From 6bd68e649110d04f70be4b7b7d3c5d24220400aa Mon Sep 17 00:00:00 2001
From: Sebastian Schmidt <isibboi@gmail.com>
Date: Thu, 28 Mar 2019 08:52:49 +0100
Subject: [PATCH] Add `eval_mut` function to `Operator` trait

Relates to #30
---
 src/operator/mod.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/operator/mod.rs b/src/operator/mod.rs
index d5e8833..1f71c08 100644
--- a/src/operator/mod.rs
+++ b/src/operator/mod.rs
@@ -1,5 +1,6 @@
 use std::fmt::{Debug, Display};
 
+use ::{ContextMut, ValueType};
 use function::builtin::builtin_function;
 
 use crate::{context::Context, error::*, value::Value};
@@ -30,6 +31,11 @@ pub trait Operator: Debug + Display {
 
     /// Evaluates the operator with the given arguments and context.
     fn eval(&self, arguments: &[Value], context: &Context) -> EvalexprResult<Value>;
+
+    /// Evaluates the operator with the given arguments and mutable context.
+    fn eval_mut(&self, arguments: &[Value], context: &mut ContextMut) -> EvalexprResult<Value> {
+        self.eval(arguments, context)
+    }
 }
 
 #[derive(Debug)]