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package dev.marksman.enhancediterables;
import com.jnape.palatable.lambda.adt.Maybe;
import com.jnape.palatable.lambda.adt.coproduct.CoProduct2;
import com.jnape.palatable.lambda.adt.hlist.Tuple2;
import com.jnape.palatable.lambda.functions.Fn1;
import com.jnape.palatable.lambda.functions.Fn2;
import com.jnape.palatable.lambda.functions.builtin.fn1.Tails;
import com.jnape.palatable.lambda.functions.builtin.fn2.*;
import com.jnape.palatable.lambda.functions.builtin.fn3.ZipWith;
import com.jnape.palatable.lambda.monoid.builtin.Concat;
import java.util.Collection;
import static com.jnape.palatable.lambda.adt.hlist.HList.tuple;
import static dev.marksman.enhancediterables.EnhancedIterables.*;
import static dev.marksman.enhancediterables.Validation.*;
import static java.util.Objects.requireNonNull;
/**
* An {@code EnhancedIterable} that is safe from mutation.
*
* May be infinite, finite, or empty.
*
* @param the element type
*/
public interface ImmutableIterable extends EnhancedIterable {
/**
* Lazily appends an element to the end of this {@code ImmutableIterable}, yielding a new {@code ImmutableNonEmptyIterable}.
*
* @param element the element to append
* @return a {@code ImmutableNonEmptyIterable}
*/
@Override
default ImmutableNonEmptyIterable append(A element) {
return immutableNonEmptyIterableOrThrow(Snoc.snoc(element, this));
}
/**
* Lazily concatenates another {@code ImmutableIterable} to the end of this {@code ImmutableIterable},
* yielding a new {@code ImmutableIterable}.
*
* @param other the other {@link ImmutableIterable}
* @return an {@code ImmutableIterable}
*/
default ImmutableIterable concat(ImmutableIterable other) {
requireNonNull(other);
return EnhancedIterables.immutableIterable(Concat.concat(this, other));
}
/**
* Lazily concatenates an {@code ImmutableNonEmptyIterable} to the end of this {@code ImmutableIterable},
* yielding a new {@code ImmutableNonEmptyIterable}.
*
* @param other an {@link ImmutableNonEmptyIterable}
* @return an {@code ImmutableNonEmptyIterable}
*/
default ImmutableNonEmptyIterable concat(ImmutableNonEmptyIterable other) {
requireNonNull(other);
return EnhancedIterables.immutableNonEmptyIterableOrThrow(Concat.concat(this, other));
}
/**
* Returns a new {@code ImmutableIterable} that drops the first {@code count} elements of this {@code ImmutableIterable}.
*
* @param count the number of elements to drop from this {@code ImmutableIterable}.
* Must be >= 0.
* May exceed size of this {@code ImmutableIterable}, in which case, the result will be an
* empty {@code ImmutableIterable}.
* @return an {@code ImmutableIterable}
*/
@Override
default ImmutableIterable drop(int count) {
validateDrop(count);
return immutableIterable(Drop.drop(count, this));
}
/**
* Returns a new {@code ImmutableIterable} that skips the first contiguous group of elements of this
* {@code ImmutableIterable} that satisfy a predicate.
*
* Iteration begins at the first element for which the predicate evaluates to false.
*
* @param predicate a predicate; should be referentially transparent and not have side-effects
* @return a {@code ImmutableIterable}
*/
@Override
default ImmutableIterable dropWhile(Fn1 predicate) {
requireNonNull(predicate);
return immutableIterable(DropWhile.dropWhile(predicate, this));
}
/**
* Returns a new {@code ImmutableIterable} that contains all elements of this {@code ImmutableIterable}
* that satisfy a predicate.
*
* @param predicate a predicate; should be referentially transparent and not have side-effects
* @return a {@code ImmutableIterable}
*/
@Override
default ImmutableIterable filter(Fn1 predicate) {
requireNonNull(predicate);
return immutableIterable(Filter.filter(predicate).apply(this));
}
/**
* Returns a new {@code ImmutableIterable} by applying a function to all elements of this {@code ImmutableIterable}.
*
* @param f a function from {@code A} to {@code B}.
* This function should be referentially transparent and not perform side-effects.
* It may be called zero or more times for each element.
* @param the type returned by {@code f}
* @return a {@code ImmutableIterable}
*/
@Override
default ImmutableIterable fmap(Fn1 f) {
requireNonNull(f);
return immutableIterable(Map.map(f, this));
}
/**
* Returns a new {@code ImmutableIterable} with the provided separator value injected between each value of this
* {@code ImmutableIterable}.
*
* If this {@code ImmutableIterable} contains fewer than two elements, it is left untouched.
*
* @param separator the separator value
* @return a {@code ImmutableIterable}
*/
@Override
default ImmutableIterable intersperse(A separator) {
return immutableIterable(Intersperse.intersperse(separator, this));
}
/**
* Returns an {@code Iterable} of contiguous groups of elements in this {@code ImmutableIterable} that match a
* predicate pairwise.
