git.delta.rocks / jrsonnet / refs/commits / 7bd5bbd0756a

difftreelog

perf static object shapes

ptmvzrqoYaroslav Bolyukin2026-05-08parent: #d0b9ff2.patch.diff
in: master

29 files changed

modifiedcrates/jrsonnet-evaluator/src/analyze.rsdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/analyze.rs
+++ b/crates/jrsonnet-evaluator/src/analyze.rs
@@ -21,16 +21,18 @@
 use jrsonnet_interner::IStr;
 use jrsonnet_ir::{
 	ArgsDesc, AssertExpr, AssertStmt, BinaryOp, BinaryOpType, BindSpec, CompSpec, Destruct, Expr,
-	ExprParams, FieldName, ForSpecData, IfElse, IfSpecData, ImportKind, LiteralType, NumValue,
-	ObjBody, ObjComp, ObjMembers, Slice, SliceDesc, Span, Spanned, UnaryOpType, Visibility,
+	ExprParams, FieldName, ForSpecData, IdentityKind, IfElse, IfSpecData, ImportKind, ObjBody,
+	ObjComp, ObjMembers, Slice, SliceDesc, Span, Spanned, TrivialVal, UnaryOpType, Visibility,
 	function::FunctionSignature,
 };
-use rustc_hash::FxHashMap;
+use rustc_hash::{FxHashMap, FxHashSet};
 use smallvec::SmallVec;
 
 use crate::{
 	arr::arridx,
 	error::{format_found, suggest_names},
+	gc::WithCapacityExt as _,
+	obj::{ObjFieldFlags, ObjShape, ShapeField, ordering::FieldIndex},
 };
 
 #[derive(Debug, Clone, Copy)]
@@ -329,6 +331,7 @@
 #[derive(Debug, Acyclic)]
 pub enum LObjBody {
 	MemberList(LObjMembers),
+	StaticMembers(Box<LObjStaticMembers>),
 	ObjComp(Box<LObjComp>),
 }
 
@@ -349,6 +352,20 @@
 }
 
 #[derive(Debug, Acyclic)]
+pub struct LObjStaticMembers {
+	pub frame_shape: ClosureShape,
+	pub this: Option<LocalSlot>,
+	pub set_dollar: bool,
+	pub uses_super: bool,
+
+	pub locals: Rc<Vec<LBind>>,
+	pub asserts: Option<Rc<LObjAsserts>>,
+
+	pub shape: Rc<ObjShape>,
+	pub bindings: Vec<Rc<(ClosureShape, LExpr)>>,
+}
+
+#[derive(Debug, Acyclic)]
 pub struct LObjComp {
 	pub frame_shape: Rc<ClosureShape>,
 	pub this: Option<LocalSlot>,
@@ -1336,7 +1353,7 @@
 	taint: &mut AnalysisResult,
 ) -> LExpr {
 	if let Expr::Function(span, params, body) = expr {
-		return analyze_function(Some(name), &span, &params, body, stack, taint);
+		return analyze_function(Some(name), span, params, body, stack, taint);
 	}
 	analyze(expr, stack, taint)
 }
@@ -1552,7 +1569,7 @@
 		BindSpec::Field {
 			value: Expr::Function(span, params, value),
 			into: Destruct::Full(name),
-		} => analyze_function(Some(name.value.clone()), &span, params, value, stack, taint),
+		} => analyze_function(Some(name.value.clone()), span, params, value, stack, taint),
 		BindSpec::Field { value, .. } => analyze(value, stack, taint),
 		BindSpec::Function {
 			params,
@@ -1694,12 +1711,69 @@
 ) -> LObjBody {
 	match obj {
 		ObjBody::MemberList(members) => {
-			LObjBody::MemberList(analyze_obj_members(members, stack, taint))
+			let lowered = analyze_obj_members(members, stack, taint);
+			match try_lower_static(lowered) {
+				Ok(static_members) => LObjBody::StaticMembers(Box::new(static_members)),
+				Err(member_list) => LObjBody::MemberList(member_list),
+			}
 		}
 		ObjBody::ObjComp(comp) => LObjBody::ObjComp(Box::new(analyze_obj_comp(comp, stack, taint))),
 	}
 }
 
