--- a/crates/jsonnet-evaluator/src/evaluate.rs
+++ b/crates/jsonnet-evaluator/src/evaluate.rs
@@ -5,8 +5,8 @@
 };
 use closure::closure;
 use jsonnet_parser::{
-	ArgsDesc, BinaryOpType, BindSpec, Expr, FieldMember, LiteralType, Member, ObjBody, ParamsDesc,
-	UnaryOpType, Visibility,
+	ArgsDesc, BinaryOpType, BindSpec, Expr, FieldMember, LiteralType, LocExpr, Member, ObjBody,
+	ParamsDesc, UnaryOpType, Visibility,
 };
 use std::{
 	collections::{BTreeMap, HashMap},
@@ -40,7 +40,7 @@
 	}
 }
 
-pub fn evaluate_method(ctx: Context, expr: &Expr, arg_spec: ParamsDesc) -> Val {
+pub fn evaluate_method(ctx: Context, expr: &LocExpr, arg_spec: ParamsDesc) -> Val {
 	Val::Func(FuncDesc {
 		ctx,
 		params: arg_spec,
@@ -236,9 +236,10 @@
 	}
 }
 
-pub fn evaluate(context: Context, expr: &Expr) -> Val {
+pub fn evaluate(context: Context, expr: &LocExpr) -> Val {
 	use Expr::*;
-	match &*expr {
+	let LocExpr(expr, _location) = expr;
+	match &**expr {
 		Literal(LiteralType::This) => Val::Obj(
 			context
 				.this()
@@ -260,7 +261,7 @@
 		}
 		UnaryOp(o, v) => evaluate_unary_op(*o, &evaluate(context, v)),
 		Var(name) => Val::Lazy(context.binding(&name)).unwrap_if_lazy(),
-		Index(box value, box index) => {
+		Index(value, index) => {
 			match (
 				evaluate(context.clone(), value).unwrap_if_lazy(),
 				evaluate(context.clone(), index),
@@ -284,7 +285,7 @@
 					.unwrap_or_else(|| panic!("out of bounds"))
 					.clone(),
 				(Val::Str(s), Val::Num(n)) => {
-					Val::Str(s.chars().skip(n as usize - 1).take(1).collect())
+					Val::Str(s.chars().skip(n as usize).take(1).collect())
 				}
 				(v, i) => todo!("not implemented: {:?}[{:?}]", v, i.unwrap_if_lazy()),
 			}
@@ -307,10 +308,10 @@
 			let context = context
 				.extend(new_bindings, None, None, None)
 				.into_future(future_context);
-			evaluate(context, &*returned.clone())
+			evaluate(context, &returned.clone())
 		}
 		Obj(body) => Val::Obj(evaluate_object(context, body.clone())),
-		Apply(box value, ArgsDesc(args)) => {
+		Apply(value, ArgsDesc(args)) => {
 			let value = evaluate(context.clone(), value).unwrap_if_lazy();
 			match value {
 				// TODO: Capture context of application
--- a/crates/jsonnet-evaluator/src/lib.rs
+++ b/crates/jsonnet-evaluator/src/lib.rs
@@ -29,7 +29,7 @@
 rc_fn_helper!(
 	FunctionDefault,
 	function_default,
-	dyn Fn(Context, Expr) -> Val
+	dyn Fn(Context, LocExpr) -> Val
 );
 
 #[cfg(test)]
@@ -39,21 +39,30 @@
 
 	macro_rules! eval {
 		($str: expr) => {
-			evaluate(Context::new(), &parse($str).unwrap())
+			evaluate(Context::new(), &parse($str, &ParserSettings {
+				loc_data: false,
+				file_name: "test.jsonnet".to_owned(),
+			}).unwrap())
 		};
 	}
 
 	macro_rules! eval_stdlib {
 		($str: expr) => {{
 			let std = "local std = ".to_owned() + jsonnet_stdlib::STDLIB_STR + ";";
-			evaluate(Context::new(), &parse(&(std + $str)).unwrap())
+			evaluate(Context::new(), &parse(&(std + $str), &ParserSettings {
+				loc_data: false,
+				file_name: "test.jsonnet".to_owned(),
+			}).unwrap())
 			}};
 	}
 
 	macro_rules! assert_eval {
 		($str: expr) => {
 			assert_eq!(
-				evaluate(Context::new(), &parse($str).unwrap()),
+				evaluate(Context::new(), &parse($str, &ParserSettings {
+					loc_data: false,
+					file_name: "test.jsonnet".to_owned(),
+				}).unwrap()),
 				Val::Literal(LiteralType::True)
 				)
 		};
@@ -61,7 +70,10 @@
 	macro_rules! assert_json {
 		($str: expr, $out: expr) => {
 			assert_eq!(
-				format!("{}", evaluate(Context::new(), &parse($str).unwrap())),
+				format!("{}", evaluate(Context::new(), &parse($str, &ParserSettings {
+					loc_data: false,
+					file_name: "test.jsonnet".to_owned(),
+				}).unwrap())),
 				$out
 				)
 		};
@@ -74,7 +86,10 @@
 	macro_rules! assert_eval_neg {
 		($str: expr) => {
 			assert_eq!(
-				evaluate(Context::new(), &parse($str).unwrap()),
+				evaluate(Context::new(), &parse($str, &ParserSettings {
+					loc_data: false,
+					file_name: "test.jsonnet".to_owned(),
+				}).unwrap()),
 				Val::Literal(LiteralType::False)
 				)
 		};