git.delta.rocks / jrsonnet / refs/commits / 5fc1275a239d

1use std::rc::Rc;23use jrsonnet_gcmodule::{Cc, Trace};4use jrsonnet_interner::IStr;5use jrsonnet_ir::{6	ArgsDesc, AssertStmt, BinaryOpType, BindSpec, CompSpec, Expr, ExprParams, FieldMember,7	FieldName, ForSpecData, IfSpecData, ImportKind, LiteralType, ObjBody, ObjMembers, Spanned,8	function::ParamName,9};10use jrsonnet_types::ValType;11use rustc_hash::FxHashMap;1213use self::destructure::destruct;14use crate::{15	Context, Error, ObjValue, ObjValueBuilder, ObjectAssertion, Pending, Result, ResultExt,16	SupThis, Unbound, Val,17	arr::ArrValue,18	bail,19	destructure::evaluate_dest,20	error::{ErrorKind::*, suggest_object_fields},21	evaluate::operator::{evaluate_binary_op_special, evaluate_unary_op},22	function::{CallLocation, FuncDesc, FuncVal, PreparedFuncVal},23	gc::WithCapacityExt as _,24	in_frame,25	typed::{FromUntyped, IntoUntyped as _, Typed},26	val::{CachedUnbound, IndexableVal, NumValue, StrValue, Thunk},27	with_state,28};29pub mod destructure;30pub mod operator;3132// This is the amount of bytes that need to be left on the stack before increasing the size.33// It must be at least as large as the stack required by any code that does not call34// `ensure_sufficient_stack`.35const RED_ZONE: usize = 100 * 1024; // 100k3637// Only the first stack that is pushed, grows exponentially (2^n * STACK_PER_RECURSION) from then38// on. This flag has performance relevant characteristics. Don't set it too high.39const STACK_PER_RECURSION: usize = 1024 * 1024; // 1MB4041/// Grows the stack on demand to prevent stack overflow. Call this in strategic locations42/// to "break up" recursive calls. E.g. almost any call to `visit_expr` or equivalent can benefit43/// from this.44///45/// Should not be sprinkled around carelessly, as it causes a little bit of overhead.46#[inline]47pub fn ensure_sufficient_stack<R>(f: impl FnOnce() -> R) -> R {48	stacker::maybe_grow(RED_ZONE, STACK_PER_RECURSION, f)49}5051pub fn evaluate_trivial(expr: &Expr) -> Option<Val> {52	fn is_trivial(expr: &Expr) -> bool {53		match expr {54			Expr::Str(_)55			| Expr::Num(_)56			| Expr::Literal(LiteralType::False | LiteralType::True | LiteralType::Null) => true,57			Expr::Arr(a) => a.iter().all(is_trivial),58			_ => false,59		}60	}61	Some(match expr {62		Expr::Str(s) => Val::string(s.clone()),63		Expr::Num(n) => {64			Val::Num(NumValue::new(*n).expect("parser will not allow non-finite values"))65		}66		Expr::Literal(LiteralType::False) => Val::Bool(false),67		Expr::Literal(LiteralType::True) => Val::Bool(true),68		Expr::Literal(LiteralType::Null) => Val::Null,69		Expr::Arr(n) => {70			if n.iter().any(|e| !is_trivial(e)) {71				return None;72			}73			Val::Arr(74				n.iter()75					.map(evaluate_trivial)76					.map(|e| e.expect("checked trivial"))77					.collect(),78			)79		}80		_ => return None,81	})82}8384pub fn evaluate_method(ctx: Context, name: IStr, params: ExprParams, body: Rc<Expr>) -> Val {85	Val::Func(FuncVal::Normal(Cc::new(FuncDesc {86		name,87		ctx,88		params,89		body,90	})))91}9293pub fn evaluate_field_name(ctx: Context, field_name: &Spanned<FieldName>) -> Result<Option<IStr>> {94	Ok(match &field_name.value {95		FieldName::Fixed(n) => Some(n.clone()),96		FieldName::Dyn(expr) => in_frame(97			CallLocation::new(&field_name.span),98			|| "evaluating field name".to_string(),99			|| {100				let v = evaluate(ctx, expr)?;101				Ok(if matches!