+fn try_lower_static(members: LObjMembers) -> Result<LObjStaticMembers, LObjMembers> {
+	let mut seen: FxHashSet<IStr> = FxHashSet::with_capacity(members.fields.len());
+	for f in &members.fields {
+		match &f.name {
+			LFieldName::Fixed(name) => {
+				if !seen.insert(name.clone()) {
+					return Err(members);
+				}
+			}
+			LFieldName::Dyn(_) => return Err(members),
+		}
+	}
+
+	let LObjMembers {
+		frame_shape,
+		this,
+		set_dollar,
+		uses_super,
+		locals,
+		asserts,
+		fields,
+	} = members;
+
+	let mut shape_fields = Vec::with_capacity(fields.len());
+	let mut bindings = Vec::with_capacity(fields.len());
+	let mut next_index = FieldIndex::default();
+	for f in fields {
+		let LFieldName::Fixed(name) = f.name else {
+			unreachable!("checked above");
+		};
+		let index = next_index;
+		next_index = next_index.next();
+		shape_fields.push(ShapeField {
+			name,
+			flags: ObjFieldFlags::new(f.plus, f.visibility),
+			location: None,
+			index,
+		});
+		bindings.push(f.value);
+	}
+
+	Ok(LObjStaticMembers {
+		frame_shape,
+		this,
+		set_dollar,
+		uses_super,
+		locals,
+		asserts,
+		shape: Rc::new(ObjShape::new(shape_fields)),
+		bindings,
+	})
+}
+
 fn analyze_obj_members(
 	members: &ObjMembers,
 	stack: &mut AnalysisStack,
modifiedcrates/jrsonnet-evaluator/src/evaluate/mod.rsdiffbeforeafterboth
after · crates/jrsonnet-evaluator/src/evaluate/mod.rs
1use std::rc::Rc;23use jrsonnet_gcmodule::{Cc, Trace};4use jrsonnet_interner::IStr;5use jrsonnet_ir::ImportKind;6use jrsonnet_types::ValType;78use self::{9	compspec::{evaluate_arr_comp, evaluate_obj_comp},10	destructure::evaluate_locals_unbound,11	operator::evaluate_binary_op_special,12};13use crate::{14	CcObjectAssertion, CcUnbound, Context, Error, MaybeUnbound, ObjValue, ObjValueBuilder,15	ObjectAssertion, Result, ResultExt as _, StaticShapeOopObject, SupThis, Unbound, Val,16	analyze::{17		ClosureShape, LArgsDesc, LAssertStmt, LExpr, LFieldMember, LFieldName, LFunction,18		LIndexPart, LObjAsserts, LObjBody, LObjMembers, LObjStaticMembers, LSlot,19	},20	arr::ArrValue,21	bail,22	error::{ErrorKind::*, suggest_object_fields},23	evaluate::{destructure::fill_letrec_binds, operator::evaluate_unary_op},24	function::{CallLocation, FuncDesc, FuncVal, prepared::PreparedFuncVal},25	in_frame,26	typed::{BoundedUsize, FromUntyped as _},27	val::{CachedUnbound, Thunk},28	with_state,29};3031pub mod compspec;32pub mod destructure;33pub mod operator;3435// This is the amount of bytes that need to be left on the stack before increasing the size.36// It must be at least as large as the stack required by any code that does not call37// `ensure_sufficient_stack`.38const RED_ZONE: usize = 100 * 1024;3940// Only the first stack that is pushed, grows exponentially (2^n * STACK_PER_RECURSION) from then41// on. This flag has performance relevant characteristics. Don't set it too high.42const STACK_PER_RECURSION: usize = 1024 * 1024;4344/// Grows the stack on demand to prevent stack overflow. Call this in strategic locations45/// to "break up" recursive calls. E.g. almost any call to `visit_expr` or equivalent can benefit46/// from this.47///48/// Should not be sprinkled around carelessly, as it causes a little bit of overhead.49#[inline]50pub fn ensure_sufficient_stack<R>(f: impl FnOnce() -> R) -> R {51	stacker::maybe_grow(RED_ZONE, STACK_PER_RECURSION, f)52}5354pub fn evaluate_trivial(expr: &LExpr) -> Option<Val> {55	if let LExpr::Trivial(tv) = expr {56		Some(tv.clone().into())57	} else {58		None59	}60}6162pub fn evaluate_method(ctx: Context, name: IStr, func: &Rc<LFunction>) -> Val {63	Val::Func(FuncVal::Normal(Cc::new(FuncDesc {64		name,65		body_captures: ctx.pack_captures_sup_this(&func.body_shape),66		func: func.clone(),67	})))68}6970pub fn evaluate_field_name(ctx: Context, field_name: &LFieldName) -> Result<Option<IStr>> {71	Ok(match field_name {72		LFieldName::Fixed(n) => Some(n.clone()),73		LFieldName::Dyn(expr) => in_frame(74			// TODO: Spanned<LFieldName>75			CallLocation::native(),76			|| "evaluating field name".to_string(),77			|| {78				let v = evaluate(ctx.clone(), expr)?;79				Ok(if matches!(v, Val::Null) {80					None81				} else {82					Some(IStr::from_untyped(v)?)83				})84			},85		)?,86	})87}8889pub fn evaluate_thunk(ctx: Context, expr: Rc<LExpr>, tailstrict: bool) -> Result<Thunk<Val>> {90	match &*expr {91		LExpr::Slot(LSlot::Local(i)) => return Ok(ctx.local(*i)),92		LExpr::Slot(LSlot::Capture(i)) => return Ok(ctx.capture(*i)),93		_ => {94			if let Some(v) = evaluate_trivial(&expr) {95				return Ok(Thunk::evaluated(v));96			}97		}98	}99	Ok(if tailstrict {100		Thunk::evaluated(evaluate(ctx, &expr)?)101	} else {102		Thunk!(move || { evaluate(ctx, &expr) })103	})104}105106mod names {107	use crate::names;108109	names! {110		anonymous: "anonymous",111	}112}113114#[allow(clippy::too_many_lines)]115pub fn evaluate(mut ctx: Context, mut expr: &LExpr) -> Result<Val> {116	loop {117		return Ok(match expr {118			LExpr::Trivial(tv) => tv.clone().into(),119			LExpr::Slot(slot) => ctx.slot(*slot).evaluate()?,120			LExpr::BadLocal(name) => panic!("unresolvable reference: {name}"),121			LExpr::ArrConst(rc) => Val::Arr(ArrValue::new(rc.clone())),122			LExpr::Arr { shape, items } => {123				let inner = Context::enter_using(&ctx, shape);124				'eager: {125					let mut out: Vec<Val> = Vec::with_capacity(items.len());126					for item in items.iter() {127						let Ok(r) = evaluate(inner.clone(), item) else {128							break 'eager;129						};130						out.push(r);131					}132					return Ok(Val::Arr(ArrValue::new(out)));133				}134				Val::Arr(ArrValue::expr(inner, items.clone()))135			}136			LExpr::UnaryOp(op, value) => {137				let value = evaluate(ctx, value)?;138				evaluate_unary_op(*op, &value)?139			}140			LExpr::BinaryOp { lhs, op, rhs } => evaluate_binary_op_special(ctx, lhs, *op, rhs)?,141			LExpr::LocalExpr(l) => {142				ctx = ctx143					.pack_captures_sup_this(&l.frame_shape)144					.enter(|fill, ctx| {145						fill_letrec_binds(fill, ctx, &l.binds);146					});147				expr = &l.body;148				continue;149			}150			LExpr::IfElse {151				cond,152				cond_then,153				cond_else,154			} => {155				let cond_val = evaluate(ctx.clone(), cond)?;156				let Val::Bool(b) = cond_val else {157					bail!