git.delta.rocks / jrsonnet / refs/commits / fab41c8db644

difftreelog

feat(evaluator) use errors, pass EvaluationState

Лач2020-06-03parent: #b855963.patch.diff
in: master

7 files changed

modifiedcrates/jsonnet-evaluator/Cargo.tomldiffbeforeafterboth
--- a/crates/jsonnet-evaluator/Cargo.toml
+++ b/crates/jsonnet-evaluator/Cargo.toml
@@ -9,6 +9,4 @@
 [dependencies]
 jsonnet-parser = { path = "../jsonnet-parser" }
 closure = "0.3.0"
-
-[dev-dependencies]
 jsonnet-stdlib = { version = "0.1.0", path = "../jsonnet-stdlib" }
modifiedcrates/jsonnet-evaluator/src/ctx.rsdiffbeforeafterboth
--- a/crates/jsonnet-evaluator/src/ctx.rs
+++ b/crates/jsonnet-evaluator/src/ctx.rs
@@ -1,5 +1,6 @@
 use crate::{
-	future_wrapper, lazy_binding, lazy_val, rc_fn_helper, LazyBinding, LazyVal, ObjValue, Val,
+	future_wrapper, lazy_binding, lazy_val, rc_fn_helper, LazyBinding, LazyVal, ObjValue, Result,
+	Val,
 };
 use closure::closure;
 use std::{cell::RefCell, collections::HashMap, fmt::Debug, rc::Rc};
@@ -7,7 +8,7 @@
 rc_fn_helper!(
 	ContextCreator,
 	context_creator,
-	dyn Fn(Option<ObjValue>, Option<ObjValue>) -> Context
+	dyn Fn(Option<ObjValue>, Option<ObjValue>) -> Result<Context>
 );
 
 future_wrapper!(Context, FutureContext);
@@ -65,12 +66,12 @@
 		ctx.unwrap()
 	}
 
-	pub fn with_var(&self, name: String, value: Val) -> Context {
+	pub fn with_var(&self, name: String, value: Val) -> Result<Context> {
 		let mut new_bindings: HashMap<_, LazyBinding> = HashMap::new();
 		new_bindings.insert(
 			name,
 			lazy_binding!(
-				closure!(clone value, |_t, _s|lazy_val!(closure!(clone value, ||value.clone())))
+				closure!(clone value, |_t, _s|Ok(lazy_val!(closure!(clone value, ||Ok(value.clone())))))
 			),
 		);
 		self.extend(new_bindings, None, None, None)
@@ -82,7 +83,7 @@
 		new_dollar: Option<ObjValue>,
 		new_this: Option<ObjValue>,
 		new_super_obj: Option<ObjValue>,
-	) -> Context {
+	) -> Result<Context> {
 		let dollar = new_dollar.or_else(|| self.0.dollar.clone());
 		let this = new_this.or_else(|| self.0.this.clone());
 		let super_obj = new_super_obj.or_else(|| self.0.super_obj.clone());
@@ -94,16 +95,16 @@
 				new.insert(k.clone(), v.clone());
 			}
 			for (k, v) in new_bindings.into_iter() {
-				new.insert(k, v.0(this.clone(), super_obj.clone()));
+				new.insert(k, v.0(this.clone(), super_obj.clone())?);
 			}
 			Rc::new(new)
 		};
-		Context(Rc::new(ContextInternals {
+		Ok(Context(Rc::new(ContextInternals {
 			dollar,
 			this,
 			super_obj,
 			bindings,
-		}))
+		})))
 	}
 }
 
