Ogre原始碼淺析——指令碼及其解析（三）
阿新 • • 發佈：2019-01-10
1 ConcreteNodeListPtr ScriptParser::parse(const ScriptTokenListPtr &tokens)
2 {
3 // MEMCATEGORY_GENERAL because SharedPtr can only free using that category
4 ConcreteNodeListPtr nodes(OGRE_NEW_T(ConcreteNodeList, MEMCATEGORY_GENERAL)(), SPFM_DELETE_T);
5
6 enum{READY, OBJECT};
7 uint32 state = READY;
8
9 ConcreteNode *parent = 0;
10 ConcreteNodePtr node;
11 ScriptToken *token = 0;
12 ScriptTokenList::iterator i = tokens->begin(), end = tokens->end();
13 while(i != end)
14 {
15 token = (*i).get();
16
17 switch(state)
18 {
19 case READY:
20 if(token->type == TID_WORD)
21 {
22 if(token->lexeme == "import")
23 {
24 node = ConcreteNodePtr(OGRE_NEW ConcreteNode());
25 node->token = token->lexeme;
26 node->file = token->file;
27 node->line = token->line;
28 node->type = CNT_IMPORT;
29
30 // The next token is the target
31 ++i;
32 if(i == end || ((*i)->type != TID_WORD && (*i)->type != TID_QUOTE))
33 OGRE_EXCEPT(Exception::ERR_INVALID_STATE,
34 Ogre::String("expected import target at line ") +
35 Ogre::StringConverter::toString(node->line),
36 "ScriptParser::parse");
37 ConcreteNodePtr temp(OGRE_NEW ConcreteNode());
38 temp->parent = node.get();
39 temp->file = (*i)->file;
40 temp->line = (*i)->line;
41 temp->type = (*i)->type == TID_WORD ? CNT_WORD : CNT_QUOTE;
42 if(temp->type == CNT_QUOTE)
43 temp->token = (*i)->lexeme.substr(1, token->lexeme.size() - 2);
44 else
45 temp->token = (*i)->lexeme;
46 node->children.push_back(temp);
47
48 // The second-next token is the source
49 ++i;
50 ++i;
51 if(i == end || ((*i)->type != TID_WORD && (*i)->type != TID_QUOTE))
52 OGRE_EXCEPT(Exception::ERR_INVALID_STATE,
53 Ogre::String("expected import source at line ") +
54 Ogre::StringConverter::toString(node->line),
55 "ScriptParser::parse");
56 temp = ConcreteNodePtr(OGRE_NEW ConcreteNode());
57 temp->parent = node.get();
58 temp->file = (*i)->file;
59 temp->line = (*i)->line;
60 temp->type = (*i)->type == TID_WORD ? CNT_WORD : CNT_QUOTE;
61 if(temp->type == CNT_QUOTE)
62 temp->token = (*i)->lexeme.substr(1, (*i)->lexeme.size() - 2);
63 else
64 temp->token = (*i)->lexeme;
65 node->children.push_back(temp);
66
67 // Consume all the newlines
68 i = skipNewlines(i, end);
69
70 // Insert the node
71 if(parent)
72 {
73 node->parent = parent;
74 parent->children.push_back(node);
75 }
76 else
77 {
78 node->parent = 0;
79 nodes->push_back(node);
80 }
81 node = ConcreteNodePtr();
82 }
83 else if(token->lexeme == "set")
84 {
85 node = ConcreteNodePtr(OGRE_NEW ConcreteNode());
86 node->token = token->lexeme;
87 node->file = token->file;
88 node->line = token->line;
89 node->type = CNT_VARIABLE_ASSIGN;
90
91 // The next token is the variable
92 ++i;
93 if(i == end || (*i)->type != TID_VARIABLE)
94 OGRE_EXCEPT(Exception::ERR_INVALID_STATE,
95 Ogre::String("expected variable name at line ") +
96 Ogre::StringConverter::toString(node->line),
97 "ScriptParser::parse");
98 ConcreteNodePtr temp(OGRE_NEW ConcreteNode());
99 temp->parent = node.get();
100 temp->file = (*i)->file;
101 temp->line = (*i)->line;
102 temp->type = CNT_VARIABLE;
