bad element");
73 }
74
75 private String string(String name) throws ParseException {
76 int start = parser.begin();
77 while( parser.noneOf("<") );
78 String s = parser.textFrom(start);
79 if( !endTag(name) )
80 return parser.failure(null);
81 return parser.success(s);
82 }
83
84 private List<XmlElement> elements(String name) throws ParseException {
85 parser.begin();
86 List<XmlElement> elements = new ArrayList<XmlElement>();
87 spaces();
88 XmlElement element;
89 while( (element=element()) != null ) {
90 elements.add(element);
91 spaces();
92 }
93 if( !endTag(name) )
94 return parser.failure(null);
95 return parser.success(elements);
96 }
97
98 private boolean endTag(String name) throws ParseException {
99 parser.begin();
100 if( !parser.match("</") || !parser.match(name) )
101 return parser.failure();
102 spaces();
103 if( !parser.match('>') )
104 return parser.failure();
105 return parser.success();
106 }
107
108 private Map.Entry<String,String> attribute() throws ParseException {
109 parser.begin();
110 if( !matchSpace() )
111 return parser.failure(null);
112 spaces();
113 String name = name();
114 if( name==null )
115 return parser.failure(null);
116 spaces();
117 required("=");
118 spaces();
119 if( !parser.anyOf("\"'") )
120 throw exception("quote expected");
121 char quote = parser.lastChar();
122 int start = parser.currentIndex();
123 while( !parser.test(quote) ) {
124 if( !parser.anyChar() )
125 throw exception("unclosed attribute value");
126 }
127 String value = parser.textFrom(start);
128 parser.match(quote);
129 Map.Entry<String,String> attribute = new AbstractMap.SimpleImmutableEntry<String,String>(name,value);
130 return parser.success(attribute);
131 }
132
133 private String name() {
134 int start = parser.currentIndex();
135 if( !matchNameChar() )
136 return null;
137 while( matchNameChar() );
138 return parser.textFrom(start);
139 }
140
141 private boolean matchNameChar() {
142 return parser.inCharRange('a','z')
143 || parser.inCharRange('A','Z')
144 || parser.inCharRange('0','9')
145 || parser.anyOf("_.-:")
146 ;
147 }
148
149 private void required(String s) throws ParseException {
150 if( !parser.match(s) )
151 exception("'"+s+"' expected");
152 }
153
154 private void spaces() throws ParseException {
155 while( matchSpace() || matchComment() );
156 }
157
158 private boolean matchComment() throws ParseException {
159 if( !parser.match("<!--") )
160 return false;
161 while( !parser.match("-->") ) {
162 if( !parser.anyChar() )
163 throw exception("unclosed comment");
164 }
165 return true;
166 }
167
168 private boolean matchSpace() {
169 return parser.anyOf(" \t\r\n");
170 }
171
172 }