summaryrefslogtreecommitdiff
path: root/src/main/java/bjc/data/ListHolder.java
diff options
context:
space:
mode:
authorbculkin2442 <bjculkin@mix.wvu.edu>2019-07-02 18:05:22 -0400
committerbculkin2442 <bjculkin@mix.wvu.edu>2019-07-02 18:05:22 -0400
commit843329de434bb334d90927c4d22345373a388530 (patch)
treeb0ad1f764bd29ff43841e1095a5b58194c20cb37 /src/main/java/bjc/data/ListHolder.java
parentac36f171a3cebb0993cc28548635e3f654f8e325 (diff)
Rename package root
The package root is now bjc, not io.github.bculkin2442.
Diffstat (limited to 'src/main/java/bjc/data/ListHolder.java')
-rw-r--r--src/main/java/bjc/data/ListHolder.java105
1 files changed, 105 insertions, 0 deletions
diff --git a/src/main/java/bjc/data/ListHolder.java b/src/main/java/bjc/data/ListHolder.java
new file mode 100644
index 0000000..077c0fb
--- /dev/null
+++ b/src/main/java/bjc/data/ListHolder.java
@@ -0,0 +1,105 @@
+package bjc.data;
+
+import java.util.function.Function;
+import java.util.function.UnaryOperator;
+
+import bjc.data.internals.BoundListHolder;
+import bjc.funcdata.FunctionalList;
+import bjc.funcdata.IList;
+
+/**
+ * A holder that represents a set of non-deterministic computations.
+ *
+ * @author ben
+ *
+ * @param <ContainedType>
+ * The type of contained value.
+ */
+public class ListHolder<ContainedType> implements IHolder<ContainedType> {
+ private IList<ContainedType> heldValues;
+
+ /**
+ * Create a new list holder.
+ *
+ * @param values
+ * The possible values for the computation.
+ */
+ @SafeVarargs
+ public ListHolder(final ContainedType... values) {
+ heldValues = new FunctionalList<>();
+
+ if(values != null) {
+ for(final ContainedType containedValue : values) {
+ heldValues.add(containedValue);
+ }
+ }
+ }
+
+ /* Create a new holder with values. */
+ private ListHolder(final IList<ContainedType> toHold) {
+ heldValues = toHold;
+ }
+
+ @Override
+ public <BoundType> IHolder<BoundType> bind(final Function<ContainedType, IHolder<BoundType>> binder) {
+ final IList<IHolder<BoundType>> boundValues = heldValues.map(binder);
+
+ return new BoundListHolder<>(boundValues);
+ }
+
+ @Override
+ public <NewType> Function<ContainedType, IHolder<NewType>> lift(final Function<ContainedType, NewType> func) {
+ return val -> {
+ return new ListHolder<>(new FunctionalList<>(func.apply(val)));
+ };
+ }
+
+ @Override
+ public <MappedType> IHolder<MappedType> map(final Function<ContainedType, MappedType> mapper) {
+ final IList<MappedType> mappedValues = heldValues.map(mapper);
+
+ return new ListHolder<>(mappedValues);
+ }
+
+ @Override
+ public IHolder<ContainedType> transform(final UnaryOperator<ContainedType> transformer) {
+ heldValues = heldValues.map(transformer);
+
+ return this;
+ }
+
+ @Override
+ public <UnwrappedType> UnwrappedType unwrap(final Function<ContainedType, UnwrappedType> unwrapper) {
+ return unwrapper.apply(heldValues.randItem());
+ }
+
+ @Override
+ public String toString() {
+ return String.format("ListHolder [heldValues=%s]", heldValues);
+ }
+
+ @Override
+ public int hashCode() {
+ final int prime = 31;
+ int result = 1;
+
+ result = prime * result + (heldValues == null ? 0 : heldValues.hashCode());
+
+ return result;
+ }
+
+ @Override
+ public boolean equals(final Object obj) {
+ if(this == obj) return true;
+ if(obj == null) return false;
+ if(!(obj instanceof ListHolder<?>)) return false;
+
+ final ListHolder<?> other = (ListHolder<?>) obj;
+
+ if(heldValues == null) {
+ if(other.heldValues != null) return false;
+ } else if(!heldValues.equals(other.heldValues)) return false;
+
+ return true;
+ }
+}