Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2014 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package com.android.calculator2; |
| 18 | |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 19 | |
| 20 | import com.hp.creals.CR; |
| 21 | import com.hp.creals.UnaryCRFunction; |
| 22 | import com.hp.creals.PrecisionOverflowError; |
| 23 | import com.hp.creals.AbortedError; |
| 24 | |
| 25 | import android.content.Context; |
| 26 | |
Hans Boehm | 4a6b7cb | 2015-04-03 18:41:52 -0700 | [diff] [blame] | 27 | import java.math.BigInteger; |
| 28 | import java.io.DataInput; |
| 29 | import java.io.DataOutput; |
| 30 | import java.io.IOException; |
| 31 | import java.text.DecimalFormatSymbols; |
| 32 | import java.util.ArrayList; |
| 33 | import java.util.HashMap; |
| 34 | import java.util.IdentityHashMap; |
| 35 | |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 36 | // A mathematical expression represented as a sequence of "tokens". |
| 37 | // Many tokes are represented by button ids for the corresponding operator. |
| 38 | // Parsed only when we evaluate the expression using the "eval" method. |
| 39 | class CalculatorExpr { |
| 40 | private ArrayList<Token> mExpr; // The actual representation |
| 41 | // as a list of tokens. Constant |
| 42 | // tokens are always nonempty. |
| 43 | |
| 44 | private static enum TokenKind { CONSTANT, OPERATOR, PRE_EVAL }; |
| 45 | private static TokenKind[] tokenKindValues = TokenKind.values(); |
| 46 | private final static BigInteger BIG_MILLION = BigInteger.valueOf(1000000); |
| 47 | private final static BigInteger BIG_BILLION = BigInteger.valueOf(1000000000); |
| 48 | |
| 49 | private static abstract class Token { |
| 50 | abstract TokenKind kind(); |
| 51 | abstract void write(DataOutput out) throws IOException; |
| 52 | // Implementation writes kind as Byte followed by |
| 53 | // data read by constructor. |
| 54 | abstract String toString(Context context); |
| 55 | // We need the context to convert button ids to strings. |
| 56 | } |
| 57 | |
| 58 | // An operator token |
| 59 | private static class Operator extends Token { |
| 60 | final int mId; // We use the button resource id |
| 61 | Operator(int resId) { |
| 62 | mId = resId; |
| 63 | } |
| 64 | Operator(DataInput in) throws IOException { |
| 65 | mId = in.readInt(); |
| 66 | } |
| 67 | @Override |
| 68 | void write(DataOutput out) throws IOException { |
| 69 | out.writeByte(TokenKind.OPERATOR.ordinal()); |
| 70 | out.writeInt(mId); |
| 71 | } |
| 72 | @Override |
| 73 | public String toString(Context context) { |
| 74 | return KeyMaps.toString(mId, context); |
| 75 | } |
| 76 | @Override |
| 77 | TokenKind kind() { return TokenKind.OPERATOR; } |
| 78 | } |
| 79 | |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 80 | // A (possibly incomplete) numerical constant. |
| 81 | // Supports addition and removal of trailing characters; hence mutable. |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 82 | private static class Constant extends Token implements Cloneable { |
| 83 | private boolean mSawDecimal; |
| 84 | String mWhole; // part before decimal point |
| 85 | private String mFraction; // part after decimal point |
| 86 | |
| 87 | Constant() { |
| 88 | mWhole = ""; |
| 89 | mFraction = ""; |
| 90 | mSawDecimal = false; |
| 91 | }; |
| 92 | |
| 93 | Constant(DataInput in) throws IOException { |
| 94 | mWhole = in.readUTF(); |
| 95 | mSawDecimal = in.readBoolean(); |
| 96 | mFraction = in.readUTF(); |
| 97 | } |
| 98 | |
| 99 | @Override |
| 100 | void write(DataOutput out) throws IOException { |
| 101 | out.writeByte(TokenKind.CONSTANT.ordinal()); |
| 102 | out.writeUTF(mWhole); |
| 103 | out.writeBoolean(mSawDecimal); |
| 104 | out.writeUTF(mFraction); |
| 105 | } |
| 106 | |
| 107 | // Given a button press, append corresponding digit. |
| 108 | // We assume id is a digit or decimal point. |
| 109 | // Just return false if this was the second (or later) decimal point |
| 110 | // in this constant. |
| 111 | boolean add(int id) { |
| 112 | if (id == R.id.dec_point) { |
| 113 | if (mSawDecimal) return false; |
| 114 | mSawDecimal = true; |
| 115 | return true; |
| 116 | } |
| 117 | int val = KeyMaps.digVal(id); |
| 118 | if (mSawDecimal) { |
| 119 | mFraction += val; |
| 120 | } else { |
| 121 | mWhole += val; |
| 122 | } |
| 123 | return true; |
| 124 | } |
| 125 | |
| 126 | // Undo the last add. |
| 127 | // Assumes the constant is nonempty. |
| 128 | void delete() { |
| 129 | if (!mFraction.isEmpty()) { |
| 130 | mFraction = mFraction.substring(0, mFraction.length() - 1); |
| 131 | } else if (mSawDecimal) { |
| 132 | mSawDecimal = false; |
| 133 | } else { |
| 134 | mWhole = mWhole.substring(0, mWhole.length() - 1); |
| 135 | } |
| 136 | } |
| 137 | |
| 138 | boolean isEmpty() { |
| 139 | return (mSawDecimal == false && mWhole.isEmpty()); |
