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Diffstat (limited to 'libjava/classpath/java/lang/Float.java')
| -rw-r--r-- | libjava/classpath/java/lang/Float.java | 633 |
1 files changed, 0 insertions, 633 deletions
diff --git a/libjava/classpath/java/lang/Float.java b/libjava/classpath/java/lang/Float.java deleted file mode 100644 index a4a766e..0000000 --- a/libjava/classpath/java/lang/Float.java +++ /dev/null @@ -1,633 +0,0 @@ -/* Float.java -- object wrapper for float - Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 - Free Software Foundation, Inc. - -This file is part of GNU Classpath. - -GNU Classpath is free software; you can redistribute it and/or modify -it under the terms of the GNU General Public License as published by -the Free Software Foundation; either version 2, or (at your option) -any later version. - -GNU Classpath is distributed in the hope that it will be useful, but -WITHOUT ANY WARRANTY; without even the implied warranty of -MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU -General Public License for more details. - -You should have received a copy of the GNU General Public License -along with GNU Classpath; see the file COPYING. If not, write to the -Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA -02110-1301 USA. - -Linking this library statically or dynamically with other modules is -making a combined work based on this library. Thus, the terms and -conditions of the GNU General Public License cover the whole -combination. - -As a special exception, the copyright holders of this library give you -permission to link this library with independent modules to produce an -executable, regardless of the license terms of these independent -modules, and to copy and distribute the resulting executable under -terms of your choice, provided that you also meet, for each linked -independent module, the terms and conditions of the license of that -module. An independent module is a module which is not derived from -or based on this library. If you modify this library, you may extend -this exception to your version of the library, but you are not -obligated to do so. If you do not wish to do so, delete this -exception statement from your version. */ - - -package java.lang; - -import gnu.java.lang.CPStringBuilder; - -/** - * Instances of class <code>Float</code> represent primitive - * <code>float</code> values. - * - * Additionally, this class provides various helper functions and variables - * related to floats. - * - * @author Paul Fisher - * @author Andrew Haley (aph@cygnus.com) - * @author Eric Blake (ebb9@email.byu.edu) - * @author Tom Tromey (tromey@redhat.com) - * @author Andrew John Hughes (gnu_andrew@member.fsf.org) - * @since 1.0 - * @status partly updated to 1.5 - */ -public final class Float extends Number implements Comparable<Float> -{ - /** - * Compatible with JDK 1.0+. - */ - private static final long serialVersionUID = -2671257302660747028L; - - /** - * The maximum positive value a <code>double</code> may represent - * is 3.4028235e+38f. - */ - public static final float MAX_VALUE = 3.4028235e+38f; - - /** - * The minimum positive value a <code>float</code> may represent - * is 1.4e-45. - */ - public static final float MIN_VALUE = 1.4e-45f; - - /** - * The value of a float representation -1.0/0.0, negative infinity. - */ - public static final float NEGATIVE_INFINITY = -1.0f / 0.0f; - - /** - * The value of a float representation 1.0/0.0, positive infinity. - */ - public static final float POSITIVE_INFINITY = 1.0f / 0.0f; - - /** - * All IEEE 754 values of NaN have the same value in Java. - */ - public static final float NaN = 0.0f / 0.0f; - - /** - * The primitive type <code>float</code> is represented by this - * <code>Class</code> object. - * @since 1.1 - */ - public static final Class<Float> TYPE = (Class<Float>) VMClassLoader.getPrimitiveClass('F'); - - /** - * The number of bits needed to represent a <code>float</code>. - * @since 1.5 - */ - public static