1 files changed, 70 insertions, 0 deletions
diff --git a/src/main/java/org/zwobble/couscous/util/FileSet.java b/src/main/java/org/zwobble/couscous/util/FileSet.java
new file mode 100644
index 0000000..c64c1e8
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/util/FileSet.java
@@ -0,0 +1,70 @@
+package org.zwobble.couscous.util;
+
+import com.google.common.base.Predicate;
+import com.google.common.collect.Iterables;
+
+import java.io.IOException;
+import java.nio.file.FileSystems;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import static org.zwobble.couscous.util.ExtraIterables.iterable;
+import static org.zwobble.couscous.util.ExtraLists.*;
+
+public class FileSet {
+    public static FileSet globs(List<String> files) {
+        return new FileSet(() -> {
+            Set<Path> paths = new HashSet<>();
+
+            for (String file : files) {
+                if (file.startsWith("!")) {
+                    walkFiles(path(file.substring(1))).forEach(paths::remove);
+                } else {
+                    walkFiles(path(file)).forEach(paths::add);
+                }
+            }
+
+            return paths.stream()
+                .sorted()
+                .iterator();
+        }, list());
+    }
+
+    private static Iterable<Path> walkFiles(Path root) {
+        return iterable(() -> {
+            try {
+                return Files.walk(root)
+                    .filter(path -> path.toFile().isFile());
+            } catch (IOException exception) {
+                throw new RuntimeException(exception);
+            }
+        });
+    }
+
+    private static Path path(String output) {
+        return FileSystems.getDefault().getPath(output);
+    }
+
+    public static FileSet directory(Path path) {
+        return new FileSet(walkFiles(path), list());
+    }
+
+    private final Iterable<Path> files;
+    private final List<Predicate<Path>> filters;
+
+    private FileSet(Iterable<Path> files, List<Predicate<Path>> filters) {
+        this.files = files;
+        this.filters = filters;
+    }
+
+    public FileSet filter(Predicate<Path> predicate) {
+        return new FileSet(files, cons(predicate, filters));
+    }
+
+    public List<Path> files() {
+        return eagerFilter(files, file -> Iterables.all(filters, filter -> filter.apply(file)));
+    }
+}