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Posted to commits@couchdb.apache.org by rn...@apache.org on 2013/12/24 00:31:17 UTC
[08/12] Replace ejson with jiffy
http://git-wip-us.apache.org/repos/asf/couchdb/blob/2e6092e4/src/jiffy/c_src/double-conversion/double-conversion.cc
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diff --git a/src/jiffy/c_src/double-conversion/double-conversion.cc b/src/jiffy/c_src/double-conversion/double-conversion.cc
new file mode 100644
index 0000000..a79fe92
--- /dev/null
+++ b/src/jiffy/c_src/double-conversion/double-conversion.cc
@@ -0,0 +1,889 @@
+// Copyright 2010 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 <limits.h>
+#include <math.h>
+
+#include "double-conversion.h"
+
+#include "bignum-dtoa.h"
+#include "fast-dtoa.h"
+#include "fixed-dtoa.h"
+#include "ieee.h"
+#include "strtod.h"
+#include "utils.h"
+
+namespace double_conversion {
+
+const DoubleToStringConverter& DoubleToStringConverter::EcmaScriptConverter() {
+ int flags = UNIQUE_ZERO | EMIT_POSITIVE_EXPONENT_SIGN;
+ static DoubleToStringConverter converter(flags,
+ "Infinity",
+ "NaN",
+ 'e',
+ -6, 21,
+ 6, 0);
+ return converter;
+}
+
+
+bool DoubleToStringConverter::HandleSpecialValues(
+ double value,
+ StringBuilder* result_builder) const {
+ Double double_inspect(value);
+ if (double_inspect.IsInfinite()) {
+ if (infinity_symbol_ == NULL) return false;
+ if (value < 0) {
+ result_builder->AddCharacter('-');
+ }
+ result_builder->AddString(infinity_symbol_);
+ return true;
+ }
+ if (double_inspect.IsNan()) {
+ if (nan_symbol_ == NULL) return false;
+ result_builder->AddString(nan_symbol_);
+ return true;
+ }
+ return false;
+}
+
+
+void DoubleToStringConverter::CreateExponentialRepresentation(
+ const char* decimal_digits,
+ int length,
+ int exponent,
+ StringBuilder* result_builder) const {
+ ASSERT(length != 0);
+ result_builder->AddCharacter(decimal_digits[0]);
+ if (length != 1) {
+ result_builder->AddCharacter('.');
+ result_builder->AddSubstring(&decimal_digits[1], length-1);
+ }
+ result_builder->AddCharacter(exponent_character_);
+ if (exponent < 0) {
+ result_builder->AddCharacter('-');
+ exponent = -exponent;
+ } else {
+ if ((flags_ & EMIT_POSITIVE_EXPONENT_SIGN) != 0) {
+ result_builder->AddCharacter('+');
+ }
+ }
+ if (exponent == 0) {
+ result_builder->AddCharacter('0');
+ return;
+ }
+ ASSERT(exponent < 1e4);
+ const int kMaxExponentLength = 5;
+ char buffer[kMaxExponentLength + 1];
+ buffer[kMaxExponentLength] = '\0';
+ int first_char_pos = kMaxExponentLength;
+ while (exponent > 0) {
+ buffer[--first_char_pos] = '0' + (exponent % 10);
+ exponent /= 10;
+ }
+ result_builder->AddSubstring(&buffer[first_char_pos],
+ kMaxExponentLength - first_char_pos);
+}
+
+
+void DoubleToStringConverter::CreateDecimalRepresentation(
+ const char* decimal_digits,
+ int length,
+ int decimal_point,
+ int digits_after_point,
+ StringBuilder* result_builder) const {
+ // Create a representation that is padded with zeros if needed.
+ if (decimal_point <= 0) {
+ // "0.00000decimal_rep".
+ result_builder->AddCharacter('0');
+ if (digits_after_point > 0) {
+ result_builder->AddCharacter('.');
+ result_builder->AddPadding('0', -decimal_point);
+ ASSERT(length <= digits_after_point - (-decimal_point));
+ result_builder->AddSubstring(decimal_digits, length);
+ int remaining_digits = digits_after_point - (-decimal_point) - length;
+ result_builder->AddPadding('0', remaining_digits);
+ }
+ } else if (decimal_point >= length) {
+ // "decimal_rep0000.00000" or "decimal_rep.0000"
+ result_builder->AddSubstring(decimal_digits, length);
+ result_builder->AddPadding('0', decimal_point - length);
+ if (digits_after_point > 0) {
+ result_builder->AddCharacter('.');
+ result_builder->AddPadding('0', digits_after_point);
+ }
+ } else {
+ // "decima.l_rep000"
+ ASSERT(digits_after_point > 0);
+ result_builder->AddSubstring(decimal_digits, decimal_point);
+ result_builder->AddCharacter('.');
+ ASSERT(length - decimal_point <= digits_after_point);
+ result_builder->AddSubstring(&decimal_digits[decimal_point],
+ length - decimal_point);
+ int remaining_digits = digits_after_point - (length - decimal_point);
+ result_builder->AddPadding('0', remaining_digits);
+ }
+ if (digits_after_point == 0) {
+ if ((flags_ & EMIT_TRAILING_DECIMAL_POINT) != 0) {
+ result_builder->AddCharacter('.');
+ }
+ if ((flags_ & EMIT_TRAILING_ZERO_AFTER_POINT) != 0) {
+ result_builder->AddCharacter('0');
+ }
+ }
+}
+
+
+bool DoubleToStringConverter::ToShortestIeeeNumber(
+ double value,
+ StringBuilder* result_builder,
+ DoubleToStringConverter::DtoaMode mode) const {
+ ASSERT(mode == SHORTEST || mode == SHORTEST_SINGLE);
+ if (Double(value).IsSpecial()) {
+ return HandleSpecialValues(value, result_builder);
+ }
+
+ int decimal_point;
+ bool sign;
+ const int kDecimalRepCapacity = kBase10MaximalLength + 1;
+ char decimal_rep[kDecimalRepCapacity];
+ int decimal_rep_length;
+
+ DoubleToAscii(value, mode, 0, decimal_rep, kDecimalRepCapacity,
+ &sign, &decimal_rep_length, &decimal_point);
+
+ bool unique_zero = (flags_ & UNIQUE_ZERO) != 0;
+ if (sign && (value != 0.0 || !unique_zero)) {
+ result_builder->AddCharacter('-');
+ }
+
+ int exponent = decimal_point - 1;
+ if ((decimal_in_shortest_low_ <= exponent) &&
+ (exponent < decimal_in_shortest_high_)) {
+ CreateDecimalRepresentation(decimal_rep, decimal_rep_length,
+ decimal_point,
+ Max(0, decimal_rep_length - decimal_point),
+ result_builder);
+ } else {
+ CreateExponentialRepresentation(decimal_rep, decimal_rep_length, exponent,
+ result_builder);
+ }
+ return true;
+}
+
+
+bool DoubleToStringConverter::ToFixed(double value,
+ int requested_digits,
+ StringBuilder* result_builder) const {
+ ASSERT(kMaxFixedDigitsBeforePoint == 60);
+ const double kFirstNonFixed = 1e60;
+
+ if (Double(value).IsSpecial()) {
+ return HandleSpecialValues(value, result_builder);
+ }
+
+ if (requested_digits > kMaxFixedDigitsAfterPoint) return false;
+ if (value >= kFirstNonFixed || value <= -kFirstNonFixed) return false;
+
+ // Find a sufficiently precise decimal representation of n.
