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1
16 package org.apache.commons.attributes.compiler;
17
18 import java.util.ArrayList  ;
19 import java.util.List ;
20
21 import org.apache.tools.ant.BuildException;
22
23
26 public class AttributeExpressionParser {
27
28 public static class Argument {
29 public final String field;
30 public final String text;
31 public final int length;
32
33 public Argument (String field, String text, int length) {
34 this.field = field;
35 this.text = text;
36 this.length = length;
37 }
38
39 public boolean equalsOrNull (String a, String b) {
40 if (a == null) {
41 return b == null;
42 } else {
43 return b != null && a.equals (b);
44 }
45 }
46
47 public boolean equals (Object o) {
48 return o instanceof Argument &&
49 equalsOrNull (field, ((Argument) o).field) &&
50 ((Argument) o).text.equals (text);
51 }
52
53 public String toString () {
54 return "[Argument: " + field + ", " + text + ", " + length + "]";
55 }
56 }
57
58 public static class ParseResult {
59 public final List arguments = new ArrayList ();
60 public final String className;
61
62 public ParseResult (String className) {
63 this.className = className;
64 }
65
66 public boolean equals (Object o) {
67 return o instanceof ParseResult &&
68 className.equals (((ParseResult) o).className) &&
69 arguments.equals (((ParseResult) o).arguments);
70 }
71
72 public String toString () {
73 return "[ParseResult: " + className + ", " + arguments + "]";
74 }
75 }
76
77 protected static Argument nextArgument (String string, int startPos, String filename, int line) {
78 if (string.charAt (startPos) == ')') {
79 return null;
80 }
81
82 StringBuffer sb = new StringBuffer ();
83
84 int i = startPos;
85 int depth = 0;
86 while (!( (string.charAt (i) == ',' || string.charAt (i) == ')') && depth == 0)) {
87 switch (string.charAt (i)) {
88 case '[':
89 case '{':
90 case '(': depth++; break;
91
92 case ']':
93 case '}':
94 case ')': depth--; break;
95
96 case '\'':
97 case '"': {
98 char endChar = string.charAt (i);
100 sb.append (string.charAt (i));
101 i++;
102 while (true) {
103 char ch = string.charAt (i);
104 if (ch == '\\') {
105 sb.append (ch);
106 i++;
107 ch = string.charAt (i);
108 sb.append (ch);
109 } else {
110 if (ch == endChar) {
111 break;
112 }
113 sb.append (ch);
114 }
115 i++;
116 }
117 }
118 }
119
120 sb.append (string.charAt (i));
121 i++;
122 if (i == string.length ()) {
123 throw new BuildException (filename + ":" + line + ": Unterminated argument: " + string);
124 }
125 }
126
127 if (string.charAt (i) == ',') {
128 i++;
129 }
130
131 String text = sb.toString ();
132 String field = null;
133 int eqPos = text.indexOf ('=');
134 if (eqPos > -1) {
135 boolean identifier = true;
136 for (int j = 0; j < eqPos; j++) {
137 char ch = text.charAt (j);
138
139 if (Character.isJavaIdentifierPart (ch) || ch == ' ') {
140 } else {
141 identifier = false;
142 }
143 }
144
145 if (identifier) {
146 field = text.substring (0, eqPos).trim ();
147 text = text.substring (eqPos + 1).trim ();
148 }
149 }
150
151 Argument arg = new Argument (field, text, i - startPos);
152
153 return arg;
154 }
155
156 public static ParseResult parse (String string, String filename, int line) {
157 StringBuffer sb = new StringBuffer ();
158 int i = 0;
159 while (i < string.length () && (Character.isJavaIdentifierPart (string.charAt (i)) || string.charAt (i) == '.' || string.charAt (i) == ' ')) {
160 sb.append (string.charAt (i));
161 i++;
162 }
163
164 if (i == string.length () || string.charAt (i) != '(') {
165 throw new BuildException (filename + ":" + line + ": Illegal expression: " + string);
166 }
167
168 ParseResult result = new ParseResult (sb.toString ());
169
170 i++;
171 Argument arg = null;
172 boolean seenField = false;
173 while ((arg = nextArgument (string, i, filename, line)) != null) {
174 if (arg.field != null) {
175 seenField = true;
176 }
177
178 if (seenField && arg.field == null) {
179 throw new BuildException (filename + ":" + line + ": Un-named parameters must come before the named parameters: " + string);
180 }
181
182 result.arguments.add (arg);
183 i += arg.length;
184 }
185
186 return result;
187 }
188 } |
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