package java.lang; import ej.annotation.Nullable; /** * The {@code Float} class wraps a value of primitive type {@code float} in an object. An object of * type {@code Float} contains a single field whose type is {@code float}. * *

* In addition, this class provides several methods for converting a {@code float} to a * {@code String} and a {@code String} to a {@code float}, as well as other constants and methods * useful when dealing with a {@code float}. * */ public final class Float extends Number implements Comparable { /** * Maximum exponent a finite {@code float} variable may have. It is equal to the value returned by * {@code Math.getExponent(Float.MAX_VALUE)}. */ public static final int MAX_EXPONENT = 127; /** * A constant holding the largest positive finite value of type {@code float}, * (2-2-23)·2127. It is equal to the hexadecimal floating-point literal * {@code 0x1.fffffeP+127f} and also equal to {@code Float.intBitsToFloat(0x7f7fffff)}. */ public static final float MAX_VALUE = 0x1.fffffeP+127f; /** * Minimum exponent a normalized {@code float} variable may have. It is equal to the value returned * by {@code Math.getExponent(Float.MIN_NORMAL)}. */ public static final int MIN_EXPONENT = -126; /** * A constant holding the smallest positive normal value of type {@code float}, 2-126. It * is equal to the hexadecimal floating-point literal {@code 0x1.0p-126f} and also equal to * {@code Float.intBitsToFloat(0x00800000)}. */ public static final float MIN_NORMAL = 0x1.0p-126f; /** * A constant holding the smallest positive nonzero value of type {@code float}, 2-149. * It is equal to the hexadecimal floating-point literal {@code 0x0.000002P-126f} and also equal to * {@code Float.intBitsToFloat(0x1)}. */ public static final float MIN_VALUE = 0x0.000002P-126f; /** * A constant holding a Not-a-Number (NaN) value of type {@code float}. It is equivalent to the * value returned by {@code Float.intBitsToFloat(0x7fc00000)}. */ public static final float NaN = 0.0f / 0.0f; /** * A constant holding the negative infinity of type {@code float}. It is equal to the value returned * by {@code Float.intBitsToFloat(0xff800000)}. */ public static final float NEGATIVE_INFINITY = -1.0f / 0.0f; /** * A constant holding the positive infinity of type {@code float}. It is equal to the value returned * by {@code Float.intBitsToFloat(0x7f800000)}. */ public static final float POSITIVE_INFINITY = 1.0f / 0.0f; /** * The number of bits used to represent a {@code float} value. */ public static final int SIZE = 32; /** * Constructs a newly allocated {@code Float} object that represents the argument converted to type * {@code float}. * * @param value * the value to be represented by the {@code Float}. */ public Float(double value) { throw new RuntimeException(); } /** * Constructs a newly allocated {@code Float} object that represents the primitive {@code float} * argument. * * @param value * the value to be represented by the {@code Float}. */ public Float(float value) { throw new RuntimeException(); } /** * Constructs a newly allocated {@code Float} object that represents the floating-point value of * type {@code float} represented by the string. The string is converted to a {@code float} value as * if by the {@code valueOf} method. * * @param s * a string to be converted to a {@code Float}. * @throws NumberFormatException * if the string does not contain a parsable number. * @see java.lang.Float#valueOf(java.lang.String) */ public Float(String s) throws NumberFormatException { throw new RuntimeException(); } /** * Compares the two specified {@code float} values. The sign of the integer value returned is the * same as that of the integer that would be returned by the call: * * 

	 * new Float(f1).compareTo(new Float(f2))
	 *
* * @param f1 * the first {@code float} to compare. * @param f2 * the second {@code float} to compare. * @return the value {@code 0} if {@code f1} is numerically equal to {@code f2}; a value less than * {@code 0} if {@code f1} is numerically less than {@code f2}; and a value greater than * {@code 0} if {@code f1} is numerically greater than {@code f2}. */ public static int compare(float f1, float f2) { throw new RuntimeException(); } /** * Returns a representation of the specified floating-point value according to the IEEE 754 * floating-point "single format" bit layout. * *

* Bit 31 (the bit that is selected by the mask {@code 0x80000000}) represents the sign of the * floating-point number. Bits 30-23 (the bits that are selected by the mask {@code 0x7f800000}) * represent the exponent. Bits 22-0 (the bits that are selected by the mask {@code 0x007fffff}) * represent the significand (sometimes called the mantissa) of the floating-point number. * *