+ int decimal_point;
+ bool sign;
+ // Add space for the '\0' byte.
+ const int kDecimalRepCapacity =
+ kMaxFixedDigitsBeforePoint + kMaxFixedDigitsAfterPoint + 1;
+ char decimal_rep[kDecimalRepCapacity];
+ int decimal_rep_length;
+ DoubleToAscii(value, FIXED, requested_digits,
+ decimal_rep, kDecimalRepCapacity,
+ &sign, &decimal_rep_length, &decimal_point);
+
+ bool unique_zero = ((flags_ & UNIQUE_ZERO) != 0);
+ if (sign && (value != 0.0 || !unique_zero)) {
+ result_builder->AddCharacter('-');
+ }
+
+ CreateDecimalRepresentation(decimal_rep, decimal_rep_length, decimal_point,
+ requested_digits, result_builder);
+ return true;
+}
+
+
+bool DoubleToStringConverter::ToExponential(
+ double value,
+ int requested_digits,
+ StringBuilder* result_builder) const {
+ if (Double(value).IsSpecial()) {
+ return HandleSpecialValues(value, result_builder);
+ }
+
+ if (requested_digits < -1) return false;
+ if (requested_digits > kMaxExponentialDigits) return false;
+
+ int decimal_point;
+ bool sign;
+ // Add space for digit before the decimal point and the '\0' character.
+ const int kDecimalRepCapacity = kMaxExponentialDigits + 2;
+ ASSERT(kDecimalRepCapacity > kBase10MaximalLength);
+ char decimal_rep[kDecimalRepCapacity];
+ int decimal_rep_length;
+
+ if (requested_digits == -1) {
+ DoubleToAscii(value, SHORTEST, 0,
+ decimal_rep, kDecimalRepCapacity,
+ &sign, &decimal_rep_length, &decimal_point);
+ } else {
+ DoubleToAscii(value, PRECISION, requested_digits + 1,
+ decimal_rep, kDecimalRepCapacity,
+ &sign, &decimal_rep_length, &decimal_point);
+ ASSERT(decimal_rep_length <= requested_digits + 1);
+
+ for (int i = decimal_rep_length; i < requested_digits + 1; ++i) {
+ decimal_rep[i] = '0';
+ }
+ decimal_rep_length = requested_digits + 1;
+ }
+
+ bool unique_zero = ((flags_ & UNIQUE_ZERO) != 0);
+ if (sign && (value != 0.0 || !unique_zero)) {
+ result_builder->AddCharacter('-');
+ }
+
+ int exponent = decimal_point - 1;
+ CreateExponentialRepresentation(decimal_rep,
+ decimal_rep_length,
+ exponent,
+ result_builder);
+ return true;
+}
+
+
+bool DoubleToStringConverter::ToPrecision(double value,
+ int precision,
+ StringBuilder* result_builder) const {
+ if (Double(value).IsSpecial()) {
+ return HandleSpecialValues(value, result_builder);
+ }
+
+ if (precision < kMinPrecisionDigits || precision > kMaxPrecisionDigits) {
+ return false;
+ }
+
+ // Find a sufficiently precise decimal representation of n.
+ int decimal_point;
+ bool sign;
+ // Add one for the terminating null character.
+ const int kDecimalRepCapacity = kMaxPrecisionDigits + 1;
+ char decimal_rep[kDecimalRepCapacity];
+ int decimal_rep_length;
+
+ DoubleToAscii(value, PRECISION, precision,
+ decimal_rep, kDecimalRepCapacity,
+ &sign, &decimal_rep_length, &decimal_point);
+ ASSERT(decimal_rep_length <= precision);
+
+ bool unique_zero = ((flags_ & UNIQUE_ZERO) != 0);
+ if (sign && (value != 0.0 || !unique_zero)) {
+ result_builder->AddCharacter('-');
+ }
+
+ // The exponent if we print the number as x.xxeyyy. That is with the
+ // decimal point after the first digit.
+ int exponent = decimal_point - 1;
+
+ int extra_zero = ((flags_ & EMIT_TRAILING_ZERO_AFTER_POINT) != 0) ? 1 : 0;
+ if ((-decimal_point + 1 > max_leading_padding_zeroes_in_precision_mode_) ||
+ (decimal_point - precision + extra_zero >
+ max_trailing_padding_zeroes_in_precision_mode_)) {
+ // Fill buffer to contain 'precision' digits.
+ // Usually the buffer is already at the correct length, but 'DoubleToAscii'
+ // is allowed to return less characters.
+ for (int i = decimal_rep_length; i < precision; ++i) {
+ decimal_rep[i] = '0';
+ }
+
+ CreateExponentialRepresentation(decimal_rep,
+ precision,
+ exponent,
+ result_builder);
+ } else {
+ CreateDecimalRepresentation(decimal_rep, decimal_rep_length, decimal_point,
+ Max(0, precision - decimal_point),
+ result_builder);
+ }
+ return true;
+}
+
+
+static BignumDtoaMode DtoaToBignumDtoaMode(
+ DoubleToStringConverter::DtoaMode dtoa_mode) {
+ switch (dtoa_mode) {
+ case DoubleToStringConverter::SHORTEST: return BIGNUM_DTOA_SHORTEST;
+ case DoubleToStringConverter::SHORTEST_SINGLE:
+ return BIGNUM_DTOA_SHORTEST_SINGLE;
+ case DoubleToStringConverter::FIXED: return BIGNUM_DTOA_FIXED;
+ case DoubleToStringConverter::PRECISION: return BIGNUM_DTOA_PRECISION;
+ default:
+ UNREACHABLE();
+ return BIGNUM_DTOA_SHORTEST; // To silence compiler.
+ }
+}
+
+
+void DoubleToStringConverter::DoubleToAscii(double v,
+ DtoaMode mode,
+ int requested_digits,
+ char* buffer,
+ int buffer_length,
+ bool* sign,
+ int* length,
+ int* point) {
+ Vector<char> vector(buffer, buffer_length);
+ ASSERT(!Double(v).IsSpecial());
+ ASSERT(mode == SHORTEST || mode == SHORTEST_SINGLE || requested_digits >= 0);
+
+ if (Double(v).Sign() < 0) {
+ *sign = true;
+ v = -v;
+ } else {
+ *sign = false;
+ }
+
+ if (mode == PRECISION && requested_digits == 0) {
+ vector[0] = '\0';
+ *length = 0;
+ return;
+ }
+
+ if (v == 0) {
+ vector[0] = '0';
+ vector[1] = '\0';
+ *length = 1;
+ *point = 1;
+ return;
+ }
+
+ bool fast_worked;
+ switch (mode) {
+ case SHORTEST:
+ fast_worked = FastDtoa(v, FAST_DTOA_SHORTEST, 0, vector, length, point);
+ break;
+ case SHORTEST_SINGLE:
+ fast_worked = FastDtoa(v, FAST_DTOA_SHORTEST_SINGLE, 0,
+ vector, length, point);
+ break;
+ case FIXED:
+ fast_worked = FastFixedDtoa(v, requested_digits, vector, length, point);
+ break;
+ case PRECISION:
+ fast_worked = FastDtoa(v, FAST_DTOA_PRECISION, requested_digits,
+ vector, length, point);
+ break;
+ default:
+ UNREACHABLE();
+ fast_worked = false;
+ }
+ if (fast_worked) return;
+
+ // If the fast dtoa didn't succeed use the slower bignum version.
