1    // Copyright 2004 Adam Megacz, see the COPYING file for licensing [GPL]
2    package org.xwt.js;
3    
4    import gnu.regexp.*;
5    
6    /** A JavaScript regular expression object */
7    public class JSRegexp extends JS {
8        private boolean global;
9        private RE re;
10       private int lastIndex;
11       
12       public JSRegexp(Object arg0, Object arg1) throws JSExn {
13           if(arg0 instanceof JSRegexp) {
14               JSRegexp r = (JSRegexp) arg0;
15               this.global = r.global;
16               this.re = r.re;
17               this.lastIndex = r.lastIndex;
18           } else {
19               String pattern = (String)arg0;
20               String sFlags = null;
21               int flags = 0;
22               if(arg1 != null) sFlags = (String)arg1;
23               if(sFlags == null) sFlags = "";
24               for(int i=0;i<sFlags.length();i++) {
25                   switch(sFlags.charAt(i)) {
26                       case 'i': flags |= RE.REG_ICASE; break;
27                       case 'm': flags |= RE.REG_MULTILINE; break;
28                       case 'g': global = true; break;
29                       default: throw new JSExn("Invalid flag in regexp \"" + sFlags.charAt(i) + "\"");
30                   }
31               }
32               re = newRE(pattern,flags);
33               put("source", pattern);
34               put("global", B(global));
35               put("ignoreCase", B(flags & RE.REG_ICASE));
36               put("multiline", B(flags & RE.REG_MULTILINE));
37           }
38       }
39   
40       public Object callMethod(Object method, Object a0, Object a1, Object a2, Object[] rest, int nargs) throws JSExn {
41           switch(nargs) {
42               case 1: {
43                   //#switch(method)
44                   case "exec": {
45                       String s = (String)a0;
46                       int start = global ? lastIndex : 0;
47                       if(start < 0 || start >= s.length()) { lastIndex = 0; return null; }
48                       REMatch match = re.getMatch(s,start);
49                       if(global) lastIndex = match == null ? s.length() : match.getEndIndex();
50                       return match == null ? null : matchToExecResult(match,re,s);
51                   }
52                   case "test": {
53                       String s = (String)a0;
54                       if (!global) return B(re.getMatch(s) != null);
55                       int start = global ? lastIndex : 0;
56                       if(start < 0 || start >= s.length()) { lastIndex = 0; return null; }
57                       REMatch match = re.getMatch(s,start);
58                       lastIndex = match != null ? s.length() : match.getEndIndex();
59                       return B(match != null);
60                   }
61                   case "toString": return toString(a0);
62                   case "stringMatch": return stringMatch(a0,a1);
63                   case "stringSearch": return stringSearch(a0,a1);
64                   //#end
65                   break;
66               }
67               case 2: {
68                   //#switch(method)
69                   case "stringReplace": return stringReplace(a0, a1,a2);
70                   //#end
71                   break;
72               }
73           }
74           return super.callMethod(method, a0, a1, a2, rest, nargs);
75       }
76       
77       public Object get(Object key) throws JSExn {
78           //#switch(key)
79           case "exec": return METHOD;
80           case "test": return METHOD;
81           case "toString": return METHOD;
82           case "lastIndex": return N(lastIndex);
83           //#end
84           return super.get(key);
85       }
86       
87       public void put(Object key, Object value) throws JSExn {
88           if(key.equals("lastIndex")) lastIndex = JS.toNumber(value).intValue();
89           super.put(key,value);
90       }
91     
92       private static Object matchToExecResult(REMatch match, RE re, String s) {
93           try {
94               JS ret = new JS();
95               ret.put("index", N(match.getStartIndex()));
96               ret.put("input",s);
97               int n = re.getNumSubs();
98               ret.put("length", N(n+1));
99               ret.put("0",match.toString());
100              for(int i=1;i<=n;i++) ret.put(Integer.toString(i),match.toString(i));
101              return ret;
102          } catch (JSExn e) {
103              throw new Error("this should never happen");
104          }
105      }
106      
107      public String toString() {
108          try {
109              StringBuffer sb = new StringBuffer();