* If the argument is positive infinity, the result is {@code 0x7f800000}. * *

* If the argument is negative infinity, the result is {@code 0xff800000}. * *

* If the argument is NaN, the result is {@code 0x7fc00000}. * *

* In all cases, the result is an integer that, when given to the {@link #intBitsToFloat(int)} * method, will produce a floating-point value the same as the argument to {@code floatToIntBits} * (except all NaN values are collapsed to a single "canonical" NaN value). * * @param value * a floating-point number. * @return the bits that represent the floating-point number. */ public static int floatToIntBits(float value) { throw new RuntimeException(); } /** * Returns a representation of the specified floating-point value according to the IEEE 754 * floating-point "single format" bit layout, preserving Not-a-Number (NaN) values. * *

* Bit 31 (the bit that is selected by the mask {@code 0x80000000}) represents the sign of the * floating-point number. Bits 30-23 (the bits that are selected by the mask {@code 0x7f800000}) * represent the exponent. Bits 22-0 (the bits that are selected by the mask {@code 0x007fffff}) * represent the significand (sometimes called the mantissa) of the floating-point number. * *

* If the argument is positive infinity, the result is {@code 0x7f800000}. * *

* If the argument is negative infinity, the result is {@code 0xff800000}. * *

* If the argument is NaN, the result is the integer representing the actual NaN value. Unlike the * {@code floatToIntBits} method, {@code floatToRawIntBits} does not collapse all the bit patterns * encoding a NaN to a single "canonical" NaN value. * *

* In all cases, the result is an integer that, when given to the {@link #intBitsToFloat(int)} * method, will produce a floating-point value the same as the argument to * {@code floatToRawIntBits}. * * @param value * a floating-point number. * @return the bits that represent the floating-point number. */ public static int floatToRawIntBits(float value) { throw new RuntimeException(); } /** * Returns the {@code float} value corresponding to a given bit representation. The argument is * considered to be a representation of a floating-point value according to the IEEE 754 * floating-point "single format" bit layout. * *

* If the argument is {@code 0x7f800000}, the result is positive infinity. * *

* If the argument is {@code 0xff800000}, the result is negative infinity. * *

* If the argument is any value in the range {@code 0x7f800001} through {@code 0x7fffffff} or in the * range {@code 0xff800001} through {@code 0xffffffff}, the result is a NaN. No IEEE 754 * floating-point operation provided by Java can distinguish between two NaN values of the same type * with different bit patterns. Distinct values of NaN are only distinguishable by use of the * {@code Float.floatToRawIntBits} method. * *

* In all other cases, let s, e, and m be three values that can be computed * from the argument: * *

* * 
	 * int s = ((bits >> 31) == 0) ? 1 : -1;
	 * int e = ((bits >> 23) & 0xff);
	 * int m = (e == 0) ? (bits & 0x7fffff) << 1 : (bits & 0x7fffff) | 0x800000;
	 *
* *
* * Then the floating-point result equals the value of the mathematical expression * s·m·2e-150. * *

* Note that this method may not be able to return a {@code float} NaN with exactly same bit pattern * as the {@code int} argument. IEEE 754 distinguishes between two kinds of NaNs, quiet NaNs and * signaling NaNs. The differences between the two kinds of NaN are generally not visible in * Java. Arithmetic operations on signaling NaNs turn them into quiet NaNs with a different, but * often similar, bit pattern. However, on some processors merely copying a signaling NaN also * performs that conversion. In particular, copying a signaling NaN to return it to the calling * method may perform this conversion. So {@code intBitsToFloat} may not be able to return a * {@code float} with a signaling NaN bit pattern. Consequently, for some {@code int} values, * {@code floatToRawIntBits(intBitsToFloat(start))} may not equal {@code start}. Moreover, * which particular bit patterns represent signaling NaNs is platform dependent; although all NaN * bit patterns, quiet or signaling, must be in the NaN range identified above. * * @param bits * an integer. * @return the {@code float} floating-point value with the same bit pattern. */ public static float intBitsToFloat(int bits) { throw new RuntimeException(); } /** * Returns {@code true} if the specified number is infinitely large in magnitude, {@code false} * otherwise. * * @param v * the value to be tested. * @return {@code true} if the argument is positive infinity or negative infinity; {@code false} * otherwise. */ public static boolean isInfinite(float v) { throw new RuntimeException(); } /** * Returns {@code true} if the specified number is a Not-a-Number (NaN) value, {@code false} * otherwise. * * @param v * the value to be tested. * @return {@code true} if the argument is NaN; {@code false} otherwise. */ public static boolean isNaN(float v) { throw new RuntimeException(); } /** * Returns a new {@code float} initialized to the value represented by the specified {@code String}, * as performed by the {@code valueOf} method of class {@code Float}. * * @param s * the string to be parsed. * @return the {@code float} value represented by the string argument. * @throws NullPointerException * if the string is null * @throws NumberFormatException * if the string does not contain a parsable {@code float}. * @see java.lang.Float#valueOf(String) */ public static float parseFloat(String s) throws NumberFormatException { throw new RuntimeException(); } /** * Returns a string representation of the {@code float} argument. All characters mentioned below are * ASCII characters. *

