updated prog and prog2

Author: BartMassey

prog.rs

@@ -1,11 +1,11 @@
-struct State {
+struct CpuState {
     r: [i32;2],
     pc: usize,
 }
 
-type Op = fn(State) -> State;
+type Op = fn(CpuState) -> CpuState;
 
-impl State {
+impl CpuState {
     fn run(mut self, prog: &[Op]) -> i32 {
         while self.pc < prog.len() {
             let pc = self.pc;
@@ -16,19 +16,18 @@ impl State {
     }
 }
 
-fn add(mut state: State) -> State {
+fn add(mut state: CpuState) -> CpuState {
     state.r[0] += state.r[1];
     state
 }
 
-fn sub(mut state: State) -> State {
+fn sub(mut state: CpuState) -> CpuState {
     state.r[0] -= state.r[1];
     state
 }
 
-
 fn main() {
-    let state = State { r: [0, 1], pc: 0 };
+    let state = CpuState { r: [0, 1], pc: 0 };
     let prog = [add, add, sub, add];
     println!("{}", state.run(&prog));
-}
+}

prog2.rs

@@ -1,11 +1,11 @@
-struct State {
+struct CpuState {
     r: [i32;4],
     pc: usize,
 }
 
-type Op = Box<dyn Fn(State) -> State>;
+type Op = Box<dyn Fn(CpuState) -> CpuState>;
 
-impl State {
+impl CpuState {
     fn run(mut self, prog: &[Op]) -> i32 {
         while self.pc < prog.len() {
             let pc = self.pc;
@@ -16,25 +16,29 @@ impl State {
     }
 }
 
-fn add(mut state: State) -> State {
-    state.r[0] += state.r[1];
-    state
+fn add() -> Op {
+    Box::new(|mut state: CpuState| -> CpuState {
+        state.r[0] += state.r[1];
+        state
+    })
 }
 
-fn sub(mut state: State) -> State {
-    state.r[0] -= state.r[1];
-    state
+fn sub() -> Op {
+    Box::new(|mut state: CpuState| -> CpuState {
+        state.r[0] -= state.r[1];
+        state
+    })
 }
 
 fn mov(from: usize, to: usize) -> Op {
-    Box::new(move |mut state: State| -> State {state.r[to] = state.r[from]; state})
+    Box::new(move |mut state: CpuState| -> CpuState {
+        state.r[to] = state.r[from];
+        state
+    })
 }
 
-
 fn main() {
-    let state = State { r: [0, 1, 0, 0], pc: 0 };
-    let add = || Box::new(add);
-    let sub = || Box::new(sub);
-    let prog = [add(), mov(0, 1), add(), mov(0, 1), add(), mov(3,1), sub()];
-    println!("{}", state.run(&prog));
+    let state = CpuState { r: [0, 1, 0, 0], pc: 0 };
+    let prog = &[add(), mov(0, 1), add(), mov(0, 1), add(), mov(3, 1), sub()];
+    println!("{}", state.run(prog));
 }