1 files changed, 58 insertions, 0 deletions
diff --git a/argparse/src/num.rs b/argparse/src/num.rs
new file mode 100644
index 0000000..9f34de7
--- /dev/null
+++ b/argparse/src/num.rs
@@ -0,0 +1,58 @@
+use std::cell::RefCell;
+use std::rc::Rc;
+use std::ops::{Add, Sub};
+
+use super::{IncrBy, DecrBy};
+use super::action::{TypedAction, Action, ParseResult};
+use super::action::ParseResult::Parsed;
+use super::action::IFlagAction;
+use super::action::Action::Flag;
+
+pub struct IncrByAction<'a, T: 'a> {
+    delta: T,
+    cell: Rc<RefCell<&'a mut T>>,
+}
+
+pub struct DecrByAction<'a, T: 'a> {
+    delta: T,
+    cell: Rc<RefCell<&'a mut T>>,
+}
+
+impl<T: 'static + Add<Output = T> + Clone> TypedAction<T> for IncrBy<T> {
+    fn bind<'x>(&self, cell: Rc<RefCell<&'x mut T>>) -> Action<'x> {
+        let IncrBy(ref delta) = *self;
+        return Flag(Box::new(IncrByAction { cell: cell, delta: delta.clone() }));
+    }
+}
+
+impl<T: 'static + Sub<Output = T> + Clone> TypedAction<T> for DecrBy<T> {
+    fn bind<'x>(&self, cell: Rc<RefCell<&'x mut T>>) -> Action<'x> {
+        let DecrBy(ref delta) = *self;
+        return Flag(Box::new(DecrByAction { cell: cell, delta: delta.clone() }));
+    }
+}
+
+impl<'a, T: Add<Output = T> + Clone> IFlagAction for IncrByAction<'a, T> {
+    fn parse_flag(&self) -> ParseResult {
+        let oldval = {
+            let targ = self.cell.borrow();
+            targ.clone()
+        };
+        let mut targ = self.cell.borrow_mut();
+        **targ = oldval + self.delta.clone();
+        return Parsed;
+    }
+}
+
+impl<'a, T: Sub<Output = T> + Clone> IFlagAction for DecrByAction<'a, T> {
+    fn parse_flag(&self) -> ParseResult {
+        let oldval = {
+            let targ = self.cell.borrow();
+            targ.clone()
+        };
+        let mut targ = self.cell.borrow_mut();
+        **targ = oldval - self.delta.clone();
+        return Parsed;
+    }
+}
+