// Copyright 2011 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include <stdarg.h>
#include <math.h>
#include <limits.h>
#include "conversions-inl.h"
#include "dtoa.h"
#include "strtod.h"
#include "utils.h"
namespace v8 {
namespace internal {
double StringToDouble(UnicodeCache* unicode_cache,
const char* str, int flags, double empty_string_val) {
const char* end = str + StrLength(str);
return InternalStringToDouble(unicode_cache, str, end, flags,
empty_string_val);
}
double StringToDouble(UnicodeCache* unicode_cache,
Vector<const char> str,
int flags,
double empty_string_val) {
const char* end = str.start() + str.length();
return InternalStringToDouble(unicode_cache, str.start(), end, flags,
empty_string_val);
}
double StringToDouble(UnicodeCache* unicode_cache,
Vector<const uc16> str,
int flags,
double empty_string_val) {
const uc16* end = str.start() + str.length();
return InternalStringToDouble(unicode_cache, str.start(), end, flags,
empty_string_val);
}
const char* DoubleToCString(double v, Vector<char> buffer) {
switch (fpclassify(v)) {
case FP_NAN: return "NaN";
case FP_INFINITE: return (v < 0.0 ? "-Infinity" : "Infinity");
case FP_ZERO: return "0";
default: {
SimpleStringBuilder builder(buffer.start(), buffer.length());
int decimal_point;
int sign;
const int kV8DtoaBufferCapacity = kBase10MaximalLength + 1;
char decimal_rep[kV8DtoaBufferCapacity];
int length;
DoubleToAscii(v, DTOA_SHORTEST, 0,
Vector<char>(decimal_rep, kV8DtoaBufferCapacity),
&sign, &length, &decimal_point);
if (sign) builder.AddCharacter('-');
if (length <= decimal_point && decimal_point <= 21) {
// ECMA-262 section 9.8.1 step 6.
builder.AddString(decimal_rep);
builder.AddPadding('0', decimal_point - length);
} else if (0 < decimal_point && decimal_point <= 21) {
// ECMA-262 section 9.8.1 step 7.
builder.AddSubstring(decimal_rep, decimal_point);
builder.AddCharacter('.');
builder.AddString(decimal_rep + decimal_point);
} else if (decimal_point <= 0 && decimal_point > -6) {
// ECMA-262 section 9.8.1 step 8.
builder.AddString("0.");
builder.AddPadding('0', -decimal_point);
builder.AddString(decimal_rep);
} else {
// ECMA-262 section 9.8.1 step 9 and 10 combined.
builder.AddCharacter(decimal_rep[0]);
if (length != 1) {
builder.AddCharacter('.');
builder.AddString(decimal_rep + 1);
}
builder.AddCharacter('e');
builder.AddCharacter((decimal_point >= 0) ? '+' : '-');
int exponent = decimal_point - 1;
if (exponent < 0) exponent = -exponent;
builder.AddDecimalInteger(exponent);
}
return builder.Finalize();
}
}
}
const char* IntToCString(int n, Vector<char> buffer) {
bool negative = false;
if (n < 0) {
// We must not negate the most negative int.
if (n == kMinInt) return DoubleToCString(n, buffer);
negative = true;
n = -n;
}
// Build the string backwards from the least significant digit.
int i = buffer.length();
buffer[--i] = '\0';
do {
buffer[--i] = '0' + (n % 10);
n /= 10;
} while (n);
if (negative) buffer[--i] = '-';
return buffer.start() + i;
}
char* DoubleToFixedCString(double value, int f) {
const int kMaxDigitsBeforePoint = 21;
const double kFirstNonFixed = 1e21;
const int kMaxDigitsAfterPoint = 20;
ASSERT(f >= 0);
ASSERT(f <= kMaxDigitsAfterPoint);
bool negative = false;
double abs_value = value;
if (value < 0) {
abs_value = -value;
negative = true;
}
// If abs_value has more than kMaxDigitsBeforePoint digits before the point
// use the non-fixed conversion routine.
if (abs_value >= kFirstNonFixed) {
char arr[100];
Vector<char> buffer(arr, ARRAY_SIZE(arr));
return StrDup(DoubleToCString(value, buffer));
}
// Find a sufficiently precise decimal representation of n.
int decimal_point;
int sign;
// Add space for the '\0' byte.