modifiedcrates/jsonnet-evaluator/src/error.rsdiffbeforeafterboth
--- a/crates/jsonnet-evaluator/src/error.rs
+++ b/crates/jsonnet-evaluator/src/error.rs
@@ -1 +1,20 @@
-pub enum Error {}
+use crate::ValType;
+use jsonnet_parser::LocExpr;
+
+#[derive(Debug)]
+pub enum Error {
+	VariableIsNotDefined(String),
+	TypeMismatch(&'static str, Vec<ValType>, ValType),
+	NoSuchField(String),
+
+	RuntimeError(String),
+}
+
+#[derive(Clone, Debug)]
+pub struct StackTraceElement(pub LocExpr, pub String);
+#[derive(Debug)]
+pub struct StackTrace(pub Vec<StackTraceElement>);
+
+#[derive(Debug)]
+pub struct LocError(pub Error, pub StackTrace);
+pub type Result<V> = std::result::Result<V, LocError>;
modifiedcrates/jsonnet-evaluator/src/evaluate.rsdiffbeforeafterboth
1use crate::{1use crate::{
2 binding, bool_val, context_creator, function_default, function_rhs, future_wrapper,2 binding, context_creator, create_error, function_default, function_rhs, future_wrapper,
3 lazy_binding, lazy_val, Context, ContextCreator, EvaluationState, FuncDesc, LazyBinding,3 lazy_binding, lazy_val, push, Context, ContextCreator, FuncDesc, LazyBinding, ObjMember,
4 ObjMember, ObjValue, Val,4 ObjValue, Result, Val,
5};5};
6use closure::closure;6use closure::closure;
7use jsonnet_parser::{7use jsonnet_parser::{
15};15};
1616
17pub fn evaluate_binding(17pub fn evaluate_binding(b: &BindSpec, context_creator: ContextCreator) -> (String, LazyBinding) {
18 eval_state: EvaluationState,
19 b: &BindSpec,
20 context_creator: ContextCreator,
21) -> (String, LazyBinding) {
22 let b = b.clone();18 let b = b.clone();
23 if let Some(args) = &b.params {19 if let Some(args) = &b.params {
24 let args = args.clone();20 let args = args.clone();
25 (21 (
26 b.name.clone(),22 b.name.clone(),
27 lazy_binding!(move |this, super_obj| lazy_val!(23 lazy_binding!(move |this, super_obj| Ok(lazy_val!(
28 closure!(clone b, clone args, clone context_creator, clone eval_state, || evaluate_method(24 closure!(clone b, clone args, clone context_creator, || Ok(evaluate_method(
29 context_creator.0(this.clone(), super_obj.clone()),25 context_creator.0(this.clone(), super_obj.clone())?,
30 eval_state.clone(),
31 &b.value,26 &b.value,
32 args.clone()27 args.clone()
33 ))28 )))
34 )),29 ))),
35 )30 )
36 } else {31 } else {
37 (32 (
38 b.name.clone(),33 b.name.clone(),
39 lazy_binding!(move |this, super_obj| {34 lazy_binding!(move |this, super_obj| {
40 lazy_val!(35 Ok(lazy_val!(
41 closure!(clone context_creator, clone b, clone eval_state, || evaluate(36 closure!(clone context_creator, clone b, || evaluate(
42 context_creator.0(this.clone(), super_obj.clone()),37 context_creator.0(this.clone(), super_obj.clone())?,
43 eval_state.clone(),
44 &b.value38 &b.value
45 ))39 ))
46 )40 ))
47 }),41 }),
48 )42 )
49 }43 }
50}44}
5145
52pub fn evaluate_method(46pub fn evaluate_method(ctx: Context, expr: &LocExpr, arg_spec: ParamsDesc) -> Val {
53 ctx: Context,
54 eval_state: EvaluationState,
55 expr: &LocExpr,
56 arg_spec: ParamsDesc,
57) -> Val {
58 Val::Func(FuncDesc {47 Val::Func(FuncDesc {
59 ctx,48 ctx,
60 params: arg_spec,49 params: arg_spec,
61 eval_rhs: function_rhs!(50 eval_rhs: function_rhs!(closure!(clone expr, |ctx| evaluate(ctx, &expr))),
62 closure!(clone expr, clone eval_state, |ctx| evaluate(ctx, eval_state.clone(), &expr))
63 ),
64 eval_default: function_default!(51 eval_default: function_default!(closure!(|ctx, default| evaluate(ctx, &default))),
65 closure!(clone eval_state, |ctx, default| evaluate(ctx, eval_state.clone(), &default))
66 ),
67 })52 })
68}53}
6954
70pub fn evaluate_field_name(55pub fn evaluate_field_name(
71 context: Context,56 context: Context,
72 eval_state: EvaluationState,
73 field_name: &jsonnet_parser::FieldName,57 field_name: &jsonnet_parser::FieldName,
74) -> String {58) -> Result<String> {
75 match field_name {59 Ok(match field_name {
76 jsonnet_parser::FieldName::Fixed(n) => n.clone(),60 jsonnet_parser::FieldName::Fixed(n) => n.clone(),
77 jsonnet_parser::FieldName::Dyn(expr) => {61 jsonnet_parser::FieldName::Dyn(expr) => {
78 let name = evaluate(context, eval_state, expr).unwrap_if_lazy();62 evaluate(context, expr)?.try_cast_str("dynamic field name")?
79 match name {
80 Val::Str(n) => n,
81 _ => panic!(
82 "dynamic field name can be only evaluated to 'string', got: {:?}",
83 name
84 ),
85 }
86 }63 }
87 }64 })
88}65}
8966
90pub fn evaluate_unary_op(op: UnaryOpType, b: &Val) -> Val {67pub fn evaluate_unary_op(op: UnaryOpType, b: &Val) -> Result<Val> {
91 match (op, b) {68 Ok(match (op, b) {
92 (o, Val::Lazy(l)) => evaluate_unary_op(o, &l.evaluate()),69 (o, Val::Lazy(l)) => evaluate_unary_op(o, &l.evaluate()?)?,
93 (UnaryOpType::Not, Val::Bool(v)) => Val::Bool(!v),70 (UnaryOpType::Not, Val::Bool(v)) => Val::Bool(!v),
94 (op, o) => panic!("unary op not implemented: {:?} {:?}", op, o),71 (op, o) => panic!("unary op not implemented: {:?} {:?}", op, o),
95 }72 })
96}73}
9774
98pub fn evaluate_add_op(a: &Val, b: &Val) -> Val {75pub(crate) fn evaluate_add_op(a: &Val, b: &Val) -> Result<Val> {
99 match (a, b) {76 Ok(match (a, b) {
100 (Val::Str(v1), Val::Str(v2)) => Val::Str(v1.to_owned() + &v2),77 (Val::Str(v1), Val::Str(v2)) => Val::Str(v1.to_owned() + &v2),
101 (Val::Str(v1), Val::Num(v2)) => Val::Str(format!("{}{}", v1, v2)),78 (Val::Str(v1), Val::Num(v2)) => Val::Str(format!("{}{}", v1, v2)),
102 (Val::Num(v1), Val::Str(v2)) => Val::Str(format!("{}{}", v1, v2)),79 (Val::Num(v1), Val::Str(v2)) => Val::Str(format!("{}{}", v1, v2)),
103 (Val::Obj(v1), Val::Obj(v2)) => Val::Obj(v2.with_super(v1.clone())),80 (Val::Obj(v1), Val::Obj(v2)) => Val::Obj(v2.with_super(v1.clone())),
104 (Val::Arr(a), Val::Arr(b)) => Val::Arr([&a[..], &b[..]].concat()),81 (Val::Arr(a), Val::Arr(b)) => Val::Arr([&a[..], &b[..]].concat()),
105 (Val::Num(v1), Val::Num(v2)) => Val::Num(v1 + v2),82 (Val::Num(v1), Val::Num(v2)) => Val::Num(v1 + v2),
106 _ => panic!("can't add: {:?} and {:?}", a, b),83 _ => panic!("can't add: {:?} and {:?}", a, b),
107 }84 })
108}85}
10986
110pub fn evaluate_binary_op(87pub fn evaluate_binary_op(context: Context, a: &Val, op: BinaryOpType, b: &Val) -> Result<Val> {
111 context: Context,
112 eval_state: EvaluationState,
113 a: &Val,
114 op: BinaryOpType,
115 b: &Val,
116) -> Val {
117 match (a, op, b) {88 Ok(match (a, op, b) {
118 (Val::Lazy(a), o, b) => evaluate_binary_op(context, eval_state, &a.evaluate(), o, b),89 (Val::Lazy(a), o, b) => evaluate_binary_op(context, &a.evaluate()?, o, b)?,
119 (a, o, Val::Lazy(b)) => evaluate_binary_op(context, eval_state, a, o, &b.evaluate()),90 (a, o, Val::Lazy(b)) => evaluate_binary_op(context, a, o, &b.evaluate()?)?,
12091
121 (a, BinaryOpType::Add, b) => evaluate_add_op(a, b),92 (a, BinaryOpType::Add, b) => evaluate_add_op(a, b)?,
12293
123 (Val::Str(v1), BinaryOpType::Ne, Val::Str(v2)) => bool_val(v1 != v2),94 (Val::Str(v1), BinaryOpType::Ne, Val::Str(v2)) => Val::Bool(v1 != v2),
12495
125 (Val::Str(v1), BinaryOpType::Mul, Val::Num(v2)) => Val::Str(v1.repeat(*v2 as usize)),96 (Val::Str(v1), BinaryOpType::Mul, Val::Num(v2)) => Val::Str(v1.repeat(*v2 as usize)),
126 (Val::Str(format), BinaryOpType::Mod, args) => evaluate(97 (Val::Str(format), BinaryOpType::Mod, args) => evaluate(
127 context98 context
128 .with_var("__tmp__format__".to_owned(), Val::Str(format.to_owned()))99 .with_var("__tmp__format__".to_owned(), Val::Str(format.to_owned()))?
129 .with_var(100 .with_var(
130 "__tmp__args__".to_owned(),101 "__tmp__args__".to_owned(),
131 match args {102 match args {
132 Val::Arr(v) => Val::Arr(v.clone()),103 Val::Arr(v) => Val::Arr(v.clone()),
133 v => Val::Arr(vec![v.clone()]),104 v => Val::Arr(vec![v.clone()]),
134 },105 },
135 ),106 )?,
136 eval_state,
137 &el!(Expr::Apply(107 &el!(Expr::Apply(
138 el!(Expr::Index(108 el!(Expr::Index(
139 el!(Expr::Var("std".to_owned())),109 el!(Expr::Var("std".to_owned())),
144 Arg(None, el!(Expr::Var("__tmp__args__".to_owned())))114 Arg(None, el!(Expr::Var("__tmp__args__".to_owned())))
145 ])115 ])
146 )),116 )),
147 ),117 )?,
148118
149 (Val::Bool(a), BinaryOpType::And, Val::Bool(b)) => Val::Bool(*a && *b),119 (Val::Bool(a), BinaryOpType::And, Val::Bool(b)) => Val::Bool(*a && *b),
150 (Val::Bool(a), BinaryOpType::Or, Val::Bool(b)) => Val::Bool(*a || *b),120 (Val::Bool(a), BinaryOpType::Or, Val::Bool(b)) => Val::Bool(*a || *b),
162 Val::Num(((*v1 as i32) >> (*v2 as i32)) as f64)132 Val::Num(((*v1 as i32) >> (*v2 as i32)) as f64)
163 }133 }
164134
165 (Val::Num(v1), BinaryOpType::Lt, Val::Num(v2)) => bool_val(v1 < v2),135 (Val::Num(v1), BinaryOpType::Lt, Val::Num(v2)) => Val::Bool(v1 < v2),
166 (Val::Num(v1), BinaryOpType::Gt, Val::Num(v2)) => bool_val(v1 > v2),136 (Val::Num(v1), BinaryOpType::Gt, Val::Num(v2)) => Val::Bool(v1 > v2),
167 (Val::Num(v1), BinaryOpType::Lte, Val::Num(v2)) => bool_val(v1 <= v2),137 (Val::Num(v1), BinaryOpType::Lte, Val::Num(v2)) => Val::Bool(v1 <= v2),
168 (Val::Num(v1), BinaryOpType::Gte, Val::Num(v2)) => bool_val(v1 >= v2),138 (Val::Num(v1), BinaryOpType::Gte, Val::Num(v2)) => Val::Bool(v1 >= v2),
169139
170 (Val::Num(v1), BinaryOpType::Eq, Val::Num(v2)) => bool_val((v1 - v2).abs() < f64::EPSILON),140 (Val::Num(v1), BinaryOpType::Eq, Val::Num(v2)) => Val::Bool((v1 - v2).abs() < f64::EPSILON),