(TypeMismatch(158						"if condition",159						vec![ValType::Bool],160						cond_val.value_type()161					))162				};163				if b {164					expr = cond_then;165					continue;166				} else if let Some(e) = cond_else {167					expr = e;168					continue;169				}170				Val::Null171			}172			LExpr::Error(s, e) => in_frame(173				CallLocation::new(s),174				|| "error statement".to_owned(),175				|| bail!(RuntimeError(evaluate(ctx, e)?.to_string()?,)),176			)?,177			LExpr::AssertExpr { assert, rest } => {178				evaluate_assert(ctx.clone(), assert)?;179				expr = rest;180				continue;181			}182183			LExpr::Function(func) => evaluate_method(184				ctx,185				func.name.clone().unwrap_or_else(names::anonymous),186				func,187			),188			LExpr::IdentityFunction => Val::Func(FuncVal::identity()),189			LExpr::Apply {190				applicable,191				args,192				tailstrict,193			} => evaluate_apply(194				ctx,195				applicable,196				args,197				CallLocation::new(&args.span),198				*tailstrict,199			)?,200			LExpr::Index { indexable, parts } => evaluate_index(ctx, indexable, parts)?,201			LExpr::Obj(body) => evaluate_obj_body(None, ctx, body)?,202			LExpr::ObjExtend(lhs, body) => {203				let lhs_val = evaluate(ctx.clone(), lhs)?;204				let Val::Obj(lhs_obj) = lhs_val else {205					bail!(TypeMismatch(206						"object extend lhs",207						vec![ValType::Obj],208						lhs_val.value_type(),209					))210				};211				evaluate_obj_body(Some(lhs_obj), ctx, body)?212			}213			LExpr::ArrComp(comp) => evaluate_arr_comp(ctx, comp)?,214			LExpr::Slice(slice) => {215				let val = evaluate(ctx.clone(), &slice.value)?;216				let indexable = val.into_indexable()?;217				let start = slice218					.start219					.as_ref()220					.map(|e| evaluate(ctx.clone(), e))221					.transpose()?222					.map(|v| -> Result<i32> {223						i32::from_untyped(v).description("slice start value")224					})225					.transpose()?;226				let end = slice227					.end228					.as_ref()229					.map(|e| evaluate(ctx.clone(), e))230					.transpose()?231					.map(|v| -> Result<i32> { i32::from_untyped(v).description("slice end value") })232					.transpose()?;233				let step = slice234					.step235					.as_ref()236					.map(|e| evaluate(ctx, e))237					.transpose()?238					.map(|v| -> Result<BoundedUsize<1, { i32::MAX as usize }>> {239						BoundedUsize::from_untyped(v).description("slice step value")240					})241					.transpose()?;242				Val::from(indexable.slice32(start, end, step)?)243			}244			LExpr::Super => Val::Obj(ctx.try_sup_this()?.standalone_super().ok_or(NoSuperFound)?),245			LExpr::Import {246				kind,247				kind_span,248				path,249			} => with_state(|state| {250				let resolved = state.resolve_from(kind_span.0.source_path(), &path.clone())?;251				Ok::<_, Error>(match kind.value {252					ImportKind::Normal => in_frame(253						CallLocation::new(&kind.span),254						|| "import".to_string(),255						|| state.import_resolved(resolved),256					)?,257					ImportKind::Str => Val::string(state.import_resolved_str(resolved)?),258					ImportKind::Bin => Val::arr(state.import_resolved_bin(resolved)?),259				})260			})?,261		});262	}263}264265fn evaluate_apply(266	ctx: Context,267	applicable: &LExpr,268	args: &LArgsDesc,269	loc: CallLocation<'_>,270	tailstrict: bool,271) -> Result<Val> {272	let func_val = evaluate(ctx.clone(), applicable)?;273	let Val::Func(func) = func_val else {274		bail!(OnlyFunctionsCanBeCalledGot(func_val.value_type()))275	};276277	if func.is_identity() && args.names.is_empty() && args.unnamed.len() == 1 {278		return evaluate_thunk(ctx, args.unnamed[0].clone(), tailstrict)?.evaluate();279	}280281	let name = func.name();282283	if args.names.is_empty() && args.unnamed.len() == 1 && func.params().len() == 1 {284		use crate::function::prepared::PreparedCall;285		let prepared_inline = PreparedCall::empty();286		let arg = evaluate_thunk(ctx, args.unnamed[0].clone(), tailstrict)?;287		let arg_slice = std::slice::from_ref(&arg);288		return in_frame(289			loc,290			|| format!("function <{name}> call"),291			|| {292				func.evaluate_prepared(293					&prepared_inline,294					CallLocation::native(),295					arg_slice,296					&[],297					tailstrict,298				)299			},300		);301	}302303	let unnamed = args304		.unnamed305		.iter()306		.cloned()307		.map(|e| evaluate_thunk(ctx.clone(), e, tailstrict))308		.collect::<Result<Vec<_>>>()?;309310	// Fast path: positional-only multi-arg call fully covering the311	// params, no defaults.312	if args.names.is_empty() && unnamed.len() == func.params().len() {313		use crate::function::prepared::PreparedCall;314		let prepared_inline = PreparedCall::empty();315		return in_frame(316			loc,317			|| format!("function <{name}> call"),318			|| {319				func.evaluate_prepared(320					&prepared_inline,321					CallLocation::native(),322					&unnamed,323					&[],324					tailstrict,325				)326			},327		);328	}329330	let named = args331		.values332		.iter()333		.cloned()334		.map(|e| evaluate_thunk(ctx.clone(), e, tailstrict))335		.collect::<Result<Vec<_>>>()?;336	let prepare = PreparedFuncVal::new(func, unnamed.len(), &args.names)337		.with_description_src(loc, || format!("function <{name}> preparation"))?;338	in_frame(339		loc,340		|| format!