From 581aec7d05f06456a384aa9adef7d781a666bf91 Mon Sep 17 00:00:00 2001
From: Michael Williamson <mike@zwobble.org>
Date: Sat, 26 Mar 2016 17:57:45 +0000
Subject: Remove Mammoth prefix from util classes

---
 .../zwobble/mammoth/internal/util/Iterables.java   | 106 +++++++++++++++++++++
 .../org/zwobble/mammoth/internal/util/Lists.java   | 101 ++++++++++++++++++++
 .../mammoth/internal/util/MammothIterables.java    | 106 ---------------------
 .../mammoth/internal/util/MammothLists.java        | 101 --------------------
 .../zwobble/mammoth/internal/util/MammothMaps.java |  97 -------------------
 .../mammoth/internal/util/MammothOptionals.java    |  38 --------
 .../zwobble/mammoth/internal/util/MammothSets.java |  36 -------
 .../mammoth/internal/util/MammothStrings.java      |  15 ---
 .../org/zwobble/mammoth/internal/util/Maps.java    |  97 +++++++++++++++++++
 .../zwobble/mammoth/internal/util/Optionals.java   |  38 ++++++++
 .../org/zwobble/mammoth/internal/util/Sets.java    |  36 +++++++
 .../org/zwobble/mammoth/internal/util/Strings.java |  15 +++
 12 files changed, 393 insertions(+), 393 deletions(-)
 create mode 100644 src/main/java/org/zwobble/mammoth/internal/util/Iterables.java
 create mode 100644 src/main/java/org/zwobble/mammoth/internal/util/Lists.java
 delete mode 100644 src/main/java/org/zwobble/mammoth/internal/util/MammothIterables.java
 delete mode 100644 src/main/java/org/zwobble/mammoth/internal/util/MammothLists.java
 delete mode 100644 src/main/java/org/zwobble/mammoth/internal/util/MammothMaps.java
 delete mode 100644 src/main/java/org/zwobble/mammoth/internal/util/MammothOptionals.java
 delete mode 100644 src/main/java/org/zwobble/mammoth/internal/util/MammothSets.java
 delete mode 100644 src/main/java/org/zwobble/mammoth/internal/util/MammothStrings.java
 create mode 100644 src/main/java/org/zwobble/mammoth/internal/util/Maps.java
 create mode 100644 src/main/java/org/zwobble/mammoth/internal/util/Optionals.java
 create mode 100644 src/main/java/org/zwobble/mammoth/internal/util/Sets.java
 create mode 100644 src/main/java/org/zwobble/mammoth/internal/util/Strings.java

(limited to 'src/main/java/org/zwobble/mammoth/internal/util')

diff --git a/src/main/java/org/zwobble/mammoth/internal/util/Iterables.java b/src/main/java/org/zwobble/mammoth/internal/util/Iterables.java
new file mode 100644
index 0000000..e9246c3
--- /dev/null
+++ b/src/main/java/org/zwobble/mammoth/internal/util/Iterables.java
@@ -0,0 +1,106 @@
+package org.zwobble.mammoth.internal.util;
+
+import java.util.Iterator;
+import java.util.Optional;
+import java.util.function.Function;
+import java.util.function.Predicate;
+import java.util.stream.Stream;
+import java.util.stream.StreamSupport;
+
+public class Iterables {
+    public static <T> Optional<T> tryFind(Iterable<T> iterable, Predicate<T> predicate) {
+        for (T element : iterable) {
+            if (predicate.test(element)) {
+                return Optional.of(element);
+            }
+        }
+        return Optional.empty();
+    }
+
+    public static <T, R> Iterable<R> lazyMap(Iterable<T> iterable, Function<T, R> function) {
+        return new Iterable<R>() {
+            @Override
+            public Iterator<R> iterator() {
+                return map(iterable.iterator(), function);
+            }
+        };
+    }
+
+    public static <T> T getFirst(Iterable<? extends T> iterable, T defaultValue) {
+        Iterator<? extends T> iterator = iterable.iterator();
+        if (iterator.hasNext()) {
+            return iterator.next();
+        } else {
+            return defaultValue;
+        }
+    }
+
+    public static <T, R> Iterable<R> lazyFlatMap(Iterable<T> iterable, Function<T, Iterable<R>> function) {
+        return lazyFlatten(lazyMap(iterable, function));
+    }
+
+    public static <T> Iterable<T> lazyConcat(Iterable<T> iterable1, Iterable<T> iterable2) {