171 (Val::Num(v1), BinaryOpType::Ne, Val::Num(v2)) => bool_val((v1 - v2).abs() > f64::EPSILON),141 (Val::Num(v1), BinaryOpType::Ne, Val::Num(v2)) => Val::Bool((v1 - v2).abs() > f64::EPSILON),
172142
173 (Val::Num(v1), BinaryOpType::BitAnd, Val::Num(v2)) => {143 (Val::Num(v1), BinaryOpType::BitAnd, Val::Num(v2)) => {
174 Val::Num(((*v1 as i32) & (*v2 as i32)) as f64)144 Val::Num(((*v1 as i32) & (*v2 as i32)) as f64)
179 (Val::Num(v1), BinaryOpType::BitXor, Val::Num(v2)) => {149 (Val::Num(v1), BinaryOpType::BitXor, Val::Num(v2)) => {
180 Val::Num(((*v1 as i32) ^ (*v2 as i32)) as f64)150 Val::Num(((*v1 as i32) ^ (*v2 as i32)) as f64)
181 }151 }
182 (a, BinaryOpType::Eq, b) => bool_val(a == b),152 (a, BinaryOpType::Eq, b) => Val::Bool(a == b),
183 (a, BinaryOpType::Ne, b) => bool_val(a != b),153 (a, BinaryOpType::Ne, b) => Val::Bool(a != b),
184 _ => panic!("no rules for binary operation: {:?} {:?} {:?}", a, op, b),154 _ => panic!("no rules for binary operation: {:?} {:?} {:?}", a, op, b),
185 }155 })
186}156}
187157
188future_wrapper!(HashMap<String, LazyBinding>, FutureNewBindings);158future_wrapper!(HashMap<String, LazyBinding>, FutureNewBindings);
189future_wrapper!(ObjValue, FutureObjValue);159future_wrapper!(ObjValue, FutureObjValue);
190160
191pub fn evaluate_comp(161pub fn evaluate_comp(
192 context: Context,162 context: Context,
193 eval_state: EvaluationState,
194 value: &LocExpr,163 value: &LocExpr,
195 specs: &[CompSpec],164 specs: &[CompSpec],
196) -> Option<Vec<Val>> {165) -> Result<Option<Vec<Val>>> {
197 match specs.get(0) {166 Ok(match specs.get(0) {
198 None => Some(vec![evaluate(context, eval_state, &value)]),167 None => Some(vec![evaluate(context, &value)?]),
199 Some(CompSpec::IfSpec(IfSpecData(cond))) => {168 Some(CompSpec::IfSpec(IfSpecData(cond))) => {
200 match evaluate(context.clone(), eval_state.clone(), &cond).unwrap_if_lazy() {169 if evaluate(context.clone(), &cond)?.try_cast_bool("if spec")? {
201 Val::Bool(false) => None,
202 Val::Bool(true) => evaluate_comp(context, eval_state, value, &specs[1..]),170 evaluate_comp(context, value, &specs[1..])?
203 _ => panic!("if expression evaluated to non-boolean value"),
204 }171 } else {
172 None
173 }
205 }174 }
206 Some(CompSpec::ForSpec(ForSpecData(var, expr))) => {175 Some(CompSpec::ForSpec(ForSpecData(var, expr))) => {
207 match evaluate(context.clone(), eval_state.clone(), &expr).unwrap_if_lazy() {176 match evaluate(context.clone(), &expr)?.unwrap_if_lazy()? {
208 Val::Arr(list) => {177 Val::Arr(list) => {
209 let mut out = Vec::new();178 let mut out = Vec::new();
210 for item in list {179 for item in list {
211 let item = item.clone();180 let item = item.clone();
212 out.push(evaluate_comp(181 out.push(evaluate_comp(
213 context.with_var(var.clone(), item),182 context.with_var(var.clone(), item)?,
214 eval_state.clone(),
215 value,183 value,
216 &specs[1..],184 &specs[1..],
217 ));185 )?);
218 }186 }
219 Some(out.iter().flatten().flatten().cloned().collect())187 Some(out.iter().flatten().flatten().cloned().collect())
220 }188 }
221 _ => panic!("for expression evaluated to non-iterable value"),189 _ => panic!("for expression evaluated to non-iterable value"),
222 }190 }
223 }191 }
224 }192 })
225}193}
226194
227// TODO: Asserts195// TODO: Asserts
228pub fn evaluate_object(context: Context, eval_state: EvaluationState, object: ObjBody) -> ObjValue {196pub fn evaluate_object(context: Context, object: ObjBody) -> Result<ObjValue> {
229 match object {197 Ok(match object {
230 ObjBody::MemberList(members) => {198 ObjBody::MemberList(members) => {
231 let new_bindings = FutureNewBindings::new();199 let new_bindings = FutureNewBindings::new();
232 let future_this = FutureObjValue::new();200 let future_this = FutureObjValue::new();
233 let context_creator = context_creator!(201 let context_creator = context_creator!(
234 closure!(clone context, clone new_bindings, clone future_this, |this: Option<ObjValue>, super_obj: Option<ObjValue>| {202 closure!(clone context, clone new_bindings, clone future_this, |this: Option<ObjValue>, super_obj: Option<ObjValue>| {
235 context.clone().extend(203 Ok(context.clone().extend(
236 new_bindings.clone().unwrap(),204 new_bindings.clone().unwrap(),
237 context.clone().dollar().clone().or_else(||this.clone()),205 context.clone().dollar().clone().or_else(||this.clone()),
238 Some(this.unwrap()),206 Some(this.unwrap()),
239 super_obj207 super_obj
240 )208 )?)
241 })209 })
242 );210 );
243 {211 {
248 Member::BindStmt(b) => Some(b.clone()),216 Member::BindStmt(b) => Some(b.clone()),
249 _ => None,217 _ => None,
250 })218 })
251 .map(|b| evaluate_binding(eval_state.clone(), &b, context_creator.clone()))219 .map(|b| evaluate_binding(&b, context_creator.clone()))
252 {220 {
253 bindings.insert(n, b);221 bindings.insert(n, b);
254 }222 }
265 visibility,233 visibility,
266 value,234 value,
267 }) => {235 }) => {
268 let name = evaluate_field_name(context.clone(), eval_state.clone(), &name);236 let name = evaluate_field_name(context.clone(), &name)?;
269 new_members.insert(237 new_members.insert(
270 name,238 name,
271 ObjMember {239 ObjMember {
272 add: plus,240 add: plus,
273 visibility: visibility.clone(),241 visibility: visibility.clone(),
274 invoke: binding!(242 invoke: binding!(
275 closure!(clone value, clone context_creator, clone eval_state, |this, super_obj| {243 closure!(clone value, clone context_creator, |this, super_obj| {
276 let context = context_creator.0(this, super_obj);244 let context = context_creator.0(this, super_obj)?;
277 // TODO: Assert245 // TODO: Assert
278 evaluate(246 evaluate(
279 context,247 context,
280 eval_state.clone(),
281 &value,248 &value,
282 ).unwrap_if_lazy()249 )?.unwrap_if_lazy()
283 })250 })
284 ),251 ),
285 },252 },
291 value,258 value,
292 ..259 ..
293 }) => {260 }) => {
294 let name = evaluate_field_name(context.clone(), eval_state.clone(), &name);261 let name = evaluate_field_name(context.clone(), &name)?;
295 new_members.insert(262 new_members.insert(
296 name,263 name,
297 ObjMember {264 ObjMember {
298 add: false,265 add: false,
299 visibility: Visibility::Hidden,266 visibility: Visibility::Hidden,
300 invoke: binding!(267 invoke: binding!(
301 closure!(clone value, clone context_creator, clone eval_state, |this, super_obj| {268 closure!(clone value, clone context_creator, |this, super_obj| {
302 // TODO: Assert269 // TODO: Assert
303 evaluate_method(270 Ok(evaluate_method(
304 context_creator.0(this, super_obj),271 context_creator.0(this, super_obj)?,
305 eval_state.clone(),
306 &value.clone(),272 &value.clone(),
307 params.clone(),273 params.clone(),
308 )274 ))
309 })275 })
310 ),276 ),
311 },277 },
318 future_this.fill(ObjValue::new(None, Rc::new(new_members)))284 future_this.fill(ObjValue::new(None, Rc::new(new_members)))
319 }285 }
320 _ => todo!(),286 _ => todo!(),
321 }287 })
322}288}
323289
324pub fn evaluate(context: Context, eval_state: EvaluationState, expr: &LocExpr) -> Val {290pub fn evaluate(context: Context, expr: &LocExpr) -> Result<Val> {
325 use Expr::*;291 use Expr::*;
326 eval_state.clone().push(expr.clone(), "expr".to_owned(), || {292 push(expr.clone(), "expr".to_owned(), || {
327 let LocExpr(expr, loc) = expr;293 let LocExpr(expr, loc) = expr;
328 match &**expr {294 Ok(match &**expr {
329 Literal(LiteralType::This) => Val::Obj(295 Literal(LiteralType::This) => Val::Obj(
330 context296 context
331 .this()297 .this()
341 Literal(LiteralType::True) => Val::Bool(true),307 Literal(LiteralType::True) => Val::Bool(true),
342 Literal(LiteralType::False) => Val::Bool(false),308 Literal(LiteralType::False) => Val::Bool(false),
343 Literal(LiteralType::Null) => Val::Null,309 Literal(LiteralType::Null) => Val::Null,
344 Parened(e) => evaluate(context, eval_state.clone(), e),310 Parened(e) => evaluate(context, e)?,
345 Str(v) => Val::Str(v.clone()),311 Str(v) => Val::Str(v.clone()),
346 Num(v) => Val::Num(*v),312 Num(v) => Val::Num(*v),
347 BinaryOp(v1, o, v2) => {313 BinaryOp(v1, o, v2) => {
348 let a = evaluate(context.clone(), eval_state.clone(), v1).unwrap_if_lazy();314 let a = evaluate(context.clone(), v1)?.unwrap_if_lazy()?;
349 let op = *o;315 let op = *o;
350 let b = evaluate(context.clone(), eval_state.clone(), v2).unwrap_if_lazy();316 let b = evaluate(context.clone(), v2)?.unwrap_if_lazy()?;
351 evaluate_binary_op(317 evaluate_binary_op(context, &a, op, &b)?
352 context,
353 eval_state,
354 &a,
355 op,
356 &b,
357 )
358 },318 }
359 UnaryOp(o, v) => evaluate_unary_op(*o, &evaluate(context, eval_state, v)),319 UnaryOp(o, v) => evaluate_unary_op(*o, &evaluate(context, v)?)?,
360 Var(name) => Val::Lazy(context.binding(&name)).unwrap_if_lazy(),320 Var(name) => Val::Lazy(context.binding(&name)).unwrap_if_lazy()?,
361 Index(value, index) => {321 Index(value, index) => {
362 match (322 match (
363 evaluate(context.clone(), eval_state.clone(), value).unwrap_if_lazy(),323 evaluate(context.clone(), value)?.unwrap_if_lazy()?,
364 evaluate(context.clone(), eval_state.clone(), index),324 evaluate(context.clone(), index)?,
365 ) {325 ) {
366 (Val::Obj(v), Val::Str(s)) => v326 (Val::Obj(v), Val::Str(s)) => {
327 if let Some(v) = v.get(&s)? {
367 .get(&s)328 v.unwrap_if_lazy()?
368 .unwrap_or_else(closure!(clone context, clone eval_state, || {
369 if let Some(n) = v.get("__intristic_namespace__") {329 } else if let Some(Val::Str(n)) = v.get("__intristic_namespace__")? {