*
* @param predicate the predicate function.
* This function should be referentially transparent and not perform side-effects.
* It may be called zero or more times for each element.
* @return an {@code ImmutableIterable>} containing the contiguous groups
*/
@Override
default ImmutableIterable> magnetizeBy(Fn2 predicate) {
requireNonNull(predicate);
return EnhancedIterables.immutableIterable(MagnetizeBy.magnetizeBy(predicate, this))
.fmap(EnhancedIterables::immutableNonEmptyIterableOrThrow);
}
/**
* Partitions this {@code ImmutableIterable} given a disjoint mapping function.
*
* Note that while the returned tuple must be constructed eagerly, the left and right iterables contained therein
* are both lazy, so comprehension over infinite iterables is supported.
*
* @param function the mapping function
* @param the output left Iterable element type, as well as the CoProduct2 A type
* @param the output right Iterable element type, as well as the CoProduct2 B type
* @return a {@code Tuple2}
*/
@Override
default Tuple2, ? extends ImmutableIterable> partition(
Fn1> function) {
requireNonNull(function);
Tuple2, Iterable> partitionResult = Partition.partition(function, this);
return tuple(immutableIterable(partitionResult._1()),
immutableIterable(partitionResult._2()));
}
/**
* Lazily prepends an element to the front of this {@code ImmutableIterable}, yielding a new {@code ImmutableNonEmptyIterable}.
*
* @param element the element to prepend
* @return an {@code ImmutableNonEmptyIterable}
*/
@Override
default ImmutableNonEmptyIterable prepend(A element) {
return ImmutableNonEmptyIterable.immutableNonEmptyIterable(element, this);
}
/**
* Returns a new {@code ImmutableIterable} with the provided separator value injected before each value of this
* {@code ImmutableIterable}.
*
* If this {@code ImmutableIterable} is empty, it is left untouched.
*
* @param separator the separator value
* @return a {@code ImmutableIterable}
*/
@Override
default ImmutableIterable prependAll(A separator) {
return immutableIterable(PrependAll.prependAll(separator, this));
}
/**
* "Slides" a window of {@code k} elements across the {@code ImmutableIterable} by one element at a time.
*
* Example:
*
* ImmutableIterable.of(1, 2, 3, 4, 5).slide(2); // [[1, 2], [2, 3], [3, 4], [4, 5]]
*
* @param k the number of elements in the sliding window. Must be >= 1.
* @return an {@code ImmutableIterable>}
*/
@Override
default ImmutableIterable> slide(int k) {
validateSlide(k);
return immutableIterable(Map.map(EnhancedIterables::immutableNonEmptyFiniteIterableOrThrow,
Slide.slide(k, this)));
}
/**
* Returns a {@code Tuple2} where the first slot is the front contiguous elements of this
* {@code ImmutableIterable} matching a predicate and the second slot is all the remaining elements.
*
* @param predicate a predicate; should be referentially transparent and not have side-effects
* @return a {@code Tuple2}
*/
@Override
default Tuple2, ? extends ImmutableIterable> span(Fn1 predicate) {
requireNonNull(predicate);
Tuple2, Iterable> spanResult = Span.span(predicate).apply(this);
return tuple(immutableIterable(spanResult._1()),
immutableIterable(spanResult._2()));
}
/**
* Returns an {@code ImmutableNonEmptyIterable} containing all of the subsequences of tail
* elements of this {@code ImmutableIterable}, ordered by size, starting with the full list.
* Example:
*
* ImmutableIterable.of(1, 2, 3).tails(); // [[1, 2, 3], [2, 3], [3], []]
*
* @return an {@code ImmutableNonEmptyIterable>}
*/
@Override
default ImmutableNonEmptyIterable> tails() {
return immutableNonEmptyIterableOrThrow(Map.map(EnhancedIterables::immutableIterable, Tails.tails(this)));
}
/**
* Returns a new {@code ImmutableFiniteIterable} that takes the first {@code count} elements of this {@code ImmutableIterable}.
*
* @param count the number of elements to take from this {@code EnhancedIterable}.
* Must be >= 0.
* May exceed size of this {@code ImmutableIterable}, in which case, the result will contain
* as many elements available.
* @return an {@code ImmutableFiniteIterable}
*/
@Override
default ImmutableFiniteIterable take(int count) {
validateTake(count);
return immutableFiniteIterable(Take.take(count, this));
}
/**
* Returns a new {@code ImmutableIterable} that limits to the first contiguous group of elements of this
* {@code FiniteIterable} that satisfy a predicate.
*
* Iteration ends at, but does not include, the first element for which the predicate evaluates to false.
*
* @param predicate a predicate; should be referentially transparent and not have side-effects
* @return a {@code ImmutableIterable}
*/
@Override
default ImmutableIterable takeWhile(Fn1 predicate) {
requireNonNull(predicate);
return immutableIterable(TakeWhile.takeWhile(predicate, this));
}
/**
* Converts this {@code ImmutableIterable} to an {@code ImmutableFiniteIterable} if there is enough
* information to do so without iterating it.