| 140 | } |
| 141 | |
Hans Boehm | 4a6b7cb | 2015-04-03 18:41:52 -0700 | [diff] [blame] | 142 | // Produces human-readable string, as typed. |
Hans Boehm | 013969e | 2015-04-13 20:29:47 -0700 | [diff] [blame^] | 143 | // Result is internationalized. |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 144 | @Override |
| 145 | public String toString() { |
| 146 | String result = mWhole; |
| 147 | if (mSawDecimal) { |
Hans Boehm | 013969e | 2015-04-13 20:29:47 -0700 | [diff] [blame^] | 148 | result += '.'; |
Hans Boehm | 4a6b7cb | 2015-04-03 18:41:52 -0700 | [diff] [blame] | 149 | result += mFraction; |
| 150 | } |
Hans Boehm | 013969e | 2015-04-13 20:29:47 -0700 | [diff] [blame^] | 151 | return KeyMaps.translateResult(result); |
Hans Boehm | 4a6b7cb | 2015-04-03 18:41:52 -0700 | [diff] [blame] | 152 | } |
| 153 | |
| 154 | // Eliminates leading decimal, which some of our |
| 155 | // other packages don't like. |
Hans Boehm | 013969e | 2015-04-13 20:29:47 -0700 | [diff] [blame^] | 156 | // Meant for machine consumption: |
| 157 | // Doesn't internationalize decimal point or digits. |
| 158 | public String toEasyString() { |
Hans Boehm | 4a6b7cb | 2015-04-03 18:41:52 -0700 | [diff] [blame] | 159 | String result = mWhole; |
| 160 | if (result.isEmpty()) result = "0"; |
| 161 | if (mSawDecimal) { |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 162 | result += '.'; |
| 163 | result += mFraction; |
| 164 | } |
| 165 | return result; |
| 166 | } |
| 167 | |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 168 | public BoundedRational toRational() { |
Hans Boehm | 4a6b7cb | 2015-04-03 18:41:52 -0700 | [diff] [blame] | 169 | String whole = mWhole; |
| 170 | if (whole.isEmpty()) whole = "0"; |
| 171 | BigInteger num = new BigInteger(whole + mFraction); |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 172 | BigInteger den = BigInteger.TEN.pow(mFraction.length()); |
| 173 | return new BoundedRational(num, den); |
| 174 | } |
| 175 | |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 176 | @Override |
| 177 | String toString(Context context) { |
| 178 | return toString(); |
| 179 | } |
| 180 | |
| 181 | @Override |
| 182 | TokenKind kind() { return TokenKind.CONSTANT; } |
| 183 | |
| 184 | // Override clone to make it public |
| 185 | @Override |
| 186 | public Object clone() { |
| 187 | Constant res = new Constant(); |
| 188 | res.mWhole = mWhole; |
| 189 | res.mFraction = mFraction; |
| 190 | res.mSawDecimal = mSawDecimal; |
| 191 | return res; |
| 192 | } |
| 193 | } |
| 194 | |
| 195 | // Hash maps used to detect duplicate subexpressions when |
| 196 | // we write out CalculatorExprs and read them back in. |
| 197 | private static final ThreadLocal<IdentityHashMap<CR,Integer>>outMap = |
| 198 | new ThreadLocal<IdentityHashMap<CR,Integer>>(); |
| 199 | // Maps expressions to indices on output |
| 200 | private static final ThreadLocal<HashMap<Integer,PreEval>>inMap = |
| 201 | new ThreadLocal<HashMap<Integer,PreEval>>(); |
| 202 | // Maps expressions to indices on output |
| 203 | private static final ThreadLocal<Integer> exprIndex = |
| 204 | new ThreadLocal<Integer>(); |
| 205 | |
| 206 | static void initExprOutput() { |
| 207 | outMap.set(new IdentityHashMap<CR,Integer>()); |
| 208 | exprIndex.set(Integer.valueOf(0)); |
| 209 | } |
| 210 | |
| 211 | static void initExprInput() { |
| 212 | inMap.set(new HashMap<Integer,PreEval>()); |
| 213 | } |
| 214 | |
| 215 | // We treat previously evaluated subexpressions as tokens |
| 216 | // These are inserted when either: |
| 217 | // - We continue an expression after evaluating some of it. |
| 218 | // - TODO: When we copy/paste expressions. |
| 219 | // The representation includes three different representations |
| 220 | // of the expression: |
| 221 | // 1) The CR value for use in computation. |
| 222 | // 2) The integer value for use in the computations, |
| 223 | // if the expression evaluates to an integer. |
| 224 | // 3a) The corresponding CalculatorExpr, together with |
| 225 | // 3b) The context (currently just deg/rad mode) used to evaluate |
| 226 | // the expression. |
| 227 | // 4) A short string representation that is used to |
| 228 | // Display the expression. |
| 229 | // |
| 230 | // (3) is present only so that we can persist the object. |
| 231 | // (4) is stored explicitly to avoid waiting for recomputation in the UI |
| 232 | // thread. |
| 233 | private static class PreEval extends Token { |
| 234 | final CR mValue; |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 235 | final BoundedRational mRatValue; |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 236 | private final CalculatorExpr mExpr; |
| 237 | private final EvalContext mContext; |
| 238 | private final String mShortRep; |
Hans Boehm | 013969e | 2015-04-13 20:29:47 -0700 | [diff] [blame^] | 239 | PreEval(CR val, BoundedRational ratVal, CalculatorExpr expr, |
