4 files changed, 84 insertions, 0 deletions
diff --git a/src/actor.rs b/src/actor.rs
new file mode 100644
index 0000000..3b03fa6
--- /dev/null
+++ b/src/actor.rs
@@ -0,0 +1,29 @@
+use crate::number::Number;
+
+#[derive(Clone)]
+pub enum Type {
+    String,
+    Record {
+        name: String,
+        fields: Vec<Slot>
+    },
+    AnyNumber,
+    NumberInRange {
+        min: Option<Number>,
+        max: Option<Number>,
+    },
+    List {
+        contents: Box<Type>,
+    },
+}
+
+#[derive(Clone)]
+pub struct Slot {
+    pub name: String,
+    pub r#type: Type,
+}
+
+pub trait Actorful {
+    fn inputs() -> Vec<Slot>;
+    fn outputs() -> Vec<Slot>;
+}
diff --git a/src/main.rs b/src/main.rs
index 424f3fc..0f87d5b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -2,6 +2,10 @@ use std::time::Duration;
 
 use minifb::{Key, Window, WindowOptions};
 
+mod actor;
+mod number;
+mod system;
+
 const WIDTH: usize = 1600;
 const HEIGHT: usize = 900;
 
diff --git a/src/number.rs b/src/number.rs
new file mode 100644
index 0000000..a71399c
--- /dev/null
+++ b/src/number.rs
@@ -0,0 +1,20 @@
+#[derive(Clone)]
+pub struct Number {
+    pub integer_part: String,
+    pub fractional_part: String,
+}
+
+macro_rules! int_conv {
+    ($($t:ty),*) => {$(
+        impl From<$t> for Number {
+            fn from(x: $t) -> Number {
+                Number {
+                    integer_part: x.to_string(),
+                    fractional_part: "".to_string(),
+                }
+            }
+        }
+    )*};
+}
+
+int_conv!(u8, u16, u32, u64, usize, i8, i16, i32, i64, isize);
diff --git a/src/system.rs b/src/system.rs
new file mode 100644
index 0000000..7df8af8
--- /dev/null
+++ b/src/system.rs
@@ -0,0 +1,31 @@
+use crate::actor::{Actorful, Slot, Type};
+use crate::number::Number;
+
+pub struct System {
+    pub screen_buffer: Vec<u32>,
+}
+
+impl Actorful for System {
+    fn inputs() -> Vec<Slot> {
+        let nonnegative_int = Type::NumberInRange {
+            min: Some(Number::from(0)),
+            max: None,
+        };
+        let screen_position_type = Type::Record {
+            name: "Screen Position".to_string(),
+            fields: vec![
+                Slot { name: "X".to_string(), r#type: nonnegative_int.clone() },
+                Slot { name: "Y".to_string(), r#type: nonnegative_int },
+            ],
+        };
+        vec![Slot { name: "mouse_position".to_string(), r#type: screen_position_type }]
+    }
+
+    fn outputs() -> Vec<Slot> {
+        let u24 = Type::NumberInRange {
+            min: Some(Number::from(0)),
+            max: Some(Number::from(1 << 24 - 1)),
+        };
+        vec![Slot { name: "screen_buffer".to_string(), r#type: Type::List { contents: Box::new(u24) }}]
+    }
+}