+        return new Iterable<T>() {
+            @Override
+            public Iterator<T> iterator() {
+                return Stream.concat(stream(iterable1), stream(iterable2)).iterator();
+            }
+        };
+    }
+
+    public static <T> Iterable<T> lazyFlatten(Iterable<? extends Iterable<T>> iterables) {
+        return new Iterable<T>() {
+            @Override
+            public Iterator<T> iterator() {
+                return stream(iterables)
+                    .flatMap(iterable -> stream(iterable))
+                    .iterator();
+            }
+        };
+    }
+
+    public static <T> Iterable<T> lazyFilter(Iterable<T> iterables, Predicate<T> predicate) {
+        return new Iterable<T>() {
+            @Override
+            public Iterator<T> iterator() {
+                return stream(iterables)
+                    .filter(predicate)
+                    .iterator();
+            }
+        };
+    }
+
+    public static <T, R> Iterable<R> lazyFilter(Iterable<T> iterables, Class<R> clazz) {
+        return new Iterable<R>() {
+            @Override
+            @SuppressWarnings("unchecked")
+            public Iterator<R> iterator() {
+                return (Iterator<R>) stream(iterables)
+                    .filter(clazz::isInstance)
+                    .iterator();
+            }
+        };
+    }
+
+    private static <T, R> Iterator<R> map(Iterator<T> iterator, Function<T, R> function) {
+        return new Iterator<R>() {
+            @Override
+            public boolean hasNext() {
+                return iterator.hasNext();
+            }
+
+            @Override
+            public R next() {
+                return function.apply(iterator.next());
+            }
+        };
+    }
+
+    public static <T> boolean any(Iterable<T> iterable, Predicate<T> predicate) {
+        return stream(iterable).anyMatch(predicate);
+    }
+
+    public static <T> Stream<T> stream(Iterable<T> iterable) {
+        return StreamSupport.stream(iterable.spliterator(), false);
+    }
+}
diff --git a/src/main/java/org/zwobble/mammoth/internal/util/Lists.java b/src/main/java/org/zwobble/mammoth/internal/util/Lists.java
new file mode 100644
index 0000000..fc45c19
--- /dev/null
+++ b/src/main/java/org/zwobble/mammoth/internal/util/Lists.java
@@ -0,0 +1,101 @@
+package org.zwobble.mammoth.internal.util;
+
+import java.util.*;
+import java.util.function.Function;
+import java.util.function.Predicate;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import static java.util.Arrays.asList;
+import static org.zwobble.mammoth.internal.util.Iterables.stream;
+
+public class Lists {
+    public static <T> List<T> list() {
+        return Collections.emptyList();
+    }
+
+    public static <T> List<T> list(T value1) {
+        return Collections.singletonList(value1);
+    }
+
+    public static <T> List<T> list(T value1, T value2) {
+        return asList(value1, value2);
+    }
+
+    public static <T> List<T> list(T value1, T value2, T value3) {
+        return asList(value1, value2, value3);
+    }
+
+    @SafeVarargs
+    public static <T> List<T> list(T... values) {
+        return asList(values);
+    }
+
+    public static <T> List<T> cons(T head, Iterable<T> tail) {
+        return eagerConcat(list(head), tail);
+    }
+
+    public static <T> List<T> eagerConcat(Iterable<T> first, Iterable<T> second) {
+        return Stream.concat(stream(first), stream(second)).collect(Collectors.toList());
+    }
+
+    public static <T> List<T> eagerFilter(Iterable<T> iterable, Predicate<T> predicate) {
+        return stream(iterable).filter(predicate).collect(Collectors.toList());
+    }
+
+    public static <T, R> List<R> eagerMap(Iterable<T> iterable, Function<T, R> function) {
+        return stream(iterable).map(function).collect(Collectors.toList());
+    }
+