("function <{name}> call"),341		|| prepare.call(CallLocation::native(), &unnamed, &named),342	)343}344345#[allow(clippy::too_many_lines)]346fn evaluate_index(ctx: Context, indexable: &LExpr, parts: &[LIndexPart]) -> Result<Val> {347	let mut parts = parts.iter();348	let mut indexable = if matches!(indexable, LExpr::Super) {349		let part = parts.next().expect("at least part should exist");350		// sup_this existence check might also be skipped here for null-coalesce...351		// But I believe this might cause errors.352		let sup_this = ctx.try_sup_this()?;353354		if !sup_this.has_super() {355			#[cfg(feature = "exp-null-coaelse")]356			if part.null_coaelse {357				return Ok(Val::Null);358			}359			bail!(NoSuperFound);360		}361		let name = evaluate(ctx.clone(), &part.value)?;362363		let Val::Str(name) = name else {364			bail!(ValueIndexMustBeTypeGot(365				ValType::Obj,366				ValType::Str,367				name.value_type(),368			))369		};370371		let name = name.into_flat();372		match sup_this373			.get_super(name.clone())374			.with_description_src(&part.span, || format!("super field <{name}> access"))?375		{376			Some(v) => v,377			#[cfg(feature = "exp-null-coaelse")]378			None if part.null_coaelse => return Ok(Val::Null),379			None => {380				let suggestions = suggest_object_fields(381					&sup_this.standalone_super().expect("super exists"),382					name.clone(),383				);384				bail!(NoSuchField(name, suggestions))385			}386		}387	} else {388		evaluate(ctx.clone(), indexable)?389	};390391	for part in parts {392		let ctx = ctx.clone();393		let loc = CallLocation::new(&part.span);394		let value = indexable;395		let key_val = evaluate(ctx, &part.value)?;396		indexable = match (&value, &key_val) {397			(Val::Obj(obj), Val::Str(key)) => {398				let key = key.clone().into_flat();399				match obj400					.get(key.clone())401					.with_description_src(loc, || format!("field <{key}> access"))?402				{403					Some(v) => v,404					#[cfg(feature = "exp-null-coaelse")]405					None if part.null_coaelse => return Ok(Val::Null),406					None => {407						return Err(Error::from(NoSuchField(408							key.clone(),409							suggest_object_fields(obj, key.clone()),410						)))411						.with_description_src(loc, || format!("field <{key}> access"));412					}413				}414			}415			(Val::Arr(arr), Val::Num(idx)) => {416				let n = idx.get();417				if n.fract() > f64::EPSILON {418					bail!(FractionalIndex)419				}420				let len = arr.len32();421				if n < 0.0 || n > f64::from(len) {422					bail!(ArrayBoundsError(n, len));423				}424				#[expect(425					clippy::cast_possible_truncation,426					clippy::cast_sign_loss,427					reason = "n is checked range"428				)]429				let i = n as u32;430				arr.get32(i)431					.with_description_src(loc, || format!("element <{i}> access"))?432					.ok_or_else(|| ArrayBoundsError(n, len))?433			}434			(Val::Str(s), Val::Num(idx)) => {435				let n = idx.get();436				if n.fract() > f64::EPSILON {437					bail!(FractionalIndex)438				}439				#[expect(440					clippy::cast_possible_truncation,441					clippy::cast_sign_loss,442					reason = "n is checked positive, overflow will truncate as expected"443				)]444				let i = n as usize;445				let flat = s.clone().into_flat();446				#[allow(clippy::cast_possible_truncation, reason = "string is max 4g")]447				if n >= 0.0448					&& n <= f64::from(u32::MAX)449					&& let Some(char) = flat.chars().nth(i)450				{451					Val::string(char)452				} else {453					let len = flat.chars().count();454					bail!(StringBoundsError(n, len as u32))455				}456			}457			#[cfg(feature = "exp-null-coaelse")]458			(Val::Null, _) if part.null_coaelse => return Ok(Val::Null),459			_ => bail!(ValueIndexMustBeTypeGot(460				value.value_type(),461				ValType::Str,462				key_val.value_type()463			)),464		};465	}466	Ok(indexable)467}468469fn evaluate_obj_body(super_obj: Option<ObjValue>, ctx: Context, body: &LObjBody) -> Result<Val> {470	match body {471		LObjBody::MemberList(members) => evaluate_obj_members(super_obj, ctx, members),472		LObjBody::StaticMembers(members) => {473			Ok(evaluate_static_obj_members(super_obj, ctx, members))474		}475		LObjBody::ObjComp(comp) => evaluate_obj_comp(super_obj, ctx, comp),476	}477}478479pub fn evaluate_field_member_unbound<B: Unbound<Bound = Context> + Clone>(480	builder: &mut ObjValueBuilder,481	ctx: Context,482	uctx: B,483	field: &LFieldMember,484) -> Result<()> {485	#[derive(Trace)]486	struct UnboundValue<B: Trace> {487		uctx: B,488		value: Rc<(ClosureShape, LExpr)>,489		name: IStr,490	}491	impl<B: Unbound<Bound = Context>> Unbound for UnboundValue<B> {492		type Bound = Val;493		fn bind(&self, sup_this: SupThis) -> Result<Val> {494			let a_ctx = self.uctx.bind(sup_this)?;495			let b_ctx = Context::enter_using(&a_ctx, &self.value.0);496			evaluate(b_ctx, &self.value.1)497		}498	}499500	let LFieldMember {501		name,502		plus,503		visibility,504		value,505	} = field;506	let Some(name) = evaluate_field_name(ctx, name)? else {507		return Ok(());508	};509510	builder511		.field(name.clone())512		.with_add(*plus)513		.with_visibility(*visibility)514		.bindable(UnboundValue {515			uctx,516			value: value.clone(),517			name,518		})519}520pub fn evaluate_field_member_static(521	builder: &mut ObjValueBuilder,522	field_ctx: Context,523	value_ctx: Context,524	field: &LFieldMember,525) -> Result<()> {526	let LFieldMember {527		name,528		plus,529		visibility,530		value,531	} = field;532	let Some(name) = evaluate_field_name(field_ctx, name)? else {533		return Ok(());534	};535536	let env = Context::enter_using(&value_ctx, &value.0);537	let value = value.clone();538	builder539		.field(name)540		.with_add(*plus)541		.with_visibility(*visibility)542		.try_thunk(Thunk!