103 temp->token = (*i)->lexeme;
104 node->children.push_back(temp);
105
106 // The next token is the assignment
107 ++i;
108 if(i == end || ((*i)->type != TID_WORD && (*i)->type != TID_QUOTE))
109 OGRE_EXCEPT(Exception::ERR_INVALID_STATE,
110 Ogre::String("expected variable value at line ") +
111 Ogre::StringConverter::toString(node->line),
112 "ScriptParser::parse");
113 temp = ConcreteNodePtr(OGRE_NEW ConcreteNode());
114 temp->parent = node.get();
115 temp->file = (*i)->file;
116 temp->line = (*i)->line;
117 temp->type = (*i)->type == TID_WORD ? CNT_WORD : CNT_QUOTE;
118 if(temp->type == CNT_QUOTE)
119 temp->token = (*i)->lexeme.substr(1, (*i)->lexeme.size() - 2);
120 else
121 temp->token = (*i)->lexeme;
122 node->children.push_back(temp);
123
124 // Consume all the newlines
125 i = skipNewlines(i, end);
126
127 // Insert the node
128 if(parent)
129 {
130 node->parent = parent;
131 parent->children.push_back(node);
132 }
133 else
134 {
135 node->parent = 0;
136 nodes->push_back(node);
137 }
138 node = ConcreteNodePtr();
139 }
140 else
141 {
142 node = ConcreteNodePtr(OGRE_NEW ConcreteNode());
143 node->file = token->file;
144 node->line = token->line;
145 node->type = token->type == TID_WORD ? CNT_WORD : CNT_QUOTE;
146 if(node->type == CNT_QUOTE)
147 node->token = token->lexeme.substr(1, token->lexeme.size() - 2);
148 else
149 node->token = token->lexeme;
150
151 // Insert the node
152 if(parent)
153 {
154 node->parent = parent;
155 parent->children.push_back(node);
156 }
157 else
158 {
159 node->parent = 0;
160 nodes->push_back(node);
161 }
162
163 // Set the parent
164 parent = node.get();
165
166 // Switch states
167 state = OBJECT;
168
169 node = ConcreteNodePtr();
170 }
171 }
172 else if(token->type == TID_RBRACKET)
173 {
174 // Go up one level if we can
175 if(parent)
176 parent = parent->parent;
177
178 node = ConcreteNodePtr(OGRE_NEW ConcreteNode());
179 node->token = token->lexeme;
180 node->file = token->file;
181 node->line = token->line;
182 node->type = CNT_RBRACE;
183
184 // Consume all the newlines
185 i = skipNewlines(i, end);
186
187 // Insert the node
188 if(parent)
189 {
190 node->parent = parent;
191 parent->children.push_back(node);
192 }
193 else
194 {
195 node->parent = 0;
196 nodes->push_back(node);
197 }
198
199 // Move up another level
200 if(parent)
201 parent = parent->parent;
202
203 node = ConcreteNodePtr();
204 }
205 break;
206 case OBJECT:
207 if(token->type == TID_NEWLINE)
208 {
209 // Look ahead to the next non-newline token and if it isn't an {, this was a property
210 ScriptTokenList::iterator next = skipNewlines(i, end);
211 if(next == end || (*next)->type != TID_LBRACKET)
212 {
213 // Ended a property here
214 if(parent)
215 parent = parent->parent;
216 state = READY;
217 }
218 }
219 else if(token->type == TID_COLON)
220 {
221 node = ConcreteNodePtr(OGRE_NEW ConcreteNode());
222 node->token = token->lexeme;
223 node->file = token->file;
224 node->line = token->line;
225 node->type = CNT_COLON;
226
227 // The following token are the parent objects (base classes).
228 // Require at least one of them.