| 240 | EvalContext ec, String shortRep) { |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 241 | mValue = val; |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 242 | mRatValue = ratVal; |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 243 | mExpr = expr; |
| 244 | mContext = ec; |
| 245 | mShortRep = shortRep; |
| 246 | } |
| 247 | // In writing out PreEvals, we are careful to avoid writing |
| 248 | // out duplicates. We assume that two expressions are |
| 249 | // duplicates if they have the same mVal. This avoids a |
| 250 | // potential exponential blow up in certain off cases and |
| 251 | // redundant evaluation after reading them back in. |
| 252 | // The parameter hash map maps expressions we've seen |
| 253 | // before to their index. |
| 254 | @Override |
| 255 | void write(DataOutput out) throws IOException { |
| 256 | out.writeByte(TokenKind.PRE_EVAL.ordinal()); |
| 257 | Integer index = outMap.get().get(mValue); |
| 258 | if (index == null) { |
| 259 | int nextIndex = exprIndex.get() + 1; |
| 260 | exprIndex.set(nextIndex); |
| 261 | outMap.get().put(mValue, nextIndex); |
| 262 | out.writeInt(nextIndex); |
| 263 | mExpr.write(out); |
| 264 | mContext.write(out); |
| 265 | out.writeUTF(mShortRep); |
| 266 | } else { |
| 267 | // Just write out the index |
| 268 | out.writeInt(index); |
| 269 | } |
| 270 | } |
| 271 | PreEval(DataInput in) throws IOException { |
| 272 | int index = in.readInt(); |
| 273 | PreEval prev = inMap.get().get(index); |
| 274 | if (prev == null) { |
| 275 | mExpr = new CalculatorExpr(in); |
| 276 | mContext = new EvalContext(in); |
| 277 | // Recompute other fields |
| 278 | // We currently do this in the UI thread, but we |
| 279 | // only create PreEval expressions that were |
| 280 | // previously successfully evaluated, and thus |
| 281 | // don't diverge. We also only evaluate to a |
| 282 | // constructive real, which involves substantial |
| 283 | // work only in fairly contrived circumstances. |
| 284 | // TODO: Deal better with slow evaluations. |
| 285 | EvalRet res = mExpr.evalExpr(0,mContext); |
| 286 | mValue = res.mVal; |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 287 | mRatValue = res.mRatVal; |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 288 | mShortRep = in.readUTF(); |
| 289 | inMap.get().put(index, this); |
| 290 | } else { |
| 291 | mValue = prev.mValue; |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 292 | mRatValue = prev.mRatValue; |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 293 | mExpr = prev.mExpr; |
| 294 | mContext = prev.mContext; |
| 295 | mShortRep = prev.mShortRep; |
| 296 | } |
| 297 | } |
| 298 | @Override |
| 299 | String toString(Context context) { |
| 300 | return mShortRep; |
| 301 | } |
| 302 | @Override |
| 303 | TokenKind kind() { return TokenKind.PRE_EVAL; } |
| 304 | } |
| 305 | |
| 306 | static Token newToken(DataInput in) throws IOException { |
| 307 | TokenKind kind = tokenKindValues[in.readByte()]; |
| 308 | switch(kind) { |
| 309 | case CONSTANT: |
| 310 | return new Constant(in); |
| 311 | case OPERATOR: |
| 312 | return new Operator(in); |
| 313 | case PRE_EVAL: |
| 314 | return new PreEval(in); |
| 315 | default: throw new IOException("Bad save file format"); |
| 316 | } |
| 317 | } |
| 318 | |
| 319 | CalculatorExpr() { |
| 320 | mExpr = new ArrayList<Token>(); |
| 321 | } |
| 322 | |
| 323 | private CalculatorExpr(ArrayList<Token> expr) { |
| 324 | mExpr = expr; |
| 325 | } |
| 326 | |
| 327 | CalculatorExpr(DataInput in) throws IOException { |
| 328 | mExpr = new ArrayList<Token>(); |
| 329 | int size = in.readInt(); |
| 330 | for (int i = 0; i < size; ++i) { |
| 331 | mExpr.add(newToken(in)); |
| 332 | } |
| 333 | } |
| 334 | |
| 335 | void write(DataOutput out) throws IOException { |
| 336 | int size = mExpr.size(); |
| 337 | out.writeInt(size); |
| 338 | for (int i = 0; i < size; ++i) { |
| 339 | mExpr.get(i).write(out); |
| 340 | } |
| 341 | } |
| 342 | |
| 343 | private boolean hasTrailingBinary() { |
| 344 | int s = mExpr.size(); |
| 345 | if (s == 0) return false; |
| 346 | Token t = mExpr.get(s-1); |
| 347 | if (!(t instanceof Operator)) return false; |
| 348 | Operator o = (Operator)t; |
| 349 | return (KeyMaps.isBinary(o.mId)); |
| 350 | } |
| 351 | |
| 352 | // Append press of button with given id to expression. |
| 353 | // Returns false and does nothing if this would clearly |
| 354 | // result in a syntax error. |
| 355 | boolean add(int id) { |
| 356 | int s = mExpr.size(); |
| 357 | int d = KeyMaps.digVal(id); |
| 358 | boolean binary = KeyMaps.isBinary(id); |
| 359 | if (s == 0 && binary && id != R.id.op_sub) return false; |
| 360 | if (binary && hasTrailingBinary() |
| 361 | && (id != R.id.op_sub || isOperator(s-1, R.id.op_sub))) { |
| 362 | return false; |
| 363 | } |