+    public static <T, R> List<R> eagerFlatMap(Iterable<T> iterable, Function<T, Iterable<R>> function) {
+        return stream(iterable)
+            .flatMap(element -> stream(function.apply(element)))
+            .collect(Collectors.toList());
+    }
+
+    public static <T, R extends Comparable<R>> List<T> orderedBy(Iterable<T> iterable, Function<T, R> getKey) {
+        return stream(iterable)
+            .sorted(orderBy(getKey))
+            .collect(Collectors.toList());
+    }
+
+    private static <T, R extends Comparable<R>> Comparator<T> orderBy(Function<T, R> getKey) {
+        return (first, second) -> getKey.apply(first).compareTo(getKey.apply(second));
+    }
+
+    public static <T> List<T> toList(Iterable<T> iterable) {
+        return stream(iterable).collect(Collectors.toList());
+    }
+
+    public static <T> Optional<T> tryGetLast(List<T> list) {
+        if (list.isEmpty()) {
+            return Optional.empty();
+        } else {
+            return Optional.of(list.get(list.size() - 1));
+        }
+    }
+
+    public static <T> List<T> skip(List<T> list, int count) {
+        return list.subList(Math.min(list.size(), count), list.size());
+    }
+
+    public static <T> Iterable<T> reversed(List<T> list) {
+        return new Iterable<T>() {
+            @Override
+            public Iterator<T> iterator() {
+                ListIterator<T> iterator = list.listIterator(list.size());
+                return new Iterator<T>() {
+                    @Override
+                    public boolean hasNext() {
+                        return iterator.hasPrevious();
+                    }
+
+                    @Override
+                    public T next() {
+                        return iterator.previous();
+                    }
+                };
+            }
+        };
+    }
+}
diff --git a/src/main/java/org/zwobble/mammoth/internal/util/MammothIterables.java b/src/main/java/org/zwobble/mammoth/internal/util/MammothIterables.java
deleted file mode 100644
index 11f4f52..0000000
--- a/src/main/java/org/zwobble/mammoth/internal/util/MammothIterables.java
+++ /dev/null
@@ -1,106 +0,0 @@
-package org.zwobble.mammoth.internal.util;
-
-import java.util.Iterator;
-import java.util.Optional;
-import java.util.function.Function;
-import java.util.function.Predicate;
-import java.util.stream.Stream;
-import java.util.stream.StreamSupport;
-
-public class MammothIterables {
-    public static <T> Optional<T> tryFind(Iterable<T> iterable, Predicate<T> predicate) {
-        for (T element : iterable) {
-            if (predicate.test(element)) {
-                return Optional.of(element);
-            }
-        }
-        return Optional.empty();
-    }
-
-    public static <T, R> Iterable<R> lazyMap(Iterable<T> iterable, Function<T, R> function) {
-        return new Iterable<R>() {
-            @Override
-            public Iterator<R> iterator() {
-                return map(iterable.iterator(), function);
-            }
-        };
-    }
-
-    public static <T> T getFirst(Iterable<? extends T> iterable, T defaultValue) {
-        Iterator<? extends T> iterator = iterable.iterator();
-        if (iterator.hasNext()) {
-            return iterator.next();
-        } else {
-            return defaultValue;
-        }
-    }
-
-    public static <T, R> Iterable<R> lazyFlatMap(Iterable<T> iterable, Function<T, Iterable<R>> function) {
-        return lazyFlatten(lazyMap(iterable, function));
-    }
-
-    public static <T> Iterable<T> lazyConcat(Iterable<T> iterable1, Iterable<T> iterable2) {
-        return new Iterable<T>() {
-            @Override
-            public Iterator<T> iterator() {
-                return Stream.concat(stream(iterable1), stream(iterable2)).iterator();
-            }
-        };
-    }
-
-    public static <T> Iterable<T> lazyFlatten(Iterable<? extends Iterable<T>> iterables) {