final int SIZE = 32; - - /** - * Cache representation of 0 - */ - private static final Float ZERO = new Float(0.0f); - - /** - * Cache representation of 1 - */ - private static final Float ONE = new Float(1.0f); - - /** - * The immutable value of this Float. - * - * @serial the wrapped float - */ - private final float value; - - /** - * Create a <code>Float</code> from the primitive <code>float</code> - * specified. - * - * @param value the <code>float</code> argument - */ - public Float(float value) - { - this.value = value; - } - - /** - * Create a <code>Float</code> from the primitive <code>double</code> - * specified. - * - * @param value the <code>double</code> argument - */ - public Float(double value) - { - this.value = (float) value; - } - - /** - * Create a <code>Float</code> from the specified <code>String</code>. - * This method calls <code>Float.parseFloat()</code>. - * - * @param s the <code>String</code> to convert - * @throws NumberFormatException if <code>s</code> cannot be parsed as a - * <code>float</code> - * @throws NullPointerException if <code>s</code> is null - * @see #parseFloat(String) - */ - public Float(String s) - { - value = parseFloat(s); - } - - /** - * Convert the <code>float</code> to a <code>String</code>. - * Floating-point string representation is fairly complex: here is a - * rundown of the possible values. "<code>[-]</code>" indicates that a - * negative sign will be printed if the value (or exponent) is negative. - * "<code><number></code>" means a string of digits ('0' to '9'). - * "<code><digit></code>" means a single digit ('0' to '9').<br> - * - * <table border=1> - * <tr><th>Value of Float</th><th>String Representation</th></tr> - * <tr><td>[+-] 0</td> <td><code>[-]0.0</code></td></tr> - * <tr><td>Between [+-] 10<sup>-3</sup> and 10<sup>7</sup>, exclusive</td> - * <td><code>[-]number.number</code></td></tr> - * <tr><td>Other numeric value</td> - * <td><code>[-]<digit>.<number> - * E[-]<number></code></td></tr> - * <tr><td>[+-] infinity</td> <td><code>[-]Infinity</code></td></tr> - * <tr><td>NaN</td> <td><code>NaN</code></td></tr> - * </table> - * - * Yes, negative zero <em>is</em> a possible value. Note that there is - * <em>always</em> a <code>.</code> and at least one digit printed after - * it: even if the number is 3, it will be printed as <code>3.0</code>. - * After the ".", all digits will be printed except trailing zeros. The - * result is rounded to the shortest decimal number which will parse back - * to the same float. - * - * <p>To create other output formats, use {@link java.text.NumberFormat}. - * - * @XXX specify where we are not in accord with the spec. - * - * @param f the <code>float</code> to convert - * @return the <code>String</code> representing the <code>float</code> - */ - public static String toString(float f) - { - return VMFloat.toString(f); - } - - /** - * Convert a float value to a hexadecimal string. This converts as - * follows: - * <ul> - * <li> A NaN value is converted to the string "NaN". - * <li> Positive infinity is converted to the string "Infinity". - * <li> Negative infinity is converted to the string "-Infinity". - * <li> For all other values, the first character of the result is '-' - * if the value is negative. This is followed by '0x1.' if the - * value is normal, and '0x0.' if the value is denormal. This is - * then followed by a (lower-case) hexadecimal representation of the - * mantissa, with leading zeros as required for denormal values. - * The next character is a 'p', and this is followed by a decimal - * representation of the unbiased exponent. - * </ul> - * @param f the float value - * @return the hexadecimal string representation - * @since 1.5 - */ - public static String toHexString(float f) - { - if (isNaN(f)) - return "NaN"; - if (isInfinite(f)) - return f < 0 ? "-Infinity" : "Infinity"; - - int bits = floatToIntBits(f); - CPStringBuilder result = new CPStringBuilder(); - - if (bits < 0) - result.append('-'); - result.append("0x"); - - final