*
* Note that if this method returns {@code nothing()}, it does NOT necessarily mean this
* {@code ImmutableIterable} is infinite.
*
* @return a {@code Maybe}
*/
@Override
default Maybe> toFinite() {
return EnhancedIterables.immutableMaybeFinite(this);
}
/**
* Converts this {@code ImmutableIterable} to a {@code ImmutableNonEmptyIterable} if it contains
* one or more elements.
*
* @return a {@code Maybe}
*/
@Override
default Maybe> toNonEmpty() {
return EnhancedIterables.maybeNonEmpty(this)
.fmap(EnhancedIterables::immutableNonEmptyIterableOrThrow);
}
/**
* Zips together this {@code ImmutableIterable} with another {@code ImmutableIterable} by applying a zipping function.
*
* Applies the function to the successive elements of each {@code Iterable} until one of them runs out of elements.
*
* @param fn the zipping function.
* Not null.
* This function should be referentially transparent and not perform side-effects.
* It may be called zero or more times for each element.
* @param other the other {@code Iterable}
* @param the element type of the other {@code Iterable}
* @param the element type of the result
* @return an {@code ImmutableIterable}
*/
default ImmutableIterable zipWith(Fn2 fn, ImmutableIterable other) {
requireNonNull(fn);
requireNonNull(other);
return immutableIterable(ZipWith.zipWith(fn, this, other));
}
/**
* Zips together this {@code ImmutableIterable} with an {@code ImmutableFiniteIterable} by applying a zipping function.
*
* Applies the function to the successive elements of each {@code Iterable} until one of them runs out of elements.
*
* @param fn the zipping function.
* Not null.
* This function should be referentially transparent and not perform side-effects.
* It may be called zero or more times for each element.
* @param other the other {@code Iterable}
* @param the element type of the other {@code Iterable}
* @param the element type of the result
* @return an {@code ImmutableFiniteIterable}
*/
default ImmutableFiniteIterable zipWith(Fn2 fn, ImmutableFiniteIterable other) {
requireNonNull(fn);
requireNonNull(other);
return immutableFiniteIterable(ZipWith.zipWith(fn, this, other));
}
/**
* Creates an {@code ImmutableFiniteIterable} by copying elements from a {@code FiniteIterable}.
*
* If {@code source} is already an {@code ImmutableFiniteIterable}, this method will return it without copying.
*
* @param source the source to copy from
* @param the element type
* @return an {@code ImmutableFiniteIterable}
*/
static ImmutableFiniteIterable copyFrom(FiniteIterable source) {
return EnhancedIterables.copyFrom(source);
}
/**
* Creates an {@code ImmutableFiniteIterable} by copying elements from a {@code Collection}.
*
* @param source the source to copy from
* @param the element type
* @return an {@code ImmutableFiniteIterable}
*/
static ImmutableFiniteIterable copyFrom(Collection source) {
return EnhancedIterables.copyFrom(source);
}
/**
* Creates an {@code ImmutableFiniteIterable} by copying elements from an {@code Iterable}.
*
* If {@code source} is already an {@code ImmutableIterable}, no copying will be performed.
*
* @param maxCount the maximum number of elements to take from the supplied {@link Iterable}.
* Must be >= 0.
* May exceed size of the {@code Iterable}, in which case, the result will contain
* as many elements available.
* @param source the source to copy from
* @param the element type
* @return an {@code ImmutableFiniteIterable}
*/
static ImmutableFiniteIterable copyFrom(int maxCount, Iterable source) {
return EnhancedIterables.copyFrom(maxCount, source);
}
/**
* Creates an empty {@code ImmutableIterable}.
*
* @param the element type
* @return an {@code ImmutableFiniteIterable}
*/
static ImmutableFiniteIterable emptyImmutableIterable() {
return EnhancedIterables.emptyEnhancedIterable();
}
/**
* Creates an {@code ImmutableIterable} containing the given elements.
*
* Note that this method actually returns an {@link ImmutableNonEmptyFiniteIterable}, which is
* also an {@link ImmutableIterable}.
*
* @param first the first element
* @param more the remaining elements
* @param the element type
* @return an {@code ImmutableNonEmptyFiniteIterable}
*/
@SuppressWarnings("varargs")
@SafeVarargs
static ImmutableNonEmptyFiniteIterable of(A first, A... more) {
if (more.length > 0) {
return EnhancedIterables.of(first, more);
} else {
return EnhancedIterables.singleton(first);
}
}
/**
* Returns an infinite {@code ImmutableNonEmptyIterable} that repeatedly iterates a given element.
*
* @param element the value to repeat
* @param the element type
* @return an {@code ImmutableNonEmptyIterable}
*/
static ImmutableNonEmptyIterable repeat(A element) {
return EnhancedIterables.repeat(element);
}
}