| 364 | boolean isConstPiece = (d != KeyMaps.NOT_DIGIT || id == R.id.dec_point); |
| 365 | if (isConstPiece) { |
| 366 | if (s == 0) { |
| 367 | mExpr.add(new Constant()); |
| 368 | s++; |
| 369 | } else { |
| 370 | Token last = mExpr.get(s-1); |
| 371 | if(!(last instanceof Constant)) { |
| 372 | if (!(last instanceof Operator)) { |
| 373 | return false; |
| 374 | } |
| 375 | int lastOp = ((Operator)last).mId; |
| 376 | if (lastOp == R.id.const_e || lastOp == R.id.const_pi |
| 377 | || lastOp == R.id.op_fact |
| 378 | || lastOp == R.id.rparen) { |
| 379 | // Constant cannot possibly follow; reject immediately |
| 380 | return false; |
| 381 | } |
| 382 | mExpr.add(new Constant()); |
| 383 | s++; |
| 384 | } |
| 385 | } |
| 386 | return ((Constant)(mExpr.get(s-1))).add(id); |
| 387 | } else { |
| 388 | mExpr.add(new Operator(id)); |
| 389 | return true; |
| 390 | } |
| 391 | } |
| 392 | |
| 393 | // Append the contents of the argument expression. |
| 394 | // It is assumed that the argument expression will not change, |
| 395 | // and thus its pieces can be reused directly. |
| 396 | // TODO: We probably only need this for expressions consisting of |
| 397 | // a single PreEval "token", and may want to check that. |
| 398 | void append(CalculatorExpr expr2) { |
| 399 | int s2 = expr2.mExpr.size(); |
| 400 | for (int i = 0; i < s2; ++i) { |
| 401 | mExpr.add(expr2.mExpr.get(i)); |
| 402 | } |
| 403 | } |
| 404 | |
| 405 | // Undo the last key addition, if any. |
| 406 | void delete() { |
| 407 | int s = mExpr.size(); |
| 408 | if (s == 0) return; |
| 409 | Token last = mExpr.get(s-1); |
| 410 | if (last instanceof Constant) { |
| 411 | Constant c = (Constant)last; |
| 412 | c.delete(); |
| 413 | if (!c.isEmpty()) return; |
| 414 | } |
| 415 | mExpr.remove(s-1); |
| 416 | } |
| 417 | |
| 418 | void clear() { |
| 419 | mExpr.clear(); |
| 420 | } |
| 421 | |
| 422 | boolean isEmpty() { |
| 423 | return mExpr.isEmpty(); |
| 424 | } |
| 425 | |
| 426 | // Returns a logical deep copy of the CalculatorExpr. |
| 427 | // Operator and PreEval tokens are immutable, and thus |
| 428 | // aren't really copied. |
| 429 | public Object clone() { |
| 430 | CalculatorExpr res = new CalculatorExpr(); |
| 431 | for (Token t: mExpr) { |
| 432 | if (t instanceof Constant) { |
| 433 | res.mExpr.add((Token)(((Constant)t).clone())); |
| 434 | } else { |
| 435 | res.mExpr.add(t); |
| 436 | } |
| 437 | } |
| 438 | return res; |
| 439 | } |
| 440 | |
| 441 | // Am I just a constant? |
| 442 | boolean isConstant() { |
| 443 | if (mExpr.size() != 1) return false; |
| 444 | return mExpr.get(0) instanceof Constant; |
| 445 | } |
| 446 | |
| 447 | // Return a new expression consisting of a single PreEval token |
| 448 | // representing the current expression. |
| 449 | // The caller supplies the value, degree mode, and short |
| 450 | // string representation, which must have been previously computed. |
| 451 | // Thus this is guaranteed to terminate reasonably quickly. |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 452 | CalculatorExpr abbreviate(CR val, BoundedRational ratVal, |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 453 | boolean dm, String sr) { |
| 454 | CalculatorExpr result = new CalculatorExpr(); |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 455 | Token t = new PreEval(val, ratVal, |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 456 | new CalculatorExpr( |
| 457 | (ArrayList<Token>)mExpr.clone()), |
| 458 | new EvalContext(dm), sr); |
| 459 | result.mExpr.add(t); |
| 460 | return result; |
| 461 | } |
| 462 | |
| 463 | // Internal evaluation functions return an EvalRet triple. |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 464 | // We compute rational (BoundedRational) results when possible, both as |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 465 | // a performance optimization, and to detect errors exactly when we can. |
| 466 | private class EvalRet { |
| 467 | int mPos; // Next position (expression index) to be parsed |
| 468 | final CR mVal; // Constructive Real result of evaluating subexpression |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 469 | final BoundedRational mRatVal; // Exact Rational value or null if |
| 470 | // irrational or hard to compute. |
| 471 | EvalRet(int p, CR v, BoundedRational r) { |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 472 | mPos = p; |
| 473 | mVal = v; |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 474 | mRatVal = r; |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 475 | } |
| 476 | } |
| 477 | |
| 478 | // And take a context argument: |
| 479 | private static class EvalContext { |
| 480 | // Memory register contents are not included here, |
| 481 | // since we now make that an explicit part of the expression |
| 482 | // If we add any other kinds of evaluation modes, they go here. |