(v, Val::Null) {102					None103				} else {104					Some(IStr::from_untyped(v)?)105				})106			},107		)?,108	})109}110111pub fn evaluate_comp(112	ctx: Context,113	specs: &[CompSpec],114	mut guaranteed_reserve: usize,115	callback: &mut impl FnMut(Context, usize) -> Result<()>,116) -> Result<()> {117	match specs.first() {118		None => callback(ctx, guaranteed_reserve)?,119		Some(CompSpec::IfSpec(IfSpecData { cond, span: _ })) => {120			if bool::from_untyped(evaluate(ctx.clone(), cond)?)? {121				evaluate_comp(ctx, &specs[1..], 0, callback)?;122			}123		}124		Some(CompSpec::ForSpec(ForSpecData {125			destruct: into,126			over,127		})) => {128			match evaluate(ctx.clone(), over)? {129				Val::Arr(list) => {130					guaranteed_reserve = guaranteed_reserve.max(1) * list.len();131					for (i, item) in list.iter_lazy().enumerate() {132						let fctx = Pending::new();133						let mut new_bindings = FxHashMap::with_capacity(into.binds_len());134						destruct(into, item, fctx.clone(), &mut new_bindings)?;135						let ctx = ctx.clone().extend_bindings(new_bindings).into_future(fctx);136137						let specs = &specs[1..];138						evaluate_comp(139							ctx,140							specs,141							if i == 0 || !specs.is_empty() {142								guaranteed_reserve143							} else {144								0145							},146							callback,147						)?;148					}149				}150				#[cfg(feature = "exp-object-iteration")]151				Val::Obj(obj) => {152					let fields = obj.fields(153						// TODO: Should there be ability to preserve iteration order?154						#[cfg(feature = "exp-preserve-order")]155						false,156					);157					guaranteed_reserve = guaranteed_reserve.max(1) * fields.len();158					for field in fields {159						let fctx = Pending::new();160						let mut new_bindings = FxHashMap::with_capacity(into.binds_len());161						let obj = obj.clone();162						let value = Thunk::evaluated(Val::arr(vec![163							Thunk::evaluated(Val::string(field.clone())),164							obj.get_lazy(field).transpose().expect(165								"field exists, as field name was obtained from object.fields()",166							),167						]));168						destruct(into, value, fctx.clone(), &mut new_bindings)?;169						let ctx = ctx.clone().extend_bindings(new_bindings).into_future(fctx);170171						evaluate_comp(ctx, &specs[1..], callback)?;172					}173				}174				_ => bail!(InComprehensionCanOnlyIterateOverArray),175			}176		}177	}178	Ok(())179}180181fn evaluate_arr_comp(ctx: Context, expr: &Rc<Expr>, comp_specs: &[CompSpec]) -> Result<ArrValue> {182	'eager: {183		let mut out = Vec::new();184185		if evaluate_comp(ctx.clone(), comp_specs, 0, &mut |ctx, reserve| {186			if reserve != 0 {187				out.reserve(reserve);188			}189			out.push(evaluate(ctx, expr)?);190			Ok(())191		})192		.is_err()193		{194			break 'eager;195		}196197		return Ok(ArrValue::new(out));198	};199	let mut out = Vec::new();200	evaluate_comp(ctx, comp_specs, 0, &mut |ctx, reserve| {201		if reserve != 0 {202			out.reserve(reserve);203		}204		let expr = expr.clone();205		out.push(Thunk!