diff options
Diffstat (limited to 'base/src/main/java/bjc/utils')
10 files changed, 376 insertions, 159 deletions
diff --git a/base/src/main/java/bjc/utils/funcutils/Callables.java b/base/src/main/java/bjc/utils/funcutils/Callables.java new file mode 100644 index 0000000..5895347 --- /dev/null +++ b/base/src/main/java/bjc/utils/funcutils/Callables.java @@ -0,0 +1,60 @@ +package bjc.utils.funcutils; + +import java.util.concurrent.*; +import java.util.function.*; + +/** + * Utility function for dealing with callables and other things. + * + * @author Ben Culkin + * + */ +public class Callables +{ + /** + * Perform a 'bind' that appends a function to a callable. + * + * @param <Input> The type originally returned by the callable. + * @param <Output> The type returned by the function. + * + * @param call The original callable. + * @param func The function to use to transform the result. + * + * @return A callable which applies the given function to the result of them. + */ + public static <Input, Output> Callable<Output> bind( + Callable<Input> call, Function<Input, Callable<Output>> func) + { + return () -> func.apply(call.call()).call(); + } + + /** + * Convert a normal function to a function on callables. + * + * @param <Input> The input to the function. + * @param <Output> The output from the function. + * + * @param func The function to convert. + * + * @return The function, made to work over callables. + */ + public static <Input, Output> Function<Callable<Input>, Callable<Output>> + fmap(Function<Input, Output> func) + { + return (inp) -> () -> func.apply(inp.call()); + } + + /** + * Convert a future into a callable. + * + * @param <Output> The type returned by the future. + * + * @param fut The future to convert. + * + * @return A future which yields that value. + */ + public static <Output> Callable<Output> obtain(Future<Output> fut) + { + return () -> fut.get(); + } +} diff --git a/base/src/main/java/bjc/utils/funcutils/ChainIterator.java b/base/src/main/java/bjc/utils/funcutils/ChainIterator.java new file mode 100644 index 0000000..36f94e5 --- /dev/null +++ b/base/src/main/java/bjc/utils/funcutils/ChainIterator.java @@ -0,0 +1,54 @@ +package bjc.utils.funcutils; + +import java.util.*; +import java.util.function.*; + +/** + * A chain iterator. This is essentially flatMap in iterator form. + * + * @author bjculkin + * + * @param <T1> + * The type of the input values. + * + * @param <T2> + * The type of the output values. + */ +public class ChainIterator<T1, T2> implements Iterator<T2> { + private Iterator<T1> mainItr; + private Function<T1, Iterator<T2>> trans; + + private Iterator<T2> curItr; + + /** + * Create a new chain iterator. + * + * @param mainItr + * The main iterator for input. + * + * @param trans + * The transformation to use to produce the outputs. + */ + public ChainIterator(Iterator<T1> mainItr, Function<T1, Iterator<T2>> trans) { + this.mainItr = mainItr; + this.trans = trans; + } + + @Override + public boolean hasNext() { + if (curItr != null) { + return curItr.hasNext() ? true : mainItr.hasNext(); + } + + return mainItr.hasNext(); + } + + @Override + public T2 next() { + if (curItr == null || !curItr.hasNext()) { + curItr = trans.apply(mainItr.next()); + } + + return curItr.next(); + } +}
\ No newline at end of file diff --git a/base/src/main/java/bjc/utils/funcutils/FuncUtils.java b/base/src/main/java/bjc/utils/funcutils/FuncUtils.java index 70e521a..2c65876 100644 --- a/base/src/main/java/bjc/utils/funcutils/FuncUtils.java +++ b/base/src/main/java/bjc/utils/funcutils/FuncUtils.java @@ -29,9 +29,12 @@ public class FuncUtils { * * @return The function transformed into a unary function returning a function. */ - public static <A, B, C> Function<A, Function<B, C>> - curry2(final BiFunction<A, B, C> func) { - return arg1 -> arg2 -> func.apply(arg1, arg2); + public static <A, B, C> Function<A, Function<B, C>> curry2( + final BiFunction<A, B, C> func) + { + return arg1 -> + arg2 -> + func.apply(arg1, arg2); } /** @@ -43,14 +46,17 @@ public class FuncUtils { * @param cons * The action to perform. */ - public static void doTimes(final int nTimes, final Consumer<Integer> cons) { - for (int i = 0; i < nTimes; i++) { - cons.accept(i); - } + public static void doTimes( + final int nTimes, + final Consumer<Integer> cons) + { + for (int i = 0; i < nTimes; i++) cons.accept(i); } /** * Return an operator that executes until it converges. + * + * @param <T> The type the operator is on. * * @param op * The operator to execute. @@ -62,12 +68,15 @@ public class FuncUtils { * @return The requested operator. */ public static <T> UnaryOperator<T> converge(final UnaryOperator<T> op, - final int maxTries) { + final int maxTries) + { return converge(op, Object::equals, maxTries); } /** * Return an operator that executes until it converges. + * + * @param <T> The type the operator is on. * * @param op * The operator to execute. @@ -81,11 +90,14 @@ public class FuncUtils { * * @return The requested operator. */ - public static <T> UnaryOperator<T> converge(final UnaryOperator<T> op, - final BiPredicate<T, T> converged, final int maxTries) { + public static <T> UnaryOperator<T> converge( + final UnaryOperator<T> op, + final BiPredicate<T, T> converged, + final int maxTries) + { return val -> { T newVal = op.apply(val); - T oldVal; + T oldVal = newVal; int tries = 0; diff --git a/base/src/main/java/bjc/utils/funcutils/Isomorphism.java b/base/src/main/java/bjc/utils/funcutils/Isomorphism.java deleted file mode 100644 index c219d7f..0000000 --- a/base/src/main/java/bjc/utils/funcutils/Isomorphism.java +++ /dev/null @@ -1,59 +0,0 @@ -package bjc.utils.funcutils; - -import java.util.function.Function; - -/** - * A pair of functions to transform between a pair of types. - * - * @author bjculkin - * - * @param <S> - * The source type of the isomorphism. - * - * @param <D> - * The destination type of isomorphism. - */ -public class Isomorphism<S, D> { - /* The function to the destination type. */ - private Function<S, D> toFunc; - /* The function to the source type. */ - private Function<D, S> fromFunc; - - /** - * Create a new isomorphism. - * - * @param to - * The 'forward' function, from the source to the definition. - * - * @param from - * The 'backward' function, from the definition to the source. - */ - public Isomorphism(Function<S, D> to, Function<D, S> from) { - toFunc = to; - fromFunc = from; - } - - /** - * Apply the isomorphism forward. - * - * @param val - * The source value. - * - * @return The destination value. - */ - public D to(S val) { - return toFunc.apply(val); - } - - /** - * Apply the isomorphism backward. - * - * @param val - * The destination value. - * - * @return The source value. - */ - public S from(D val) { - return fromFunc.apply(val); - } -} diff --git a/base/src/main/java/bjc/utils/funcutils/IteratorUtils.java b/base/src/main/java/bjc/utils/funcutils/IteratorUtils.java index 8d51996..ea67295 100644 --- a/base/src/main/java/bjc/utils/funcutils/IteratorUtils.java +++ b/base/src/main/java/bjc/utils/funcutils/IteratorUtils.java @@ -3,7 +3,7 @@ package bjc.utils.funcutils; import java.util.*; import java.util.function.*; -import bjc.data.ArrayIterator; +import bjc.data.*; /** * Utility methods for dealing with iterators. @@ -13,57 +13,9 @@ import bjc.data.ArrayIterator; */ public class IteratorUtils { /** - * A chain iterator. This is essentially flatMap in iterator form. - * - * @author bjculkin - * - * @param <T1> - * The type of the input values. - * - * @param <T2> - * The type of the output values. - */ - public static class ChainIterator<T1, T2> implements Iterator<T2> { - private Iterator<T1> mainItr; - private Function<T1, Iterator<T2>> trans; - - private Iterator<T2> curItr; - - /** - * Create a new chain iterator. - * - * @param mainItr - * The main iterator for input. - * - * @param trans - * The transformation to use to produce the outputs. - */ - public ChainIterator(Iterator<T1> mainItr, Function<T1, Iterator<T2>> trans) { - this.mainItr = mainItr; - this.trans = trans; - } - - @Override - public boolean hasNext() { - if (curItr != null) { - return curItr.hasNext() ? true : mainItr.hasNext(); - } - - return mainItr.hasNext(); - } - - @Override - public T2 next() { - if (curItr == null || !curItr.hasNext()) { - curItr = trans.apply(mainItr.next()); - } - - return curItr.next(); - } - } - - /** * Convert an iterator to an iterable. + * + * @param <E> The type being iterated over. * * @param itr * The iterator to convert. @@ -77,6 +29,8 @@ public class IteratorUtils { /** * Convert an iterable to an iterator. * + * @param <E> The type being iterated over. + * * @param itr * The iterable to convert. * @@ -89,18 +43,23 @@ public class IteratorUtils { /** * Convert an array to an iterator. * + * @param <E> The type being iterated over. + * * @param parms * The array to iterate over. * * @return An iterator over the provided array. */ @SafeVarargs - public static <E> Iterator<E> AI(E... parms) { + public static <E> Iterator<E> I(E... parms) { return new ArrayIterator<>(parms); } /** * Create a chain iterator. + * + * @param <A> The initial type being iterated over. + * @param <B> The resulting type being iterated over. * * @param itrA * The iterator for input values. @@ -114,4 +73,43 @@ public class IteratorUtils { Function<A, Iterator<B>> itrB) { return new ChainIterator<>(itrA, itrB); } + + /** + * Perform a left-fold over an iterator. + * + * @param <ElementType> The type of elements in the iterator. + * @param <ResultType> The result from the fold. + * + * @param itr The items to iterate over. + * @param zero The initial element for the fold. + * @param folder The function that does the folding. + * + * @return The result of folding over the iterator. + */ + public static <ElementType, ResultType> ResultType foldLeft( + Iterable<ElementType> itr, + ResultType zero, + BiFunction<ElementType, ResultType, ResultType> folder) + { + ResultType state = zero; + for (ElementType elem : itr) { + state = folder.apply(elem, state); + } + return state; + } + + /** + * Creates an 'entangled' pair of a consumer and an iterator. + * + * @param <ElementType> The type of value involved. + * + * @return A pair consisting of a consumer of values, and an iterator that + * yields the consumed values. + */ + public static <ElementType> + IPair<Consumer<ElementType>, Iterator<ElementType>> entangle() + { + Queue<ElementType> backer = new ArrayDeque<>(); + return IPair.pair(backer::add, new QueueBackedIterator<>(backer)); + } } diff --git a/base/src/main/java/bjc/utils/funcutils/QueueBackedIterator.java b/base/src/main/java/bjc/utils/funcutils/QueueBackedIterator.java new file mode 100644 index 0000000..8b9f401 --- /dev/null +++ b/base/src/main/java/bjc/utils/funcutils/QueueBackedIterator.java @@ -0,0 +1,36 @@ +package bjc.utils.funcutils; + +import java.util.*; + +/** + * An iterator backed by a queue. + * + * @author Ben Culkin + * + * @param <ElementType> The type of element + */ +public class QueueBackedIterator<ElementType> + implements Iterator<ElementType> +{ + private final Queue<ElementType> backer; + + /** + * Create a new queue-backed iterator. + * + * @param backer The queue which backs this iterator. + */ + public QueueBackedIterator(Queue<ElementType> backer) + { + this.backer = backer; + } + + @Override + public boolean hasNext() { + return !backer.isEmpty(); + } + + @Override + public ElementType next() { + return backer.remove(); + } +}
\ No newline at end of file diff --git a/base/src/main/java/bjc/utils/funcutils/Strategy.java b/base/src/main/java/bjc/utils/funcutils/Strategy.java new file mode 100644 index 0000000..316879f --- /dev/null +++ b/base/src/main/java/bjc/utils/funcutils/Strategy.java @@ -0,0 +1,81 @@ +package bjc.utils.funcutils; + +import java.util.concurrent.*; +import java.util.function.