summaryrefslogtreecommitdiffstats
path: root/intl/icu/source/i18n/precision.cpp
blob: 086ce417f8991575ca35b98ed1e97c9e93eafbcc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
// Copyright (C) 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
 * Copyright (C) 2015, International Business Machines
 * Corporation and others.  All Rights Reserved.
 *
 * file name: precisison.cpp
 */

#include <math.h>

#include "unicode/utypes.h"

#if !UCONFIG_NO_FORMATTING

#include "digitlst.h"
#include "fmtableimp.h"
#include "precision.h"
#include "putilimp.h"
#include "visibledigits.h"

U_NAMESPACE_BEGIN

static const int32_t gPower10[] = {1, 10, 100, 1000};

FixedPrecision::FixedPrecision() 
        : fExactOnly(FALSE), fFailIfOverMax(FALSE), fRoundingMode(DecimalFormat::kRoundHalfEven) {
    fMin.setIntDigitCount(1);
    fMin.setFracDigitCount(0);
}

UBool
FixedPrecision::isRoundingRequired(
        int32_t upperExponent, int32_t lowerExponent) const {
    int32_t leastSigAllowed = fMax.getLeastSignificantInclusive();
    int32_t maxSignificantDigits = fSignificant.getMax();
    int32_t roundDigit;
    if (maxSignificantDigits == INT32_MAX) {
        roundDigit = leastSigAllowed;
    } else {
        int32_t limitDigit = upperExponent - maxSignificantDigits;
        roundDigit =
                limitDigit > leastSigAllowed ? limitDigit : leastSigAllowed;
    }
    return (roundDigit > lowerExponent);
}

DigitList &
FixedPrecision::round(
        DigitList &value, int32_t exponent, UErrorCode &status) const {
    if (U_FAILURE(status)) {
        return value;
    }
    value .fContext.status &= ~DEC_Inexact;
    if (!fRoundingIncrement.isZero()) {
        if (exponent == 0) {
            value.quantize(fRoundingIncrement, status);
        } else {
            DigitList adjustedIncrement(fRoundingIncrement);
            adjustedIncrement.shiftDecimalRight(exponent);
            value.quantize(adjustedIncrement, status);
        }
        if (U_FAILURE(status)) {
            return value;
        }
    }
    int32_t leastSig = fMax.getLeastSignificantInclusive();
    if (leastSig == INT32_MIN) {
        value.round(fSignificant.getMax());
    } else {
        value.roundAtExponent(
                exponent + leastSig,
                fSignificant.getMax());
    }
    if (fExactOnly && (value.fContext.status & DEC_Inexact)) {
        status = U_FORMAT_INEXACT_ERROR;
    } else if (fFailIfOverMax) {
        // Smallest interval for value stored in interval
        DigitInterval interval;
        value.getSmallestInterval(interval);
        if (fMax.getIntDigitCount() < interval.getIntDigitCount()) {
            status = U_ILLEGAL_ARGUMENT_ERROR;
        }
    }
    return value;
}

DigitInterval &
FixedPrecision::getIntervalForZero(DigitInterval &interval) const {
    interval = fMin;
    if (fSignificant.getMin() > 0) {
        interval.expandToContainDigit(interval.getIntDigitCount() - fSignificant.getMin());
    }
    interval.shrinkToFitWithin(fMax);
    return interval;
}

DigitInterval &
FixedPrecision::getInterval(
        int32_t upperExponent, DigitInterval &interval) const {
    if (fSignificant.getMin() > 0) {
        interval.expandToContainDigit(
                upperExponent - fSignificant.getMin());
    }
    interval.expandToContain(fMin);
    interval.shrinkToFitWithin(fMax);
    return interval;
}

DigitInterval &
FixedPrecision::getInterval(
        const DigitList &value, DigitInterval &interval) const {
    if (value.isZero()) {
        interval = fMin;
        if (fSignificant.getMin() > 0) {
            interval.expandToContainDigit(interval.getIntDigitCount() - fSignificant.getMin());
        }
    } else {
        value.getSmallestInterval(interval);
        if (fSignificant.getMin() > 0) {
            interval.expandToContainDigit(
                    value.getUpperExponent() - fSignificant.getMin());
        }
        interval.expandToContain(fMin);
    }
    interval.shrinkToFitWithin(fMax);
    return interval;
}

UBool
FixedPrecision::isFastFormattable() const {
    return (fMin.getFracDigitCount() == 0 && fSignificant.isNoConstraints() && fRoundingIncrement.isZero() && !fFailIfOverMax);
}

UBool
FixedPrecision::handleNonNumeric(DigitList &value, VisibleDigits &digits) {
    if (value.isNaN()) {
        digits.setNaN();
        return TRUE;
    }
    if (value.isInfinite()) {
        digits.setInfinite();
        if (!value.isPositive()) {
            digits.setNegative();
        }
        return TRUE;
    }
    return FALSE;
}