(move || evaluate(env, &value.1)))?;543	Ok(())544}545546fn evaluate_static_obj_members(547	super_obj: Option<ObjValue>,548	ctx: Context,549	members: &LObjStaticMembers,550) -> Val {551	#[derive(Trace)]552	struct UnboundField<B: Trace> {553		uctx: B,554		value: Rc<(ClosureShape, LExpr)>,555		name: IStr,556	}557	impl<B: Unbound<Bound = Context>> Unbound for UnboundField<B> {558		type Bound = Val;559		fn bind(&self, sup_this: SupThis) -> Result<Val> {560			let a_ctx = self.uctx.bind(sup_this)?;561			let b_ctx = Context::enter_using(&a_ctx, &self.value.0);562			evaluate(b_ctx, &self.value.1)563		}564	}565566	let needs_unbound = members.this.is_some() || members.uses_super;567568	let mut bindings: Vec<MaybeUnbound> = Vec::with_capacity(members.bindings.len());569570	let assertion = if needs_unbound {571		let uctx = CachedUnbound::new(evaluate_locals_unbound(572			&ctx,573			&members.frame_shape,574			members.this,575			members.locals.clone(),576		));577		for (binding, field) in members.bindings.iter().zip(members.shape.fields()) {578			if let Some(v) = evaluate_trivial(&binding.1) {579				bindings.push(MaybeUnbound::Const(v));580				continue;581			}582			bindings.push(MaybeUnbound::Unbound(CcUnbound::new(UnboundField {583				uctx: uctx.clone(),584				value: binding.clone(),585				name: field.name.clone(),586			})));587		}588		members589			.asserts590			.as_ref()591			.map(|a| CcObjectAssertion::new(evaluate_object_assertions_unbound(uctx, a.clone())))592	} else {593		let a_ctx = ctx594			.pack_captures_sup_this(&members.frame_shape)595			.enter(|fill, ctx| {596				fill_letrec_binds(fill, ctx, &members.locals);597			});598		for binding in &members.bindings {599			if let Some(v) = evaluate_trivial(&binding.1) {600				bindings.push(MaybeUnbound::Const(v));601				continue;602			}603			let env = Context::enter_using(&a_ctx, &binding.0);604			let value = binding.clone();605			bindings.push(MaybeUnbound::Bound(Thunk!(move || evaluate(env, &value.1))));606		}607		members.asserts.as_ref().map(|a| {608			CcObjectAssertion::new(evaluate_object_assertions_static(a_ctx.clone(), a.clone()))609		})610	};611612	let mut builder = ObjValueBuilder::with_capacity(0);613	if let Some(sup) = super_obj {614		builder.with_super(sup);615	}616	builder.extend_with_core(StaticShapeOopObject::new(617		members.shape.clone(),618		bindings,619		assertion,620	));621	Val::Obj(builder.build())622}623624fn evaluate_obj_members(625	super_obj: Option<ObjValue>,626	ctx: Context,627	members: &LObjMembers,628) -> Result<Val> {629	let mut builder = ObjValueBuilder::with_capacity(members.fields.len());630	if let Some(sup) = super_obj {631		builder.with_super(sup);632	}633634	let needs_unbound = members.this.is_some() || members.uses_super;635636	if needs_unbound {637		let uctx = CachedUnbound::new(evaluate_locals_unbound(638			&ctx,639			&members.frame_shape,640			members.this,641			members.locals.clone(),642		));643		for field in &members.fields {644			evaluate_field_member_unbound(&mut builder, ctx.clone(), uctx.clone(), field)?;645		}646		if let Some(asserts_block) = &members.asserts {647			builder.assert(evaluate_object_assertions_unbound(648				uctx,649				asserts_block.clone(),650			));651		}652	} else {653		let a_ctx = ctx654			.pack_captures_sup_this(&members.frame_shape)655			.enter(|fill, ctx| {656				fill_letrec_binds(fill, ctx, &members.locals);657			});658		for field in &members.fields {659			evaluate_field_member_static(&mut builder, ctx.clone(), a_ctx.clone(), field)?;660		}661		if let Some(asserts_block) = &members.asserts {662			builder.assert(evaluate_object_assertions_static(663				a_ctx,664				asserts_block.clone(),665			));666		}667	}668669	Ok(Val::Obj(builder.build()))670}671672pub fn evaluate_assert(ctx: Context, assertion: &LAssertStmt) -> Result<()> {673	let LAssertStmt { cond, message } = assertion;674	let assertion_result = in_frame(675		CallLocation::new(&cond.span),676		|| "assertion condition".to_owned(),677		|| bool::from_untyped(evaluate(ctx.clone(), cond)?),678	)?;679	if !assertion_result {680		in_frame(681			CallLocation::new(&cond.span),682			|| "assertion failure".to_owned(),683			|| {684				if let Some(msg) = message {685					bail!(AssertionFailed(evaluate(ctx, msg)?.to_string()?));686				}687				bail!(AssertionFailed(Val::Null.to_string()?));688			},689		)?;690	}691	Ok(())692}693694fn evaluate_object_assertions_unbound<B: Unbound<Bound = Context>>(695	uctx: B,696	asserts: Rc<LObjAsserts>,697) -> impl ObjectAssertion {698	#[derive(Trace)]699	struct ObjectAssert<B: Trace> {700		uctx: B,701		asserts: Rc<LObjAsserts>,702	}703	impl<B: Unbound<Bound = Context>> ObjectAssertion for ObjectAssert<B> {704		fn run(&self, sup_this: SupThis) -> Result<()> {705			let a_ctx = self.uctx.bind(sup_this)?;706			let assert_env = Context::enter_using(&a_ctx, &self.asserts.shape);707			for assert in &self.asserts.asserts {708				evaluate_assert(assert_env.clone(), assert)?;709			}710			Ok(())711		}712	}713	ObjectAssert { uctx, asserts }714}715fn evaluate_object_assertions_static(716	a_ctx: Context,717	asserts: Rc<LObjAsserts>,718) -> impl ObjectAssertion {719	#[derive(Trace)]720	struct ObjectAssert {721		assert_env: Context,722		asserts: Rc<LObjAsserts>,723	}724	impl ObjectAssertion for ObjectAssert {725		fn run(&self, _sup_this: SupThis) -> Result<()> {726			for assert in &self.asserts.asserts {727				evaluate_assert(self.assert_env.clone(), assert)?;728			}729			Ok(())730		}731	}732	let assert_env = Context::enter_using(&a_ctx, &asserts.shape);733	ObjectAssert {734		assert_env,735		asserts,736	}737}
modifiedcrates/jrsonnet-evaluator/src/lib.rsdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/lib.rs
+++ b/crates/jrsonnet-evaluator/src/lib.rs
@@ -144,6 +144,7 @@
 	Unbound(CcUnbound<Val>),
 	/// Value is object-independent
 	Bound(Thunk<Val>),
+	Const(Val),
 }
 
