diff options
| author | Benjamin J. Culkin <bjculkin@mix.wvu.edu> | 2017-10-08 22:39:59 -0300 |
|---|---|---|
| committer | Benjamin J. Culkin <bjculkin@mix.wvu.edu> | 2017-10-08 22:39:59 -0300 |
| commit | c82e3b3b2de0633317ec8fc85925e91422820597 (patch) | |
| tree | 96567416ce23c5ce85601f9cedc3a94bb1c55cba /base/src/main/java/bjc/utils/data/Identity.java | |
| parent | b3ac1c8690c3e14c879913e5dcc03a5f5e14876e (diff) | |
Start splitting into maven modules
Diffstat (limited to 'base/src/main/java/bjc/utils/data/Identity.java')
| -rw-r--r-- | base/src/main/java/bjc/utils/data/Identity.java | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/base/src/main/java/bjc/utils/data/Identity.java b/base/src/main/java/bjc/utils/data/Identity.java new file mode 100644 index 0000000..a8c8d70 --- /dev/null +++ b/base/src/main/java/bjc/utils/data/Identity.java @@ -0,0 +1,118 @@ +package bjc.utils.data; + +import java.util.function.Function; +import java.util.function.UnaryOperator; + +/** + * @author ben + * + * @param <ContainedType> + */ +/** + * Simple implementation of IHolder that has no hidden behavior + * + * @author ben + * + * @param <ContainedType> + * The type contained in the holder + */ +public class Identity<ContainedType> implements IHolder<ContainedType> { + private ContainedType heldValue; + + /** + * Create a holder holding null + */ + public Identity() { + heldValue = null; + } + + /** + * Create a holder holding the specified value + * + * @param value + * The value to hold + */ + public Identity(final ContainedType value) { + heldValue = value; + } + + @Override + public <BoundType> IHolder<BoundType> bind(final Function<ContainedType, IHolder<BoundType>> binder) { + return binder.apply(heldValue); + } + + @Override + public int hashCode() { + final int prime = 31; + int result = 1; + + result = prime * result + (heldValue == null ? 0 : heldValue.hashCode()); + + return result; + } + + @Override + public boolean equals(final Object obj) { + if (this == obj) return true; + if (obj == null) return false; + if (!(obj instanceof Identity)) return false; + + final Identity<?> other = (Identity<?>) obj; + + if (heldValue == null) { + if (other.heldValue != null) return false; + } else if (!heldValue.equals(other.heldValue)) return false; + + return true; + } + + @Override + public <NewType> Function<ContainedType, IHolder<NewType>> lift(final Function<ContainedType, NewType> func) { + return (val) -> { + return new Identity<>(func.apply(val)); + }; + } + + @Override + public <MappedType> IHolder<MappedType> map(final Function<ContainedType, MappedType> mapper) { + return new Identity<>(mapper.apply(heldValue)); + } + + @Override + public String toString() { + return String.format("Identity [heldValue=%s]", heldValue); + } + + @Override + public IHolder<ContainedType> transform(final UnaryOperator<ContainedType> transformer) { + heldValue = transformer.apply(heldValue); + + return this; + } + + @Override + public <UnwrappedType> UnwrappedType unwrap(final Function<ContainedType, UnwrappedType> unwrapper) { + return unwrapper.apply(heldValue); + } + + /** + * Create a new identity container. + * + * @param val + * The contained value. + * + * @return A new identity container. + */ + public static <ContainedType> Identity<ContainedType> id(final ContainedType val) { + return new Identity<>(val); + } + + /** + * Create a new empty identity container. + * + * @return A new empty identity container. + */ + public static <ContainedType> Identity<ContainedType> id() { + return new Identity<>(); + } +}
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