+ BignumDtoaMode bignum_mode = DtoaToBignumDtoaMode(mode);
+ BignumDtoa(v, bignum_mode, requested_digits, vector, length, point);
+ vector[*length] = '\0';
+}
+
+
+// Consumes the given substring from the iterator.
+// Returns false, if the substring does not match.
+static bool ConsumeSubString(const char** current,
+ const char* end,
+ const char* substring) {
+ ASSERT(**current == *substring);
+ for (substring++; *substring != '\0'; substring++) {
+ ++*current;
+ if (*current == end || **current != *substring) return false;
+ }
+ ++*current;
+ return true;
+}
+
+
+// Maximum number of significant digits in decimal representation.
+// The longest possible double in decimal representation is
+// (2^53 - 1) * 2 ^ -1074 that is (2 ^ 53 - 1) * 5 ^ 1074 / 10 ^ 1074
+// (768 digits). If we parse a number whose first digits are equal to a
+// mean of 2 adjacent doubles (that could have up to 769 digits) the result
+// must be rounded to the bigger one unless the tail consists of zeros, so
+// we don't need to preserve all the digits.
+const int kMaxSignificantDigits = 772;
+
+
+// Returns true if a nonspace found and false if the end has reached.
+static inline bool AdvanceToNonspace(const char** current, const char* end) {
+ while (*current != end) {
+ if (**current != ' ') return true;
+ ++*current;
+ }
+ return false;
+}
+
+
+static bool isDigit(int x, int radix) {
+ return (x >= '0' && x <= '9' && x < '0' + radix)
+ || (radix > 10 && x >= 'a' && x < 'a' + radix - 10)
+ || (radix > 10 && x >= 'A' && x < 'A' + radix - 10);
+}
+
+
+static double SignedZero(bool sign) {
+ return sign ? -0.0 : 0.0;
+}
+
+
+// Parsing integers with radix 2, 4, 8, 16, 32. Assumes current != end.
+template <int radix_log_2>
+static double RadixStringToIeee(const char* current,
+ const char* end,
+ bool sign,
+ bool allow_trailing_junk,
+ double junk_string_value,
+ bool read_as_double,
+ const char** trailing_pointer) {
+ ASSERT(current != end);
+
+ const int kDoubleSize = Double::kSignificandSize;
+ const int kSingleSize = Single::kSignificandSize;
+ const int kSignificandSize = read_as_double? kDoubleSize: kSingleSize;
+
+ // Skip leading 0s.
+ while (*current == '0') {
+ ++current;
+ if (current == end) {
+ *trailing_pointer = end;
+ return SignedZero(sign);
+ }
+ }
+
+ int64_t number = 0;
+ int exponent = 0;
+ const int radix = (1 << radix_log_2);
+
+ do {
+ int digit;
+ if (*current >= '0' && *current <= '9' && *current < '0' + radix) {
+ digit = static_cast<char>(*current) - '0';
+ } else if (radix > 10 && *current >= 'a' && *current < 'a' + radix - 10) {
+ digit = static_cast<char>(*current) - 'a' + 10;
+ } else if (radix > 10 && *current >= 'A' && *current < 'A' + radix - 10) {
+ digit = static_cast<char>(*current) - 'A' + 10;
+ } else {
+ if (allow_trailing_junk || !AdvanceToNonspace(¤t, end)) {
+ break;
+ } else {
+ return junk_string_value;
+ }
+ }
+
+ number = number * radix + digit;
+ int overflow = static_cast<int>(number >> kSignificandSize);
+ if (overflow != 0) {
+ // Overflow occurred. Need to determine which direction to round the
+ // result.
+ int overflow_bits_count = 1;
+ while (overflow > 1) {
+ overflow_bits_count++;
+ overflow >>= 1;
+ }
+
+ int dropped_bits_mask = ((1 << overflow_bits_count) - 1);
+ int dropped_bits = static_cast<int>(number) & dropped_bits_mask;
+ number >>= overflow_bits_count;
+ exponent = overflow_bits_count;
+
+ bool zero_tail = true;
+ while (true) {
+ ++current;
+ if (current == end || !isDigit(*current, radix)) break;
+ zero_tail = zero_tail && *current == '0';
+ exponent += radix_log_2;
+ }
+
+ if (!allow_trailing_junk && AdvanceToNonspace(¤t, end)) {
+ return junk_string_value;
+ }
+
+ int middle_value = (1 << (overflow_bits_count - 1));
+ if (dropped_bits > middle_value) {
+ number++; // Rounding up.
+ } else if (dropped_bits == middle_value) {
+ // Rounding to even to consistency with decimals: half-way case rounds
+ // up if significant part is odd and down otherwise.
+ if ((number & 1) != 0 || !zero_tail) {
+ number++; // Rounding up.
+ }
+ }
+
+ // Rounding up may cause overflow.
+ if ((number & ((int64_t)1 << kSignificandSize)) != 0) {
+ exponent++;
+ number >>= 1;
+ }
+ break;
+ }
+ ++current;
+ } while (current != end);
+
+ ASSERT(number < ((int64_t)1 << kSignificandSize));
+ ASSERT(static_cast<int64_t>(static_cast<double>(number)) == number);
+
+ *trailing_pointer = current;
+
+ if (exponent == 0) {
+ if (sign) {
+ if (number == 0) return -0.0;
+ number = -number;
+ }
+ return static_cast<double>(number);
+ }
+
+ ASSERT(number != 0);
+ return Double(DiyFp(number, exponent)).value();
+}
+
+
+double StringToDoubleConverter::StringToIeee(
+ const char* input,
+ int length,
+ int* processed_characters_count,
+ bool read_as_double) {
+ const char* current = input;
+ const char* end = input + length;
+
+ *processed_characters_count = 0;
+
+ const bool allow_trailing_junk = (flags_ & ALLOW_TRAILING_JUNK) != 0;
+ const bool allow_leading_spaces = (flags_ & ALLOW_LEADING_SPACES) != 0;
+ const bool allow_trailing_spaces = (flags_ & ALLOW_TRAILING_SPACES) != 0;
+ const bool allow_spaces_after_sign = (flags_ & ALLOW_SPACES_AFTER_SIGN) != 0;
+
+ // To make sure that iterator dereferencing is valid the following
+ // convention is used:
+ // 1. Each '++current' statement is followed by check for equality to 'end'.
+ // 2. If AdvanceToNonspace returned false then current == end.
+ // 3. If 'current' becomes equal to 'end' the function returns or goes to
+ // 'parsing_done'.
