diff options
Diffstat (limited to 'src/main/java/sevenUnits/unit/UnitPrefix.java')
| -rw-r--r-- | src/main/java/sevenUnits/unit/UnitPrefix.java | 100 |
1 files changed, 64 insertions, 36 deletions
diff --git a/src/main/java/sevenUnits/unit/UnitPrefix.java b/src/main/java/sevenUnits/unit/UnitPrefix.java index 9035969..af106b9 100644 --- a/src/main/java/sevenUnits/unit/UnitPrefix.java +++ b/src/main/java/sevenUnits/unit/UnitPrefix.java @@ -1,5 +1,5 @@ /** - * Copyright (C) 2019 Adrien Hopkins + * Copyright (C) 2019, 2021, 2022, 2024, 2025 Adrien Hopkins * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as published by @@ -25,17 +25,19 @@ import sevenUnits.utils.Nameable; /** * A prefix that can be applied to a {@code LinearUnit} to multiply it by some * value - * + * * @author Adrien Hopkins * @since 2019-10-16 + * @since v0.3.0 */ public final class UnitPrefix implements Nameable { /** * Gets a {@code UnitPrefix} from a multiplier - * + * * @param multiplier multiplier of prefix * @return prefix * @since 2019-10-16 + * @since v0.3.0 */ public static UnitPrefix valueOf(final double multiplier) { return new UnitPrefix(multiplier, NameSymbol.EMPTY); @@ -43,11 +45,12 @@ public final class UnitPrefix implements Nameable { /** * Gets a {@code UnitPrefix} from a multiplier and a name - * + * * @param multiplier multiplier of prefix * @param ns name(s) and symbol of prefix * @return prefix * @since 2019-10-16 + * @since v0.3.0 * @throws NullPointerException if ns is null */ public static UnitPrefix valueOf(final double multiplier, @@ -58,21 +61,23 @@ public final class UnitPrefix implements Nameable { /** * This prefix's name(s) and symbol. - * + * * @since 2022-04-16 + * @since v0.4.0 */ private final NameSymbol nameSymbol; /** * The number that this prefix multiplies units by - * + * * @since 2019-10-16 + * @since v0.3.0 */ private final double multiplier; /** * Creates the {@code DefaultUnitPrefix}. - * + * * @param multiplier * @since 2019-01-14 * @since v0.2.0 @@ -84,10 +89,11 @@ public final class UnitPrefix implements Nameable { /** * Divides this prefix by a scalar - * + * * @param divisor number to divide by * @return quotient of prefix and scalar * @since 2019-10-16 + * @since v0.3.0 */ public UnitPrefix dividedBy(final double divisor) { return valueOf(this.getMultiplier() / divisor); @@ -95,7 +101,7 @@ public final class UnitPrefix implements Nameable { /** * Divides this prefix by {@code other}. - * + * * @param other prefix to divide by * @return quotient of prefixes * @since 2019-04-13 @@ -107,18 +113,32 @@ public final class UnitPrefix implements Nameable { /** * {@inheritDoc} - * + * * Uses the prefix's multiplier to determine equality. */ @Override public boolean equals(final Object obj) { if (this == obj) return true; - if (obj == null) + if ((obj == null) || !(obj instanceof UnitPrefix)) return false; - if (!(obj instanceof UnitPrefix)) + final var other = (UnitPrefix) obj; + return Double.compare(this.getMultiplier(), other.getMultiplier()) == 0; + } + + /** + * @param other prefix to compare to + * @return true iff this prefix and other are equal, ignoring small + * differences caused by floating-point error. + * + * @apiNote This method is not transitive, so it cannot be used as an equals + * method. + */ + public boolean equalsApproximately(final UnitPrefix other) { + if (this == other) + return true; + if (other == null) return false; - final UnitPrefix other = (UnitPrefix) obj; return DecimalComparison.equals(this.getMultiplier(), other.getMultiplier()); } @@ -126,6 +146,7 @@ public final class UnitPrefix implements Nameable { /** * @return prefix's multiplier * @since 2019-11-26 + * @since v0.3.0 */ public double getMultiplier() { return this.multiplier; @@ -138,46 +159,55 @@ public final class UnitPrefix implements Nameable { /** * {@inheritDoc} - * + * * Uses the prefix's multiplier to determine a hash code. */ @Override public int hashCode() { - return DecimalComparison.hash(this.getMultiplier()); + return Double.hashCode(this.getMultiplier()); } /** - * Multiplies this prefix by a scalar - * - * @param multiplicand number to multiply by - * @return product of prefix and scalar - * @since 2019-10-16 + * Subtracts {@code other} from this prefix and returns the result. + * + * @param other prefix to subtract + * @return difference of prefixes + * + * @since 2024-03-03 + * @since v0.5.0 */ - public UnitPrefix times(final double multiplicand) { - return valueOf(this.getMultiplier() * multiplicand); + public UnitPrefix minus(final UnitPrefix other) { + return valueOf(this.getMultiplier() - other.getMultiplier()); } /** * Adds {@code other} to this prefix and returns the result. - * + * + * @param other prefix to add + * @return sum of prefixes + * * @since 2024-03-03 + * @since v0.5.0 */ public UnitPrefix plus(final UnitPrefix other) { return valueOf(this.getMultiplier() + other.getMultiplier()); } /** - * Subtracts {@code other} from this prefix and returns the result. - * - * @since 2024-03-03 + * Multiplies this prefix by a scalar + * + * @param multiplicand number to multiply by + * @return product of prefix and scalar + * @since 2019-10-16 + * @since v0.3.0 */ - public UnitPrefix minus(final UnitPrefix other) { - return valueOf(this.getMultiplier() - other.getMultiplier()); + public UnitPrefix times(final double multiplicand) { + return valueOf(this.getMultiplier() * multiplicand); } /** * Multiplies this prefix by {@code other}. - * + * * @param other prefix to multiply by * @return product of prefixes * @since 2019-04-13 @@ -189,7 +219,7 @@ public final class UnitPrefix implements Nameable { /** * Raises this prefix to an exponent. - * + * * @param exponent exponent to raise to * @return result of exponentiation. * @since 2019-04-13 @@ -199,25 +229,23 @@ public final class UnitPrefix implements Nameable { return valueOf(Math.pow(this.getMultiplier(), exponent)); } - /** - * @return a string describing the prefix and its multiplier - */ + /** @return a string describing the prefix and its multiplier */ @Override public String toString() { if (this.getPrimaryName().isPresent()) return String.format("%s (\u00D7 %s)", this.getPrimaryName().get(), this.multiplier); - else if (this.getSymbol().isPresent()) + if (this.getSymbol().isPresent()) return String.format("%s (\u00D7 %s)", this.getSymbol().get(), this.multiplier); - else - return String.format("Unit Prefix (\u00D7 %s)", this.multiplier); + return String.format("Unit Prefix (\u00D7 %s)", this.multiplier); } /** * @param ns name(s) and symbol to use * @return copy of this prefix with provided name(s) and symbol * @since 2019-11-26 + * @since v0.3.0 * @throws NullPointerException if ns is null */ public UnitPrefix withName(final NameSymbol ns) { |