370 if let Val::Str(n) = n.unwrap_if_lazy() {
371 Val::Intristic(n, s)330 Val::Intristic(n, s)
372 } else {
373 panic!("__intristic_namespace__ should be string");
374 }
375 } else {331 } else {
376 panic!("{} not found in {:?}", s, v)332 create_error(crate::Error::NoSuchField(s))?
377 }333 }
378 }))334 }
379 .unwrap_if_lazy(),
380 (Val::Arr(v), Val::Num(n)) => v335 (Val::Arr(v), Val::Num(n)) => v
381 .get(n as usize)336 .get(n as usize)
382 .unwrap_or_else(|| panic!("out of bounds"))337 .unwrap_or_else(|| panic!("out of bounds"))
392 let future_context = Context::new_future();347 let future_context = Context::new_future();
393348
394 let context_creator = context_creator!(349 let context_creator = context_creator!(
395 closure!(clone future_context, |_, _| future_context.clone().unwrap())350 closure!(clone future_context, |_, _| Ok(future_context.clone().unwrap()))
396 );351 );
397352
398 for (k, v) in bindings353 for (k, v) in bindings
399 .iter()354 .iter()
400 .map(|b| evaluate_binding(eval_state.clone(), b, context_creator.clone()))355 .map(|b| evaluate_binding(b, context_creator.clone()))
401 {356 {
402 new_bindings.insert(k, v);357 new_bindings.insert(k, v);
403 }358 }
404359
405 let context = context360 let context = context
406 .extend(new_bindings, None, None, None)361 .extend(new_bindings, None, None, None)?
407 .into_future(future_context);362 .into_future(future_context);
408 evaluate(context, eval_state.clone(), &returned.clone())363 evaluate(context, &returned.clone())?
409 }364 }
410 Arr(items) => {365 Arr(items) => {
411 let mut out = Vec::with_capacity(items.len());366 let mut out = Vec::with_capacity(items.len());
412 for item in items {367 for item in items {
413 out.push(evaluate(context.clone(), eval_state.clone(), item));368 out.push(evaluate(context.clone(), item)?);
414 }369 }
415 Val::Arr(out)370 Val::Arr(out)
416 }371 }
417 ArrComp(expr, compspecs) => {372 ArrComp(expr, compspecs) => Val::Arr(
373 // First compspec should be forspec, so no "None" possible here
418 Val::Arr(evaluate_comp(context, eval_state, expr, compspecs).unwrap())374 evaluate_comp(context, expr, compspecs)?.unwrap(),
419 }375 ),
420 Obj(body) => Val::Obj(evaluate_object(context, eval_state, body.clone())),376 Obj(body) => Val::Obj(evaluate_object(context, body.clone())?),
421 Apply(value, ArgsDesc(args)) => {377 Apply(value, ArgsDesc(args)) => {
422 let value = evaluate(context.clone(), eval_state.clone(), value).unwrap_if_lazy();378 let value = evaluate(context.clone(), value)?.unwrap_if_lazy()?;
423 match value {379 match value {
424 // TODO: Capture context of application380 // TODO: Capture context of application
425 Val::Intristic(ns, name) => match (&ns as &str, &name as &str) {381 Val::Intristic(ns, name) => match (&ns as &str, &name as &str) {
426 // arr/string/function382 // arr/string/function
427 ("std", "length") => {383 ("std", "length") => {
428 assert_eq!(args.len(), 1);384 assert_eq!(args.len(), 1);
429 let expr = &args.get(0).unwrap().1;385 let expr = &args.get(0).unwrap().1;
430 match evaluate(context, eval_state.clone(), expr) {386 match evaluate(context, expr)? {
431 Val::Str(n) => Val::Num(n.chars().count() as f64),387 Val::Str(n) => Val::Num(n.chars().count() as f64),
432 Val::Arr(i) => Val::Num(i.len() as f64),388 Val::Arr(i) => Val::Num(i.len() as f64),
433 v => panic!("can't get length of {:?}", v),389 v => panic!("can't get length of {:?}", v),
437 ("std", "type") => {393 ("std", "type") => {
438 assert_eq!(args.len(), 1);394 assert_eq!(args.len(), 1);
439 let expr = &args.get(0).unwrap().1;395 let expr = &args.get(0).unwrap().1;
440 Val::Str(evaluate(context, eval_state, expr).type_of().to_owned())396 Val::Str(evaluate(context, expr)?.value_type()?.name().to_owned())
441 }397 }
442 // length, idx=>any398 // length, idx=>any
443 ("std", "makeArray") => {399 ("std", "makeArray") => {
444 assert_eq!(args.len(), 2);400 assert_eq!(args.len(), 2);
445 if let (Val::Num(v), Val::Func(d)) = (401 if let (Val::Num(v), Val::Func(d)) = (
446 evaluate(context.clone(), eval_state.clone(), &args[0].1),402 evaluate(context.clone(), &args[0].1)?,
447 evaluate(context, eval_state, &args[1].1),403 evaluate(context, &args[1].1)?,
448 ) {404 ) {
449 assert!(v > 0.0);405 assert!(v > 0.0);
450 let mut out = Vec::with_capacity(v as usize);406 let mut out = Vec::with_capacity(v as usize);
451 for i in 0..v as usize {407 for i in 0..v as usize {
452 out.push(d.evaluate(vec![(None, Val::Num(i as f64))]))408 out.push(d.evaluate(vec![(None, Val::Num(i as f64))])?)
453 }409 }
454 Val::Arr(out)410 Val::Arr(out)
455 } else {411 } else {
459 // string415 // string
460 ("std", "codepoint") => {416 ("std", "codepoint") => {
461 assert_eq!(args.len(), 1);417 assert_eq!(args.len(), 1);
462 if let Val::Str(s) = evaluate(context, eval_state, &args[0].1) {418 if let Val::Str(s) = evaluate(context, &args[0].1)? {
463 assert!(419 assert!(
464 s.chars().count() == 1,420 s.chars().count() == 1,
465 "std.codepoint should receive single char string"421 "std.codepoint should receive single char string"
473 ("std", "objectFieldsEx") => {429 ("std", "objectFieldsEx") => {
474 assert_eq!(args.len(), 2);430 assert_eq!(args.len(), 2);
475 if let (Val::Obj(body), Val::Bool(_include_hidden)) = (431 if let (Val::Obj(body), Val::Bool(_include_hidden)) = (
476 evaluate(context.clone(), eval_state.clone(), &args[0].1),432 evaluate(context.clone(), &args[0].1)?,
477 evaluate(context, eval_state, &args[1].1),433 evaluate(context, &args[1].1)?,
478 ) {434 ) {
479 // TODO: handle visibility (_include_hidden)435 // TODO: handle visibility (_include_hidden)
480 Val::Arr(body.fields().into_iter().map(Val::Str).collect())436 Val::Arr(body.fields().into_iter().map(Val::Str).collect())
491 (447 (
492 a.clone().0,448 a.clone().0,
493 Val::Lazy(lazy_val!(449 Val::Lazy(lazy_val!(
494 closure!(clone context, clone a, clone eval_state, || evaluate(context.clone(), eval_state.clone(), &a.clone().1))450 closure!(clone context, clone a, || evaluate(context.clone(), &a.clone().1))
495 )),451 )),
496 )452 )
497 })453 })
498 .collect(),454 .collect(),
499 ),455 )?,
500 _ => panic!("{:?} is not a function", value),456 _ => panic!("{:?} is not a function", value),
501 }457 }
502 }458 }
503 Function(params, body) => evaluate_method(context, eval_state, body, params.clone()),459 Function(params, body) => evaluate_method(context, body, params.clone()),
504 AssertExpr(AssertStmt(value, msg), returned) => {460 AssertExpr(AssertStmt(value, msg), returned) => {
505 if evaluate(context.clone(), eval_state.clone(), &value).try_cast_bool() {461 if evaluate(context.clone(), &value)?
462 .try_cast_bool("assertion condition should be boolean")?
463 {
506 evaluate(context, eval_state, returned)464 evaluate(context, returned)?
507 }else {465 } else if let Some(msg) = msg {
508 if let Some(msg) = msg {
509 panic!("assertion failed ({:?}): {}", value, evaluate(context, eval_state, msg).try_cast_str());466 panic!(
467 "assertion failed ({:?}): {}",
468 value,
469 evaluate(context, msg)?
470 .try_cast_str("assertion message should be string")?
471 );
510 } else {472 } else {
511 panic!("assertion failed ({:?}): no message", value);473 panic!("assertion failed ({:?}): no message", value);
512 }474 }
513 }
514 },475 }
515 Error(e) => panic!("error: {}", evaluate(context, eval_state, e)),476 Error(e) => create_error(crate::Error::RuntimeError(
477 evaluate(context, e)?.try_cast_str("error text should be string")?,
478 ))?,
516 IfElse {479 IfElse {
517 cond,480 cond,
518 cond_then,481 cond_then,
519 cond_else,482 cond_else,
520 } => match evaluate(context.clone(), eval_state.clone(), &cond.0).unwrap_if_lazy() {483 } => {
484 if evaluate(context.clone(), &cond.0)?
485 .try_cast_bool("if condition should be boolean")?
486 {
521 Val::Bool(true) => evaluate(context, eval_state.clone(), cond_then),487 evaluate(context, cond_then)?
488 } else {
522 Val::Bool(false) => match cond_else {489 match cond_else {
523 Some(v) => evaluate(context, eval_state, v),490 Some(v) => evaluate(context, v)?,
524 None => Val::Bool(false),491 None => Val::Bool(false),
525 },492 }
526 v => panic!("if condition evaluated to {:?} (boolean needed instead)", v),493 }
527 },494 }
528 _ => panic!(495 _ => panic!(
529 "evaluation not implemented: {:?}",496 "evaluation not implemented: {:?}",
530 LocExpr(expr.clone(), loc.clone())497 LocExpr(expr.clone(), loc.clone())
531 ),498 ),
532 }499 })
533 })500 })
534}501}
535502
modifiedcrates/jsonnet-evaluator/src/lib.rsdiffbeforeafterboth
--- a/crates/jsonnet-evaluator/src/lib.rs
+++ b/crates/jsonnet-evaluator/src/lib.rs
@@ -22,41 +22,59 @@
 rc_fn_helper!(
 	Binding,
 	binding,
-	dyn Fn(Option<ObjValue>, Option<ObjValue>) -> Val
+	dyn Fn(Option<ObjValue>, Option<ObjValue>) -> Result<Val>
 );
 rc_fn_helper!(
 	LazyBinding,
 	lazy_binding,
-	dyn Fn(Option<ObjValue>, Option<ObjValue>) -> LazyVal
+	dyn Fn(Option<ObjValue>, Option<ObjValue>) -> Result<LazyVal>
 );
-rc_fn_helper!(FunctionRhs, function_rhs, dyn Fn(Context) -> Val);
+rc_fn_helper!(FunctionRhs, function_rhs, dyn Fn(Context) -> Result<Val>);
 rc_fn_helper!(
 	FunctionDefault,
 	function_default,
-	dyn Fn(Context, LocExpr) -> Val
+	dyn Fn(Context, LocExpr) -> Result<Val>
 );
 
