| // 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; |
| |
| /** |
| * An integer or floating-point number. |
| * |
| * It is a compile-time error for any type other than [int] or [double] |
| * to attempt to extend or implement num. |
| */ |
| abstract class num implements Comparable<num> { |
| /** |
| * Test whether this value is numerically equal to `other`. |
| * |
| * If both operands are doubles, they are equal if they have the same |
| * representation, except that: |
| * |
| * * zero and minus zero (0.0 and -0.0) are considered equal. They |
| * both have the numerical value zero. |
| * * NaN is not equal to anything, including NaN. If either operand is |
| * NaN, the result is always false. |
| * |
| * If one operand is a double and the other is an int, they are equal if |
| * the double has an integer value (finite with no fractional part) and |
| * `identical(doubleValue.toInt(), intValue)` is true. |
| * |
| * If both operands are integers, they are equal if they have the same value. |
| * |
| * Returns false if `other` is not a [num]. |
| * |
| * Notice that the behavior for NaN is non-reflexive. This means that |
| * equality of double values is not a proper equality relation, as is |
| * otherwise required of `operator==`. Using NaN in, e.g., a [HashSet] |
| * will fail to work. The behavior is the standard IEEE-754 equality of |
| * doubles. |
| * |
| * If you can avoid NaN values, the remaining doubles do have a proper |
| * equality relation, and can be used safely. |
| * |
| * Use [compareTo] for a comparison that distinguishes zero and minus zero, |
| * and that considers NaN values as equal. |
| */ |
| bool operator ==(Object other); |
| |
| /** |
| * Returns a hash code for a numerical value. |
| * |
| * The hash code is compatible with equality. It returns the same value |
| * for an [int] and a [double] with the same numerical value, and therefore |
| * the same value for the doubles zero and minus zero. |
| * |
| * No guarantees are made about the hash code of NaN values. |
| */ |
| int get hashCode; |
| |
| /** |
| * Compares this to `other`. |
| * |
| * Returns a negative number if `this` is less than `other`, zero if they are |
| * equal, and a positive number if `this` is greater than `other`. |
| * |
| * The ordering represented by this method is a total ordering of [num] |
| * values. All distinct doubles are non-equal, as are all distinct integers, |
| * but integers are equal to doubles if they have the same numerical |
| * value. |
| * |
| * For doubles, the `compareTo` operation is different from the partial |
| * ordering given by [operator==], [operator<] and [operator>]. For example, |
| * IEEE doubles impose that `0.0 == -0.0` and all comparison operations on |
| * NaN return false. |
| * |
| * This function imposes a complete ordering for doubles. When using |
| * `compareTo` the following properties hold: |
| * |
| * - All NaN values are considered equal, and greater than any numeric value. |
| * - -0.0 is less than 0.0 (and the integer 0), but greater than any non-zero |
| * negative value. |
| * - Negative infinity is less than all other values and positive infinity is |
| * greater than all non-NaN values. |
| * - All other values are compared using their numeric value. |
| * |
| * Examples: |
| * ``` |
| * print(1.compareTo(2)); // => -1 |
| * print(2.compareTo(1)); // => 1 |
| * print(1.compareTo(1)); // => 0 |
| * |
| * // The following comparisons yield different results than the |
| * // corresponding comparison operators. |
| * print((-0.0).compareTo(0.0)); // => -1 |
| * print(double.nan.compareTo(double.nan)); // => 0 |
| * print(double.infinity.compareTo(double.nan)); // => -1 |
| * |
| * // -0.0, and NaN comparison operators have rules imposed by the IEEE |
| * // standard. |
| * print(-0.0 == 0.0); // => true |
| * print(double.nan == double.nan); // => false |
| * print(double.infinity < double.nan); // => false |
| * print(double.nan < double.infinity); // => false |