int mantissaBits = 23; - final int exponentBits = 8; - int mantMask = (1 << mantissaBits) - 1; - int mantissa = bits & mantMask; - int expMask = (1 << exponentBits) - 1; - int exponent = (bits >>> mantissaBits) & expMask; - - result.append(exponent == 0 ? '0' : '1'); - result.append('.'); - // For Float only, we have to adjust the mantissa. - mantissa <<= 1; - result.append(Integer.toHexString(mantissa)); - if (exponent == 0 && mantissa != 0) - { - // Treat denormal specially by inserting '0's to make - // the length come out right. The constants here are - // to account for things like the '0x'. - int offset = 4 + ((bits < 0) ? 1 : 0); - // The silly +3 is here to keep the code the same between - // the Float and Double cases. In Float the value is - // not a multiple of 4. - int desiredLength = offset + (mantissaBits + 3) / 4; - while (result.length() < desiredLength) - result.insert(offset, '0'); - } - result.append('p'); - if (exponent == 0 && mantissa == 0) - { - // Zero, so do nothing special. - } - else - { - // Apply bias. - boolean denormal = exponent == 0; - exponent -= (1 << (exponentBits - 1)) - 1; - // Handle denormal. - if (denormal) - ++exponent; - } - - result.append(Integer.toString(exponent)); - return result.toString(); - } - - /** - * Creates a new <code>Float</code> object using the <code>String</code>. - * - * @param s the <code>String</code> to convert - * @return the new <code>Float</code> - * @throws NumberFormatException if <code>s</code> cannot be parsed as a - * <code>float</code> - * @throws NullPointerException if <code>s</code> is null - * @see #parseFloat(String) - */ - public static Float valueOf(String s) - { - return valueOf(parseFloat(s)); - } - - /** - * Returns a <code>Float</code> object wrapping the value. - * In contrast to the <code>Float</code> constructor, this method - * may cache some values. It is used by boxing conversion. - * - * @param val the value to wrap - * @return the <code>Float</code> - * @since 1.5 - */ - public static Float valueOf(float val) - { - if ((val == 0.0) && (floatToRawIntBits(val) == 0)) - return ZERO; - else if (val == 1.0) - return ONE; - else - return new Float(val); - } - - /** - * Parse the specified <code>String</code> as a <code>float</code>. The - * extended BNF grammar is as follows:<br> - * <pre> - * <em>DecodableString</em>: - * ( [ <code>-</code> | <code>+</code> ] <code>NaN</code> ) - * | ( [ <code>-</code> | <code>+</code> ] <code>Infinity</code> ) - * | ( [ <code>-</code> | <code>+</code> ] <em>FloatingPoint</em> - * [ <code>f</code> | <code>F</code> | <code>d</code> - * | <code>D</code>] ) - * <em>FloatingPoint</em>: - * ( { <em>Digit</em> }+ [ <code>.</code> { <em>Digit</em> } ] - * [ <em>Exponent</em> ] ) - * | ( <code>.</code> { <em>Digit</em> }+ [ <em>Exponent</em> ] ) - * <em>Exponent</em>: - * ( ( <code>e</code> | <code>E</code> ) - * [ <code>-</code> | <code>+</code> ] { <em>Digit</em> }+ ) - * <em>Digit</em>: <em><code>'0'</code> through <code>'9'</code></em> - * </pre> - * - * <p>NaN and infinity are special cases, to allow parsing of the output - * of toString. Otherwise, the result is determined by calculating - * <em>n * 10<sup>exponent</sup></em> to infinite precision, then rounding - * to the nearest float. Remember that many numbers cannot be precisely - * represented in floating point. In case of overflow, infinity is used, - * and in case of underflow, signed zero is used. Unlike Integer.parseInt, - * this does not accept Unicode digits outside the ASCII range. - * - * <p>If an unexpected character is found in the <code>String</code>, a - * <code>NumberFormatException</code> will be thrown. Leading and trailing - * 'whitespace' is ignored via <code>String.trim()</code>, but spaces - * internal to the actual number are not allowed. - * - * <p>To parse numbers according to another format, consider using - * {@link java.text.NumberFormat}. - * - * @XXX specify where/how we are not in