110              sb.append('/');
111              sb.append(get("source"));
112              sb.append('/');
113              if(global) sb.append('g');
114              if(Boolean.TRUE.equals(get("ignoreCase"))) sb.append('i');
115              if(Boolean.TRUE.equals(get("multiline"))) sb.append('m');
116              return sb.toString();
117          } catch (JSExn e) {
118              throw new Error("this should never happen");
119          }
120      }
121      
122      public static Object stringMatch(Object o, Object arg0) throws JSExn {
123          String s = o.toString();
124          RE re;
125          JSRegexp regexp = null;
126          if(arg0 instanceof JSRegexp) {
127              regexp = (JSRegexp) arg0;
128              re = regexp.re;
129          } else {
130              re = newRE(arg0.toString(),0);
131          }
132          
133          if(regexp == null) {
134              REMatch match = re.getMatch(s);
135              return matchToExecResult(match,re,s);
136          }
137          if(!regexp.global) return regexp.callMethod("exec", s, null, null, null, 1);
138          
139          JSArray ret = new JSArray();
140          REMatch[] matches = re.getAllMatches(s);
141          for(int i=0;i<matches.length;i++) ret.addElement(matches[i].toString());
142          regexp.lastIndex = matches.length > 0 ? matches[matches.length-1].getEndIndex() : s.length();
143          return ret;
144      }
145      
146      public static Object stringSearch(Object o, Object arg0) throws JSExn  {
147          String s = o.toString();
148          RE re = arg0 instanceof JSRegexp ? ((JSRegexp)arg0).re : newRE(arg0.toString(),0);
149          REMatch match = re.getMatch(s);
150          return match == null ? N(-1) : N(match.getStartIndex());
151      }
152      
153      public static Object stringReplace(Object o, Object arg0, Object arg1) throws JSExn {
154          String s = o.toString();
155          RE re;
156          JSFunction replaceFunc = null;
157          String replaceString = null;
158          JSRegexp regexp = null;
159          if(arg0 instanceof JSRegexp) {
160              regexp = (JSRegexp) arg0;
161              re = regexp.re;
162          } else {
163              re = newRE(arg0.toString(),0);
164          }
165          if(arg1 instanceof JSFunction)
166              replaceFunc = (JSFunction) arg1;
167          else
168              replaceString = JS.toString(arg1.toString());
169          REMatch[] matches;
170          if(regexp != null && regexp.global) {
171              matches = re.getAllMatches(s);
172              if(regexp != null) {
173                  if(matches.length > 0)
174                      regexp.lastIndex = matches[matches.length-1].getEndIndex();
175                  else
176                      regexp.lastIndex = s.length();
177              }
178          } else {
179              REMatch match = re.getMatch(s);
180              if(match != null)
181                  matches = new REMatch[]{ match };
182              else
183                  matches = new REMatch[0];
184          }
185          
186          StringBuffer sb = new StringBuffer(s.length());
187          int pos = 0;
188          char[] sa = s.toCharArray();
189          for(int i=0;i<matches.length;i++) {
190              REMatch match = matches[i];
191              sb.append(sa,pos,match.getStartIndex()-pos);
192              pos = match.getEndIndex();
193              if(replaceFunc != null) {
194                  int n = (regexp == null ? 0 : re.getNumSubs());
195                  int numArgs = 3 + n;
196                  Object[] rest = new Object[numArgs - 3];
197                  Object a0 = match.toString();
198                  Object a1 = null;
199                  Object a2 = null;
200                  for(int j=1;j<=n;j++)
201                      switch(j) {
202                          case 1: a1 = match.toString(j); break;
203                          case 2: a2 = match.toString(j); break;
204                          default: rest[j - 3] = match.toString(j); break;
205                      }
206                  switch(numArgs) {
207                      case 3:
208                          a1 = N(match.getStartIndex());
209                          a2 = s;
210                          break;
211                      case 4:
212                          a2 = N(match.getStartIndex());
213                          rest[0] = s;
214                          break;
215                      default:
216                          rest[rest.length - 2] = N(match.getStartIndex());
217                          rest[rest.length - 1] = s;
218                  }
219  