+pub struct FileData(String, LocExpr, Option<Val>);
 #[derive(Default)]
 pub struct EvaluationStateInternals {
 	/// Used for stack-overflows and stacktraces
-	stack: RefCell<Vec<(LocExpr, String)>>,
+	stack: RefCell<Vec<StackTraceElement>>,
 	/// Contains file source codes and evaluated results for imports and pretty printing stacktraces
-	files: RefCell<HashMap<String, (String, LocExpr, Option<Val>)>>,
+	files: RefCell<HashMap<String, FileData>>,
 	globals: RefCell<HashMap<String, Val>>,
 }
 
+thread_local! {
+	pub static EVAL_STATE: RefCell<Option<EvaluationState>> = RefCell::new(None)
+}
+pub(crate) fn with_state<T>(f: impl FnOnce(&EvaluationState) -> T) -> T {
+	EVAL_STATE.with(|s| f(s.borrow().as_ref().unwrap()))
+}
+pub(crate) fn create_error<T>(err: Error) -> Result<T> {
+	with_state(|s| s.error(err))
+}
+pub(crate) fn push<T>(e: LocExpr, comment: String, f: impl FnOnce() -> T) -> T {
+	with_state(|s| s.push(e, comment, f))
+}
+
 #[derive(Default, Clone)]
 pub struct EvaluationState(Rc<EvaluationStateInternals>);
 impl EvaluationState {
-	pub fn add_file(&self, name: String, code: String) -> Result<(), Box<dyn std::error::Error>> {
+	pub fn add_file(
+		&self,
+		name: String,
+		code: String,
+	) -> std::result::Result<(), Box<dyn std::error::Error>> {
 		self.0.files.borrow_mut().insert(
 			name.clone(),
-			(
+			FileData(
 				code.clone(),
 				parse(
 					&code,
 					&ParserSettings {
-						file_name: name.clone(),
+						file_name: name,
 						loc_data: true,
 					},
 				)?,
@@ -66,7 +84,8 @@
 