| * print(double.nan == double.infinity); // => false |
| */ |
| int compareTo(num other); |
| |
| /** Addition operator. */ |
| num operator +(num other); |
| |
| /** Subtraction operator. */ |
| num operator -(num other); |
| |
| /** Multiplication operator. */ |
| num operator *(num other); |
| |
| /** |
| * Euclidean modulo operator. |
| * |
| * Returns the remainder of the Euclidean division. The Euclidean division of |
| * two integers `a` and `b` yields two integers `q` and `r` such that |
| * `a == b * q + r` and `0 <= r < b.abs()`. |
| * |
| * The Euclidean division is only defined for integers, but can be easily |
| * extended to work with doubles. In that case `r` may have a non-integer |
| * value, but it still verifies `0 <= r < |b|`. |
| * |
| * The sign of the returned value `r` is always positive. |
| * |
| * See [remainder] for the remainder of the truncating division. |
| */ |
| num operator %(num other); |
| |
| /** Division operator. */ |
| double operator /(num other); |
| |
| /** |
| * Truncating division operator. |
| * |
| * If either operand is a [double] then the result of the truncating division |
| * `a ~/ b` is equivalent to `(a / b).truncate().toInt()`. |
| * |
| * If both operands are [int]s then `a ~/ b` performs the truncating |
| * integer division. |
| */ |
| int operator ~/(num other); |
| |
| /** Negate operator. */ |
| num operator -(); |
| |
| /** |
| * Returns the remainder of the truncating division of `this` by [other]. |
| * |
| * The result `r` of this operation satisfies: |
| * `this == (this ~/ other) * other + r`. |
| * As a consequence the remainder `r` has the same sign as the divider `this`. |
| */ |
| num remainder(num other); |
| |
| /** Relational less than operator. */ |
| bool operator <(num other); |
| |
| /** Relational less than or equal operator. */ |
| bool operator <=(num other); |
| |
| /** Relational greater than operator. */ |
| bool operator >(num other); |
| |
| /** Relational greater than or equal operator. */ |
| bool operator >=(num other); |
| |
| /** True if the number is the double Not-a-Number value; otherwise, false. */ |
| bool get isNaN; |
| |
| /** |
| * True if the number is negative; otherwise, false. |
| * |
| * Negative numbers are those less than zero, and the double `-0.0`. |
| */ |
| bool get isNegative; |
| |
| /** |
| * True if the number is positive infinity or negative infinity; otherwise, |
| * false. |
| */ |
| bool get isInfinite; |
| |
| /** |
| * True if the number is finite; otherwise, false. |
| * |
| * The only non-finite numbers are NaN, positive infinity, and |
| * negative infinity. |
| */ |
| bool get isFinite; |
| |
| /** Returns the absolute value of this [num]. */ |
| num abs(); |
| |
| /** |
| * Returns minus one, zero or plus one depending on the sign and |
| * numerical value of the number. |
| * |
| * Returns minus one if the number is less than zero, |
| * plus one if the number is greater than zero, |
| * and zero if the number is equal to zero. |
| * |
| * Returns NaN if the number is the double NaN value. |
| * |
| * Returns a number of the same type as this number. |
| * For doubles, `-0.0.sign == -0.0`. |
| |
| * The result satisfies: |
| * |
| * n == n.sign * n.abs() |
| * |
| * for all numbers `n` (except NaN, because NaN isn't `==` to itself). |
| */ |
| num 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 double integer 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 a |
| * non-finite double 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`. |
| * |
| * The result is always a double. |
| * If this is a numerically large integer, the result may be an infinite |
| * double. |
| */ |
| double roundToDouble(); |
| |
| /** |
| * Returns the greatest double integer value no greater than `this`. |
| * |
| * If this is already an integer valued double, including `-0.0`, or it is a |
| * non-finite double 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`. |
