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-rw-r--r--src/tools/parser.cpp89
1 files changed, 80 insertions, 9 deletions
diff --git a/src/tools/parser.cpp b/src/tools/parser.cpp
index 76d4a72..7933f31 100644
--- a/src/tools/parser.cpp
+++ b/src/tools/parser.cpp
@@ -151,10 +151,43 @@ private:
151 151
152void redAdd( Bu::Parser &p ) 152void redAdd( Bu::Parser &p )
153{ 153{
154 Lexer::Token *a = p.popToken();
155 Lexer::Token *b = p.popToken();
156
157 sio << "Add! " << b->vExtra.get<double>() << " + "
158 << a->vExtra.get<double>() << sio.nl;
159
160 Lexer::Token *c = new Lexer::Token( tokNumber,
161 b->vExtra.get<double>() + a->vExtra.get<double>()
162 );
163 p.pushToken( c );
164
165 delete a;
166 delete b;
167}
168
169void redSubtract( Bu::Parser &p )
170{
171 Lexer::Token *a = p.popToken();
172 Lexer::Token *b = p.popToken();
173
174 sio << "Subtract! " << b->vExtra.get<double>() << " - "
175 << a->vExtra.get<double>() << sio.nl;
176
177 Lexer::Token *c = new Lexer::Token( tokNumber,
178 b->vExtra.get<double>() - a->vExtra.get<double>()
179 );
180 p.pushToken( c );
181
182 delete a;
183 delete b;
154} 184}
155 185
156void redPrint( Bu::Parser &p ) 186void redPrint( Bu::Parser &p )
157{ 187{
188 Lexer::Token *a = p.popToken();
189 sio << "Print! = " << a->vExtra.get<double>() << sio.nl;
190 delete a;
158} 191}
159 192
160/* Basic grammer example: 193/* Basic grammer example:
@@ -170,14 +203,15 @@ void redPrint( Bu::Parser &p )
170 * The problem is, that we can't actually make something left hand recursive, 203 * The problem is, that we can't actually make something left hand recursive,
171 * so we break it into two exprs: 204 * so we break it into two exprs:
172 * 205 *
173 * expr': '(' expr ')' 206 * expr-sub1: '(' expr ')'
174 * | NUMBER 207 * | NUMBER
175 * ; 208 * ;
176 * 209 *
177 * expr: expr' expr'' 210 * expr: expr-sub1 expr-sub2
178 * ; 211 * ;
179 * 212 *
180 * expr'': '+' expr 213 * expr-sub2: '+' expr
214 * | '-' expr
181 * | 215 * |
182 * ; 216 * ;
183 * 217 *
@@ -191,8 +225,8 @@ int main( int argc, char *argv[] )
191 Parser p; 225 Parser p;
192 226
193 p.addNonTerminal("expr"); 227 p.addNonTerminal("expr");
194 p.addNonTerminal("expr'"); 228 p.addNonTerminal("expr-sub1");
195 p.addNonTerminal("expr''"); 229 p.addNonTerminal("expr-sub2");
196 { 230 {
197 Parser::NonTerminal nt; 231 Parser::NonTerminal nt;
198 nt.addProduction( 232 nt.addProduction(
@@ -215,10 +249,28 @@ int main( int argc, char *argv[] )
215 ); 249 );
216 nt.addProduction( 250 nt.addProduction(
217 Parser::Production( 251 Parser::Production(
252 Parser::State(
253 Parser::State::typeTerminal,
254 tokMinus
255 )
256 ).append(
257 Parser::State(
258 Parser::State::typeNonTerminal,
259 p.getNonTerminalId("expr")
260 )
261 ).append(
262 Parser::State(
263 Parser::State::typeReduction,
264 p.addReduction("subtract")
265 )
266 )
267 );
268 nt.addProduction(
269 Parser::Production(
218 ) 270 )
219 ); 271 );
220 nt.setCanSkip(); 272 nt.setCanSkip();
221 p.setNonTerminal("expr''", nt ); 273 p.setNonTerminal("expr-sub2", nt );
222 } 274 }
223 { 275 {
224 Parser::NonTerminal nt; 276 Parser::NonTerminal nt;
@@ -230,7 +282,25 @@ int main( int argc, char *argv[] )
230 ) 282 )
231 ) 283 )
232 ); 284 );
233 p.setNonTerminal("expr'", nt ); 285 nt.addProduction(
286 Parser::Production(
287 Parser::State(
288 Parser::State::typeTerminal,
289 tokOpenParen
290 )
291 ).append(
292 Parser::State(
293 Parser::State::typeNonTerminal,
294 p.getNonTerminalId("expr")
295 )
296 ).append(
297 Parser::State(
298 Parser::State::typeTerminal,
299 tokCloseParen
300 )
301 )
302 );
303 p.setNonTerminal("expr-sub1", nt );
234 } 304 }
235 { 305 {
236 Parser::NonTerminal nt; 306 Parser::NonTerminal nt;
@@ -238,12 +308,12 @@ int main( int argc, char *argv[] )
238 Parser::Production( 308 Parser::Production(
239 Parser::State( 309 Parser::State(
240 Parser::State::typeNonTerminal, 310 Parser::State::typeNonTerminal,
241 p.getNonTerminalId("expr'") 311 p.getNonTerminalId("expr-sub1")
242 ) 312 )
243 ).append( 313 ).append(
244 Parser::State( 314 Parser::State(
245 Parser::State::typeNonTerminal, 315 Parser::State::typeNonTerminal,
246 p.getNonTerminalId("expr''") 316 p.getNonTerminalId("expr-sub2")
247 ) 317 )
248 ) 318 )
249 ); 319 );
@@ -275,6 +345,7 @@ int main( int argc, char *argv[] )
275 p.setRootNonTerminal("input"); 345 p.setRootNonTerminal("input");
276 346
277 p.setReduction("add", Bu::slot( &redAdd ) ); 347 p.setReduction("add", Bu::slot( &redAdd ) );
348 p.setReduction("subtract", Bu::slot( &redSubtract ) );
278 p.setReduction("print", Bu::slot( &redPrint ) ); 349 p.setReduction("print", Bu::slot( &redPrint ) );
279 350
280 p.pushLexer( new MathLexer( fIn ) ); 351 p.pushLexer( new MathLexer( fIn ) );