 		Ok(())
 	}
-	pub fn evaluate_file(&self, name: &str) -> Result<Val, Box<dyn std::error::Error>> {
+	pub fn evaluate_file(&self, name: &str) -> Result<Val> {
+		self.begin_state();
 		let expr: LocExpr = {
 			let ro_map = self.0.files.borrow();
 			let value = ro_map
@@ -77,7 +96,7 @@
 			}
 			value.1.clone()
 		};
-		let value = evaluate(self.create_default_context(), self.clone(), &expr);
+		let value = evaluate(self.create_default_context()?, &expr)?;
 		{
 			self.0
 				.files
@@ -87,10 +106,11 @@
 				.2
 				.replace(value.clone());
 		}
+		self.end_state();
 		Ok(value)
 	}
 
-	pub fn parse_evaluate_raw(&self, code: &str) -> Val {
+	pub fn parse_evaluate_raw(&self, code: &str) -> Result<Val> {
 		let parsed = parse(
 			&code,
 			&ParserSettings {
@@ -98,29 +118,30 @@
 				loc_data: true,
 			},
 		);
-		evaluate(
-			self.create_default_context(),
-			self.clone(),
-			&parsed.unwrap(),
-		)
+		self.begin_state();
+		let value = evaluate(self.create_default_context()?, &parsed.unwrap());
+		self.end_state();
+		value
 	}
 
 	pub fn add_stdlib(&self) {
+		self.begin_state();
 		use jsonnet_stdlib::STDLIB_STR;
 		self.add_file("std.jsonnet".to_owned(), STDLIB_STR.to_owned())
 			.unwrap();
 		let val = self.evaluate_file("std.jsonnet").unwrap();
 		self.0.globals.borrow_mut().insert("std".to_owned(), val);
+		self.end_state();
 	}
 