+ // 4. 'current' is not dereferenced after the 'parsing_done' label.
+ // 5. Code before 'parsing_done' may rely on 'current != end'.
+ if (current == end) return empty_string_value_;
+
+ if (allow_leading_spaces || allow_trailing_spaces) {
+ if (!AdvanceToNonspace(¤t, end)) {
+ *processed_characters_count = current - input;
+ return empty_string_value_;
+ }
+ if (!allow_leading_spaces && (input != current)) {
+ // No leading spaces allowed, but AdvanceToNonspace moved forward.
+ return junk_string_value_;
+ }
+ }
+
+ // The longest form of simplified number is: "-<significant digits>.1eXXX\0".
+ const int kBufferSize = kMaxSignificantDigits + 10;
+ char buffer[kBufferSize]; // NOLINT: size is known at compile time.
+ int buffer_pos = 0;
+
+ // Exponent will be adjusted if insignificant digits of the integer part
+ // or insignificant leading zeros of the fractional part are dropped.
+ int exponent = 0;
+ int significant_digits = 0;
+ int insignificant_digits = 0;
+ bool nonzero_digit_dropped = false;
+
+ bool sign = false;
+
+ if (*current == '+' || *current == '-') {
+ sign = (*current == '-');
+ ++current;
+ const char* next_non_space = current;
+ // Skip following spaces (if allowed).
+ if (!AdvanceToNonspace(&next_non_space, end)) return junk_string_value_;
+ if (!allow_spaces_after_sign && (current != next_non_space)) {
+ return junk_string_value_;
+ }
+ current = next_non_space;
+ }
+
+ if (infinity_symbol_ != NULL) {
+ if (*current == infinity_symbol_[0]) {
+ if (!ConsumeSubString(¤t, end, infinity_symbol_)) {
+ return junk_string_value_;
+ }
+
+ if (!(allow_trailing_spaces || allow_trailing_junk) && (current != end)) {
+ return junk_string_value_;
+ }
+ if (!allow_trailing_junk && AdvanceToNonspace(¤t, end)) {
+ return junk_string_value_;
+ }
+
+ ASSERT(buffer_pos == 0);
+ *processed_characters_count = current - input;
+ return sign ? -Double::Infinity() : Double::Infinity();
+ }
+ }
+
+ if (nan_symbol_ != NULL) {
+ if (*current == nan_symbol_[0]) {
+ if (!ConsumeSubString(¤t, end, nan_symbol_)) {
+ return junk_string_value_;
+ }
+
+ if (!(allow_trailing_spaces || allow_trailing_junk) && (current != end)) {
+ return junk_string_value_;
+ }
+ if (!allow_trailing_junk && AdvanceToNonspace(¤t, end)) {
+ return junk_string_value_;
+ }
+
+ ASSERT(buffer_pos == 0);
+ *processed_characters_count = current - input;
+ return sign ? -Double::NaN() : Double::NaN();
+ }
+ }
+
+ bool leading_zero = false;
+ if (*current == '0') {
+ ++current;
+ if (current == end) {
+ *processed_characters_count = current - input;
+ return SignedZero(sign);
+ }
+
+ leading_zero = true;
+
+ // It could be hexadecimal value.
+ if ((flags_ & ALLOW_HEX) && (*current == 'x' || *current == 'X')) {
+ ++current;
+ if (current == end || !isDigit(*current, 16)) {
+ return junk_string_value_; // "0x".
+ }
+
+ const char* tail_pointer = NULL;
+ double result = RadixStringToIeee<4>(current,
+ end,
+ sign,
+ allow_trailing_junk,
+ junk_string_value_,
+ read_as_double,
+ &tail_pointer);
+ if (tail_pointer != NULL) {
+ if (allow_trailing_spaces) AdvanceToNonspace(&tail_pointer, end);
+ *processed_characters_count = tail_pointer - input;
+ }
+ return result;
+ }
+
+ // Ignore leading zeros in the integer part.
+ while (*current == '0') {
+ ++current;
+ if (current == end) {
+ *processed_characters_count = current - input;
+ return SignedZero(sign);
+ }
+ }
+ }
+
+ bool octal = leading_zero && (flags_ & ALLOW_OCTALS) != 0;
+
+ // Copy significant digits of the integer part (if any) to the buffer.
+ while (*current >= '0' && *current <= '9') {
+ if (significant_digits < kMaxSignificantDigits) {
+ ASSERT(buffer_pos < kBufferSize);
+ buffer[buffer_pos++] = static_cast<char>(*current);
+ significant_digits++;
+ // Will later check if it's an octal in the buffer.
+ } else {
+ insignificant_digits++; // Move the digit into the exponential part.
+ nonzero_digit_dropped = nonzero_digit_dropped || *current != '0';
+ }
+ octal = octal && *current < '8';
+ ++current;
+ if (current == end) goto parsing_done;
+ }
+
+ if (significant_digits == 0) {
+ octal = false;
+ }
+
+ if (*current == '.') {
+ if (octal && !allow_trailing_junk) return junk_string_value_;
+ if (octal) goto parsing_done;
+
+ ++current;
+ if (current == end) {
+ if (significant_digits == 0 && !leading_zero) {
+ return junk_string_value_;
+ } else {
+ goto parsing_done;
+ }
+ }
+
+ if (significant_digits == 0) {
+ // octal = false;
+ // Integer part consists of 0 or is absent. Significant digits start after
+ // leading zeros (if any).
+ while (*current == '0') {
+ ++current;
+ if (current == end) {
+ *processed_characters_count = current - input;
+ return SignedZero(sign);
+ }
+ exponent--; // Move this 0 into the exponent.
+ }
+ }
+
+ // There is a fractional part.
+ // We don't emit a '.', but adjust the exponent instead.
+ while (*current >= '0' && *current <= '9') {
+ if (significant_digits < kMaxSignificantDigits) {
+ ASSERT(buffer_pos < kBufferSize);
+ buffer[buffer_pos++] = static_cast<char>(*current);
+ significant_digits++;
+ exponent--;
+ } else {
+ // Ignore insignificant digits in the fractional part.
+ nonzero_digit_dropped = nonzero_digit_dropped || *current != '0';
+ }
+ ++current;
+ if (current == end) goto parsing_done;
+ }
+ }
+
+ if (!leading_zero && exponent == 0 && significant_digits == 0) {
+ // If leading_zeros is true then the string contains zeros.
+ // If exponent < 0 then string was [+-]\.0*...
+ // If significant_digits != 0 the string is not equal to 0.
+ // Otherwise there are no digits in the string.
+ return junk_string_value_;
+ }
+
+ // Parse exponential part.
