add string split method

src/stl.rs

@@ -74,6 +74,17 @@ pub fn static_stdlib(syms: &mut SymTable) -> Result<(), String> {
         },
     );
 
+    syms.insert(
+        "split".to_string(),
+        Symbol {
+            name: String::from("split"),
+            args: Args::Strict(vec![Type::String, Type::String]),
+            conditional_branches: false,
+            docs: strings::SPLIT_DOCSTRING.to_string(),
+            value: ValueType::Internal(Rc::new(strings::split_callback)),
+        },
+    );
+
     syms.insert(
         "strlen".to_string(),
         Symbol {