(move || evaluate(ctx, &expr)));206		Ok(())207	})?;208	Ok(ArrValue::new(out))209}210211trait CloneableUnbound<T>: Unbound<Bound = T> + Clone {}212impl<V, T> CloneableUnbound<T> for V where V: Unbound<Bound = T> + Clone {}213214fn evaluate_object_locals(215	fctx: Context,216	locals: Rc<Vec<BindSpec>>,217) -> impl CloneableUnbound<Context> {218	#[derive(Trace, Clone)]219	struct UnboundLocals {220		fctx: Context,221		locals: Rc<Vec<BindSpec>>,222	}223	impl Unbound for UnboundLocals {224		type Bound = Context;225226		fn bind(&self, sup_this: SupThis) -> Result<Context> {227			let fctx = Context::new_future();228			let mut new_bindings =229				FxHashMap::with_capacity(self.locals.iter().map(BindSpec::binds_len).sum());230			for b in self.locals.iter() {231				evaluate_dest(b, fctx.clone(), &mut new_bindings)?;232			}233234			let ctx = self.fctx.clone();235236			let ctx = ctx237				.extend_bindings_sup_this(new_bindings, sup_this)238				.into_future(fctx);239240			Ok(ctx)241		}242	}243244	UnboundLocals { fctx, locals }245}246247pub fn evaluate_field_member<B: Unbound<Bound = Context> + Clone>(248	builder: &mut ObjValueBuilder,249	ctx: Context,250	uctx: B,251	field: &FieldMember,252) -> Result<()> {253	let name = evaluate_field_name(ctx, &field.name)?;254	let Some(name) = name else {255		return Ok(());256	};257258	match field {259		FieldMember {260			plus,261			params: None,262			visibility,263			value,264			..265		} => {266			#[derive(Trace)]267			struct UnboundValue<B: Trace> {268				uctx: B,269				value: Rc<Expr>,270				name: IStr,271			}272			impl<B: Unbound<Bound = Context>> Unbound for UnboundValue<B> {273				type Bound = Val;274				fn bind(&self, sup_this: SupThis) -> Result<Val> {275					evaluate_named(self.uctx.bind(sup_this)?, &self.value, self.name.clone())276				}277			}278279			builder280				.field(name.clone())281				.with_add(*plus)282				.with_visibility(*visibility)283				.with_location(field.name.span.clone())284				.bindable(UnboundValue {285					uctx,286					value: value.clone(),287					name,288				})?;289		}290		FieldMember {291			params: Some(params),292			visibility,293			value,294			..295		} => {296			#[derive(Trace)]297			struct UnboundMethod<B: Trace> {298				uctx: B,299				value: Rc<Expr>,300				params: ExprParams,301				name: IStr,302			}303			impl<B: Unbound<Bound = Context>> Unbound for UnboundMethod<B> {304				type Bound = Val;305				fn bind(&self, sup_this: SupThis) -> Result<Val> {306					Ok(evaluate_method(307						self.uctx.bind(sup_this)?,308						self.name.clone(),309						self.params.clone(),310						self.value.clone(),311					))312				}313			}314315			builder316				.field(name.clone())317				.with_visibility(*visibility)318				// .with_location(value.span())319				.bindable(UnboundMethod {320					uctx,321					value: value.clone(),322					params: params.clone(),323					name,324				})?;325		}326	}327	Ok(())328}329330#[derive(Trace, Clone)]331struct DirectUnbound(Context);332impl Unbound for DirectUnbound {333	type Bound = Context;334	fn bind(&self, sup_this: SupThis) -> Result<Context> {335		Ok(self336			.0337			.clone()338			.extend_bindings_sup_this(FxHashMap::new(), sup_this))339	}340}341342#[allow(clippy::too_many_lines)]343pub fn evaluate_member_list_object(344	super_obj: Option<ObjValue>,345	ctx: Context,346	members: &ObjMembers,347) -> Result<ObjValue> {348	#[derive(Trace)]349	struct ObjectAssert<B: Trace> {350		uctx: B,351		asserts: Rc<Vec<AssertStmt>>,352	}353	impl<B: Unbound<Bound = Context>> ObjectAssertion for ObjectAssert<B> {354		fn run(&self, sup_this: SupThis) -> Result<()> {355			let ctx = self.uctx.bind(sup_this)?;356			for assert in &*self.asserts {357				evaluate_assert(ctx.clone(), assert)?;358			}359			Ok(())360		}361	}362363	let mut builder = ObjValueBuilder::new();364	if let Some(super_obj) = super_obj {365		builder.with_super(super_obj);366	}367368	if members.locals.is_empty() {369		// We can use the same context for all field evaluation, it doesn't depends on locals, only on this/super370		let uctx = DirectUnbound(ctx.clone());371		for field in &members.fields {372			evaluate_field_member(&mut builder, ctx.clone(), uctx.clone(), field)?;373		}374		if !members.asserts.is_empty() {375			builder.assert(ObjectAssert {376				uctx,377				asserts: members.asserts.clone(),378			});379		}380	} else {381		let locals = members.locals.clone();382		// We have single context for all fields, so we can cache them together383		let uctx = CachedUnbound::new(evaluate_object_locals(ctx.clone(), locals));384		for field in &members.fields {385			evaluate_field_member(&mut builder, ctx.clone(), uctx.clone(), field)?;386		}387		if !members.asserts.is_empty() {388			builder.assert(ObjectAssert {389				uctx,390				asserts: members.asserts.clone(),391			});392		}393	}394395	Ok(builder.build())396}397398pub fn evaluate_object(399	super_obj: Option<ObjValue>,400	ctx: Context,401	object: &ObjBody,402) -> Result<ObjValue> {403	Ok(match object {404		ObjBody::MemberList(members) => evaluate_member_list_object(super_obj, ctx, members)?,405		ObjBody::ObjComp(obj) => {406			let mut builder = ObjValueBuilder::new();407			if let Some(super_obj) = super_obj {408				builder.with_super(super_obj);409			}410			let locals = obj.locals.clone();411			evaluate_comp(ctx, &obj.compspecs, 0, &mut |ctx, reserve| {412				let uctx = evaluate_object_locals(ctx.clone(), locals.clone());413				builder.reserve_cores(reserve);414415				evaluate_field_member(&mut builder, ctx, uctx, &obj.field)416			})?;417418			builder.build()419		}420	})421}422423pub fn evaluate_apply(424	ctx: Context,425	value: &Expr,426	args: &ArgsDesc,427	loc: CallLocation<'_>,428	tailstrict: bool,429) -> Result<Val> {430	let value = evaluate(ctx.clone(), value)?;431	Ok(match value {432		Val::Func(f) => {433			let name = f.name();434			let unnamed = args435				.unnamed436				.iter()437				.cloned()438				.map(|un| evaluate_thunk(ctx.clone(), un, tailstrict))439				.collect::<Result<Vec<_>>>()?;440			let named = args441				.values442				.iter()443				.cloned()444				.map(|un| evaluate_thunk(ctx.clone(), un, tailstrict))445				.collect::<Result<Vec<_>>>()?;446			let prepare = PreparedFuncVal::new(f, args.unnamed.len(), &args.names)447				.with_description_src(loc, || format!("function <{name}> call"))?;448			let body = || prepare.call(loc, &unnamed, &named);449			if tailstrict {450				body()?451			} else {452				in_frame(loc, || format!("function <{name}> call"), body)?453			}454		}455		v => bail!(OnlyFunctionsCanBeCalledGot(v.value_type())),456	})457}458459pub fn evaluate_assert(ctx: Context, assertion: &AssertStmt) -> Result<()> {460	let value = &assertion.0;461	let msg = &assertion.1;462	let assertion_result = in_frame(463		CallLocation::new(&value.span),464		|| "assertion condition".to_owned(),465		|| bool::from_untyped(evaluate(ctx.clone(), value)?),466	)?;467	if !assertion_result {468		in_frame(469			CallLocation::new(&value.span),470			|| "assertion failure".to_owned(),471			|| {472				if let Some(msg) = msg {473					bail!(AssertionFailed(evaluate(ctx, msg)?.to_string()?));474				}475				bail!