1 files changed, 60 insertions, 0 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();
+	}
+}