accord with the spec. - * - * @param str the <code>String</code> to convert - * @return the <code>float</code> value of <code>s</code> - * @throws NumberFormatException if <code>str</code> cannot be parsed as a - * <code>float</code> - * @throws NullPointerException if <code>str</code> is null - * @see #MIN_VALUE - * @see #MAX_VALUE - * @see #POSITIVE_INFINITY - * @see #NEGATIVE_INFINITY - * @since 1.2 - */ - public static float parseFloat(String str) - { - return VMFloat.parseFloat(str); - } - - /** - * Return <code>true</code> if the <code>float</code> has the same - * value as <code>NaN</code>, otherwise return <code>false</code>. - * - * @param v the <code>float</code> to compare - * @return whether the argument is <code>NaN</code> - */ - public static boolean isNaN(float v) - { - // This works since NaN != NaN is the only reflexive inequality - // comparison which returns true. - return v != v; - } - - /** - * Return <code>true</code> if the <code>float</code> has a value - * equal to either <code>NEGATIVE_INFINITY</code> or - * <code>POSITIVE_INFINITY</code>, otherwise return <code>false</code>. - * - * @param v the <code>float</code> to compare - * @return whether the argument is (-/+) infinity - */ - public static boolean isInfinite(float v) - { - return v == POSITIVE_INFINITY || v == NEGATIVE_INFINITY; - } - - /** - * Return <code>true</code> if the value of this <code>Float</code> - * is the same as <code>NaN</code>, otherwise return <code>false</code>. - * - * @return whether this <code>Float</code> is <code>NaN</code> - */ - public boolean isNaN() - { - return isNaN(value); - } - - /** - * Return <code>true</code> if the value of this <code>Float</code> - * is the same as <code>NEGATIVE_INFINITY</code> or - * <code>POSITIVE_INFINITY</code>, otherwise return <code>false</code>. - * - * @return whether this <code>Float</code> is (-/+) infinity - */ - public boolean isInfinite() - { - return isInfinite(value); - } - - /** - * Convert the <code>float</code> value of this <code>Float</code> - * to a <code>String</code>. This method calls - * <code>Float.toString(float)</code> to do its dirty work. - * - * @return the <code>String</code> representation - * @see #toString(float) - */ - public String toString() - { - return toString(value); - } - - /** - * Return the value of this <code>Float</code> as a <code>byte</code>. - * - * @return the byte value - * @since 1.1 - */ - public byte byteValue() - { - return (byte) value; - } - - /** - * Return the value of this <code>Float</code> as a <code>short</code>. - * - * @return the short value - * @since 1.1 - */ - public short shortValue() - { - return (short) value; - } - - /** - * Return the value of this <code>Integer</code> as an <code>int</code>. - * - * @return the int value - */ - public int intValue() - { - return (int) value; - } - - /** - * Return the value of this <code>Integer</code> as a <code>long</code>. - * - * @return the long value - */ - public long longValue() - { - return (long) value; - } - - /** - * Return the value of this <code>Float</code>. - * - * @return the float value - */ - public float floatValue() - { - return value; - } - - /** - * Return the value of this <code>Float</code> as a <code>double</code> - * - * @return the double value - */ - public double doubleValue() - { - return value; - } - - /** - * Return a hashcode representing this Object. <code>Float</code>'s hash - * code is calculated by calling <code>floatToIntBits(floatValue())</code>. - * - * @return this Object's hash code - * @see #floatToIntBits(float) - */ - public int hashCode() - { - return floatToIntBits(value); - } - - /** - * Returns <code>true</code> if <code>obj</code> is an instance of - * <code>Float</code> and represents the same float value. Unlike comparing - * two floats with <code>==</code>, this treats two instances of - * <code>Float.NaN</code> as equal, but treats <code>0.0</code> and - * <code>-0.0</code> as unequal. - * - * <p>Note that <code>f1.equals(f2)</code> is identical to - * <code>floatToIntBits(f1.floatValue()) == - * floatToIntBits(f2.floatValue())</code>. - * - * @param obj the object to compare - * @return whether the objects are semantically equal - */ - public boolean equals(Object obj) - { - if (obj instanceof Float) - { - float f = ((Float) obj).value; - return (floatToRawIntBits(value) == floatToRawIntBits(f)) || - (isNaN(value) && isNaN(f)); - } - return false; - } - - /** - * Convert the float to the IEEE 754 floating-point "single format" bit - * layout. Bit 31 (the most significant) is the sign bit, bits 30-23 - * (masked by 0x7f800000) represent the exponent, and bits 22-0 - * (masked by 0x007fffff) are the mantissa. This function collapses all - * versions of NaN to 0x7fc00000. The result of this function can be used - * as the argument to <code>Float.intBitsToFloat(int)</code> to obtain the - * original <code>float</code> value. - * - * @param value the <code>float</code> to convert - * @return the bits of the <code>float</code> - * @see #intBitsToFloat(int) - */ - public static int floatToIntBits(float value) - { - if (isNaN(value)) - return 0x7fc00000; - else - return VMFloat.floatToRawIntBits(value); - } - - /** - * Convert the float to the IEEE 754 floating-point "single format" bit - * layout. Bit 31 (the most significant) is the sign bit, bits 30-23 - * (masked by 0x7f800000) represent the exponent, and bits 22-0 - * (masked by 0x007fffff) are the mantissa. This function leaves NaN alone, - * rather than collapsing to a canonical value. The result of this function - * can be used as the argument to <code>Float.intBitsToFloat(int)</code> to - * obtain the original <code>float</code> value. - * - * @param value the <code>float</code> to convert - * @return the bits of the <code>float</code> - * @see #intBitsToFloat(int) - */ - public static int floatToRawIntBits(float value) - { - return VMFloat.floatToRawIntBits(value); - } - - /** - * Convert the argument in IEEE 754 floating-point "single format" bit - * layout to the corresponding float. Bit 31 (the most significant) is the - * sign bit, bits 30-23 (masked by 0x7f800000) represent the exponent, and - * bits 22-0 (masked by 0x007fffff) are the mantissa. This function leaves - * NaN alone, so that you can recover the bit pattern with - * <code>Float.floatToRawIntBits(float)</code>. - * - * @param bits the bits to convert - * @return the <code>float</code> represented by the bits - * @see #floatToIntBits(float) - * @see #floatToRawIntBits(float) - */ - public static float intBitsToFloat(int bits) - { - return VMFloat.intBitsToFloat(bits); - } - - /** - * Compare two Floats numerically by comparing their <code>float</code> - * values. The result is positive if the first is greater, negative if the - * second is greater, and 0 if the two are equal. However, this special - * cases NaN and signed zero as follows: NaN is considered greater than - * all other floats, including <code>POSITIVE_INFINITY</code>, and positive - * zero is considered greater than negative zero. - * - * @param f the Float to compare - * @return the comparison - * @since 1.2 - */ - public int compareTo(Float f) - { - return compare(value, f.value); - } - - /** - * Behaves like <code>new Float(x).compareTo(new Float(y))</code>; in - * other words this compares two floats, special casing NaN and zero, - * without the overhead of objects. - * - * @param x the first float to compare - * @param y the second float to compare - * @return the comparison - * @since 1.4 - */ - public static int compare(float x, float y) - { - // handle the easy cases: - if (x < y) - return -1; - if (x > y) - return 1; - - // handle equality respecting that 0.0 != -0.0 (hence not using x == y): - int ix = floatToRawIntBits(x); - int iy = floatToRawIntBits(y); - if (ix == iy) - return 0; - - // handle NaNs: - if (x != x) - return (y != y) ? 0 : 1; - else if (y != y) - return -1; - - // handle +/- 0.0 - return (ix < iy) ? -1 : 1; - } -} |