-        return new Iterable<T>() {
-            @Override
-            public Iterator<T> iterator() {
-                return stream(iterables)
-                    .flatMap(iterable -> stream(iterable))
-                    .iterator();
-            }
-        };
-    }
-
-    public static <T> Iterable<T> lazyFilter(Iterable<T> iterables, Predicate<T> predicate) {
-        return new Iterable<T>() {
-            @Override
-            public Iterator<T> iterator() {
-                return stream(iterables)
-                    .filter(predicate)
-                    .iterator();
-            }
-        };
-    }
-
-    public static <T, R> Iterable<R> lazyFilter(Iterable<T> iterables, Class<R> clazz) {
-        return new Iterable<R>() {
-            @Override
-            @SuppressWarnings("unchecked")
-            public Iterator<R> iterator() {
-                return (Iterator<R>) stream(iterables)
-                    .filter(clazz::isInstance)
-                    .iterator();
-            }
-        };
-    }
-
-    private static <T, R> Iterator<R> map(Iterator<T> iterator, Function<T, R> function) {
-        return new Iterator<R>() {
-            @Override
-            public boolean hasNext() {
-                return iterator.hasNext();
-            }
-
-            @Override
-            public R next() {
-                return function.apply(iterator.next());
-            }
-        };
-    }
-
-    public static <T> boolean any(Iterable<T> iterable, Predicate<T> predicate) {
-        return stream(iterable).anyMatch(predicate);
-    }
-
-    public static <T> Stream<T> stream(Iterable<T> iterable) {
-        return StreamSupport.stream(iterable.spliterator(), false);
-    }
-}
diff --git a/src/main/java/org/zwobble/mammoth/internal/util/MammothLists.java b/src/main/java/org/zwobble/mammoth/internal/util/MammothLists.java
deleted file mode 100644
index 10d5be3..0000000
--- a/src/main/java/org/zwobble/mammoth/internal/util/MammothLists.java
+++ /dev/null
@@ -1,101 +0,0 @@
-package org.zwobble.mammoth.internal.util;
-
-import java.util.*;
-import java.util.function.Function;
-import java.util.function.Predicate;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
-
-import static java.util.Arrays.asList;
-import static org.zwobble.mammoth.internal.util.MammothIterables.stream;
-
-public class MammothLists {
-    public static <T> List<T> list() {
-        return Collections.emptyList();
-    }
-
-    public static <T> List<T> list(T value1) {
-        return Collections.singletonList(value1);
-    }
-
-    public static <T> List<T> list(T value1, T value2) {
-        return asList(value1, value2);
-    }
-
-    public static <T> List<T> list(T value1, T value2, T value3) {
-        return asList(value1, value2, value3);
-    }
-
-    @SafeVarargs
-    public static <T> List<T> list(T... values) {
-        return asList(values);
-    }
-
-    public static <T> List<T> cons(T head, Iterable<T> tail) {
-        return eagerConcat(list(head), tail);
-    }
-
-    public static <T> List<T> eagerConcat(Iterable<T> first, Iterable<T> second) {
-        return Stream.concat(stream(first), stream(second)).collect(Collectors.toList());
-    }
-
-    public static <T> List<T> eagerFilter(Iterable<T> iterable, Predicate<T> predicate) {
-        return stream(iterable).filter(predicate).collect(Collectors.toList());
-    }
-
-    public static <T, R> List<R> eagerMap(Iterable<T> iterable, Function<T, R> function) {
-        return stream(iterable).map(function).collect(Collectors.toList());
-    }
-
-    public static <T, R> List<R> eagerFlatMap(Iterable<T> iterable, Function<T, Iterable<R>> function) {
-        return stream(iterable)
-            .flatMap(element -> stream(function.apply(element)))
-            .collect(Collectors.toList());
-    }
-
-    public static <T, R extends Comparable<R>> List<T> orderedBy(Iterable<T> iterable, Function<T, R> getKey) {