| 483 | boolean mDegreeMode; |
| 484 | EvalContext(boolean degreeMode) { |
| 485 | mDegreeMode = degreeMode; |
| 486 | } |
| 487 | EvalContext(DataInput in) throws IOException { |
| 488 | mDegreeMode = in.readBoolean(); |
| 489 | } |
| 490 | void write(DataOutput out) throws IOException { |
| 491 | out.writeBoolean(mDegreeMode); |
| 492 | } |
| 493 | } |
| 494 | |
| 495 | private final CR RADIANS_PER_DEGREE = CR.PI.divide(CR.valueOf(180)); |
| 496 | |
| 497 | private final CR DEGREES_PER_RADIAN = CR.valueOf(180).divide(CR.PI); |
| 498 | |
| 499 | private CR toRadians(CR x, EvalContext ec) { |
| 500 | if (ec.mDegreeMode) { |
| 501 | return x.multiply(RADIANS_PER_DEGREE); |
| 502 | } else { |
| 503 | return x; |
| 504 | } |
| 505 | } |
| 506 | |
| 507 | private CR fromRadians(CR x, EvalContext ec) { |
| 508 | if (ec.mDegreeMode) { |
| 509 | return x.multiply(DEGREES_PER_RADIAN); |
| 510 | } else { |
| 511 | return x; |
| 512 | } |
| 513 | } |
| 514 | |
| 515 | // The following methods can all throw IndexOutOfBoundsException |
| 516 | // in the event of a syntax error. We expect that to be caught in |
| 517 | // eval below. |
| 518 | |
| 519 | private boolean isOperator(int i, int op) { |
| 520 | if (i >= mExpr.size()) return false; |
| 521 | Token t = mExpr.get(i); |
| 522 | if (!(t instanceof Operator)) return false; |
| 523 | return ((Operator)(t)).mId == op; |
| 524 | } |
| 525 | |
| 526 | static class SyntaxError extends Error { |
| 527 | public SyntaxError() { |
| 528 | super(); |
| 529 | } |
| 530 | public SyntaxError(String s) { |
| 531 | super(s); |
| 532 | } |
| 533 | } |
| 534 | |
| 535 | // The following functions all evaluate some kind of expression |
| 536 | // starting at position i in mExpr in a specified evaluation context. |
| 537 | // They return both the expression value (as constructive real and, |
| 538 | // if applicable, as BigInteger) and the position of the next token |
| 539 | // that was not used as part of the evaluation. |
| 540 | private EvalRet evalUnary(int i, EvalContext ec) |
| 541 | throws ArithmeticException { |
| 542 | Token t = mExpr.get(i); |
| 543 | CR value; |
| 544 | if (t instanceof Constant) { |
| 545 | Constant c = (Constant)t; |
Hans Boehm | 013969e | 2015-04-13 20:29:47 -0700 | [diff] [blame^] | 546 | value = CR.valueOf(c.toEasyString(),10); |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 547 | return new EvalRet(i+1, value, c.toRational()); |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 548 | } |
| 549 | if (t instanceof PreEval) { |
| 550 | PreEval p = (PreEval)t; |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 551 | return new EvalRet(i+1, p.mValue, p.mRatValue); |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 552 | } |
| 553 | EvalRet argVal; |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 554 | BoundedRational ratVal; |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 555 | switch(((Operator)(t)).mId) { |
| 556 | case R.id.const_pi: |
| 557 | return new EvalRet(i+1, CR.PI, null); |
| 558 | case R.id.const_e: |
| 559 | return new EvalRet(i+1, CR.valueOf(1).exp(), null); |
| 560 | case R.id.op_sqrt: |
| 561 | // Seems to have highest precedence |
| 562 | // Does not add implicit paren |
| 563 | argVal = evalUnary(i+1, ec); |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 564 | ratVal = BoundedRational.sqrt(argVal.mRatVal); |
| 565 | if (ratVal != null) break; |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 566 | return new EvalRet(argVal.mPos, argVal.mVal.sqrt(), null); |
| 567 | case R.id.lparen: |
| 568 | argVal = evalExpr(i+1, ec); |
| 569 | if (isOperator(argVal.mPos, R.id.rparen)) argVal.mPos++; |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 570 | return new EvalRet(argVal.mPos, argVal.mVal, argVal.mRatVal); |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 571 | case R.id.fun_sin: |
| 572 | argVal = evalExpr(i+1, ec); |
| 573 | if (isOperator(argVal.mPos, R.id.rparen)) argVal.mPos++; |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 574 | ratVal = ec.mDegreeMode? BoundedRational.degreeSin(argVal.mRatVal) |
| 575 | : BoundedRational.sin(argVal.mRatVal); |
| 576 | if (ratVal != null) break; |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 577 | return new EvalRet(argVal.mPos, |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 578 | toRadians(argVal.mVal,ec).sin(), null); |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 579 | case R.id.fun_cos: |
| 580 | argVal = evalExpr(i+1, ec); |
| 581 | if (isOperator(argVal.mPos, R.id.rparen)) argVal.mPos++; |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 582 | ratVal = ec.mDegreeMode? BoundedRational.degreeCos(argVal.mRatVal) |
| 583 | : BoundedRational.cos(argVal.mRatVal); |
