From 0e355684a2561bd2718cc74ba5af7811fb47fcf6 Mon Sep 17 00:00:00 2001
From: Sergey Pepyakin <s.pepyakin@gmail.com>
Date: Mon, 5 Feb 2018 18:05:59 +0300
Subject: [PATCH] Publish FuncInstance::invoke

---
 src/func.rs | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/src/func.rs b/src/func.rs
index 7662e85..5b5b038 100644
--- a/src/func.rs
+++ b/src/func.rs
@@ -75,7 +75,6 @@ impl fmt::Debug for FuncInstance {
 }
 
 impl FuncInstance {
-
 	/// Allocate a function instance for a host function.
 	///
 	/// When this function instance will be called by the wasm code,
@@ -128,20 +127,30 @@ impl FuncInstance {
 		}
 	}
 
-	pub(crate) fn invoke<E: Externals>(
+	/// Invoke this function.
+	///
+	/// # Errors
+	///
+	/// Returns `Err` if `args` types is not match function [`signature`] or
+	/// if [`Trap`] at execution time occured.
+	///
+	/// [`signature`]: #method.signature
+	/// [`Trap`]: #enum.Trap.html
+	pub fn invoke<E: Externals>(
 		func: &FuncRef,
 		args: &[RuntimeValue],
 		externals: &mut E,
 	) -> Result<Option<RuntimeValue>, Trap> {
-		debug_assert!(check_function_args(func.signature(), &args).is_ok());
+		check_function_args(func.signature(), &args).map_err(|_| Trap::UnexpectedSignature)?;
 		match *func.as_internal() {
 			FuncInstanceInternal::Internal { .. } => {
 				let mut interpreter = Interpreter::new(externals);
 				interpreter.start_execution(func, args)
 			}
-			FuncInstanceInternal::Host { ref host_func_index, .. } => {
-				externals.invoke_index(*host_func_index, args.into())
-			}
+			FuncInstanceInternal::Host {
+				ref host_func_index,
+				..
+			} => externals.invoke_index(*host_func_index, args.into()),
 		}
 	}
 }