 impl Debug for MaybeUnbound {
@@ -157,6 +158,7 @@
 		match self {
 			Self::Unbound(v) => v.0.bind(sup_this),
 			Self::Bound(v) => Ok(v.evaluate()?),
+			Self::Const(v) => Ok(v.clone()),
 		}
 	}
 }
modifiedcrates/jrsonnet-evaluator/src/obj/mod.rsdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/obj/mod.rs
+++ b/crates/jrsonnet-evaluator/src/obj/mod.rs
@@ -17,9 +17,11 @@
 use rustc_hash::{FxHashMap, FxHashSet};
 
 mod oop;
+mod static_shape;
 
 pub use jrsonnet_ir::Visibility;
 pub use oop::ObjValueBuilder;
+pub use static_shape::{ObjShape, ObjShapeBuilder, ShapeField, StaticShapeOopObject};
 
 use crate::{
 	CcUnbound, MaybeUnbound, Result, Thunk, Unbound, Val,
@@ -99,7 +101,7 @@
 #[derive(Clone, Copy, Acyclic)]
 pub struct ObjFieldFlags(u8);
 impl ObjFieldFlags {
-	fn new(add: bool, visibility: Visibility) -> Self {
+	pub fn new(add: bool, visibility: Visibility) -> Self {
 		let mut v = 0;
 		if add {
 			v |= 1;
@@ -140,7 +142,7 @@
 	pub location: Option<Span>,
 }
 
-cc_dyn!(CcObjectAssertion, ObjectAssertion);
+cc_dyn!(CcObjectAssertion, ObjectAssertion, pub fn new() {...});
 pub trait ObjectAssertion: Trace {
 	fn run(&self, sup_this: SupThis) -> Result<()>;
 }
@@ -203,6 +205,10 @@
 	fn field_visibility_core(&self, field: IStr) -> FieldVisibility;
 
 	fn run_assertions_core(&self, sup_this: SupThis) -> Result<()>;
+
+	fn has_assertion(&self) -> bool {
+		false
+	}
 }
 
 #[derive(Clone, Trace)]
@@ -1117,7 +1123,7 @@
 pub struct ExtendBuilder<'v>(&'v mut ObjValue);
 impl ObjMemberBuilder<ExtendBuilder<'_>> {
 	pub fn value(self, value: impl Into<Val>) {
-		self.binding(MaybeUnbound::Bound(Thunk::evaluated(value.into())));
+		self.binding(MaybeUnbound::Const(value.into()));
 	}
 	pub fn bindable(self, bindable: impl Unbound<Bound = Val>) {
 		self.binding(MaybeUnbound::Unbound(CcUnbound::new(bindable)));
modifiedcrates/jrsonnet-evaluator/src/obj/oop.rsdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/obj/oop.rs
+++ b/crates/jrsonnet-evaluator/src/obj/oop.rs
@@ -113,6 +113,10 @@
 		}
 		Ok(())
 	}
+
+	fn has_assertion(&self) -> bool {
+		self.assertion.is_some()
+	}
 }
 
 #[allow(clippy::module_name_repetitions)]
@@ -177,6 +181,7 @@
 
 	pub fn extend_with_core(&mut self, core: impl ObjectCore) {
 		self.commit();
+		self.has_assertions |= core.has_assertion();
 		self.sup.push(CcObjectCore::new(core));
 	}
 
@@ -219,8 +224,7 @@
 impl ObjMemberBuilder<ValueBuilder<'_>> {
 	/// Inserts value, replacing if it is already defined
 	pub fn value(self, value: impl Into<Val>) {
-		let (receiver, name, idx, member) =
-			self.build_member(MaybeUnbound::Bound(Thunk::evaluated(value.into())));
+		let (receiver, name, idx, member) = self.build_member(MaybeUnbound::Const(value.into()));
 		let entry = receiver.0.new.this_entries.entry(name);
 		entry.insert_entry((member, idx));
 	}
@@ -233,7 +237,7 @@
 