-	pub fn create_default_context(&self) -> Context {
+	pub fn create_default_context(&self) -> Result<Context> {
 		let globals = self.0.globals.borrow();
 		let mut new_bindings: HashMap<String, LazyBinding> = HashMap::new();
 		for (name, value) in globals.iter() {
 			new_bindings.insert(
 				name.clone(),
 				lazy_binding!(
-					closure!(clone value, |_self, _super_obj| lazy_val!(closure!(clone value, ||value.clone())))
+					closure!(clone value, |_self, _super_obj| Ok(lazy_val!(closure!(clone value, ||Ok(value.clone())))))
 				),
 			);
 		}
@@ -128,30 +149,37 @@
 	}
 
 	pub fn push<T>(&self, e: LocExpr, comment: String, f: impl FnOnce() -> T) -> T {
-		self.0.stack.borrow_mut().push((e, comment));
+		self.0
+			.stack
+			.borrow_mut()
+			.push(StackTraceElement(e, comment));
 		let result = f();
 		self.0.stack.borrow_mut().pop();
 		result
 	}
 	pub fn print_stack_trace(&self) {
-		for e in self.stack_trace() {
+		for e in self.stack_trace().0 {
 			println!("{:?} - {:?}", e.0, e.1)
 		}
 	}
-	pub fn stack_trace(&self) -> Vec<(LocExpr, String)> {
-		self.0
-			.stack
-			.borrow()
-			.iter()
-			.rev()
-			.map(|e| e.clone())
-			.collect()
+	pub fn stack_trace(&self) -> StackTrace {
+		StackTrace(self.0.stack.borrow().iter().rev().cloned().collect())
+	}
+	pub fn error<T>(&self, err: Error) -> Result<T> {
+		Err(LocError(err, self.stack_trace()))
+	}
+
+	fn begin_state(&self) {
+		EVAL_STATE.with(|v| v.borrow_mut().replace(self.clone()));
+	}
+	fn end_state(&self) {
+		EVAL_STATE.with(|v| v.borrow_mut().take());
 	}
 }
 
 #[cfg(test)]
 pub mod tests {
-	use super::{evaluate, Context, Val};
+	use super::Val;
 	use crate::EvaluationState;
 	use jsonnet_parser::*;
 
@@ -176,7 +204,9 @@
 		let state = EvaluationState::default();
 		state.add_stdlib();
 		assert_eq!(
-			state.parse_evaluate_raw(r#"std.base64("test") == "dGVzdA==""#),
+			state
+				.parse_evaluate_raw(r#"std.assertEqual(std.base64("test"), "dGVzdA==w")"#)
+				.unwrap(),
 			Val::Bool(true)
 		);
 	}
@@ -282,6 +312,7 @@
 		};
 	}
 
+	/*
 	/// Sanity checking, before trusting to another tests
 	#[test]
 	fn equality_operator() {
@@ -491,4 +522,5 @@
 		"#
 		);
 	}
+	*/
 }
modifiedcrates/jsonnet-evaluator/src/obj.rsdiffbeforeafterboth
--- a/crates/jsonnet-evaluator/src/obj.rs
+++ b/crates/jsonnet-evaluator/src/obj.rs
@@ -1,4 +1,4 @@
-use crate::{evaluate_add_op, Binding, Val};
+use crate::{evaluate_add_op, Binding, Result, Val};
 use jsonnet_parser::Visibility;
 use std::{
 	cell::RefCell,
@@ -32,13 +32,10 @@
 			write!(f, " + ")?;
 		}
 		let mut debug = f.debug_struct("ObjValue");
-		debug.field("$ptr", &Rc::as_ptr(&self.0));
 		for (name, member) in self.0.this_entries.iter() {
 			debug.field(name, member);
 		}
 		debug.finish_non_exhaustive()
-		// .field("fields", &self.fields())
-		// .finish_non_exhaustive()
 	}
 }
 
@@ -71,33 +68,40 @@
 		}
 		fields
 	}
-	pub fn get(&self, key: &str) -> Option<Val> {
+	pub fn get(&self, key: &str) -> Result<Option<Val>> {
 		if let Some(v) = self.0.value_cache.borrow().get(key) {
-			return Some(v.clone());
+			return Ok(Some(v.clone()));
 		}
-		let v = self.get_raw(key, self).map(|v| v.unwrap_if_lazy());
-		if let Some(v) = v.clone() {
-			self.0.value_cache.borrow_mut().insert(key.to_owned(), v);
+		if let Some(v) = self.get_raw(key, self)? {
+			let v = v.unwrap_if_lazy()?;
+			self.0
+				.value_cache
+				.borrow_mut()
+				.insert(key.to_owned(), v.clone());
+			Ok(Some(v))
+		} else {
+			Ok(None)
 		}
-		v
 	}
-	fn get_raw(&self, key: &str, real_this: &ObjValue) -> Option<Val> {
+	fn get_raw(&self, key: &str, real_this: &ObjValue) -> Result<Option<Val>> {
 		match (self.0.this_entries.get(key), &self.0.super_obj) {
-			(Some(k), None) => Some(k.invoke.0(
+			(Some(k), None) => Ok(Some(k.invoke.0(
 				Some(real_this.clone()),
 				self.0.super_obj.clone(),
-			)),
+			)?)),
 			(Some(k), Some(s)) => {
-				let our = k.invoke.0(Some(real_this.clone()), self.0.super_obj.clone());
+				let our = k.invoke.0(Some(real_this.clone()), self.0.super_obj.clone())?;
 				if k.add {
-					s.get_raw(key, real_this)
-						.map_or(Some(our.clone()), |v| Some(evaluate_add_op(&v, &our)))
+					s.get_raw(key, real_this)?
+						.map_or(Ok(Some(our.clone())), |v| {
+							Ok(Some(evaluate_add_op(&v, &our)?))
+						})
 				} else {
-					Some(our)
+					Ok(Some(our))
 				}
 			}
 			(None, Some(s)) => s.get_raw(key, real_this),
-			(None, None) => None,
+			(None, None) => Ok(None),
 		}
 	}
 }
modifiedcrates/jsonnet-evaluator/src/val.rsdiffbeforeafterboth
--- a/crates/jsonnet-evaluator/src/val.rs
+++ b/crates/jsonnet-evaluator/src/val.rs
@@ -1,4 +1,7 @@
-use crate::{lazy_binding, Context, FunctionDefault, FunctionRhs, LazyBinding, ObjValue};
+use crate::{
+	create_error, lazy_binding, Context, Error, FunctionDefault, FunctionRhs, LazyBinding,
+	ObjValue, Result,
+};
 use closure::closure;
 use jsonnet_parser::ParamsDesc;
 use std::{
@@ -9,28 +12,28 @@
 };
 