+ if (*current == 'e' || *current == 'E') {
+ if (octal && !allow_trailing_junk) return junk_string_value_;
+ if (octal) goto parsing_done;
+ ++current;
+ if (current == end) {
+ if (allow_trailing_junk) {
+ goto parsing_done;
+ } else {
+ return junk_string_value_;
+ }
+ }
+ char sign = '+';
+ if (*current == '+' || *current == '-') {
+ sign = static_cast<char>(*current);
+ ++current;
+ if (current == end) {
+ if (allow_trailing_junk) {
+ goto parsing_done;
+ } else {
+ return junk_string_value_;
+ }
+ }
+ }
+
+ if (current == end || *current < '0' || *current > '9') {
+ if (allow_trailing_junk) {
+ goto parsing_done;
+ } else {
+ return junk_string_value_;
+ }
+ }
+
+ const int max_exponent = INT_MAX / 2;
+ ASSERT(-max_exponent / 2 <= exponent && exponent <= max_exponent / 2);
+ int num = 0;
+ do {
+ // Check overflow.
+ int digit = *current - '0';
+ if (num >= max_exponent / 10
+ && !(num == max_exponent / 10 && digit <= max_exponent % 10)) {
+ num = max_exponent;
+ } else {
+ num = num * 10 + digit;
+ }
+ ++current;
+ } while (current != end && *current >= '0' && *current <= '9');
+
+ exponent += (sign == '-' ? -num : num);
+ }
+
+ if (!(allow_trailing_spaces || allow_trailing_junk) && (current != end)) {
+ return junk_string_value_;
+ }
+ if (!allow_trailing_junk && AdvanceToNonspace(¤t, end)) {
+ return junk_string_value_;
+ }
+ if (allow_trailing_spaces) {
+ AdvanceToNonspace(¤t, end);
+ }
+
+ parsing_done:
+ exponent += insignificant_digits;
+
+ if (octal) {
+ double result;
+ const char* tail_pointer = NULL;
+ result = RadixStringToIeee<3>(buffer,
+ buffer + buffer_pos,
+ sign,
+ allow_trailing_junk,
+ junk_string_value_,
+ read_as_double,
+ &tail_pointer);
+ ASSERT(tail_pointer != NULL);
+ *processed_characters_count = current - input;
+ return result;
+ }
+
+ if (nonzero_digit_dropped) {
+ buffer[buffer_pos++] = '1';
+ exponent--;
+ }
+
+ ASSERT(buffer_pos < kBufferSize);
+ buffer[buffer_pos] = '\0';
+
+ double converted;
+ if (read_as_double) {
+ converted = Strtod(Vector<const char>(buffer, buffer_pos), exponent);
+ } else {
+ converted = Strtof(Vector<const char>(buffer, buffer_pos), exponent);
+ }
+ *processed_characters_count = current - input;
+ return sign? -converted: converted;
+}
+
+} // namespace double_conversion
http://git-wip-us.apache.org/repos/asf/couchdb/blob/2e6092e4/src/jiffy/c_src/double-conversion/double-conversion.h
----------------------------------------------------------------------
diff --git a/src/jiffy/c_src/double-conversion/double-conversion.h b/src/jiffy/c_src/double-conversion/double-conversion.h
new file mode 100644
index 0000000..f98edae
--- /dev/null
+++ b/src/jiffy/c_src/double-conversion/double-conversion.h
@@ -0,0 +1,536 @@
+// Copyright 2012 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.
+
+#ifndef DOUBLE_CONVERSION_DOUBLE_CONVERSION_H_
+#define DOUBLE_CONVERSION_DOUBLE_CONVERSION_H_
+
+#include "utils.h"
+
+namespace double_conversion {
+
+class DoubleToStringConverter {
+ public:
+ // When calling ToFixed with a double > 10^kMaxFixedDigitsBeforePoint
+ // or a requested_digits parameter > kMaxFixedDigitsAfterPoint then the
+ // function returns false.
+ static const int kMaxFixedDigitsBeforePoint = 60;
+ static const int kMaxFixedDigitsAfterPoint = 60;
+
+ // When calling ToExponential with a requested_digits
+ // parameter > kMaxExponentialDigits then the function returns false.
+ static const int kMaxExponentialDigits = 120;
+
+ // When calling ToPrecision with a requested_digits
+ // parameter < kMinPrecisionDigits or requested_digits > kMaxPrecisionDigits
+ // then the function returns false.
+ static const int kMinPrecisionDigits = 1;
+ static const int kMaxPrecisionDigits = 120;
+
+ enum Flags {
+ NO_FLAGS = 0,
+ EMIT_POSITIVE_EXPONENT_SIGN = 1,
+ EMIT_TRAILING_DECIMAL_POINT = 2,
+ EMIT_TRAILING_ZERO_AFTER_POINT = 4,
+ UNIQUE_ZERO = 8
+ };
+
+ // Flags should be a bit-or combination of the possible Flags-enum.
+ // - NO_FLAGS: no special flags.
+ // - EMIT_POSITIVE_EXPONENT_SIGN: when the number is converted into exponent
+ // form, emits a '+' for positive exponents. Example: 1.2e+2.
+ // - EMIT_TRAILING_DECIMAL_POINT: when the input number is an integer and is
+ // converted into decimal format then a trailing decimal point is appended.
+ // Example: 2345.0 is converted to "2345.".
+ // - EMIT_TRAILING_ZERO_AFTER_POINT: in addition to a trailing decimal point
+ // emits a trailing '0'-character. This flag requires the
+ // EXMIT_TRAILING_DECIMAL_POINT flag.
+ // Example: 2345.0 is converted to "2345.0".
+ // - UNIQUE_ZERO: "-0.0" is converted to "0.0".
+ //
+ // Infinity symbol and nan_symbol provide the string representation for these
+ // special values. If the string is NULL and the special value is encountered
+ // then the conversion functions return false.
+ //
+ // The exponent_character is used in exponential representations. It is
+ // usually 'e' or 'E'.
+ //
+ // When converting to the shortest representation the converter will
+ // represent input numbers in decimal format if they are in the interval
+ // [10^decimal_in_shortest_low; 10^decimal_in_shortest_high[
+ // (lower boundary included, greater boundary excluded).
+ // Example: with decimal_in_shortest_low = -6 and
+ // decimal_in_shortest_high = 21:
+ // ToShortest(0.000001) -> "0.000001"
+ // ToShortest(0.0000001) -> "1e-7"
+ // ToShortest(111111111111111111111.0) -> "111111111111111110000"
+ // ToShortest(100000000000000000000.0) -> "100000000000000000000"
+ // ToShortest(1111111111111111111111.0) -> "1.1111111111111111e+21"
+ //
+ // When converting to precision mode the converter may add
+ // max_leading_padding_zeroes before returning the number in exponential
+ // format.
+ // Example with max_leading_padding_zeroes_in_precision_mode = 6.
+ // ToPrecision(0.0000012345, 2) -> "0.0000012"
+ // ToPrecision(0.00000012345, 2) -> "1.2e-7"
+ // Similarily the converter may add up to
+ // max_trailing_padding_zeroes_in_precision_mode in precision mode to avoid
+ // returning an exponential representation. A zero added by the
+ // EMIT_TRAILING_ZERO_AFTER_POINT flag is counted for this limit.
+ // Examples for max_trailing_padding_zeroes_in_precision_mode = 1:
+ // ToPrecision(230.0, 2) -> "230"
+ // ToPrecision(230.0, 2) -> "230." with EMIT_TRAILING_DECIMAL_POINT.
+ // ToPrecision(230.0, 2) -> "2.3e2" with EMIT_TRAILING_ZERO_AFTER_POINT.
