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Diffstat (limited to 'src/main/java/org/unitConverter/unit/UnitPrefix.java')
| -rw-r--r-- | src/main/java/org/unitConverter/unit/UnitPrefix.java | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/src/main/java/org/unitConverter/unit/UnitPrefix.java b/src/main/java/org/unitConverter/unit/UnitPrefix.java new file mode 100644 index 0000000..31cc0b3 --- /dev/null +++ b/src/main/java/org/unitConverter/unit/UnitPrefix.java @@ -0,0 +1,242 @@ +/** + * Copyright (C) 2019 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 + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program 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 Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <https://www.gnu.org/licenses/>. + */ +package org.unitConverter.unit; + +import java.util.Objects; +import java.util.Optional; +import java.util.Set; + +import org.unitConverter.math.DecimalComparison; + +/** + * A prefix that can be applied to a {@code LinearUnit} to multiply it by some value + * + * @author Adrien Hopkins + * @since 2019-10-16 + */ +public final class UnitPrefix { + /** + * Gets a {@code UnitPrefix} from a multiplier + * + * @param multiplier + * multiplier of prefix + * @return prefix + * @since 2019-10-16 + */ + public static UnitPrefix valueOf(final double multiplier) { + return new UnitPrefix(multiplier, NameSymbol.EMPTY); + } + + /** + * 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 + * @throws NullPointerException + * if ns is null + */ + public static UnitPrefix valueOf(final double multiplier, final NameSymbol ns) { + return new UnitPrefix(multiplier, Objects.requireNonNull(ns, "ns must not be null.")); + } + + /** + * This prefix's primary name + */ + private final Optional<String> primaryName; + + /** + * This prefix's symbol + */ + private final Optional<String> symbol; + + /** + * Other names and symbols used by this prefix + */ + private final Set<String> otherNames; + + /** + * The number that this prefix multiplies units by + * + * @since 2019-10-16 + */ + private final double multiplier; + + /** + * Creates the {@code DefaultUnitPrefix}. + * + * @param multiplier + * @since 2019-01-14 + * @since v0.2.0 + */ + private UnitPrefix(final double multiplier, final NameSymbol ns) { + this.multiplier = multiplier; + this.primaryName = ns.getPrimaryName(); + this.symbol = ns.getSymbol(); + this.otherNames = ns.getOtherNames(); + } + + /** + * Divides this prefix by a scalar + * + * @param divisor + * number to divide by + * @return quotient of prefix and scalar + * @since 2019-10-16 + */ + public UnitPrefix dividedBy(final double divisor) { + return valueOf(this.getMultiplier() / divisor); + } + + /** + * Divides this prefix by {@code other}. + * + * @param other + * prefix to divide by + * @return quotient of prefixes + * @since 2019-04-13 + * @since v0.2.0 + */ + public UnitPrefix dividedBy(final UnitPrefix other) { + return valueOf(this.getMultiplier() / other.getMultiplier()); + } + + /** + * {@inheritDoc} + * + * Uses the prefix's multiplier to determine equality. + */ + @Override + public boolean equals(final Object obj) { + if (this == obj) + return true; + if (obj == null) + return false; + if (!(obj instanceof UnitPrefix)) + return false; + final UnitPrefix other = (UnitPrefix) obj; + return DecimalComparison.equals(this.getMultiplier(), other.getMultiplier()); + } + + /** + * @return prefix's multiplier + * @since 2019-11-26 + */ + public double getMultiplier() { + return this.multiplier; + } + + /** + * @return other names + * @since 2019-11-26 + */ + public final Set<String> getOtherNames() { + return this.otherNames; + } + + /** + * @return primary name + * @since 2019-11-26 + */ + public final Optional<String> getPrimaryName() { + return this.primaryName; + } + + /** + * @return symbol + * @since 2019-11-26 + */ + public final Optional<String> getSymbol() { + return this.symbol; + } + + /** + * {@inheritDoc} + * + * Uses the prefix's multiplier to determine a hash code. + */ + @Override + public int hashCode() { + return DecimalComparison.hash(this.getMultiplier()); + } + + /** + * Multiplies this prefix by a scalar + * + * @param multiplicand + * number to multiply by + * @return product of prefix and scalar + * @since 2019-10-16 + */ + 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 + * @since v0.2.0 + */ + public UnitPrefix times(final UnitPrefix other) { + return valueOf(this.getMultiplier() * other.getMultiplier()); + } + + /** + * Raises this prefix to an exponent. + * + * @param exponent + * exponent to raise to + * @return result of exponentiation. + * @since 2019-04-13 + * @since v0.2.0 + */ + public UnitPrefix toExponent(final double exponent) { + return valueOf(Math.pow(this.getMultiplier(), exponent)); + } + + /** + * @return a string describing the prefix and its multiplier + */ + @Override + public String toString() { + if (this.primaryName.isPresent()) + return String.format("%s (\u00D7 %s)", this.primaryName.get(), this.multiplier); + else if (this.symbol.isPresent()) + return String.format("%s (\u00D7 %s)", this.symbol.get(), this.multiplier); + else + 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 + * @throws NullPointerException + * if ns is null + */ + public UnitPrefix withName(final NameSymbol ns) { + return valueOf(this.multiplier, ns); + } +} |