Hans Boehm | 4a6b7cb | 2015-04-03 18:41:52 -0700 | [diff] [blame] | 584 | if (ratVal != null) break; |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 585 | return new EvalRet(argVal.mPos, |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 586 | toRadians(argVal.mVal,ec).cos(), null); |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 587 | case R.id.fun_tan: |
| 588 | argVal = evalExpr(i+1, ec); |
| 589 | if (isOperator(argVal.mPos, R.id.rparen)) argVal.mPos++; |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 590 | ratVal = ec.mDegreeMode? BoundedRational.degreeTan(argVal.mRatVal) |
| 591 | : BoundedRational.tan(argVal.mRatVal); |
| 592 | if (ratVal != null) break; |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 593 | CR argCR = toRadians(argVal.mVal, ec); |
| 594 | return new EvalRet(argVal.mPos, |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 595 | argCR.sin().divide(argCR.cos()), null); |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 596 | case R.id.fun_ln: |
| 597 | argVal = evalExpr(i+1, ec); |
| 598 | if (isOperator(argVal.mPos, R.id.rparen)) argVal.mPos++; |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 599 | ratVal = BoundedRational.ln(argVal.mRatVal); |
| 600 | if (ratVal != null) break; |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 601 | return new EvalRet(argVal.mPos, argVal.mVal.ln(), null); |
| 602 | case R.id.fun_log: |
| 603 | argVal = evalExpr(i+1, ec); |
| 604 | if (isOperator(argVal.mPos, R.id.rparen)) argVal.mPos++; |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 605 | ratVal = BoundedRational.log(argVal.mRatVal); |
| 606 | if (ratVal != null) break; |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 607 | return new EvalRet(argVal.mPos, |
| 608 | argVal.mVal.ln().divide(CR.valueOf(10).ln()), |
| 609 | null); |
| 610 | case R.id.fun_arcsin: |
| 611 | argVal = evalExpr(i+1, ec); |
| 612 | if (isOperator(argVal.mPos, R.id.rparen)) argVal.mPos++; |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 613 | ratVal = ec.mDegreeMode? BoundedRational.degreeAsin(argVal.mRatVal) |
| 614 | : BoundedRational.asin(argVal.mRatVal); |
| 615 | if (ratVal != null) break; |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 616 | return new EvalRet(argVal.mPos, |
| 617 | fromRadians(UnaryCRFunction |
| 618 | .asinFunction.execute(argVal.mVal),ec), |
| 619 | null); |
| 620 | case R.id.fun_arccos: |
| 621 | argVal = evalExpr(i+1, ec); |
| 622 | if (isOperator(argVal.mPos, R.id.rparen)) argVal.mPos++; |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 623 | ratVal = ec.mDegreeMode? BoundedRational.degreeAcos(argVal.mRatVal) |
| 624 | : BoundedRational.acos(argVal.mRatVal); |
| 625 | if (ratVal != null) break; |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 626 | return new EvalRet(argVal.mPos, |
| 627 | fromRadians(UnaryCRFunction |
| 628 | .acosFunction.execute(argVal.mVal),ec), |
| 629 | null); |
| 630 | case R.id.fun_arctan: |
| 631 | argVal = evalExpr(i+1, ec); |
| 632 | if (isOperator(argVal.mPos, R.id.rparen)) argVal.mPos++; |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 633 | ratVal = ec.mDegreeMode? BoundedRational.degreeAtan(argVal.mRatVal) |
| 634 | : BoundedRational.atan(argVal.mRatVal); |
| 635 | if (ratVal != null) break; |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 636 | return new EvalRet(argVal.mPos, |
| 637 | fromRadians(UnaryCRFunction |
| 638 | .atanFunction.execute(argVal.mVal),ec), |
| 639 | null); |
| 640 | default: |
| 641 | throw new SyntaxError("Unrecognized token in expression"); |
| 642 | } |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 643 | // We have a rational value. |
| 644 | return new EvalRet(argVal.mPos, ratVal.CRValue(), ratVal); |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 645 | } |
| 646 | |
| 647 | // Compute an integral power of a constructive real. |
| 648 | // Unlike the "general" case using logarithms, this handles a negative |
| 649 | // base. |
| 650 | private static CR pow(CR base, BigInteger exp) { |
| 651 | if (exp.compareTo(BigInteger.ZERO) < 0) { |
| 652 | return pow(base, exp.negate()).inverse(); |
| 653 | } |
| 654 | if (exp.equals(BigInteger.ONE)) return base; |
| 655 | if (exp.and(BigInteger.ONE).intValue() == 1) { |
| 656 | return pow(base, exp.subtract(BigInteger.ONE)).multiply(base); |
| 657 | } |
| 658 | if (exp.equals(BigInteger.ZERO)) { |
| 659 | return CR.valueOf(1); |
| 660 | } |
| 661 | CR tmp = pow(base, exp.shiftRight(1)); |
| 662 | return tmp.multiply(tmp); |
| 663 | } |
| 664 | |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 665 | private static final int TEST_PREC = -100; |
| 666 | // Test for integer-ness to 100 bits past binary point. |
| 667 | private static final BigInteger MASK = |
| 668 | BigInteger.ONE.shiftLeft(-TEST_PREC).subtract(BigInteger.ONE); |
| 669 | private static boolean isApprInt(CR x) { |
| 670 | BigInteger appr = x.get_appr(TEST_PREC); |
