Pass state in ExecutionParams

src/interpreter/module.rs

@@ -20,9 +20,12 @@ const DEFAULT_FRAME_STACK_LIMIT: usize = 1024;
 
 /// Execution context.
 #[derive(Clone)]
-pub struct ExecutionParams {
+pub struct ExecutionParams<St: 'static> {
 	/// Arguments.
 	pub args: Vec<RuntimeValue>,
+
+	/// State that can be used by host functions,
+	pub state: St,
 }
 
 /// Export type.
@@ -76,7 +79,7 @@ pub struct InternalFunction<'a> {
 	pub labels: &'a HashMap<usize, usize>,
 }
 
-impl ExecutionParams {
+impl<St> ExecutionParams<St> {
 	/// Add argument.
 	pub fn add_argument(mut self, arg: RuntimeValue) -> Self {
 		self.args.push(arg);
@@ -84,18 +87,20 @@ impl ExecutionParams {
 	}
 }
 
-impl Default for ExecutionParams {
+impl<St: Default> Default for ExecutionParams<St> {
 	fn default() -> Self {
 		ExecutionParams {
 			args: Vec::default(),
+			state: St::default(),
 		}
 	}
 }
 
-impl<'a> From<Vec<RuntimeValue>> for ExecutionParams {
-	fn from(args: Vec<RuntimeValue>) -> ExecutionParams {
+impl<'a, St: Default> From<Vec<RuntimeValue>> for ExecutionParams<St> {
+	fn from(args: Vec<RuntimeValue>) -> ExecutionParams<St> {
 		ExecutionParams {
-			args: args
+			args: args,
+			state: St::default(),
 		}
 	}
 }