* How many digits must be printed for the fractional part of m or a? There must be at * least one digit to represent the fractional part, and beyond that as many, but only as many, more * digits as are needed to uniquely distinguish the argument value from adjacent values of type * {@code float}. That is, suppose that x is the exact mathematical value represented by the * decimal representation produced by this method for a finite nonzero argument f. Then * f must be the {@code float} value nearest to x; or, if two {@code float} values are * equally close to x, then f must be one of them and the least significant bit of the * significand of f must be {@code 0}. * * @param f * the float to be converted. * @return a string representation of the argument. */ public static String toString(float f) { throw new RuntimeException(); } /** * Returns a {@code Float} instance representing the specified {@code float} value. If a new * {@code Float} instance is not required, this method should generally be used in preference to the * constructor {@link #Float(float)}, as this method is likely to yield significantly better space * and time performance by caching frequently requested values. * * @param f * a float value. * @return a {@code Float} instance representing {@code f}. */ public static Float valueOf(float f) { throw new RuntimeException(); } /** * Returns a {@code Float} object holding the {@code float} value represented by the argument string * {@code s}. * *

* If {@code s} is {@code null}, then a {@code NullPointerException} is thrown. * *

* Leading and trailing whitespace characters in {@code s} are ignored. Whitespace is removed as if * by the {@link String#trim} method; that is, both ASCII space and control characters are removed. * The rest of {@code s} should constitute a FloatValue as described by the lexical syntax * rules: * *

*
*
FloatValue: *
Signopt {@code NaN} *
Signopt {@code Infinity} *
Signopt FloatingPointLiteral *
Signopt HexFloatingPointLiteral *
SignedInteger *
* *
*
HexFloatingPointLiteral: *
HexSignificand BinaryExponent FloatTypeSuffixopt *
* *
*
HexSignificand: *
HexNumeral *
HexNumeral {@code .} *
{@code 0x} HexDigitsopt {@code .} HexDigits *
{@code 0X} HexDigitsopt {@code .} HexDigits *
* *
*
BinaryExponent: *
BinaryExponentIndicator SignedInteger *
* *
*
BinaryExponentIndicator: *
{@code p} *
{@code P} *
* *
* * where Sign, FloatingPointLiteral, HexNumeral, HexDigits, * SignedInteger and FloatTypeSuffix are as defined in the lexical structure sections * of The Java™ Language Specification, except that underscores are not accepted * between digits. If {@code s} does not have the form of a FloatValue, then a * {@code NumberFormatException} is thrown. Otherwise, {@code s} is regarded as representing an * exact decimal value in the usual "computerized scientific notation" or as an exact hexadecimal * value; this exact numerical value is then conceptually converted to an "infinitely precise" * binary value that is then rounded to type {@code float} by the usual round-to-nearest rule of * IEEE 754 floating-point arithmetic, which includes preserving the sign of a zero value. * * Note that the round-to-nearest rule also implies overflow and underflow behaviour; if the exact * value of {@code s} is large enough in magnitude (greater than or equal to ( {@link #MAX_VALUE} + * {@link Math#ulp(float) ulp(MAX_VALUE)}/2), rounding to {@code float} will result in an infinity * and if the exact value of {@code s} is small enough in magnitude (less than or equal to * {@link #MIN_VALUE}/2), rounding to float will result in a zero. * * Finally, after rounding a {@code Float} object representing this {@code float} value is returned. * *