| 671 | return appr.and(MASK).signum() == 0; |
| 672 | } |
| 673 | |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 674 | private EvalRet evalFactorial(int i, EvalContext ec) { |
| 675 | EvalRet tmp = evalUnary(i, ec); |
| 676 | int cpos = tmp.mPos; |
| 677 | CR cval = tmp.mVal; |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 678 | BoundedRational ratVal = tmp.mRatVal; |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 679 | while (isOperator(cpos, R.id.op_fact)) { |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 680 | if (ratVal == null) { |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 681 | // Assume it was an integer, but we |
| 682 | // didn't figure it out. |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 683 | // KitKat may have used the Gamma function. |
| 684 | if (!isApprInt(cval)) { |
| 685 | throw new ArithmeticException("factorial(non-integer)"); |
| 686 | } |
| 687 | ratVal = new BoundedRational(cval.BigIntegerValue()); |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 688 | } |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 689 | ratVal = BoundedRational.fact(ratVal); |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 690 | ++cpos; |
| 691 | } |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 692 | if (ratVal != null) cval = ratVal.CRValue(); |
| 693 | return new EvalRet(cpos, cval, ratVal); |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 694 | } |
| 695 | |
| 696 | private EvalRet evalFactor(int i, EvalContext ec) |
| 697 | throws ArithmeticException { |
| 698 | final EvalRet result1 = evalFactorial(i, ec); |
| 699 | int cpos = result1.mPos; // current position |
| 700 | CR cval = result1.mVal; // value so far |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 701 | BoundedRational ratVal = result1.mRatVal; // int value so far |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 702 | if (isOperator(cpos, R.id.op_pow)) { |
| 703 | final EvalRet exp = evalSignedFactor(cpos+1, ec); |
| 704 | cpos = exp.mPos; |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 705 | // Try completely rational evaluation first. |
| 706 | ratVal = BoundedRational.pow(ratVal, exp.mRatVal); |
| 707 | if (ratVal != null) { |
| 708 | return new EvalRet(cpos, ratVal.CRValue(), ratVal); |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 709 | } |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 710 | // Power with integer exponent is defined for negative base. |
| 711 | // Thus we handle that case separately. |
| 712 | // We punt if the exponent is an integer computed from irrational |
| 713 | // values. That wouldn't work reliably with floating point either. |
| 714 | BigInteger int_exp = BoundedRational.asBigInteger(exp.mRatVal); |
| 715 | if (int_exp != null) { |
| 716 | cval = pow(cval, int_exp); |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 717 | } else { |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 718 | cval = cval.ln().multiply(exp.mVal).exp(); |
| 719 | } |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 720 | ratVal = null; |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 721 | } |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 722 | return new EvalRet(cpos, cval, ratVal); |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 723 | } |
| 724 | |
| 725 | private EvalRet evalSignedFactor(int i, EvalContext ec) |
| 726 | throws ArithmeticException { |
| 727 | final boolean negative = isOperator(i, R.id.op_sub); |
| 728 | int cpos = negative? i + 1 : i; |
| 729 | EvalRet tmp = evalFactor(cpos, ec); |
| 730 | cpos = tmp.mPos; |
| 731 | CR cval = negative? tmp.mVal.negate() : tmp.mVal; |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 732 | BoundedRational ratVal = negative? BoundedRational.negate(tmp.mRatVal) |
| 733 | : tmp.mRatVal; |
| 734 | return new EvalRet(cpos, cval, ratVal); |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 735 | } |
| 736 | |
| 737 | private boolean canStartFactor(int i) { |
| 738 | if (i >= mExpr.size()) return false; |
| 739 | Token t = mExpr.get(i); |
| 740 | if (!(t instanceof Operator)) return true; |
| 741 | int id = ((Operator)(t)).mId; |
| 742 | if (KeyMaps.isBinary(id)) return false; |
| 743 | switch (id) { |
| 744 | case R.id.op_fact: |
| 745 | case R.id.rparen: |
| 746 | return false; |
| 747 | default: |
| 748 | return true; |
| 749 | } |
| 750 | } |
| 751 | |
| 752 | private EvalRet evalTerm(int i, EvalContext ec) |
| 753 | throws ArithmeticException { |
| 754 | EvalRet tmp = evalSignedFactor(i, ec); |
| 755 | boolean is_mul = false; |
| 756 | boolean is_div = false; |
| 757 | int cpos = tmp.mPos; // Current position in expression. |
| 758 | CR cval = tmp.mVal; // Current value. |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 759 | BoundedRational ratVal = tmp.mRatVal; // Current rational value. |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 760 | while ((is_mul = isOperator(cpos, R.id.op_mul)) |