 	/// Tries to insert value, returns an error if it was already defined
 	pub fn try_value(self, value: impl Into<Val>) -> Result<()> {
-		self.try_thunk(Thunk::evaluated(value.into()))
+		self.binding(MaybeUnbound::Const(value.into()))
 	}
 	pub fn try_thunk(self, value: impl Into<Thunk<Val>>) -> Result<()> {
 		self.binding(MaybeUnbound::Bound(value.into()))
addedcrates/jrsonnet-evaluator/src/obj/static_shape.rsdiffbeforeafterboth
--- /dev/null
+++ b/crates/jrsonnet-evaluator/src/obj/static_shape.rs
@@ -0,0 +1,213 @@
+use std::{fmt, ops::ControlFlow, rc::Rc};
+
+use jrsonnet_gcmodule::{Acyclic, Trace, TraceBox};
+use jrsonnet_interner::IStr;
+use jrsonnet_ir::Span;
+
+use super::{
+	CcObjectAssertion, EnumFields, EnumFieldsHandler, FieldVisibility, GetFor,
+	HasFieldIncludeHidden, ObjFieldFlags, ObjectCore, SupThis, Visibility,
+	ordering::{FieldIndex, SuperDepth},
+};
+use crate::{MaybeUnbound, Result};
+
+#[derive(Acyclic, Debug)]
+pub struct ShapeField {
+	pub name: IStr,
+	pub flags: ObjFieldFlags,
+	pub location: Option<Span>,
+	pub index: FieldIndex,
+}
+
+#[derive(Acyclic, Debug)]
+pub struct ObjShape {
+	fields: Vec<ShapeField>,
+}
+
+impl ObjShape {
+	#[must_use]
+	pub fn new(fields: Vec<ShapeField>) -> Self {
+		Self { fields }
+	}
+
+	#[inline]
+	pub fn fields(&self) -> &[ShapeField] {
+		&self.fields
+	}
+
+	#[inline]
+	#[must_use]
+	pub fn len(&self) -> usize {
+		self.fields.len()
+	}
+
+	#[inline]
+	#[must_use]
+	pub fn is_empty(&self) -> bool {
+		self.fields.is_empty()
+	}
+
+	#[inline]
+	pub fn find_index(&self, name: &IStr) -> Option<usize> {
+		self.fields.iter().position(|f| &f.name == name)
+	}
+}
+
+#[derive(Trace)]
+pub struct StaticShapeOopObject {
+	shape: Rc<ObjShape>,
+	bindings: TraceBox<[MaybeUnbound]>,
+	assertion: Option<CcObjectAssertion>,
+}
+
+impl fmt::Debug for StaticShapeOopObject {
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+		f.debug_struct("StaticShapeOopObject")
+			.field("shape", &self.shape)
+			.field("has_assertion", &self.assertion.is_some())
+			.finish_non_exhaustive()
+	}
+}
+
+impl StaticShapeOopObject {
+	pub fn new(
+		shape: Rc<ObjShape>,
+		bindings: Vec<MaybeUnbound>,
+		assertion: Option<CcObjectAssertion>,
+	) -> Self {
+		debug_assert_eq!(
+			shape.fields.len(),
+			bindings.len(),
+			"shape arity must match bindings"
+		);
+		Self {
+			shape,
+			bindings: TraceBox(bindings.into_boxed_slice()),
+			assertion,
+		}
+	}
+
+	#[inline]
+	#[must_use]
+	pub const fn shape(&self) -> &Rc<ObjShape> {
+		&self.shape
+	}
+}
+
+impl ObjectCore for StaticShapeOopObject {
+	fn enum_fields_core(
+		&self,
+		super_depth: &mut SuperDepth,
+		handler: &mut EnumFieldsHandler<'_>,
+	) -> bool {
+		for field in &self.shape.fields {
+			if matches!(
+				handler(
+					*super_depth,
+					field.index,
+					field.name.clone(),
+					EnumFields::Normal(field.flags.visibility()),
+				),
+				ControlFlow::Break(())
+			) {
+				return false;
+			}
+		}
+		true
+	}
+
+	fn has_field_include_hidden_core(&self, name: IStr) -> HasFieldIncludeHidden {
+		if self.shape.find_index(&name).is_some() {
+			HasFieldIncludeHidden::Exists
+		} else {
+			HasFieldIncludeHidden::NotFound
+		}
+	}
+
+	fn get_for_core(&self, key: IStr, sup_this: SupThis, omit_only: bool) -> Result<GetFor> {
+		if omit_only {
+			return Ok(GetFor::NotFound);
+		}
+		let Some(i) = self.shape.find_index(&key) else {
+			return Ok(GetFor::NotFound);
+		};
+		let field = &self.shape.fields[i];
+		let v = self.bindings[i].evaluate(sup_this)?;
+		Ok(if field.flags.add() {
+			GetFor::SuperPlus(v)
+		} else {
+			GetFor::Final(v)
+		})
+	}
+
+	fn field_visibility_core(&self, field: IStr) -> FieldVisibility {
+		self.shape
+			.find_index(&field)
+			.map_or(FieldVisibility::NotFound, |i| {
+				FieldVisibility::Found(self.shape.fields[i].flags.visibility())
+			})
+	}
+
+	fn run_assertions_core(&self, sup_this: SupThis) -> Result<()> {
+		if let Some(assertion) = &self.assertion {
+			assertion.0.run(sup_this)?;
+		}
+		Ok(())
+	}
+
+	fn has_assertion(&self) -> bool {
+		self.assertion.is_some()
+	}
+}
+
+pub struct ObjShapeBuilder {
+	fields: Vec<ShapeField>,
+	next_index: FieldIndex,
+}
+
+impl ObjShapeBuilder {
+	#[must_use]
+	pub fn new() -> Self {
+		Self {
+			fields: Vec::new(),
+			next_index: FieldIndex::default(),
+		}
+	}
+
+	#[must_use]
+	pub fn with_capacity(cap: usize) -> Self {
+		Self {
+			fields: Vec::with_capacity(cap),
+			next_index: FieldIndex::default(),
+		}
+	}
+
+	pub fn field(
+		&mut self,
+		name: impl Into<IStr>,
+		visibility: Visibility,
+		add: bool,
+		location: Option<Span>,
+	) -> &mut Self {
+		let index = self.next_index;
+		self.next_index = self.next_index.next();
+		self.fields.push(ShapeField {
+			name: name.into(),
+			flags: ObjFieldFlags::new(add, visibility),
+			location,
+			index,
+		});
+		self
+	}
+
+	#[must_use]
+	pub fn build(self) -> ObjShape {
+		ObjShape::new(self.fields)
+	}
+}
+
+impl Default for ObjShapeBuilder {
+	fn default() -> Self {
+		Self::new()
+	}
+}
modifiedcrates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@array_comp.jsonnet.snapdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@array_comp.jsonnet.snap
+++ b/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@array_comp.jsonnet.snap
@@ -1,5 +1,6 @@
 ---
 source: crates/jrsonnet-evaluator/src/analyze.rs
+assertion_line: 2175
 expression: rendered
 input_file: crates/jrsonnet-evaluator/src/analysis_tests/array_comp.jsonnet
 ---
@@ -26,8 +27,10 @@
                 ),
             ),
             op: Mul,
-            rhs: Num(
-                2.0,
+            rhs: Trivial(
+                Num(
+                    2.0,
+                ),
             ),
         },
         compspecs: [
@@ -41,12 +44,8 @@
                         0,
                     ),
                 ),
-                over: Arr {
-                    shape: ClosureShape {
-                        captures: [],
-                        n_locals: 0,
-                    },
-                    items: [
+                over: ArrConst(
+                    [
                         Num(
                             1.0,
                         ),
@@ -57,7 +56,7 @@
                             3.0,
                         ),
                     ],
-                },
+                ),
                 loop_invariant: true,