(AssertionFailed(Val::Null.to_string()?));476			},477		)?;478	}479	Ok(())480}481482pub fn evaluate_named_param(ctx: Context, expr: &Expr, name: ParamName) -> Result<Val> {483	match name {484		ParamName::Named(name) => evaluate_named(ctx, expr, name),485		ParamName::Unnamed => evaluate(ctx, expr),486	}487}488489pub fn evaluate_named(ctx: Context, expr: &Expr, name: IStr) -> Result<Val> {490	use Expr::*;491	Ok(match expr {492		Function(params, body) => evaluate_method(ctx, name, params.clone(), body.clone()),493		_ => evaluate(ctx, expr)?,494	})495}496497pub fn evaluate_thunk(ctx: Context, expr: Rc<Expr>, tailstrict: bool) -> Result<Thunk<Val>> {498	Ok(if tailstrict {499		Thunk::evaluated(evaluate(ctx, &expr)?)500	} else {501		Thunk!(move || { evaluate(ctx, &expr) })502	})503}504#[allow(clippy::too_many_lines)]505pub fn evaluate(ctx: Context, expr: &Expr) -> Result<Val> {506	use Expr::*;507508	Ok(match expr {509		Literal(LiteralType::This) => Val::Obj(ctx.try_this()?),510		Literal(LiteralType::Super) => Val::Obj(ctx.try_sup_this()?.standalone_super()?),511		Literal(LiteralType::Dollar) => Val::Obj(ctx.try_dollar()?),512		Literal(LiteralType::True) => Val::Bool(true),513		Literal(LiteralType::False) => Val::Bool(false),514		Literal(LiteralType::Null) => Val::Null,515		Str(v) => Val::string(v.clone()),516		Num(v) => Val::try_num(*v)?,517		// I have tried to remove special behavior from super by implementing standalone-super518		// expresion, but looks like this case still needs special treatment.519		//520		// Note that other jsonnet implementations will fail on `if value in (super)` expression,521		// because the standalone super literal is not supported, that is because in other522		// implementations `in super` treated differently from `in smth_else`.523		BinaryOp(bin)524			if matches!(&bin.rhs, Expr::Literal(LiteralType::Super))525				&& bin.op == BinaryOpType::In =>526		{527			let sup_this = ctx.try_sup_this()?;528			// In jsonnet, "field" in e is eager, LHS expression is always executed regardless of super existence.529			// In jrsonnet, however, this wasn't true, this was kept here for compatibility.530			if !sup_this.has_super() {531				return Ok(Val::Bool(false));532			}533			let field = evaluate(ctx, &bin.lhs)?;534			Val::Bool(sup_this.field_in_super(field.to_string()?))535		}536		BinaryOp(bin) => evaluate_binary_op_special(ctx, &bin.lhs, bin.op, &bin.rhs)?,537		UnaryOp(o, v) => evaluate_unary_op(*o, &evaluate(ctx, v)?)?,538		Var(name) => in_frame(539			CallLocation::new(&name.span),540			|| format!("local <{}> access", &**name),541			|| ctx.binding((**name).clone())?.evaluate(),542		)?,543		Index { indexable, parts } => ensure_sufficient_stack(|| {544			let mut parts = parts.iter();545			let mut indexable = if matches!(&**indexable, Expr::Literal(LiteralType::Super)) {546				let part = parts.next().expect("at least part should exist");547				// sup_this existence check might also be skipped here for null-coalesce...548				// But I believe this might cause errors.549				let sup_this = ctx.try_sup_this()?;550				if !sup_this.has_super() {551					#[cfg(feature = "exp-null-coaelse")]552					if part.null_coaelse {553						return Ok(Val::Null);554					}555					bail!(NoSuperFound)556				}557				let name = evaluate(ctx.clone(), &part.value)?;558559				let Val::Str(name) = name else {560					bail!(ValueIndexMustBeTypeGot(561						ValType::Obj,562						ValType::Str,563						name.value_type(),564					))565				};566567				let name = name.into_flat();568				match sup_this569					.get_super(name.clone())570					.with_description_src(&part.span, || format!