| 761 | || (is_div = isOperator(cpos, R.id.op_div)) |
| 762 | || canStartFactor(cpos)) { |
| 763 | if (is_mul || is_div) ++cpos; |
Hans Boehm | 4a6b7cb | 2015-04-03 18:41:52 -0700 | [diff] [blame] | 764 | tmp = evalSignedFactor(cpos, ec); |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 765 | if (is_div) { |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 766 | ratVal = BoundedRational.divide(ratVal, tmp.mRatVal); |
| 767 | if (ratVal == null) { |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 768 | cval = cval.divide(tmp.mVal); |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 769 | } else { |
| 770 | cval = ratVal.CRValue(); |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 771 | } |
| 772 | } else { |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 773 | ratVal = BoundedRational.multiply(ratVal, tmp.mRatVal); |
| 774 | if (ratVal == null) { |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 775 | cval = cval.multiply(tmp.mVal); |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 776 | } else { |
| 777 | cval = ratVal.CRValue(); |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 778 | } |
| 779 | } |
| 780 | cpos = tmp.mPos; |
| 781 | is_mul = is_div = false; |
| 782 | } |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 783 | return new EvalRet(cpos, cval, ratVal); |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 784 | } |
| 785 | |
| 786 | private EvalRet evalExpr(int i, EvalContext ec) throws ArithmeticException { |
| 787 | EvalRet tmp = evalTerm(i, ec); |
| 788 | boolean is_plus; |
| 789 | int cpos = tmp.mPos; |
| 790 | CR cval = tmp.mVal; |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 791 | BoundedRational ratVal = tmp.mRatVal; |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 792 | while ((is_plus = isOperator(cpos, R.id.op_add)) |
| 793 | || isOperator(cpos, R.id.op_sub)) { |
| 794 | tmp = evalTerm(cpos+1, ec); |
| 795 | if (is_plus) { |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 796 | ratVal = BoundedRational.add(ratVal, tmp.mRatVal); |
| 797 | if (ratVal == null) { |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 798 | cval = cval.add(tmp.mVal); |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 799 | } else { |
| 800 | cval = ratVal.CRValue(); |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 801 | } |
| 802 | } else { |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 803 | ratVal = BoundedRational.subtract(ratVal, tmp.mRatVal); |
| 804 | if (ratVal == null) { |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 805 | cval = cval.subtract(tmp.mVal); |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 806 | } else { |
| 807 | cval = ratVal.CRValue(); |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 808 | } |
| 809 | } |
| 810 | cpos = tmp.mPos; |
| 811 | } |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 812 | return new EvalRet(cpos, cval, ratVal); |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 813 | } |
| 814 | |
| 815 | // Externally visible evaluation result. |
| 816 | public class EvalResult { |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 817 | EvalResult (CR val, BoundedRational ratVal) { |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 818 | mVal = val; |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 819 | mRatVal = ratVal; |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 820 | } |
| 821 | final CR mVal; |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 822 | final BoundedRational mRatVal; |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 823 | } |
| 824 | |
| 825 | // Evaluate the entire expression, returning null in the event |
| 826 | // of an error. |
| 827 | // Not called from the UI thread, but should not be called |
| 828 | // concurrently with modifications to the expression. |
| 829 | EvalResult eval(boolean degreeMode) throws SyntaxError, |
| 830 | ArithmeticException, PrecisionOverflowError |
| 831 | { |
| 832 | try { |
| 833 | EvalContext ec = new EvalContext(degreeMode); |
| 834 | EvalRet res = evalExpr(0, ec); |
| 835 | if (res.mPos != mExpr.size()) return null; |
Hans Boehm | 682ff5e | 2015-03-09 14:40:25 -0700 | [diff] [blame] | 836 | return new EvalResult(res.mVal, res.mRatVal); |
Hans Boehm | 8461495 | 2014-11-25 18:46:17 -0800 | [diff] [blame] | 837 | } catch (IndexOutOfBoundsException e) { |
| 838 | throw new SyntaxError("Unexpected expression end"); |
| 839 | } |
| 840 | } |
| 841 | |
| 842 | // Produce a string representation of the expression itself |
| 843 | String toString(Context context) { |
| 844 | StringBuilder sb = new StringBuilder(); |
| 845 | for (Token t: mExpr) { |
| 846 | sb.append(t.toString(context)); |
| 847 | } |
| 848 | return sb.toString(); |
| 849 | } |
| 850 | } |