+ DoubleToStringConverter(int flags,
+ const char* infinity_symbol,
+ const char* nan_symbol,
+ char exponent_character,
+ int decimal_in_shortest_low,
+ int decimal_in_shortest_high,
+ int max_leading_padding_zeroes_in_precision_mode,
+ int max_trailing_padding_zeroes_in_precision_mode)
+ : flags_(flags),
+ infinity_symbol_(infinity_symbol),
+ nan_symbol_(nan_symbol),
+ exponent_character_(exponent_character),
+ decimal_in_shortest_low_(decimal_in_shortest_low),
+ decimal_in_shortest_high_(decimal_in_shortest_high),
+ max_leading_padding_zeroes_in_precision_mode_(
+ max_leading_padding_zeroes_in_precision_mode),
+ max_trailing_padding_zeroes_in_precision_mode_(
+ max_trailing_padding_zeroes_in_precision_mode) {
+ // When 'trailing zero after the point' is set, then 'trailing point'
+ // must be set too.
+ ASSERT(((flags & EMIT_TRAILING_DECIMAL_POINT) != 0) ||
+ !((flags & EMIT_TRAILING_ZERO_AFTER_POINT) != 0));
+ }
+
+ // Returns a converter following the EcmaScript specification.
+ static const DoubleToStringConverter& EcmaScriptConverter();
+
+ // Computes the shortest string of digits that correctly represent the input
+ // number. Depending on decimal_in_shortest_low and decimal_in_shortest_high
+ // (see constructor) it then either returns a decimal representation, or an
+ // exponential representation.
+ // Example with decimal_in_shortest_low = -6,
+ // decimal_in_shortest_high = 21,
+ // EMIT_POSITIVE_EXPONENT_SIGN activated, and
+ // EMIT_TRAILING_DECIMAL_POINT deactived:
+ // ToShortest(0.000001) -> "0.000001"
+ // ToShortest(0.0000001) -> "1e-7"
+ // ToShortest(111111111111111111111.0) -> "111111111111111110000"
+ // ToShortest(100000000000000000000.0) -> "100000000000000000000"
+ // ToShortest(1111111111111111111111.0) -> "1.1111111111111111e+21"
+ //
+ // Note: the conversion may round the output if the returned string
+ // is accurate enough to uniquely identify the input-number.
+ // For example the most precise representation of the double 9e59 equals
+ // "899999999999999918767229449717619953810131273674690656206848", but
+ // the converter will return the shorter (but still correct) "9e59".
+ //
+ // Returns true if the conversion succeeds. The conversion always succeeds
+ // except when the input value is special and no infinity_symbol or
+ // nan_symbol has been given to the constructor.
+ bool ToShortest(double value, StringBuilder* result_builder) const {
+ return ToShortestIeeeNumber(value, result_builder, SHORTEST);
+ }
+
+ // Same as ToShortest, but for single-precision floats.
+ bool ToShortestSingle(float value, StringBuilder* result_builder) const {
+ return ToShortestIeeeNumber(value, result_builder, SHORTEST_SINGLE);
+ }
+
+
+ // Computes a decimal representation with a fixed number of digits after the
+ // decimal point. The last emitted digit is rounded.
+ //
+ // Examples:
+ // ToFixed(3.12, 1) -> "3.1"
+ // ToFixed(3.1415, 3) -> "3.142"
+ // ToFixed(1234.56789, 4) -> "1234.5679"
+ // ToFixed(1.23, 5) -> "1.23000"
+ // ToFixed(0.1, 4) -> "0.1000"
+ // ToFixed(1e30, 2) -> "1000000000000000019884624838656.00"
+ // ToFixed(0.1, 30) -> "0.100000000000000005551115123126"
+ // ToFixed(0.1, 17) -> "0.10000000000000001"
+ //
+ // If requested_digits equals 0, then the tail of the result depends on
+ // the EMIT_TRAILING_DECIMAL_POINT and EMIT_TRAILING_ZERO_AFTER_POINT.
+ // Examples, for requested_digits == 0,
+ // let EMIT_TRAILING_DECIMAL_POINT and EMIT_TRAILING_ZERO_AFTER_POINT be
+ // - false and false: then 123.45 -> 123
+ // 0.678 -> 1
+ // - true and false: then 123.45 -> 123.
+ // 0.678 -> 1.
+ // - true and true: then 123.45 -> 123.0
+ // 0.678 -> 1.0
+ //
+ // Returns true if the conversion succeeds. The conversion always succeeds
+ // except for the following cases:
+ // - the input value is special and no infinity_symbol or nan_symbol has
+ // been provided to the constructor,
+ // - 'value' > 10^kMaxFixedDigitsBeforePoint, or
+ // - 'requested_digits' > kMaxFixedDigitsAfterPoint.
+ // The last two conditions imply that the result will never contain more than
+ // 1 + kMaxFixedDigitsBeforePoint + 1 + kMaxFixedDigitsAfterPoint characters
+ // (one additional character for the sign, and one for the decimal point).
+ bool ToFixed(double value,
+ int requested_digits,
+ StringBuilder* result_builder) const;
+
+ // Computes a representation in exponential format with requested_digits
+ // after the decimal point. The last emitted digit is rounded.
+ // If requested_digits equals -1, then the shortest exponential representation
+ // is computed.
+ //
+ // Examples with EMIT_POSITIVE_EXPONENT_SIGN deactivated, and
+ // exponent_character set to 'e'.
+ // ToExponential(3.12, 1) -> "3.1e0"
+ // ToExponential(5.0, 3) -> "5.000e0"
+ // ToExponential(0.001, 2) -> "1.00e-3"
+ // ToExponential(3.1415, -1) -> "3.1415e0"
+ // ToExponential(3.1415, 4) -> "3.1415e0"
+ // ToExponential(3.1415, 3) -> "3.142e0"
+ // ToExponential(123456789000000, 3) -> "1.235e14"
+ // ToExponential(1000000000000000019884624838656.0, -1) -> "1e30"
+ // ToExponential(1000000000000000019884624838656.0, 32) ->
+ // "1.00000000000000001988462483865600e30"
+ // ToExponential(1234, 0) -> "1e3"
+ //
+ // Returns true if the conversion succeeds. The conversion always succeeds
+ // except for the following cases:
+ // - the input value is special and no infinity_symbol or nan_symbol has
+ // been provided to the constructor,
+ // - 'requested_digits' > kMaxExponentialDigits.
+ // The last condition implies that the result will never contain more than
+ // kMaxExponentialDigits + 8 characters (the sign, the digit before the
+ // decimal point, the decimal point, the exponent character, the
+ // exponent's sign, and at most 3 exponent digits).
+ bool ToExponential(double value,
+ int requested_digits,
+ StringBuilder* result_builder) const;
+
+ // Computes 'precision' leading digits of the given 'value' and returns them
+ // either in exponential or decimal format, depending on
+ // max_{leading|trailing}_padding_zeroes_in_precision_mode (given to the
+ // constructor).
+ // The last computed digit is rounded.
+ //
+ // Example with max_leading_padding_zeroes_in_precision_mode = 6.