* Note that trailing format specifiers, specifiers that determine the type of a floating-point * literal ({@code 1.0f} is a {@code float} value; {@code 1.0d} is a {@code double} value), do * not influence the results of this method. In other words, the numerical value of the * input string is converted directly to the target floating-point type. In general, the two-step * sequence of conversions, string to {@code double} followed by {@code double} to {@code float}, is * not equivalent to converting a string directly to {@code float}. For example, if first * converted to an intermediate {@code double} and then to {@code float}, the string
* {@code "1.00000017881393421514957253748434595763683319091796875001d"}
* results in the {@code float} value {@code 1.0000002f}; if the string is converted directly to * {@code float}, 1.0000001f results. * * @param s * the string to be parsed. * @return a {@code Float} object holding the value represented by the {@code String} argument. * @throws NumberFormatException * if the string does not contain a parsable number. */ public static Float valueOf(String s) throws NumberFormatException { throw new RuntimeException(); } /** * Returns the value of this {@code Float} as a {@code byte} (by casting to a {@code byte}). * * @return the {@code float} value represented by this object converted to type {@code byte} */ @Override public byte byteValue() { throw new RuntimeException(); } /** * Compares two {@code Float} objects numerically. There are two ways in which comparisons performed * by this method differ from those performed by the Java language numerical comparison operators * ({@code <, <=, ==, >=, >}) when applied to primitive {@code float} values: * *

* * This ensures that the natural ordering of {@code Float} objects imposed by this method is * consistent with equals. * * @param anotherFloat * the {@code Float} to be compared. * @return the value {@code 0} if {@code anotherFloat} is numerically equal to this {@code Float}; a * value less than {@code 0} if this {@code Float} is numerically less than * {@code anotherFloat}; and a value greater than {@code 0} if this {@code Float} is * numerically greater than {@code anotherFloat}. * * @see Comparable#compareTo(Object) */ @Override public int compareTo(Float anotherFloat) { throw new RuntimeException(); } /** * Returns the {@code double} value of this {@code Float} object. * * @return the {@code float} value represented by this object is converted to type {@code double} * and the result of the conversion is returned. */ @Override public double doubleValue() { throw new RuntimeException(); } /** * * Compares this object against the specified object. The result is {@code true} if and only if the * argument is not {@code null} and is a {@code Float} object that represents a {@code float} with * the same value as the {@code float} represented by this object. For this purpose, two * {@code float} values are considered to be the same if and only if the method * {@link #floatToIntBits(float)} returns the identical {@code int} value when applied to each. * *

* Note that in most cases, for two instances of class {@code Float}, {@code f1} and {@code f2}, the * value of {@code f1.equals(f2)} is {@code true} if and only if * *

* * 
	 * f1.floatValue() == f2.floatValue()
	 *
* *
* *

* also has the value {@code true}. However, there are two exceptions: *

* * This definition allows hash tables to operate properly. * * @param obj * the object to be compared * @return {@code true} if the objects are the same; {@code false} otherwise. * @see java.lang.Float#floatToIntBits(float) */ @Override public boolean equals(@Nullable Object obj) { throw new RuntimeException(); } /** * Returns the {@code float} value of this {@code Float} object. * * @return the {@code float} value represented by this object */ @Override public float floatValue() { throw new RuntimeException(); } /** * Returns a hash code for this {@code Float} object. The result is the integer bit representation, * exactly as produced by the method {@link #floatToIntBits(float)}, of the primitive {@code float} * value represented by this {@code Float} object. * * @return a hash code value for this object. */ @Override public int hashCode() { throw new RuntimeException(); } /** * Returns the value of this {@code Float} as an {@code int} (by casting to type {@code int}). * * @return the {@code float} value represented by this object converted to type {@code int} */ @Override public int intValue() { throw new RuntimeException(); } /** * Returns {@code true} if this {@code Float} value is infinitely large in magnitude, {@code false} * otherwise. * * @return {@code true} if the value represented by this object is positive infinity or negative * infinity; {@code false} otherwise. */ public boolean isInfinite() { throw new RuntimeException(); } /** * Returns {@code true} if this {@code Float} value is a Not-a-Number (NaN), {@code false} * otherwise. * * @return {@code true} if the value represented by this object is NaN; {@code false} otherwise. */ public boolean isNaN() { throw new RuntimeException(); } /** * Returns value of this {@code Float} as a {@code long} (by casting to type {@code long}). * * @return the {@code float} value represented by this object converted to type {@code long} */ @Override public long longValue() { throw new RuntimeException(); } /** * Returns the value of this {@code Float} as a {@code short} (by casting to a {@code short}). * * @return the {@code float} value represented by this object converted to type {@code short} */ @Override public short shortValue() { throw new RuntimeException(); } /** * Returns a string representation of this {@code Float} object. The primitive {@code float} value * represented by this object is converted to a {@code String} exactly as if by the method * {@code toString} of one argument. * * @return a {@code String} representation of this object. * @see java.lang.Float#toString(float) */ @Override public String toString() { throw new RuntimeException(); } }