("field <{name}> access"))?571				{572					Some(v) => v,573					#[cfg(feature = "exp-null-coaelse")]574					None if part.null_coaelse => return Ok(Val::Null),575					None => {576						let suggestions = suggest_object_fields(577							&sup_this.standalone_super().expect("super exists"),578							name.clone(),579						);580581						bail!(NoSuchField(name, suggestions))582					}583				}584			} else {585				evaluate(ctx.clone(), indexable)?586			};587588			for part in parts {589				indexable = match (indexable, evaluate(ctx.clone(), &part.value)?) {590					(Val::Obj(v), Val::Str(key)) => match v591						.get(key.clone().into_flat())592						.with_description_src(&part.span, || format!("field <{key}> access"))?593					{594						Some(v) => v,595						#[cfg(feature = "exp-null-coaelse")]596						None if part.null_coaelse => return Ok(Val::Null),597						None => {598							let suggestions = suggest_object_fields(&v, key.into_flat());599600							return Err(Error::from(NoSuchField(601								key.clone().into_flat(),602								suggestions,603							)))604							.with_description_src(&part.span, || format!("field <{key}> access"));605						}606					},607					(Val::Obj(_), n) => bail!(ValueIndexMustBeTypeGot(608						ValType::Obj,609						ValType::Str,610						n.value_type(),611					)),612					(Val::Arr(v), Val::Num(n)) => {613						let n = n.get();614						if n.fract() > f64::EPSILON {615							bail!(FractionalIndex)616						}617						if n < 0.0 {618							#[expect(619								clippy::cast_possible_truncation,620								reason = "it would be truncated anyway"621							)]622							let n = n as isize;623							bail!(ArrayBoundsError(n, v.len()));624						}625						#[expect(626							clippy::cast_possible_truncation,627							clippy::cast_sign_loss,628							reason = "n is checked postive"629						)]630						v.get(n as usize)?631							.ok_or_else(|| ArrayBoundsError(n as isize, v.len()))?632					}633					(Val::Arr(_), Val::Str(n)) => {634						bail!(AttemptedIndexAnArrayWithString(n.into_flat()))635					}636					(Val::Arr(_), n) => bail!(ValueIndexMustBeTypeGot(637						ValType::Arr,638						ValType::Num,639						n.value_type(),640					)),641642					(Val::Str(s), Val::Num(n)) => Val::Str({643						let n = n.get();644						if n.fract() > f64::EPSILON {645							bail!(FractionalIndex)646						}647						if n < 0.0 {648							#[expect(649								clippy::cast_possible_truncation,650								reason = "it would be truncated anyway"651							)]652							let n = n as isize;653							bail!(ArrayBoundsError(n, s.into_flat().chars().count()));654						}655						#[expect(656							clippy::cast_sign_loss,657							clippy::cast_possible_truncation,658							reason = "n is positive, overflow will truncate as expected"659						)]660						let n = n as usize;661						let v: IStr = s662							.clone()663							.into_flat()664							.chars()665							.skip(n)666							.take(1)667							.collect::<String>()668							.into();669						if v.is_empty() {670							bail!(StringBoundsError(n, s.into_flat().chars().count()))671						}672						StrValue::Flat(v)673					}),674					(Val::Str(_), n) => bail!(ValueIndexMustBeTypeGot(675						ValType::Str,676						ValType::Num,677						n.value_type(),678					)),679					#[cfg(feature = "exp-null-coaelse")]680					(Val::Null, _) if part.null_coaelse => return Ok(Val::Null),681					(v, _) => bail!