Fix a compatability issue and a compilation error

src/execute.rs

@@ -1,6 +1,6 @@
 use crate::{
     instructions,
-    stack::{Instruction, Stack, StackVec},
+    stack::{Instruction, Stack},
 };
 
 fn find_labels(stack: &mut Stack) {
@@ -28,18 +28,17 @@ fn find_labels(stack: &mut Stack) {
     stack.program_counter = stack.labels[0].unwrap_or(0) as u16;
 }
 
-fn find_prefix_operators(instruction: &mut Instruction, memory: &mut StackVec) {
+fn find_prefix_operators(instruction: &mut Instruction) {
     match instruction.name.chars().nth(0) {
         Some('|') => {
             instruction.name = instruction.name.chars().skip(1).collect();
 
-            instruction.data = memory.pop();
+            instruction.ispiped = true;
         }
         Some('/') => {
             instruction.name = instruction.name.chars().skip(1).collect();
 
-            memory.push(instruction.data);
+            instruction.isdrained = true;
-            instruction.data = 0;
         }
         _ => {}
     }
@@ -51,7 +50,16 @@ pub fn execute(stack: &mut Stack, mut origin_stack: Option<&mut Stack>, mod_name
     while let Some(mut instruction) = stack.program.get_mut(stack.program_counter as usize) {
         stack.program_counter += 1;
 
-        find_prefix_operators(&mut instruction, &mut stack.memory);
+        find_prefix_operators(&mut instruction);
+
+        if instruction.ispiped {
+            instruction.data = stack.memory.pop();
+        }
+
+        if instruction.isdrained {
+            stack.memory.push(instruction.data);
+            instruction.data = 0;
+        }
 
         if instruction.name.chars().nth(0) == Some('#')
             || instruction.name.chars().nth(0) == Some('$')

src/instructions/native.rs

@@ -11,11 +11,10 @@ extern fn stack_pop_callback() -> u16  {
 }
 
 #[no_mangle]
-extern fn stack_push_callback(data: u16) -> i32 { 
+extern fn stack_push_callback(data: u16){ 
     unsafe { 
         (*STACKPTR).memory.push(data) 
     }; 
-    return 0; 
 }
 
 #[no_mangle]

src/instructions/self_modify.rs

@@ -22,5 +22,7 @@ pub fn insert(program: &mut Vec<Instruction>, arg: String, data: u16) {
         name: arg.to_string(),
         arg: "\n".to_string(),
         data,
+        ispiped: false,
+        isdrained: false
     });
 }

src/parse.rs

@@ -48,7 +48,7 @@ pub fn parse(stack: &mut Stack, file_content: &str) {
         }
 
         if name != "" {
-            let inst = Instruction { name, arg, data };
+            let inst = Instruction { name, arg, data, ispiped: false, isdrained: false };
             stack.program.push(inst);
         }
     }

src/stack.rs

@@ -7,6 +7,8 @@ pub struct Instruction {
     pub name: String,
     pub arg: String,
     pub data: u16,
+    pub ispiped: bool,
+    pub isdrained: bool
 }
 
 pub struct Stack {