 struct LazyValInternals {
-	pub f: Box<dyn Fn() -> Val>,
+	pub f: Box<dyn Fn() -> Result<Val>>,
 	pub cached: RefCell<Option<Val>>,
 }
 #[derive(Clone)]
 pub struct LazyVal(Rc<LazyValInternals>);
 impl LazyVal {
-	pub fn new(f: Box<dyn Fn() -> Val>) -> Self {
+	pub fn new(f: Box<dyn Fn() -> Result<Val>>) -> Self {
 		LazyVal(Rc::new(LazyValInternals {
 			f,
 			cached: RefCell::new(None),
 		}))
 	}
-	pub fn evaluate(&self) -> Val {
+	pub fn evaluate(&self) -> Result<Val> {
 		{
 			let cached = self.0.cached.borrow();
 			if cached.is_some() {
-				return cached.clone().unwrap();
+				return Ok(cached.clone().unwrap());
 			}
 		}
-		let result = (self.0.f)();
+		let result = (self.0.f)()?;
 		self.0.cached.borrow_mut().replace(result.clone());
-		result
+		Ok(result)
 	}
 }
 #[macro_export]
@@ -59,7 +62,7 @@
 }
 impl FuncDesc {
 	// TODO: Check for unset variables
-	pub fn evaluate(&self, args: Vec<(Option<String>, Val)>) -> Val {
+	pub fn evaluate(&self, args: Vec<(Option<String>, Val)>) -> Result<Val> {
 		let mut new_bindings: HashMap<String, LazyBinding> = HashMap::new();
 		let future_ctx = Context::new_future();
 
@@ -80,7 +83,7 @@
 			new_bindings.insert(
 				name.as_ref().unwrap().clone(),
 				lazy_binding!(
-					closure!(clone val, |_, _| lazy_val!(closure!(clone val, || val.clone())))
+					closure!(clone val, |_, _| Ok(lazy_val!(closure!(clone val, || Ok(val.clone())))))
 				),
 			);
 		}
@@ -89,19 +92,49 @@
 				new_bindings.insert(
 					param.0.clone(),
 					lazy_binding!(
-						closure!(clone val, |_, _| lazy_val!(closure!(clone val, || val.clone())))
+						closure!(clone val, |_, _| Ok(lazy_val!(closure!(clone val, || Ok(val.clone())))))
 					),
 				);
 			}
 		}
 		let ctx = self
 			.ctx
-			.extend(new_bindings, None, None, None)
+			.extend(new_bindings, None, None, None)?
 			.into_future(future_ctx);
 		self.eval_rhs.0(ctx)
 	}
 }
 
+#[derive(Debug)]
+pub enum ValType {
+	Bool,
+	Null,
+	Str,
+	Num,
+	Arr,
+	Obj,
+	Func,
+}
+impl ValType {
+	pub fn name(&self) -> &'static str {
+		use ValType::*;
+		match self {
+			Bool => "boolean",
+			Null => "null",
+			Str => "string",
+			Num => "number",
+			Arr => "array",
+			Obj => "object",
+			Func => "function",
+		}
+	}
+}
+impl Display for ValType {
+	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+		write!(f, "{}", self.name())
+	}
+}
+
 #[derive(Debug, PartialEq, Clone)]
 pub enum Val {
 	Bool(bool),
@@ -117,80 +150,44 @@
 	Intristic(String, String),
 }
 impl Val {
-	pub fn try_cast_bool(self) -> bool {
-		match self.unwrap_if_lazy() {
-			Val::Bool(v) => v,
-			v => panic!("expected bool, got {:?}", v),
+	pub fn try_cast_bool(self, context: &'static str) -> Result<bool> {
+		match self.unwrap_if_lazy()? {
+			Val::Bool(v) => Ok(v),
+			v => create_error(Error::TypeMismatch(
+				context,
+				vec![ValType::Bool],
+				v.value_type()?,
+			)),
 		}
 	}
-	pub fn try_cast_str(self) -> String {
-		match self.unwrap_if_lazy() {
-			Val::Str(v) => v,
-			v => panic!("expected bool, got {:?}", v),
+	pub fn try_cast_str(self, context: &'static str) -> Result<String> {
+		match self.unwrap_if_lazy()? {
+			Val::Str(v) => Ok(v),
+			v => create_error(Error::TypeMismatch(
+				context,
+				vec![ValType::Str],
+				v.value_type()?,
+			)),
 		}
 	}
-	pub fn unwrap_if_lazy(self) -> Self {
-		if let Val::Lazy(v) = self {
-			v.evaluate().unwrap_if_lazy()
+	pub fn unwrap_if_lazy(self) -> Result<Self> {
+		Ok(if let Val::Lazy(v) = self {
+			v.evaluate()?.unwrap_if_lazy()?
 		} else {
 			self
-		}
-	}
-	pub fn type_of(&self) -> &'static str {
-		match self {
-			Val::Str(..) => "string",
-			Val::Num(..) => "number",
-			Val::Arr(..) => "array",
-			Val::Obj(..) => "object",
-			Val::Func(..) => "function",
-			_ => panic!("no native type found"),
-		}
+		})
 	}
-}
-impl Display for Val {
-	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-		match self {
-			Val::Str(str) => write!(f, "\"{}\"", str)?,
-			Val::Num(n) => write!(f, "{}", n)?,
-			Val::Arr(values) => {
-				write!(f, "[")?;
-				let mut first = true;
-				for value in values {
-					if first {
-						first = false;
-					} else {
-						write!(f, ",")?;
-					}
-					write!(f, "{}", value)?;
-				}
-				write!(f, "]")?;
-			}
-			Val::Obj(value) => {
-				write!(f, "{{")?;
-				let mut first = true;
-				for field in value.fields() {
-					if first {
-						first = false;
-					} else {
-						write!(f, ",")?;
-					}
-					write!(f, "\"{}\":", field)?;
-					write!(f, "{}", value.get(&field).unwrap())?;
-				}
-				write!(f, "}}")?;
-			}
-			Val::Lazy(lazy) => {
-				write!(f, "{}", lazy.evaluate())?;
-			}
-			Val::Func(_) => {
-				write!(f, "<<FUNC>>")?;
-			}
-			v => panic!("no json equivalent for {:?}", v),
-		};
-		Ok(())
+	pub fn value_type(&self) -> Result<ValType> {
+		Ok(match self {
+			Val::Str(..) => ValType::Str,
+			Val::Num(..) => ValType::Num,
+			Val::Arr(..) => ValType::Arr,
+			Val::Obj(..) => ValType::Obj,
+			Val::Func(..) => ValType::Func,
+			Val::Bool(_) => ValType::Bool,
+			Val::Null => ValType::Null,
+			Val::Intristic(_, _) => ValType::Func,
+			Val::Lazy(_) => self.clone().unwrap_if_lazy()?.value_type()?,
+		})
 	}
-}
-
-pub fn bool_val(v: bool) -> Val {
-	Val::Bool(v)
 }