-        return stream(iterable)
-            .sorted(orderBy(getKey))
-            .collect(Collectors.toList());
-    }
-
-    private static <T, R extends Comparable<R>> Comparator<T> orderBy(Function<T, R> getKey) {
-        return (first, second) -> getKey.apply(first).compareTo(getKey.apply(second));
-    }
-
-    public static <T> List<T> toList(Iterable<T> iterable) {
-        return stream(iterable).collect(Collectors.toList());
-    }
-
-    public static <T> Optional<T> tryGetLast(List<T> list) {
-        if (list.isEmpty()) {
-            return Optional.empty();
-        } else {
-            return Optional.of(list.get(list.size() - 1));
-        }
-    }
-
-    public static <T> List<T> skip(List<T> list, int count) {
-        return list.subList(Math.min(list.size(), count), list.size());
-    }
-
-    public static <T> Iterable<T> reversed(List<T> list) {
-        return new Iterable<T>() {
-            @Override
-            public Iterator<T> iterator() {
-                ListIterator<T> iterator = list.listIterator(list.size());
-                return new Iterator<T>() {
-                    @Override
-                    public boolean hasNext() {
-                        return iterator.hasPrevious();
-                    }
-
-                    @Override
-                    public T next() {
-                        return iterator.previous();
-                    }
-                };
-            }
-        };
-    }
-}
diff --git a/src/main/java/org/zwobble/mammoth/internal/util/MammothMaps.java b/src/main/java/org/zwobble/mammoth/internal/util/MammothMaps.java
deleted file mode 100644
index d3ba8c5..0000000
--- a/src/main/java/org/zwobble/mammoth/internal/util/MammothMaps.java
+++ /dev/null
@@ -1,97 +0,0 @@
-package org.zwobble.mammoth.internal.util;
-
-import java.util.*;
-import java.util.function.Function;
-
-public class MammothMaps {
-    public static <K, V> Map<K, V> map() {
-        return Collections.emptyMap();
-    }
-
-    public static <K, V> Map<K, V> map(K key1, V value1) {
-        return Collections.singletonMap(key1, value1);
-    }
-
-    public static <K, V> Map<K, V> map(K key1, V value1, K key2, V value2) {
-        Map<K, V> map = new HashMap<>();
-        map.put(key1, value1);
-        map.put(key2, value2);
-        return map;
-    }
-
-    public static <K, V> Map<K, V> map(K key1, V value1, K key2, V value2, K key3, V value3) {
-        Map<K, V> map = new HashMap<>();
-        map.put(key1, value1);
-        map.put(key2, value2);
-        map.put(key3, value3);
-        return map;
-    }
-
-    public static <K, V> Map.Entry<K, V> entry(K key, V value) {
-        return new AbstractMap.SimpleImmutableEntry<K, V>(key, value);
-    }
-
-    public static <K, V> Optional<V> lookup(Map<K, V> map, K key) {
-        return Optional.ofNullable(map.get(key));
-    }
-
-    public static <T, K> Map<K, T> toMapWithKey(Iterable<T> iterable, Function<T, K> function) {
-        return toMap(iterable, element -> entry(function.apply(element), element));
-    }
-
-    public static <T, K, V> Map<K, V> toMap(Iterable<T> iterable, Function<T, Map.Entry<K, V>> function) {
-        Map<K, V> map = new HashMap<>();
-        for (T element : iterable) {
-            Map.Entry<K, V> entry = function.apply(element);
-            map.put(entry.getKey(), entry.getValue());
-        }
-        return map;
-    }
-
-    public static <T, K> Map<K, List<T>> toMultiMapWithKey(Iterable<T> iterable, Function<T, K> function) {
-        return toMultiMap(iterable, element -> entry(function.apply(element), element));
-    }
-
-    public static <T, K, V> Map<K, List<V>> toMultiMap(Iterable<T> iterable, Function<T, Map.Entry<K, V>> function) {
-        Map<K, List<V>> map = new HashMap<>();
-        for (T element : iterable) {