220                  // note: can't perform pausing operations in here
221                  sb.append((String)replaceFunc.call(a0, a1, a2, rest, numArgs));
222  
223              } else {
224                  sb.append(mySubstitute(match,replaceString,s));
225              }
226          }
227          int end = matches.length == 0 ? 0 : matches[matches.length-1].getEndIndex();
228          sb.append(sa,end,sa.length-end);
229          return sb.toString();
230      }
231      
232      private static String mySubstitute(REMatch match, String s, String source) {
233          StringBuffer sb = new StringBuffer();
234          int i,n;
235          char c,c2;
236          for(i=0;i<s.length()-1;i++) {
237             c = s.charAt(i);
238              if(c != '$') {
239                  sb.append(c);
240                  continue;
241              }
242              i++;
243              c = s.charAt(i);
244              switch(c) {
245                  case '0': case '1': case '2': case '3': case '4':
246                  case '5': case '6': case '7': case '8': case '9':
247                      if(i < s.length()-1 && (c2 = s.charAt(i+1)) >= '0' && c2 <= '9') {
248                          n = (c - '0') * 10 + (c2 - '0');
249                          i++;
250                      } else {
251                          n = c - '0';
252                      }
253                      if(n > 0)
254                          sb.append(match.toString(n));
255                      break;
256                  case '$':
257                      sb.append('$'); break;
258                  case '&':
259                      sb.append(match.toString()); break;
260                  case '`':
261                      sb.append(source.substring(0,match.getStartIndex())); break;
262                  case '\'':
263                      sb.append(source.substring(match.getEndIndex())); break;
264                  default:
265                      sb.append('$');
266                      sb.append(c);
267              }
268          }
269          if(i < s.length()) sb.append(s.charAt(i));
270          return sb.toString();
271      }
272                      
273      
274      public static Object stringSplit(String s, Object arg0, Object arg1, int nargs) {
275          int limit = nargs < 2 ? Integer.MAX_VALUE : JS.toInt(arg1);
276          if(limit < 0) limit = Integer.MAX_VALUE;
277          if(limit == 0) return new JSArray();
278          
279          RE re = null;
280          JSRegexp regexp = null;
281          String sep = null;
282          JSArray ret = new JSArray();
283          int p = 0;
284          
285          if(arg0 instanceof JSRegexp) {
286              regexp = (JSRegexp) arg0;
287              re = regexp.re;
288          } else {
289              sep = arg0.toString();
290          }
291          
292          // special case this for speed. additionally, the code below doesn't properly handle
293          // zero length strings
294          if(sep != null && sep.length()==0) {
295              int len = s.length();
296              for(int i=0;i<len;i++)
297                  ret.addElement(s.substring(i,i+1));
298              return ret;
299          }
300          
301          OUTER: while(p < s.length()) {
302              if(re != null) {
303                  REMatch m = re.getMatch(s,p);
304                  if(m == null) break OUTER;
305                  boolean zeroLength = m.getStartIndex() == m.getEndIndex();
306                  ret.addElement(s.substring(p,zeroLength ? m.getStartIndex()+1 : m.getStartIndex()));
307                  p = zeroLength ? p + 1 : m.getEndIndex();
308                  if(!zeroLength) {
309                      for(int i=1;i<=re.getNumSubs();i++) {
310                          ret.addElement(m.toString(i));
311                          if(ret.length() == limit) break OUTER;
312                      }
313                  }
314              } else {
315                  int x = s.indexOf(sep,p);
316                  if(x == -1) break OUTER;
317                  ret.addElement(s.substring(p,x));
318                  p = x + sep.length();
319              }
320              if(ret.length() == limit) break;
321          }
322          if(p < s.length() && ret.length() != limit)
323              ret.addElement(s.substring(p));
324          return ret;
325      }
326      
327      public static RE newRE(String pattern, int flags) throws JSExn {
328          try {
329              return new RE(pattern,flags,RESyntax.RE_SYNTAX_PERL5);
330          } catch(REException e) {
331              throw new JSExn(e.toString());
332          }
333      }
334      
335      public String typeName() { return "regexp"; }
336  }
337