| * |
| * The result is always a double. |
| * If this is a numerically large integer, the result may be an infinite |
| * double. |
| */ |
| double floorToDouble(); |
| |
| /** |
| * Returns the least double integer value no smaller than `this`. |
| * |
| * If this is already an integer valued double, including `-0.0`, or it is a |
| * non-finite double 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`. |
| * |
| * The result is always a double. |
| * If this is a numerically large integer, the result may be an infinite |
| * double. |
| */ |
| double ceilToDouble(); |
| |
| /** |
| * Returns the double integer value obtained by discarding any fractional |
| * digits from the double value of `this`. |
| * |
| * If this is already an integer valued double, including `-0.0`, or it is a |
| * non-finite double 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. |
| * |
| * The result is always a double. |
| * If this is a numerically large integer, the result may be an infinite |
| * double. |
| */ |
| double truncateToDouble(); |
| |
| /** |
| * Returns this [num] clamped to be in the range [lowerLimit]-[upperLimit]. |
| * |
| * The comparison is done using [compareTo] and therefore takes `-0.0` into |
| * account. This also implies that [double.nan] is treated as the maximal |
| * double value. |
| * |
| * The arguments [lowerLimit] and [upperLimit] must form a valid range where |
| * `lowerLimit.compareTo(upperLimit) <= 0`. |
| */ |
| num clamp(num lowerLimit, num upperLimit); |
| |
| /** Truncates this [num] to an integer and returns the result as an [int]. */ |
| int toInt(); |
| |
| /** |
| * Return this [num] as a [double]. |
| * |
| * If the number is not representable as a [double], an |
| * approximation is returned. For numerically large integers, the |
| * approximation may be infinite. |
| */ |
| double toDouble(); |
| |
| /** |
| * Returns a decimal-point string-representation of `this`. |
| * |
| * Converts `this` to a [double] before computing the string representation. |
| * |
| * If the absolute value of `this` is greater or equal to `10^21` then this |
| * methods returns an exponential representation computed by |
| * `this.toStringAsExponential()`. Otherwise the result |
| * is the closest string representation with exactly [fractionDigits] digits |
| * after the decimal point. If [fractionDigits] equals 0 then the decimal |
| * point is omitted. |
| * |
| * The parameter [fractionDigits] must be an integer satisfying: |
| * `0 <= fractionDigits <= 20`. |
| * |
| * Examples: |
| * |
| * 1.toStringAsFixed(3); // 1.000 |
| * (4321.12345678).toStringAsFixed(3); // 4321.123 |
| * (4321.12345678).toStringAsFixed(5); // 4321.12346 |
| * 123456789012345678901.toStringAsFixed(3); // 123456789012345683968.000 |
| * 1000000000000000000000.toStringAsFixed(3); // 1e+21 |
| * 5.25.toStringAsFixed(0); // 5 |
| */ |
| String toStringAsFixed(int fractionDigits); |
| |
| /** |
| * Returns an exponential string-representation of `this`. |
| * |
| * Converts `this` to a [double] before computing the string representation. |
| * |
| * If [fractionDigits] is given then it must be an integer satisfying: |
| * `0 <= fractionDigits <= 20`. In this case the string contains exactly |
| * [fractionDigits] after the decimal point. Otherwise, without the parameter, |
| * the returned string uses the shortest number of digits that accurately |
| * represent [this]. |
| * |
| * If [fractionDigits] equals 0 then the decimal point is omitted. |
| * Examples: |
| * |
| * 1.toStringAsExponential(); // 1e+0 |
| * 1.toStringAsExponential(3); // 1.000e+0 |
| * 123456.toStringAsExponential(); // 1.23456e+5 |
| * 123456.toStringAsExponential(3); // 1.235e+5 |
| * 123.toStringAsExponential(0); // 1e+2 |
| */ |
| String toStringAsExponential([int fractionDigits]); |
| |
| /** |
| * Converts `this` to a double and returns a string representation with |
| * exactly [precision] significant digits. |
| * |