-            Map.Entry<K, V> pair = function.apply(element);
-            map.computeIfAbsent(pair.getKey(), key -> new ArrayList<V>())
-                .add(pair.getValue());
-        }
-        return map;
-    }
-
-    public static <K1, K2, V> Map<K2, V> eagerMapKeys(Map<K1, V> map, Function<K1, K2> function) {
-        Map<K2, V> result = new HashMap<>();
-        for (Map.Entry<K1, V> element : map.entrySet()) {
-            result.put(function.apply(element.getKey()), element.getValue());
-        }
-        return result;
-    }
-
-    public static <K, V1, V2> Map<K, V2> eagerMapValues(Map<K, V1> map, Function<V1, V2> function) {
-        Map<K, V2> result = new HashMap<>();
-        for (Map.Entry<K, V1> element : map.entrySet()) {
-            result.put(element.getKey(), function.apply(element.getValue()));
-        }
-        return result;
-    }
-
-    public static <K, V> Builder<K, V> builder() {
-        return new Builder<>();
-    }
-
-    public static class Builder<K, V> {
-        private final Map<K, V> values = new HashMap<>();
-
-        public Builder<K, V> put(K key, V value) {
-            values.put(key, value);
-            return this;
-        }
-
-        public Map<K, V> build() {
-            return values;
-        }
-    }
-}
diff --git a/src/main/java/org/zwobble/mammoth/internal/util/MammothOptionals.java b/src/main/java/org/zwobble/mammoth/internal/util/MammothOptionals.java
deleted file mode 100644
index 6f2c100..0000000
--- a/src/main/java/org/zwobble/mammoth/internal/util/MammothOptionals.java
+++ /dev/null
@@ -1,38 +0,0 @@
-package org.zwobble.mammoth.internal.util;
-
-import java.util.Optional;
-import java.util.function.BiFunction;
-
-public class MammothOptionals {
-    public static <T> Optional<T> first(Optional<T> first, Optional<T> second) {
-        if (first.isPresent()) {
-            return first;
-        } else {
-            return second;
-        }
-    }
-
-    public static <T1, T2, R> Optional<R> flatMap(
-        Optional<T1> first,
-        Optional<T2> second,
-        BiFunction<T1, T2, Optional<R>> function)
-    {
-        if (first.isPresent() && second.isPresent()) {
-            return function.apply(first.get(), second.get());
-        } else {
-            return Optional.empty();
-        }
-    }
-
-    public static <T1, T2, R> Optional<R> map(
-        Optional<T1> first,
-        Optional<T2> second,
-        BiFunction<T1, T2, R> function)
-    {
-        if (first.isPresent() && second.isPresent()) {
-            return Optional.of(function.apply(first.get(), second.get()));
-        } else {
-            return Optional.empty();
-        }
-    }
-}
diff --git a/src/main/java/org/zwobble/mammoth/internal/util/MammothSets.java b/src/main/java/org/zwobble/mammoth/internal/util/MammothSets.java
deleted file mode 100644
index 4f06efc..0000000
--- a/src/main/java/org/zwobble/mammoth/internal/util/MammothSets.java
+++ /dev/null
@@ -1,36 +0,0 @@
-package org.zwobble.mammoth.internal.util;
-
-import java.util.Collections;
-import java.util.HashSet;
-import java.util.Set;
-import java.util.stream.Collectors;
-
-import static java.util.Arrays.asList;
-import static org.zwobble.mammoth.internal.util.MammothIterables.stream;
-
-public class MammothSets {
-    public static <T> Set<T> set() {
-        return Collections.emptySet();
-    }
-
-    public static <T> Set<T> set(T value1) {
-        return Collections.singleton(value1);
-    }
-
-    @SafeVarargs
-    public static <T> Set<T> set(T... values) {
-        HashSet<T> set = new HashSet<>();
-        set.addAll(asList(values));
-        return set;
-    }
-
-    public static <T> Set<T> difference(Set<? extends T> set1, Set<? extends T> set2) {
-        HashSet<T> result = new HashSet<>(set1);
-        result.removeAll(set2);
-        return result;
-    }
-
-    public static <T> Set<T> toSet(Iterable<T> iterable) {