229
230 ScriptTokenList::iterator j = i + 1;
231 j = skipNewlines(j, end);
232 if(j == end || ((*j)->type != TID_WORD && (*j)->type != TID_QUOTE)) {
233 OGRE_EXCEPT(Exception::ERR_INVALID_STATE,
234 Ogre::String("expected object identifier at line ") +
235 Ogre::StringConverter::toString(node->line),
236 "ScriptParser::parse");
237 }
238
239 while(j != end && ((*j)->type == TID_WORD || (*j)->type == TID_QUOTE))
240 {
241 ConcreteNodePtr tempNode = ConcreteNodePtr(OGRE_NEW ConcreteNode());
242 tempNode->token = (*j)->lexeme;
243 tempNode->file = (*j)->file;
244 tempNode->line = (*j)->line;
245 tempNode->type = (*j)->type == TID_WORD ? CNT_WORD : CNT_QUOTE;
246 tempNode->parent = node.get();
247 node->children.push_back(tempNode);
248 ++j;
249 }
250
251 // Move it backwards once, since the end of the loop moves it forwards again anyway
252 j--;
253 i = j;
254
255 // Insert the node
256 if(parent)
257 {
258 node->parent = parent;
259 parent->children.push_back(node);
260 }
261 else
262 {
263 node->parent = 0;
264 nodes->push_back(node);
265 }
266 node = ConcreteNodePtr();
267 }
268 else if(token->type == TID_LBRACKET)
269 {
270 node = ConcreteNodePtr(OGRE_NEW ConcreteNode());
271 node->token = token->lexeme;
272 node->file = token->file;
273 node->line = token->line;
274 node->type = CNT_LBRACE;
275
276 // Consume all the newlines
277 i = skipNewlines(i, end);
278
279 // Insert the node
280 if(parent)
281 {
282 node->parent = parent;
283 parent->children.push_back(node);
284 }
285 else
286 {
287 node->parent = 0;
288 nodes->push_back(node);
289 }
290
291 // Set the parent
292 parent = node.get();
293
294 // Change the state
295 state = READY;
296
297 node = ConcreteNodePtr();
298 }
299 else if(token->type == TID_RBRACKET)
300 {
301 // Go up one level if we can
302 if(parent)
303 parent = parent->parent;
304
305 // If the parent is currently a { then go up again
306 if(parent && parent->type == CNT_LBRACE && parent->parent)
307 parent = parent->parent;
308
309 node = ConcreteNodePtr(OGRE_NEW ConcreteNode());
310 node->token = token->lexeme;
311 node->file = token->file;
312 node->line = token->line;
313 node->type = CNT_RBRACE;
314
315 // Consume all the newlines
316 i = skipNewlines(i, end);
317
318 // Insert the node
319 if(parent)
320 {
321 node->parent = parent;
322 parent->children.push_back(node);
323 }
324 else
325 {
326 node->parent = 0;
327 nodes->push_back(node);
328 }
329
330 // Move up another level
331 if(parent)
332 parent = parent->parent;
333
334 node = ConcreteNodePtr();
335 state = READY;
336 }
337 else if(token->type == TID_VARIABLE)
338 {
339 node = ConcreteNodePtr(OGRE_NEW ConcreteNode());
340 node->token = token->lexeme;
341 node->file = token->file;
342 node->line = token->line;
343 node->type = CNT_VARIABLE;
344
345 // Insert the node
346 if(parent)
347 {
348 node->parent = parent;
349 parent->children.push_back(node);
350 }
351 else
352 {
353 node->parent = 0;
354 nodes->push_back(node);
355 }
356 node = ConcreteNodePtr();
357 }
358 else if(token->type == TID_QUOTE)
359 {
360 node = ConcreteNodePtr(OGRE_NEW ConcreteNode());
361 node->token = token->lexeme.substr(1, token->lexeme.size() - 2);
362 node->file = token->file;
363 node->line = token->line;
364 node->type = CNT_QUOTE;
365
366 // Insert the node
367 if(parent)
368 {
369 node->parent = parent;
370 parent->children.push_back(node);
371 }
372 else
373 {
374 node->parent = 0;
375 nodes->push_back(node);
376 }
377 node = ConcreteNodePtr();
378 }
379 else if(token->type == TID_WORD)
380 {
381 node = ConcreteNodePtr(OGRE_NEW ConcreteNode());
382 node->token = token->lexeme;
383 node->file = token->file;
384 node->line = token->line;
385 node->type = CNT_WORD;
386
387 // Insert the node
388 if(parent)
389 {
390 node->parent = parent;
391 parent->children.push_back(node);
392 }
393 else
394 {
395 node->parent = 0;
396 nodes->push_back(node);
397 }
398 node = ConcreteNodePtr();
399 }
400 break;
401 }
402
403 ++i;
404 }
405
406 return nodes;
407 }