(CantIndexInto(v.value_type())),682				};683			}684			Ok(indexable)685		})?,686		LocalExpr(bindings, returned) => {687			let mut new_bindings: FxHashMap<IStr, Thunk<Val>> =688				FxHashMap::with_capacity(bindings.iter().map(BindSpec::binds_len).sum());689			let fctx = Context::new_future();690			for b in bindings {691				evaluate_dest(b, fctx.clone(), &mut new_bindings)?;692			}693			let ctx = ctx.extend_bindings(new_bindings).into_future(fctx);694			evaluate(ctx, returned)?695		}696		Arr(items) => {697			if items.is_empty() {698				Val::arr(())699			} else {700				Val::Arr(ArrValue::expr(ctx, items.clone()))701			}702		}703		ArrComp(expr, comp_specs) => Val::Arr(evaluate_arr_comp(ctx, expr, comp_specs)?),704		Obj(body) => Val::Obj(evaluate_object(None, ctx, body)?),705		ObjExtend(a, b) => {706			let base = evaluate(ctx.clone(), a)?;707			match base {708				Val::Obj(base_obj) => Val::Obj(evaluate_object(Some(base_obj), ctx, b)?),709				_ => bail!("ObjExtend lhs should be an object value"),710			}711		}712		Apply(value, args, tailstrict) => ensure_sufficient_stack(|| {713			evaluate_apply(ctx, value, args, CallLocation::new(&args.span), *tailstrict)714		})?,715		Function(params, body) => {716			evaluate_method(ctx, "anonymous".into(), params.clone(), body.clone())717		}718		AssertExpr(assert) => {719			evaluate_assert(ctx.clone(), &assert.assert)?;720			evaluate(ctx, &assert.rest)?721		}722		ErrorStmt(s, e) => in_frame(723			CallLocation::new(s),724			|| "error statement".to_owned(),725			|| bail!(RuntimeError(evaluate(ctx, e)?.to_string()?,)),726		)?,727		IfElse(if_else) => {728			if in_frame(729				CallLocation::new(&if_else.cond.span),730				|| "if condition".to_owned(),731				|| bool::from_untyped(evaluate(ctx.clone(), &if_else.cond.cond)?),732			)? {733				evaluate(ctx, &if_else.cond_then)?734			} else {735				match &if_else.cond_else {736					Some(v) => evaluate(ctx, v)?,737					None => Val::Null,738				}739			}740		}741		Slice(slice) => {742			fn parse_idx<T: Typed + FromUntyped>(743				ctx: Context,744				expr: Option<&Spanned<Expr>>,745				desc: &'static str,746			) -> Result<Option<T>> {747				if let Some(value) = expr {748					Ok(in_frame(749						CallLocation::new(&value.span),750						|| format!("slice {desc}"),751						|| <Option<T>>::from_untyped(evaluate(ctx, value)?),752					)?)753				} else {754					Ok(None)755				}756			}757758			let indexable = evaluate(ctx.clone(), &slice.value)?;759760			let start = parse_idx(ctx.clone(), slice.slice.start.as_ref(), "start")?;761			let end = parse_idx(ctx.clone(), slice.slice.end.as_ref(), "end")?;762			let step = parse_idx(ctx, slice.slice.step.as_ref(), "step")?;763764			IndexableVal::into_untyped(indexable.into_indexable()?.slice(start, end, step)?)?765		}766		Import(kind, path) => {767			let Expr::Str(path) = &**path else {768				bail!("computed imports are not supported")769			};770			with_state(|s| {771				let span = &kind.span;772				let resolved_path = s.resolve_from(span.0.source_path(), path)?;773				Ok(match &**kind {774					ImportKind::Normal => in_frame(775						CallLocation::new(span),776						|| format!("import {:?}", path.clone()),777						|| s.import_resolved(resolved_path),778					)?,779					ImportKind::Str => Val::string(s.import_resolved_str(resolved_path)?),780					ImportKind::Bin => Val::arr(s.import_resolved_bin(resolved_path)?),781				}) as Result<Val>782			})?783		}784	})785}