-        return stream(iterable).collect(Collectors.toSet());
-    }
-}
diff --git a/src/main/java/org/zwobble/mammoth/internal/util/MammothStrings.java b/src/main/java/org/zwobble/mammoth/internal/util/MammothStrings.java
deleted file mode 100644
index e5f98aa..0000000
--- a/src/main/java/org/zwobble/mammoth/internal/util/MammothStrings.java
+++ /dev/null
@@ -1,15 +0,0 @@
-package org.zwobble.mammoth.internal.util;
-
-public class MammothStrings {
-    public static String trimLeft(String value, char character) {
-        int index = 0;
-        while (index < value.length() && value.charAt(index) == character) {
-            index++;
-        }
-        return value.substring(index);
-    }
-
-    public static boolean isNullOrEmpty(String value) {
-        return value == null || value.isEmpty();
-    }
-}
diff --git a/src/main/java/org/zwobble/mammoth/internal/util/Maps.java b/src/main/java/org/zwobble/mammoth/internal/util/Maps.java
new file mode 100644
index 0000000..76ce5cf
--- /dev/null
+++ b/src/main/java/org/zwobble/mammoth/internal/util/Maps.java
@@ -0,0 +1,97 @@
+package org.zwobble.mammoth.internal.util;
+
+import java.util.*;
+import java.util.function.Function;
+
+public class Maps {
+    public static <K, V> Map<K, V> map() {
+        return Collections.emptyMap();
+    }
+
+    public static <K, V> Map<K, V> map(K key1, V value1) {
+        return Collections.singletonMap(key1, value1);
+    }
+
+    public static <K, V> Map<K, V> map(K key1, V value1, K key2, V value2) {
+        Map<K, V> map = new HashMap<>();
+        map.put(key1, value1);
+        map.put(key2, value2);
+        return map;
+    }
+
+    public static <K, V> Map<K, V> map(K key1, V value1, K key2, V value2, K key3, V value3) {
+        Map<K, V> map = new HashMap<>();
+        map.put(key1, value1);
+        map.put(key2, value2);
+        map.put(key3, value3);
+        return map;
+    }
+
+    public static <K, V> Map.Entry<K, V> entry(K key, V value) {
+        return new AbstractMap.SimpleImmutableEntry<K, V>(key, value);
+    }
+
+    public static <K, V> Optional<V> lookup(Map<K, V> map, K key) {
+        return Optional.ofNullable(map.get(key));
+    }
+
+    public static <T, K> Map<K, T> toMapWithKey(Iterable<T> iterable, Function<T, K> function) {
+        return toMap(iterable, element -> entry(function.apply(element), element));
+    }
+
+    public static <T, K, V> Map<K, V> toMap(Iterable<T> iterable, Function<T, Map.Entry<K, V>> function) {
+        Map<K, V> map = new HashMap<>();
+        for (T element : iterable) {
+            Map.Entry<K, V> entry = function.apply(element);
+            map.put(entry.getKey(), entry.getValue());
+        }
+        return map;
+    }
+
+    public static <T, K> Map<K, List<T>> toMultiMapWithKey(Iterable<T> iterable, Function<T, K> function) {
+        return toMultiMap(iterable, element -> entry(function.apply(element), element));
+    }
+
+    public static <T, K, V> Map<K, List<V>> toMultiMap(Iterable<T> iterable, Function<T, Map.Entry<K, V>> function) {
+        Map<K, List<V>> map = new HashMap<>();
+        for (T element : iterable) {
+            Map.Entry<K, V> pair = function.apply(element);
+            map.computeIfAbsent(pair.getKey(), key -> new ArrayList<V>())
+                .add(pair.getValue());
+        }
+        return map;
+    }
+
+    public static <K1, K2, V> Map<K2, V> eagerMapKeys(Map<K1, V> map, Function<K1, K2> function) {
+        Map<K2, V> result = new HashMap<>();
+        for (Map.Entry<K1, V> element : map.entrySet()) {
+            result.put(function.apply(element.getKey()), element.getValue());
+        }
+        return result;
+    }
+
+    public static <K, V1, V2> Map<K, V2> eagerMapValues(Map<K, V1> map, Function<V1, V2> function) {
+        Map<K, V2> result = new HashMap<>();
+        for (Map.Entry<K, V1> element : map.entrySet()) {