| * The parameter [precision] must be an integer satisfying: |
| * `1 <= precision <= 21`. |
| * |
| * Examples: |
| * |
| * 1.toStringAsPrecision(2); // 1.0 |
| * 1e15.toStringAsPrecision(3); // 1.00e+15 |
| * 1234567.toStringAsPrecision(3); // 1.23e+6 |
| * 1234567.toStringAsPrecision(9); // 1234567.00 |
| * 12345678901234567890.toStringAsPrecision(20); // 12345678901234567168 |
| * 12345678901234567890.toStringAsPrecision(14); // 1.2345678901235e+19 |
| * 0.00000012345.toStringAsPrecision(15); // 1.23450000000000e-7 |
| * 0.0000012345.toStringAsPrecision(15); // 0.00000123450000000000 |
| */ |
| String toStringAsPrecision(int precision); |
| |
| /** |
| * Returns the shortest string that correctly represent the input number. |
| * |
| * All [double]s in the range `10^-6` (inclusive) to `10^21` (exclusive) |
| * are converted to their decimal representation with at least one digit |
| * after the decimal point. For all other doubles, |
| * except for special values like `NaN` or `Infinity`, this method returns an |
| * exponential representation (see [toStringAsExponential]). |
| * |
| * Returns `"NaN"` for [double.nan], `"Infinity"` for [double.infinity], and |
| * `"-Infinity"` for [double.negativeInfinity]. |
| * |
| * An [int] is converted to a decimal representation with no decimal point. |
| * |
| * Examples: |
| * |
| * (0.000001).toString(); // "0.000001" |
| * (0.0000001).toString(); // "1e-7" |
| * (111111111111111111111.0).toString(); // "111111111111111110000.0" |
| * (100000000000000000000.0).toString(); // "100000000000000000000.0" |
| * (1000000000000000000000.0).toString(); // "1e+21" |
| * (1111111111111111111111.0).toString(); // "1.1111111111111111e+21" |
| * 1.toString(); // "1" |
| * 111111111111111111111.toString(); // "111111111111111110000" |
| * 100000000000000000000.toString(); // "100000000000000000000" |
| * 1000000000000000000000.toString(); // "1000000000000000000000" |
| * 1111111111111111111111.toString(); // "1111111111111111111111" |
| * 1.234e5.toString(); // 123400 |
| * 1234.5e6.toString(); // 1234500000 |
| * 12.345e67.toString(); // 1.2345e+68 |
| * |
| * 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 |
| * this method returns the shorter (but still uniquely identifying) `"9e59"`. |
| * |
| */ |
| String toString(); |
| |
| /** |
| * Parses a string containing a number literal into a number. |
| * |
| * The method first tries to read the [input] as integer (similar to |
| * [int.parse] without a radix). |
| * If that fails, it tries to parse the [input] as a double (similar to |
| * [double.parse]). |
| * If that fails, too, it invokes [onError] with [input], and the result |
| * of that invocation becomes the result of calling `parse`. |
| * |
| * If no [onError] is supplied, it defaults to a function that throws a |
| * [FormatException]. |
| * |
| * For any number `n`, this function satisfies |
| * `identical(n, num.parse(n.toString()))` (except when `n` is a NaN `double` |
| * with a payload). |
| * |
| * The [onError] parameter is deprecated and will be removed. |
| * Instead of `num.parse(string, (string) { ... })`, |
| * you should use `num.tryParse(string) ?? (...)`. |
| */ |
| static num parse(String input, [@deprecated num onError(String input)]) { |
| num result = tryParse(input); |
| if (result != null) return result; |
| if (onError == null) throw new FormatException(input); |
| return onError(input); |
| } |
| |
| /** |
| * Parses a string containing a number literal into a number. |
| * |
| * Like [parse] except that this function returns `null` for invalid inputs |
| * instead of throwing. |
| */ |
| static num tryParse(String input) { |
| String source = input.trim(); |
| // TODO(lrn): Optimize to detect format and result type in one check. |
| return int.tryParse(source) ?? double.tryParse(source); |
| } |
| |
| /** Helper functions for [parse]. */ |
| static int _returnIntNull(String _) => null; |
| static double _returnDoubleNull(String _) => null; |
| } |