*; + +/** + * Strategy for dealing with parallel execution. + * + * @author Ben Culkin + * + * @param <Output> The type returned by the tasks. + * + */ +public interface Strategy<Output> extends Function<Callable<Output>, Future<Output>> +{ + /** + * Convert a function into one which operates concurrently, using this strategy. + * + * @param <Input> The type of the function argument. + * + * @param func The type of the function. + * + * @return A function which executes concurrently. + */ + public default <Input> Function<Input, Future<Output>> using(Function<Input, Output> func) + { + return (input) -> this.apply(() -> func.apply(input)); + } + + /** + * A strategy which will run tasks in serial. + * + * @param <Output> The type returned by the task. + * + * @return A strategy which executes things serially. + */ + public static <Output> Strategy<Output> serial() + { + return (call) -> { + FutureTask<Output> task = new FutureTask<>(call); + task.run(); + return task; + }; + } + /** + * A strategy which creates a fresh thread to execute a task on. + * + * @param <Output> The type returned by the task. + * + * @return A strategy which uses threads to create tasks. + */ + public static <Output> Strategy<Output> simpleThread() + { + // I leave this as an example as of what is possible with combinators. + // return (call) -> invoke(introducing( + // () -> new FutureTask<>(call), + // (task, input) -> doWith( + // (FutureTask<Output> tsk) -> + // new Thread(task).start()).apply(task) + // )); + return (call) -> { + FutureTask<Output> task = new FutureTask<>(call); + new Thread(task).start(); + return task; + }; + } + + /** + * A strategy that uses an executor service. + * + * @param <Output> The type returned by the task. + * + * @param svc The executor service to use. + * + * @return A strategy which uses the provided executor. + */ + public static <Output> Strategy<Output> executorService(ExecutorService svc) + { + return svc::submit; + } +} diff --git a/base/src/main/java/bjc/utils/patterns/ComplexPattern.java b/base/src/main/java/bjc/utils/patterns/ComplexPattern.java index 3926f2c..e9035df 100644 --- a/base/src/main/java/bjc/utils/patterns/ComplexPattern.java +++ b/base/src/main/java/bjc/utils/patterns/ComplexPattern.java @@ -35,6 +35,8 @@ public interface ComplexPattern<ReturnType, PredType, InputType> { */ ReturnType apply(InputType input, PredType state); + /* Pattern producing functions */ + /** * Create a pattern composed from a predicate & a function. * @@ -49,7 +51,8 @@ public interface ComplexPattern<ReturnType, PredType, InputType> { */ static <RetType, PreType, InpType> ComplexPattern<RetType, PreType, InpType> from( Function<InpType, IPair<Boolean, PreType>> matcher, - BiFunction<InpType, PreType, RetType> accepter) { + BiFunction<InpType, PreType, RetType> accepter) + { return new FunctionalPattern<>(matcher, accepter); } @@ -68,7 +71,8 @@ public interface ComplexPattern<ReturnType, PredType, InputType> { @SuppressWarnings("unchecked") static <ClassType, RetType, InpType> ComplexPattern<RetType, ?, InpType> ofClass( Class<ClassType> clasz, - Function<ClassType, RetType> action) { + Function<ClassType, RetType> action) + { return from( (input) -> IPair.pair(clasz.isInstance(input), null), (input, ignored) -> action.apply((ClassType)input) @@ -89,11 +93,12 @@ public interface ComplexPattern<ReturnType, PredType, InputType> { static <RetType, InpType> ComplexPattern<RetType, ?, InpType> matchesObject( InpType obj, Function<InpType, RetType> action - ) { + ) + { return from( - (input) -> IPair.pair(obj.equals(input), null), - (input, ignored) -> action.apply(input) - ); + (input) -> IPair.pair(obj.equals(input), null), + (input, ignored) -> action.apply(input) + ); } /** @@ -113,13 +118,16 @@ public interface ComplexPattern<ReturnType, PredType, InputType> { static <RetType, InpType> ComplexPattern<RetType, ?, InpType> equalsString( String pattern, BiFunction<InpType, String, RetType> action - ) { + ) + { + Function<InpType, IPair<Boolean, String>> matcher = (input) -> { + String objString = input.toString(); + + return IPair.pair(pattern.equals(objString), objString); + }; + return from( - (input) -> { - String objString = input.toString(); - - return IPair.pair(pattern.equals(objString), objString); - }, + matcher, (input, objString) -> action.apply(input, objString) ); } @@ -140,21 +148,21 @@ public interface ComplexPattern<ReturnType, PredType, InputType> { String regex, Predicate<Matcher> cond, BiFunction<InpType, Matcher, RetType> action - ) { + ) + { java.util.regex.Pattern regexPat = java.util.regex.Pattern.compile(regex); + Function<InpType, IPair<Boolean, Matcher>> matcher = (input) -> { + String inpString = input.toString(); + + Matcher mat = regexPat.matcher(inpString); + + if (cond.test(mat)) return IPair.pair(true, mat); + else return IPair.pair(false, null); + }; + return from( - (input) -> { - String inpString = input.toString(); - - Matcher mat = regexPat.matcher(inpString); - - if (cond.test(mat)) { - return IPair.pair(true, mat); - } else { - return IPair.pair(false, null); - } - }, + matcher, (input, res) -> action.apply(input, res) ); } @@ -162,6 +170,7 @@ public interface ComplexPattern<ReturnType, PredType, InputType> { // @TODO Nov 21, 2020 Ben Culkin :MorePatterns // Try and write something to iterate over Iterator in a type-safe manner // Also, something for doing a sub-pattern match + /** * Create a pattern which will always execute. * @@ -174,10 +183,41 @@ public interface ComplexPattern<ReturnType, PredType, InputType> { */ static <RetType, InpType> ComplexPattern<RetType, ?, InpType> otherwise( Function<InpType, RetType> action - ) { + ) + { return from( (input) -> IPair.pair(true, null), (input, ignored) -> action.apply(input) ); } + + /** + * Create a pattern which checks if the string form of a given object starts + * with a specific string. + * + * @param <RetType> The type returned by the matcher. + * @param <InpType> The type being matched against. + * + * @param pattern The string to check against. + * @param action The action to execute. + * + * @return A pattern which functions as described. + */ + static <RetType, InpType> ComplexPattern<RetType, String, InpType> startsWith( + String pattern, + Function<String, RetType> action) + { + return from((input) -> { + String objString = input.toString(); + + if (objString.startsWith(pattern)) { + return IPair.pair( + true, + objString.substring( + pattern.length())); + } else { + return IPair.pair(false, null); + } + }, (ignored, input) -> action.apply(input)); + } }
\ No newline at end of file diff --git a/base/src/main/java/bjc/utils/patterns/MutablePatternMatcher.java b/base/src/main/java/bjc/utils/patterns/MutablePatternMatcher.java index 7900262..8e040fe 100644 --- a/base/src/main/java/bjc/utils/patterns/MutablePatternMatcher.java +++ b/base/src/main/java/bjc/utils/patterns/MutablePatternMatcher.java @@ -13,9 +13,10 @@ import bjc.data.*; * @author Ben Culkin * * @param <ReturnType> The type returned by the pattern matcher. + * @param <InputType> The type of the input to match against. */ public class MutablePatternMatcher<ReturnType, InputType> - implements IPatternMatcher<ReturnType, InputType>{ + implements IPatternMatcher<ReturnType, InputType> { private final List<ComplexPattern<ReturnType, Object, InputType>> patterns; /** @@ -45,15 +46,15 @@ public class MutablePatternMatcher<ReturnType, InputType> @Override public ReturnType matchFor(InputType input) throws NonExhaustiveMatch { Iterator<ComplexPattern<ReturnType, Object, InputType>> iterator; - for (iterator = new NonCMEIterator<>(patterns); - iterator.hasNext();) { + iterator = new NonCMEIterator<>(patterns); + while(iterator.hasNext()) { ComplexPattern<ReturnType, Object, InputType> pattern = iterator.next(); IPair<Boolean, Object> matches = pattern.matches(input); - if (matches.getLeft()) { - pattern.apply(input, matches.getRight()); - } + matches.doWith((bool, obj) -> { + if (bool) pattern.apply(input, obj); + }); } throw new NonExhaustiveMatch("Non-exhaustive match against " + input); diff --git a/base/src/main/java/bjc/utils/patterns/Pattern.java b/base/src/main/java/bjc/utils/patterns/Pattern.java index e03623e..c9902e8 100644 --- a/base/src/main/java/bjc/utils/patterns/Pattern.java +++ b/base/src/main/java/bjc/utils/patterns/Pattern.java @@ -1,11 +1,5 @@ package bjc.utils.patterns; -import java.util.*; -import java.util.function.*; -import java.util.regex.*; - -import bjc.data.*; - /** * A simpler version of ComplexPattern, which always applies against Object * |