+            result.put(element.getKey(), function.apply(element.getValue()));
+        }
+        return result;
+    }
+
+    public static <K, V> Builder<K, V> builder() {
+        return new Builder<>();
+    }
+
+    public static class Builder<K, V> {
+        private final Map<K, V> values = new HashMap<>();
+
+        public Builder<K, V> put(K key, V value) {
+            values.put(key, value);
+            return this;
+        }
+
+        public Map<K, V> build() {
+            return values;
+        }
+    }
+}
diff --git a/src/main/java/org/zwobble/mammoth/internal/util/Optionals.java b/src/main/java/org/zwobble/mammoth/internal/util/Optionals.java
new file mode 100644
index 0000000..d98b579
--- /dev/null
+++ b/src/main/java/org/zwobble/mammoth/internal/util/Optionals.java
@@ -0,0 +1,38 @@
+package org.zwobble.mammoth.internal.util;
+
+import java.util.Optional;
+import java.util.function.BiFunction;
+
+public class Optionals {
+    public static <T> Optional<T> first(Optional<T> first, Optional<T> second) {
+        if (first.isPresent()) {
+            return first;
+        } else {
+            return second;
+        }
+    }
+
+    public static <T1, T2, R> Optional<R> flatMap(
+        Optional<T1> first,
+        Optional<T2> second,
+        BiFunction<T1, T2, Optional<R>> function)
+    {
+        if (first.isPresent() && second.isPresent()) {
+            return function.apply(first.get(), second.get());
+        } else {
+            return Optional.empty();
+        }
+    }
+
+    public static <T1, T2, R> Optional<R> map(
+        Optional<T1> first,
+        Optional<T2> second,
+        BiFunction<T1, T2, R> function)
+    {
+        if (first.isPresent() && second.isPresent()) {
+            return Optional.of(function.apply(first.get(), second.get()));
+        } else {
+            return Optional.empty();
+        }
+    }
+}
diff --git a/src/main/java/org/zwobble/mammoth/internal/util/Sets.java b/src/main/java/org/zwobble/mammoth/internal/util/Sets.java
new file mode 100644
index 0000000..c979740
--- /dev/null
+++ b/src/main/java/org/zwobble/mammoth/internal/util/Sets.java
@@ -0,0 +1,36 @@
+package org.zwobble.mammoth.internal.util;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+import static java.util.Arrays.asList;
+import static org.zwobble.mammoth.internal.util.Iterables.stream;
+
+public class Sets {
+    public static <T> Set<T> set() {
+        return Collections.emptySet();
+    }
+
+    public static <T> Set<T> set(T value1) {
+        return Collections.singleton(value1);
+    }
+
+    @SafeVarargs
+    public static <T> Set<T> set(T... values) {
+        HashSet<T> set = new HashSet<>();
+        set.addAll(asList(values));
+        return set;
+    }
+
+    public static <T> Set<T> difference(Set<? extends T> set1, Set<? extends T> set2) {
+        HashSet<T> result = new HashSet<>(set1);
+        result.removeAll(set2);
+        return result;
+    }
+
+    public static <T> Set<T> toSet(Iterable<T> iterable) {
+        return stream(iterable).collect(Collectors.toSet());
+    }
+}
diff --git a/src/main/java/org/zwobble/mammoth/internal/util/Strings.java b/src/main/java/org/zwobble/mammoth/internal/util/Strings.java
new file mode 100644
index 0000000..4f173ad
--- /dev/null
+++ b/src/main/java/org/zwobble/mammoth/internal/util/Strings.java
@@ -0,0 +1,15 @@
+package org.zwobble.mammoth.internal.util;
+
+public class Strings {
+    public static String trimLeft(String value, char character) {
+        int index = 0;
+        while (index < value.length() && value.charAt(index) == character) {
+            index++;
+        }
+        return value.substring(index);
+    }
+
+    public static boolean isNullOrEmpty(String value) {
+        return value == null || value.isEmpty();
+    }
+}
-- 
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