+ // ToPrecision(0.0000012345, 2) -> "0.0000012"
+ // ToPrecision(0.00000012345, 2) -> "1.2e-7"
+ // Similarily the converter may add up to
+ // max_trailing_padding_zeroes_in_precision_mode in precision mode to avoid
+ // returning an exponential representation. A zero added by the
+ // EMIT_TRAILING_ZERO_AFTER_POINT flag is counted for this limit.
+ // Examples for max_trailing_padding_zeroes_in_precision_mode = 1:
+ // ToPrecision(230.0, 2) -> "230"
+ // ToPrecision(230.0, 2) -> "230." with EMIT_TRAILING_DECIMAL_POINT.
+ // ToPrecision(230.0, 2) -> "2.3e2" with EMIT_TRAILING_ZERO_AFTER_POINT.
+ // Examples for max_trailing_padding_zeroes_in_precision_mode = 3, and no
+ // EMIT_TRAILING_ZERO_AFTER_POINT:
+ // ToPrecision(123450.0, 6) -> "123450"
+ // ToPrecision(123450.0, 5) -> "123450"
+ // ToPrecision(123450.0, 4) -> "123500"
+ // ToPrecision(123450.0, 3) -> "123000"
+ // ToPrecision(123450.0, 2) -> "1.2e5"
+ //
+ // Returns true if the conversion succeeds. The conversion always succeeds
+ // except for the following cases:
+ // - the input value is special and no infinity_symbol or nan_symbol has
+ // been provided to the constructor,
+ // - precision < kMinPericisionDigits
+ // - precision > kMaxPrecisionDigits
+ // The last condition implies that the result will never contain more than
+ // kMaxPrecisionDigits + 7 characters (the sign, the decimal point, the
+ // exponent character, the exponent's sign, and at most 3 exponent digits).
+ bool ToPrecision(double value,
+ int precision,
+ StringBuilder* result_builder) const;
+
+ enum DtoaMode {
+ // Produce the shortest correct representation.
+ // For example the output of 0.299999999999999988897 is (the less accurate
+ // but correct) 0.3.
+ SHORTEST,
+ // Same as SHORTEST, but for single-precision floats.
+ SHORTEST_SINGLE,
+ // Produce a fixed number of digits after the decimal point.
+ // For instance fixed(0.1, 4) becomes 0.1000
+ // If the input number is big, the output will be big.
+ FIXED,
+ // Fixed number of digits (independent of the decimal point).
+ PRECISION
+ };
+
+ // The maximal number of digits that are needed to emit a double in base 10.
+ // A higher precision can be achieved by using more digits, but the shortest
+ // accurate representation of any double will never use more digits than
+ // kBase10MaximalLength.
+ // Note that DoubleToAscii null-terminates its input. So the given buffer
+ // should be at least kBase10MaximalLength + 1 characters long.
+ static const int kBase10MaximalLength = 17;
+
+ // Converts the given double 'v' to ascii. 'v' must not be NaN, +Infinity, or
+ // -Infinity. In SHORTEST_SINGLE-mode this restriction also applies to 'v'
+ // after it has been casted to a single-precision float. That is, in this
+ // mode static_cast<float>(v) must not be NaN, +Infinity or -Infinity.
+ //
+ // The result should be interpreted as buffer * 10^(point-length).
+ //
+ // The output depends on the given mode:
+ // - SHORTEST: produce the least amount of digits for which the internal
+ // identity requirement is still satisfied. If the digits are printed
+ // (together with the correct exponent) then reading this number will give
+ // 'v' again. The buffer will choose the representation that is closest to
+ // 'v'. If there are two at the same distance, than the one farther away
+ // from 0 is chosen (halfway cases - ending with 5 - are rounded up).
+ // In this mode the 'requested_digits' parameter is ignored.
+ // - SHORTEST_SINGLE: same as SHORTEST but with single-precision.
+ // - FIXED: produces digits necessary to print a given number with
+ // 'requested_digits' digits after the decimal point. The produced digits
+ // might be too short in which case the caller has to fill the remainder
+ // with '0's.
+ // Example: toFixed(0.001, 5) is allowed to return buffer="1", point=-2.
+ // Halfway cases are rounded towards +/-Infinity (away from 0). The call
+ // toFixed(0.15, 2) thus returns buffer="2", point=0.
+ // The returned buffer may contain digits that would be truncated from the
+ // shortest representation of the input.
+ // - PRECISION: produces 'requested_digits' where the first digit is not '0'.
+ // Even though the length of produced digits usually equals
+ // 'requested_digits', the function is allowed to return fewer digits, in
+ // which case the caller has to fill the missing digits with '0's.
+ // Halfway cases are again rounded away from 0.
+ // DoubleToAscii expects the given buffer to be big enough to hold all
+ // digits and a terminating null-character. In SHORTEST-mode it expects a
+ // buffer of at least kBase10MaximalLength + 1. In all other modes the
+ // requested_digits parameter and the padding-zeroes limit the size of the
+ // output. Don't forget the decimal point, the exponent character and the
+ // terminating null-character when computing the maximal output size.
+ // The given length is only used in debug mode to ensure the buffer is big
+ // enough.
+ static void DoubleToAscii(double v,
+ DtoaMode mode,
+ int requested_digits,
+ char* buffer,
+ int buffer_length,
+ bool* sign,
+ int* length,
+ int* point);
+
+ private:
+ // Implementation for ToShortest and ToShortestSingle.
+ bool ToShortestIeeeNumber(double value,
+ StringBuilder* result_builder,
+ DtoaMode mode) const;
+
+ // If the value is a special value (NaN or Infinity) constructs the
+ // corresponding string using the configured infinity/nan-symbol.
+ // If either of them is NULL or the value is not special then the
+ // function returns false.
+ bool HandleSpecialValues(double value, StringBuilder* result_builder) const;
+ // Constructs an exponential representation (i.e. 1.234e56).
+ // The given exponent assumes a decimal point after the first decimal digit.
+ void CreateExponentialRepresentation(const char* decimal_digits,
+ int length,
+ int exponent,
+ StringBuilder* result_builder) const;
+ // Creates a decimal representation (i.e 1234.5678).
+ void CreateDecimalRepresentation(const char* decimal_digits,
+ int length,
+ int decimal_point,
+ int digits_after_point,
+ StringBuilder* result_builder) const;
+
+ const int flags_;
+ const char* const infinity_symbol_;
+ const char* const nan_symbol_;
+ const char exponent_character_;
+ const int decimal_in_shortest_low_;
+ const int decimal_in_shortest_high_;
+ const int max_leading_padding_zeroes_in_precision_mode_;
+ const int max_trailing_padding_zeroes_in_precision_mode_;
+
+ DISALLOW_IMPLICIT_CONSTRUCTORS(DoubleToStringConverter);
+};
+
+
+class StringToDoubleConverter {
+ public:
+ // Enumeration for allowing octals and ignoring junk when converting
+ // strings to numbers.