const int kDecimalRepCapacity =
kMaxDigitsBeforePoint + kMaxDigitsAfterPoint + 1;
char decimal_rep[kDecimalRepCapacity];
int decimal_rep_length;
DoubleToAscii(value, DTOA_FIXED, f,
Vector<char>(decimal_rep, kDecimalRepCapacity),
&sign, &decimal_rep_length, &decimal_point);
// Create a representation that is padded with zeros if needed.
int zero_prefix_length = 0;
int zero_postfix_length = 0;
if (decimal_point <= 0) {
zero_prefix_length = -decimal_point + 1;
decimal_point = 1;
}
if (zero_prefix_length + decimal_rep_length < decimal_point + f) {
zero_postfix_length = decimal_point + f - decimal_rep_length -
zero_prefix_length;
}
unsigned rep_length =
zero_prefix_length + decimal_rep_length + zero_postfix_length;
SimpleStringBuilder rep_builder(rep_length + 1);
rep_builder.AddPadding('0', zero_prefix_length);
rep_builder.AddString(decimal_rep);
rep_builder.AddPadding('0', zero_postfix_length);
char* rep = rep_builder.Finalize();
// Create the result string by appending a minus and putting in a
// decimal point if needed.
unsigned result_size = decimal_point + f + 2;
SimpleStringBuilder builder(result_size + 1);
if (negative) builder.AddCharacter('-');
builder.AddSubstring(rep, decimal_point);
if (f > 0) {
builder.AddCharacter('.');
builder.AddSubstring(rep + decimal_point, f);
}
DeleteArray(rep);
return builder.Finalize();
}
static char* CreateExponentialRepresentation(char* decimal_rep,
int exponent,
bool negative,
int significant_digits) {
bool negative_exponent = false;
if (exponent < 0) {
negative_exponent = true;
exponent = -exponent;
}
// Leave room in the result for appending a minus, for a period, the
// letter 'e', a minus or a plus depending on the exponent, and a
// three digit exponent.
unsigned result_size = significant_digits + 7;
SimpleStringBuilder builder(result_size + 1);
if (negative) builder.AddCharacter('-');
builder.AddCharacter(decimal_rep[0]);
if (significant_digits != 1) {
builder.AddCharacter('.');
builder.AddString(decimal_rep + 1);
int rep_length = StrLength(decimal_rep);
builder.AddPadding('0', significant_digits - rep_length);
}
builder.AddCharacter('e');
builder.AddCharacter(negative_exponent ? '-' : '+');
builder.AddDecimalInteger(exponent);
return builder.Finalize();
}
char* DoubleToExponentialCString(double value, int f) {
const int kMaxDigitsAfterPoint = 20;
// f might be -1 to signal that f was undefined in JavaScript.
ASSERT(f >= -1 && f <= kMaxDigitsAfterPoint);
bool negative = false;
if (value < 0) {
value = -value;
negative = true;
}
// Find a sufficiently precise decimal representation of n.
int decimal_point;
int sign;
// f corresponds to the digits after the point. There is always one digit
// before the point. The number of requested_digits equals hence f + 1.
// And we have to add one character for the null-terminator.
const int kV8DtoaBufferCapacity = kMaxDigitsAfterPoint + 1 + 1;
// Make sure that the buffer is big enough, even if we fall back to the
// shortest representation (which happens when f equals -1).
ASSERT(kBase10MaximalLength <= kMaxDigitsAfterPoint + 1);
char decimal_rep[kV8DtoaBufferCapacity];
int decimal_rep_length;
if (f == -1) {
DoubleToAscii(value, DTOA_SHORTEST, 0,
Vector<char>(decimal_rep, kV8DtoaBufferCapacity),
&sign, &decimal_rep_length, &decimal_point);
f = decimal_rep_length - 1;
} else {
DoubleToAscii(value, DTOA_PRECISION, f + 1,
Vector<char>(decimal_rep, kV8DtoaBufferCapacity),
&sign, &decimal_rep_length, &decimal_point);
}
ASSERT(decimal_rep_length > 0);
ASSERT(decimal_rep_length <= f + 1);
int exponent = decimal_point - 1;
char* result =
CreateExponentialRepresentation(decimal_rep, exponent, negative, f+1);
return result;
}
char* DoubleToPrecisionCString(double value, int p) {
const int kMinimalDigits = 1;
const int kMaximalDigits = 21;
ASSERT(p >= kMinimalDigits && p <= kMaximalDigits);
USE(kMinimalDigits);
bool negative = false;
if (value < 0) {
value = -value;
negative = true;
}
// Find a sufficiently precise decimal representation of n.
int decimal_point;
int sign;
// Add one for the terminating null character.
const int kV8DtoaBufferCapacity = kMaximalDigits + 1;
char decimal_rep[kV8DtoaBufferCapacity];
int decimal_rep_length;
DoubleToAscii(value, DTOA_PRECISION, p,
Vector<char>(decimal_rep, kV8DtoaBufferCapacity),
&sign, &decimal_rep_length, &decimal_point);
ASSERT(decimal_rep_length <= p);
int exponent = decimal_point - 1;
char* result = NULL;
if (exponent < -6 || exponent >= p) {
result =
CreateExponentialRepresentation(decimal_rep, exponent, negative, p);
} else {
// Use fixed notation.