VisibleDigits &
FixedPrecision::initVisibleDigits(
        DigitList &value,
        VisibleDigits &digits,
        UErrorCode &status) const {
    if (U_FAILURE(status)) {
        return digits;
    }
    digits.clear();
    if (handleNonNumeric(value, digits)) {
        return digits;
    }
    if (!value.isPositive()) {
        digits.setNegative();
    }
    value.setRoundingMode(fRoundingMode);
    round(value, 0, status);
    getInterval(value, digits.fInterval);
    digits.fExponent = value.getLowerExponent();
    value.appendDigitsTo(digits.fDigits, status);
    return digits;
}

VisibleDigits &
FixedPrecision::initVisibleDigits(
        int64_t value,
        VisibleDigits &digits,
        UErrorCode &status) const {
    if (U_FAILURE(status)) {
        return digits;
    }
    if (!fRoundingIncrement.isZero()) {
        // If we have round increment, use digit list.
        DigitList digitList;
        digitList.set(value);
        return initVisibleDigits(digitList, digits, status);
    }
    // Try fast path
    if (initVisibleDigits(value, 0, digits, status)) {
        digits.fAbsDoubleValue = fabs((double) value);
        digits.fAbsDoubleValueSet = U_SUCCESS(status) && !digits.isOverMaxDigits();
        return digits;
    }
    // Oops have to use digit list
    DigitList digitList;
    digitList.set(value);
    return initVisibleDigits(digitList, digits, status);
}

VisibleDigits &
FixedPrecision::initVisibleDigits(
        double value,
        VisibleDigits &digits,
        UErrorCode &status) const {
    if (U_FAILURE(status)) {
        return digits;
    }
    digits.clear();
    if (uprv_isNaN(value)) {
        digits.setNaN();
        return digits;
    }
    if (uprv_isPositiveInfinity(value)) {
        digits.setInfinite();
        return digits;
    }
    if (uprv_isNegativeInfinity(value)) {
        digits.setInfinite();
        digits.setNegative();
        return digits;
    }
    if (!fRoundingIncrement.isZero()) {
        // If we have round increment, use digit list.
        DigitList digitList;
        digitList.set(value);
        return initVisibleDigits(digitList, digits, status);
    }
    // Try to find n such that value * 10^n is an integer
    int32_t n = -1;
    double scaled;
    for (int32_t i = 0; i < UPRV_LENGTHOF(gPower10); ++i) {
        scaled = value * gPower10[i];
        if (scaled > MAX_INT64_IN_DOUBLE || scaled < -MAX_INT64_IN_DOUBLE) {
            break;
        }
        if (scaled == floor(scaled)) {
            n = i;
            break;
        }
    }
    // Try fast path
    if (n >= 0 && initVisibleDigits(scaled, -n, digits, status)) {
        digits.fAbsDoubleValue = fabs(value);
        digits.fAbsDoubleValueSet = U_SUCCESS(status) && !digits.isOverMaxDigits();
        // Adjust for negative 0 becuase when we cast to an int64,
        // negative 0 becomes positive 0.
        if (scaled == 0.0 && uprv_isNegative(scaled)) {
            digits.setNegative();
        }
        return digits;
    }

    // Oops have to use digit list
    DigitList digitList;
    digitList.set(value);
    return initVisibleDigits(digitList, digits, status);
}

UBool
FixedPrecision::initVisibleDigits(
        int64_t mantissa,
        int32_t exponent,
        VisibleDigits &digits,
        UErrorCode &status) const {
    if (U_FAILURE(status)) {
        return TRUE;
    }
    digits.clear();

    // Precompute fAbsIntValue if it is small enough, but we don't know yet
    // if it will be valid.
    UBool absIntValueComputed = FALSE;
    if (mantissa > -1000000000000000000LL /* -1e18 */
            && mantissa < 1000000000000000000LL /* 1e18 */) {
        digits.fAbsIntValue = mantissa;
        if (digits.fAbsIntValue < 0) {
            digits.fAbsIntValue = -digits.fAbsIntValue;
        }
        int32_t i = 0;
        int32_t maxPower10Exp = UPRV_LENGTHOF(gPower10) - 1;
        for (; i > exponent + maxPower10Exp; i -= maxPower10Exp) {
            digits.fAbsIntValue /= gPower10[maxPower10Exp];
        }
        digits.fAbsIntValue /= gPower10[i - exponent];
        absIntValueComputed = TRUE;
    }
    if (mantissa == 0) {
        getIntervalForZero(digits.fInterval);
        digits.fAbsIntValueSet = absIntValueComputed;
        return TRUE;
    }
    // be sure least significant digit is non zero
    while (mantissa % 10 == 0) {
        mantissa /= 10;
        ++exponent;
    }
    if (mantissa < 0) {
        digits.fDigits.append((char) -(mantissa % -10), status);
        mantissa /= -10;
        digits.setNegative();
    }
    while (mantissa) {
        digits.fDigits.append((char) (mantissa % 10), status);
        mantissa /= 10;
    }
    if (U_FAILURE(status)) {
        return TRUE;
    }
    digits.fExponent = exponent;
    int32_t upperExponent = exponent + digits.fDigits.length();
    if (fFailIfOverMax && upperExponent > fMax.getIntDigitCount()) {
        status = U_ILLEGAL_ARGUMENT_ERROR;
        return TRUE;
    }
    UBool roundingRequired =
            isRoundingRequired(upperExponent, exponent);
    if (roundingRequired) {
        if (fExactOnly) {
            status = U_FORMAT_INEXACT_ERROR;
            return TRUE;
        }
        return FALSE;
    }
    digits.fInterval.setLeastSignificantInclusive(exponent);
    digits.fInterval.setMostSignificantExclusive(upperExponent);
    getInterval(upperExponent, digits.fInterval);