+ enum Flags {
+ NO_FLAGS = 0,
+ ALLOW_HEX = 1,
+ ALLOW_OCTALS = 2,
+ ALLOW_TRAILING_JUNK = 4,
+ ALLOW_LEADING_SPACES = 8,
+ ALLOW_TRAILING_SPACES = 16,
+ ALLOW_SPACES_AFTER_SIGN = 32
+ };
+
+ // Flags should be a bit-or combination of the possible Flags-enum.
+ // - NO_FLAGS: no special flags.
+ // - ALLOW_HEX: recognizes the prefix "0x". Hex numbers may only be integers.
+ // Ex: StringToDouble("0x1234") -> 4660.0
+ // In StringToDouble("0x1234.56") the characters ".56" are trailing
+ // junk. The result of the call is hence dependent on
+ // the ALLOW_TRAILING_JUNK flag and/or the junk value.
+ // With this flag "0x" is a junk-string. Even with ALLOW_TRAILING_JUNK,
+ // the string will not be parsed as "0" followed by junk.
+ //
+ // - ALLOW_OCTALS: recognizes the prefix "0" for octals:
+ // If a sequence of octal digits starts with '0', then the number is
+ // read as octal integer. Octal numbers may only be integers.
+ // Ex: StringToDouble("01234") -> 668.0
+ // StringToDouble("012349") -> 12349.0 // Not a sequence of octal
+ // // digits.
+ // In StringToDouble("01234.56") the characters ".56" are trailing
+ // junk. The result of the call is hence dependent on
+ // the ALLOW_TRAILING_JUNK flag and/or the junk value.
+ // In StringToDouble("01234e56") the characters "e56" are trailing
+ // junk, too.
+ // - ALLOW_TRAILING_JUNK: ignore trailing characters that are not part of
+ // a double literal.
+ // - ALLOW_LEADING_SPACES: skip over leading spaces.
+ // - ALLOW_TRAILING_SPACES: ignore trailing spaces.
+ // - ALLOW_SPACES_AFTER_SIGN: ignore spaces after the sign.
+ // Ex: StringToDouble("- 123.2") -> -123.2.
+ // StringToDouble("+ 123.2") -> 123.2
+ //
+ // empty_string_value is returned when an empty string is given as input.
+ // If ALLOW_LEADING_SPACES or ALLOW_TRAILING_SPACES are set, then a string
+ // containing only spaces is converted to the 'empty_string_value', too.
+ //
+ // junk_string_value is returned when
+ // a) ALLOW_TRAILING_JUNK is not set, and a junk character (a character not
+ // part of a double-literal) is found.
+ // b) ALLOW_TRAILING_JUNK is set, but the string does not start with a
+ // double literal.
+ //
+ // infinity_symbol and nan_symbol are strings that are used to detect
+ // inputs that represent infinity and NaN. They can be null, in which case
+ // they are ignored.
+ // The conversion routine first reads any possible signs. Then it compares the
+ // following character of the input-string with the first character of
+ // the infinity, and nan-symbol. If either matches, the function assumes, that
+ // a match has been found, and expects the following input characters to match
+ // the remaining characters of the special-value symbol.
+ // This means that the following restrictions apply to special-value symbols:
+ // - they must not start with signs ('+', or '-'),
+ // - they must not have the same first character.
+ // - they must not start with digits.
+ //
+ // Examples:
+ // flags = ALLOW_HEX | ALLOW_TRAILING_JUNK,
+ // empty_string_value = 0.0,
+ // junk_string_value = NaN,
+ // infinity_symbol = "infinity",
+ // nan_symbol = "nan":
+ // StringToDouble("0x1234") -> 4660.0.
+ // StringToDouble("0x1234K") -> 4660.0.
+ // StringToDouble("") -> 0.0 // empty_string_value.
+ // StringToDouble(" ") -> NaN // junk_string_value.
+ // StringToDouble(" 1") -> NaN // junk_string_value.
+ // StringToDouble("0x") -> NaN // junk_string_value.
+ // StringToDouble("-123.45") -> -123.45.
+ // StringToDouble("--123.45") -> NaN // junk_string_value.
+ // StringToDouble("123e45") -> 123e45.
+ // StringToDouble("123E45") -> 123e45.
+ // StringToDouble("123e+45") -> 123e45.
+ // StringToDouble("123E-45") -> 123e-45.
+ // StringToDouble("123e") -> 123.0 // trailing junk ignored.
+ // StringToDouble("123e-") -> 123.0 // trailing junk ignored.
+ // StringToDouble("+NaN") -> NaN // NaN string literal.
+ // StringToDouble("-infinity") -> -inf. // infinity literal.
+ // StringToDouble("Infinity") -> NaN // junk_string_value.
+ //
+ // flags = ALLOW_OCTAL | ALLOW_LEADING_SPACES,
+ // empty_string_value = 0.0,
+ // junk_string_value = NaN,
+ // infinity_symbol = NULL,
+ // nan_symbol = NULL:
+ // StringToDouble("0x1234") -> NaN // junk_string_value.
+ // StringToDouble("01234") -> 668.0.
+ // StringToDouble("") -> 0.0 // empty_string_value.
+ // StringToDouble(" ") -> 0.0 // empty_string_value.
+ // StringToDouble(" 1") -> 1.0
+ // StringToDouble("0x") -> NaN // junk_string_value.
+ // StringToDouble("0123e45") -> NaN // junk_string_value.
+ // StringToDouble("01239E45") -> 1239e45.
+ // StringToDouble("-infinity") -> NaN // junk_string_value.
+ // StringToDouble("NaN") -> NaN // junk_string_value.
+ StringToDoubleConverter(int flags,
+ double empty_string_value,
+ double junk_string_value,
+ const char* infinity_symbol,
+ const char* nan_symbol)
+ : flags_(flags),
+ empty_string_value_(empty_string_value),
+ junk_string_value_(junk_string_value),
+ infinity_symbol_(infinity_symbol),
+ nan_symbol_(nan_symbol) {
+ }
+
+ // Performs the conversion.
+ // The output parameter 'processed_characters_count' is set to the number
+ // of characters that have been processed to read the number.
+ // Spaces than are processed with ALLOW_{LEADING|TRAILING}_SPACES are included
+ // in the 'processed_characters_count'. Trailing junk is never included.
+ double StringToDouble(const char* buffer,
+ int length,
+ int* processed_characters_count) {
+ return StringToIeee(buffer, length, processed_characters_count, true);
+ }
+
+ // Same as StringToDouble but reads a float.
+ // Note that this is not equivalent to static_cast<float>(StringToDouble(...))
+ // due to potential double-rounding.
+ float StringToFloat(const char* buffer,
+ int length,
+ int* processed_characters_count) {
+ return static_cast<float>(StringToIeee(buffer, length,
+ processed_characters_count, false));
+ }
+
+ private:
+ const int flags_;
+ const double empty_string_value_;
+ const double junk_string_value_;
+ const char* const infinity_symbol_;
+ const char* const nan_symbol_;
+
+ double StringToIeee(const char* buffer,
+ int length,
+ int* processed_characters_count,
+ bool read_as_double);
+
+ DISALLOW_IMPLICIT_CONSTRUCTORS(StringToDoubleConverter);
+};
+
+} // namespace double_conversion
+
+#endif // DOUBLE_CONVERSION_DOUBLE_CONVERSION_H_