//
// Leave room in the result for appending a minus, a period and in
// the case where decimal_point is not positive for a zero in
// front of the period.
unsigned result_size = (decimal_point <= 0)
? -decimal_point + p + 3
: p + 2;
SimpleStringBuilder builder(result_size + 1);
if (negative) builder.AddCharacter('-');
if (decimal_point <= 0) {
builder.AddString("0.");
builder.AddPadding('0', -decimal_point);
builder.AddString(decimal_rep);
builder.AddPadding('0', p - decimal_rep_length);
} else {
const int m = Min(decimal_rep_length, decimal_point);
builder.AddSubstring(decimal_rep, m);
builder.AddPadding('0', decimal_point - decimal_rep_length);
if (decimal_point < p) {
builder.AddCharacter('.');
const int extra = negative ? 2 : 1;
if (decimal_rep_length > decimal_point) {
const int len = StrLength(decimal_rep + decimal_point);
const int n = Min(len, p - (builder.position() - extra));
builder.AddSubstring(decimal_rep + decimal_point, n);
}
builder.AddPadding('0', extra + (p - builder.position()));
}
}
result = builder.Finalize();
}
return result;
}
char* DoubleToRadixCString(double value, int radix) {
ASSERT(radix >= 2 && radix <= 36);
// Character array used for conversion.
static const char chars[] = "0123456789abcdefghijklmnopqrstuvwxyz";
// Buffer for the integer part of the result. 1024 chars is enough
// for max integer value in radix 2. We need room for a sign too.
static const int kBufferSize = 1100;
char integer_buffer[kBufferSize];
integer_buffer[kBufferSize - 1] = '\0';
// Buffer for the decimal part of the result. We only generate up
// to kBufferSize - 1 chars for the decimal part.
char decimal_buffer[kBufferSize];
decimal_buffer[kBufferSize - 1] = '\0';
// Make sure the value is positive.
bool is_negative = value < 0.0;
if (is_negative) value = -value;
// Get the integer part and the decimal part.
double integer_part = floor(value);
double decimal_part = value - integer_part;
// Convert the integer part starting from the back. Always generate
// at least one digit.
int integer_pos = kBufferSize - 2;
do {
integer_buffer[integer_pos--] =
chars[static_cast<int>(fmod(integer_part, radix))];
integer_part /= radix;
} while (integer_part >= 1.0);
// Sanity check.
ASSERT(integer_pos > 0);
// Add sign if needed.
if (is_negative) integer_buffer[integer_pos--] = '-';
// Convert the decimal part. Repeatedly multiply by the radix to
// generate the next char. Never generate more than kBufferSize - 1
// chars.
//
// TODO(1093998): We will often generate a full decimal_buffer of
// chars because hitting zero will often not happen. The right
// solution would be to continue until the string representation can
// be read back and yield the original value. To implement this
// efficiently, we probably have to modify dtoa.
int decimal_pos = 0;
while ((decimal_part > 0.0) && (decimal_pos < kBufferSize - 1)) {
decimal_part *= radix;
decimal_buffer[decimal_pos++] =
chars[static_cast<int>(floor(decimal_part))];
decimal_part -= floor(decimal_part);
}
decimal_buffer[decimal_pos] = '\0';
// Compute the result size.
int integer_part_size = kBufferSize - 2 - integer_pos;
// Make room for zero termination.
unsigned result_size = integer_part_size + decimal_pos;
// If the number has a decimal part, leave room for the period.
if (decimal_pos > 0) result_size++;
// Allocate result and fill in the parts.
SimpleStringBuilder builder(result_size + 1);
builder.AddSubstring(integer_buffer + integer_pos + 1, integer_part_size);
if (decimal_pos > 0) builder.AddCharacter('.');
builder.AddSubstring(decimal_buffer, decimal_pos);
return builder.Finalize();
}
} } // namespace v8::internal