// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file | |

// for details. All rights reserved. Use of this source code is governed by a | |

// BSD-style license that can be found in the LICENSE file. | |

part of dart.core; | |

// TODO: Convert this abstract class into a concrete class double | |

// that uses the patch class functionality to account for the | |

// different platform implementations. | |

/** | |

* A double-precision floating point number. | |

* | |

* Representation of Dart doubles containing double specific constants | |

* and operations and specializations of operations inherited from | |

* [num]. Dart doubles are 64-bit floating-point numbers as specified in the | |

* IEEE 754 standard. | |

* | |

* The [double] type is contagious. Operations on [double]s return | |

* [double] results. | |

* | |

* It is a compile-time error for a class to attempt to extend or implement | |

* double. | |

*/ | |

abstract class double extends num { | |

static const double NAN = 0.0 / 0.0; | |

static const double INFINITY = 1.0 / 0.0; | |

static const double NEGATIVE_INFINITY = -INFINITY; | |

static const double MIN_POSITIVE = 5e-324; | |

static const double MAX_FINITE = 1.7976931348623157e+308; | |

/** | |

* Truncating division operator. | |

* | |

* The result of the truncating division `a ~/ b` is equivalent to | |

* `(a / b).truncate()`. | |

*/ | |

int operator ~/(double other); | |

/** Negate operator. */ | |

double operator -(); | |

/** Returns the absolute value of this [double]. */ | |

double abs(); | |

/** | |

* Returns the sign of the double's numerical value. | |

* | |

* Returns -1.0 if the value is less than zero, | |

* +1.0 if the value is greater than zero, | |

* and the value itself if it is -0.0, 0.0 or NaN. | |

*/ | |

double get sign; | |

/** | |

* Returns the integer closest to `this`. | |

* | |

* Rounds away from zero when there is no closest integer: | |

* `(3.5).round() == 4` and `(-3.5).round() == -4`. | |

* | |

* If `this` is not finite (`NaN` or infinity), throws an [UnsupportedError]. | |

*/ | |

int round(); | |

/** | |

* Returns the greatest integer no greater than `this`. | |

* | |

* If `this` is not finite (`NaN` or infinity), throws an [UnsupportedError]. | |

*/ | |

int floor(); | |

/** | |

* Returns the least integer no smaller than `this`. | |

* | |

* If `this` is not finite (`NaN` or infinity), throws an [UnsupportedError]. | |

*/ | |

int ceil(); | |

/** | |

* Returns the integer obtained by discarding any fractional | |

* digits from `this`. | |

* | |

* If `this` is not finite (`NaN` or infinity), throws an [UnsupportedError]. | |

*/ | |

int truncate(); | |

/** | |

* Returns the integer double value closest to `this`. | |

* | |

* Rounds away from zero when there is no closest integer: | |

* `(3.5).roundToDouble() == 4` and `(-3.5).roundToDouble() == -4`. | |

* | |

* If this is already an integer valued double, including `-0.0`, or it is not | |

* a finite value, the value is returned unmodified. | |

* | |

* For the purpose of rounding, `-0.0` is considered to be below `0.0`, | |

* and `-0.0` is therefore considered closer to negative numbers than `0.0`. | |

* This means that for a value, `d` in the range `-0.5 < d < 0.0`, | |

* the result is `-0.0`. | |

*/ | |

double roundToDouble(); | |

/** | |

* Returns the greatest integer double value no greater than `this`. | |

* | |

* If this is already an integer valued double, including `-0.0`, or it is not | |

* a finite value, the value is returned unmodified. | |

* | |

* For the purpose of rounding, `-0.0` is considered to be below `0.0`. | |

* A number `d` in the range `0.0 < d < 1.0` will return `0.0`. | |

*/ | |

double floorToDouble(); | |

/** | |

* Returns the least integer double value no smaller than `this`. | |

* | |

* If this is already an integer valued double, including `-0.0`, or it is not | |

* a finite value, the value is returned unmodified. | |

* | |

* For the purpose of rounding, `-0.0` is considered to be below `0.0`. | |

* A number `d` in the range `-1.0 < d < 0.0` will return `-0.0`. | |

*/ | |

double ceilToDouble(); | |

/** | |

* Returns the integer double value obtained by discarding any fractional | |

* digits from `this`. | |

* | |

* If this is already an integer valued double, including `-0.0`, or it is not | |

* a finite value, the value is returned unmodified. | |

* | |

* For the purpose of rounding, `-0.0` is considered to be below `0.0`. | |

* A number `d` in the range `-1.0 < d < 0.0` will return `-0.0`, and | |

* in the range `0.0 < d < 1.0` it will return 0.0. | |

*/ | |

double truncateToDouble(); | |

/** | |

* Provide a representation of this [double] value. | |

* | |

* The representation is a number literal such that the closest double value | |

* to the representation's mathematical value is this [double]. | |

* | |

* Returns "NaN" for the Not-a-Number value. | |

* Returns "Infinity" and "-Infinity" for positive and negative Infinity. | |

* Returns "-0.0" for negative zero. | |

* | |

* For all doubles, `d`, converting to a string and parsing the string back | |

* gives the same value again: `d == double.parse(d.toString())` (except when | |

* `d` is NaN). | |

*/ | |

String toString(); | |

/** | |

* Parse [source] as an double literal and return its value. | |

* | |

* Accepts an optional sign (`+` or `-`) followed by either the characters | |

* "Infinity", the characters "NaN" or a floating-point representation. | |

* A floating-point representation is composed of a mantissa and an optional | |

* exponent part. The mantissa is either a decimal point (`.`) followed by a | |

* sequence of (decimal) digits, or a sequence of digits | |

* optionally followed by a decimal point and optionally more digits. The | |

* (optional) exponent part consists of the character "e" or "E", an optional | |

* sign, and one or more digits. | |

* | |

* Leading and trailing whitespace is ignored. | |

* | |

* If the [source] is not a valid double literal, the [onError] | |

* is called with the [source] as argument, and its return value is | |

* used instead. If no `onError` is provided, a [FormatException] | |

* is thrown instead. | |

* | |

* The [onError] function is only invoked if [source] is a [String] with an | |

* invalid format. It is not invoked if the [source] is invalid for some | |

* other reason, for example by being `null`. | |

* | |

* Examples of accepted strings: | |

* | |

* "3.14" | |

* " 3.14 \xA0" | |

* "0." | |

* ".0" | |

* "-1.e3" | |

* "1234E+7" | |

* "+.12e-9" | |

* "-NaN" | |

*/ | |

external static double parse(String source, [double onError(String source)]); | |

} |