[commands] Add StartRun command factory (#6572)

wpilibNewCommands/src/main/native/cpp/frc2/command/Commands.cpp

@@ -58,6 +58,14 @@ CommandPtr cmd::RunEnd(std::function<void()> run, std::function<void()> end,
       .ToPtr();
 }
 
+CommandPtr cmd::StartRun(std::function<void()> start, std::function<void()> run,
+                         Requirements requirements) {
+  return FunctionalCommand(
+             std::move(start), std::move(run), [](bool interrupted) {},
+             [] { return false; }, requirements)
+      .ToPtr();
+}
+
 CommandPtr cmd::Print(std::string_view msg) {
   return PrintCommand(msg).ToPtr();
 }

wpilibNewCommands/src/main/native/cpp/frc2/command/Subsystem.cpp

@@ -61,6 +61,11 @@ CommandPtr Subsystem::RunEnd(std::function<void()> run,
   return cmd::RunEnd(std::move(run), std::move(end), {this});
 }
 
+CommandPtr Subsystem::StartRun(std::function<void()> start,
+                               std::function<void()> run) {
+  return cmd::StartRun(std::move(start), std::move(run), {this});
+}
+
 CommandPtr Subsystem::Defer(wpi::unique_function<CommandPtr()> supplier) {
   return cmd::Defer(std::move(supplier), {this});
 }

wpilibNewCommands/src/main/native/include/frc2/command/Commands.h

@@ -86,6 +86,18 @@ CommandPtr StartEnd(std::function<void()> start, std::function<void()> end,
 CommandPtr RunEnd(std::function<void()> run, std::function<void()> end,
                   Requirements requirements = {});
 
+/**
+ * Constructs a command that runs an action once, and then runs an action every
+ * iteration until interrupted.
+ *
+ * @param start the action to run on start
+ * @param run the action to run every iteration
+ * @param requirements subsystems the action requires
+ */
+[[nodiscard]]
+CommandPtr StartRun(std::function<void()> start, std::function<void()> run,
+                    Requirements requirements = {});
+
 /**
  * Constructs a command that prints a message and finishes.
  *

wpilibNewCommands/src/main/native/include/frc2/command/Subsystem.h

@@ -159,6 +159,16 @@ class Subsystem {
   [[nodiscard]]
   CommandPtr RunEnd(std::function<void()> run, std::function<void()> end);
 
+  /**
+   * Constructs a command that runs an action once, and then runs an action
+   * every iteration until interrupted. Requires this subsystem.
+   *
+   * @param start the action to run on start
+   * @param run the action to run every iteration
+   */
+  [[nodiscard]]
+  CommandPtr StartRun(std::function<void()> start, std::function<void()> run);
+
   /**
    * Constructs a DeferredCommand with the provided supplier. This subsystem is
    * added as a requirement.