    // The intValue we computed above is only valid if our visible digits
    // doesn't exceed the maximum integer digits allowed.
    digits.fAbsIntValueSet = absIntValueComputed && !digits.isOverMaxDigits();
    return TRUE;
}

VisibleDigitsWithExponent &
FixedPrecision::initVisibleDigitsWithExponent(
        DigitList &value,
        VisibleDigitsWithExponent &digits,
        UErrorCode &status) const {
    digits.clear();
    initVisibleDigits(value, digits.fMantissa, status);
    return digits;
}

VisibleDigitsWithExponent &
FixedPrecision::initVisibleDigitsWithExponent(
        double value,
        VisibleDigitsWithExponent &digits,
        UErrorCode &status) const {
    digits.clear();
    initVisibleDigits(value, digits.fMantissa, status);
    return digits;
}

VisibleDigitsWithExponent &
FixedPrecision::initVisibleDigitsWithExponent(
        int64_t value,
        VisibleDigitsWithExponent &digits,
        UErrorCode &status) const {
    digits.clear();
    initVisibleDigits(value, digits.fMantissa, status);
    return digits;
}

ScientificPrecision::ScientificPrecision() : fMinExponentDigits(1) {
}

DigitList &
ScientificPrecision::round(DigitList &value, UErrorCode &status) const {
    if (U_FAILURE(status)) {
        return value;
    }
    int32_t exponent = value.getScientificExponent(
            fMantissa.fMin.getIntDigitCount(), getMultiplier());
    return fMantissa.round(value, exponent, status);
}

int32_t
ScientificPrecision::toScientific(DigitList &value) const {
    return value.toScientific(
            fMantissa.fMin.getIntDigitCount(), getMultiplier());
}

int32_t
ScientificPrecision::getMultiplier() const {
    int32_t maxIntDigitCount = fMantissa.fMax.getIntDigitCount();
    if (maxIntDigitCount == INT32_MAX) {
        return 1;
    }
    int32_t multiplier =
        maxIntDigitCount - fMantissa.fMin.getIntDigitCount() + 1;
    return (multiplier < 1 ? 1 : multiplier);
}

VisibleDigitsWithExponent &
ScientificPrecision::initVisibleDigitsWithExponent(
        DigitList &value,
        VisibleDigitsWithExponent &digits,
        UErrorCode &status) const {
    if (U_FAILURE(status)) {
        return digits;
    }
    digits.clear();
    if (FixedPrecision::handleNonNumeric(value, digits.fMantissa)) {
        return digits;
    }
    value.setRoundingMode(fMantissa.fRoundingMode);
    int64_t exponent = toScientific(round(value, status));
    fMantissa.initVisibleDigits(value, digits.fMantissa, status);
    FixedPrecision exponentPrecision;
    exponentPrecision.fMin.setIntDigitCount(fMinExponentDigits);
    exponentPrecision.initVisibleDigits(exponent, digits.fExponent, status);
    digits.fHasExponent = TRUE;
    return digits;
}

VisibleDigitsWithExponent &
ScientificPrecision::initVisibleDigitsWithExponent(
        double value,
        VisibleDigitsWithExponent &digits,
        UErrorCode &status) const {
    if (U_FAILURE(status)) {
        return digits;
    }
    DigitList digitList;
    digitList.set(value);
    return initVisibleDigitsWithExponent(digitList, digits, status);
}

VisibleDigitsWithExponent &
ScientificPrecision::initVisibleDigitsWithExponent(
        int64_t value,
        VisibleDigitsWithExponent &digits,
        UErrorCode &status) const {
    if (U_FAILURE(status)) {
        return digits;
    }
    DigitList digitList;
    digitList.set(value);
    return initVisibleDigitsWithExponent(digitList, digits, status);
}


U_NAMESPACE_END
#endif /* #if !UCONFIG_NO_FORMATTING */