             },
             If(
@@ -70,8 +69,10 @@
                         ),
                     ),
                     op: Gt,
-                    rhs: Num(
-                        1.0,
+                    rhs: Trivial(
+                        Num(
+                            1.0,
+                        ),
                     ),
                 },
             ),
modifiedcrates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@dollar_deeply_nested.jsonnet.snapdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@dollar_deeply_nested.jsonnet.snap
+++ b/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@dollar_deeply_nested.jsonnet.snap
@@ -20,8 +20,8 @@
 --- diagnostics ---
 --- lir ---
 Obj(
-    MemberList(
-        LObjMembers {
+    StaticMembers(
+        LObjStaticMembers {
             frame_shape: ClosureShape {
                 captures: [],
                 n_locals: 1,
@@ -35,74 +35,145 @@
             uses_super: false,
             locals: [],
             asserts: None,
-            fields: [
-                LFieldMember {
-                    name: Fixed(
-                        "top",
-                    ),
-                    plus: false,
-                    visibility: Normal,
-                    value: (
-                        ClosureShape {
-                            captures: [],
-                            n_locals: 0,
+            shape: ObjShape {
+                fields: [
+                    ShapeField {
+                        name: "top",
+                        flags: ObjFieldFlags {
+                            add: false,
+                            visibility: Normal,
+                        },
+                        location: None,
+                        index: FieldIndex(
+                            (),
+                        ),
+                    },
+                    ShapeField {
+                        name: "a",
+                        flags: ObjFieldFlags {
+                            add: false,
+                            visibility: Normal,
                         },
+                        location: None,
+                        index: FieldIndex(
+                            (),
+                        ),
+                    },
+                ],
+            },
+            bindings: [
+                (
+                    ClosureShape {
+                        captures: [],
+                        n_locals: 0,
+                    },
+                    Trivial(
                         Str(
                             "outer",
                         ),
                     ),
-                },
-                LFieldMember {
-                    name: Fixed(
-                        "a",
-                    ),
-                    plus: false,
-                    visibility: Normal,
-                    value: (
-                        ClosureShape {
-                            captures: [],
-                            n_locals: 0,
-                        },
-                        Obj(
-                            MemberList(
-                                LObjMembers {
-                                    frame_shape: ClosureShape {
-                                        captures: [
-                                            Local(
-                                                LocalSlot(
-                                                    0,
-                                                ),
+                ),
+                (
+                    ClosureShape {
+                        captures: [],
+                        n_locals: 0,
+                    },
+                    Obj(
+                        StaticMembers(
+                            LObjStaticMembers {
+                                frame_shape: ClosureShape {
+                                    captures: [
+                                        Local(
+                                            LocalSlot(
+                                                0,
                                             ),
-                                        ],
-                                        n_locals: 1,
-                                    },
-                                    this: None,
-                                    set_dollar: false,
-                                    uses_super: false,
-                                    locals: [],
-                                    asserts: None,
+                                        ),
+                                    ],
+                                    n_locals: 1,
+                                },
+                                this: None,
+                                set_dollar: false,
+                                uses_super: false,
+                                locals: [],
+                                asserts: None,
+                                shape: ObjShape {
                                     fields: [
-                                        LFieldMember {
-                                            name: Fixed(
-                                                "b",
+                                        ShapeField {
+                                            name: "b",
+                                            flags: ObjFieldFlags {
+                                                add: false,
+                                                visibility: Normal,
+                                            },
+                                            location: None,
+                                            index: FieldIndex(
+                                                (),
                                             ),
-                                            plus: false,
-                                            visibility: Normal,
-                                            value: (
-                                                ClosureShape {
-                                                    captures: [
-                                                        Capture(
-                                                            CaptureSlot(
-                                                                0,
+                                        },
+                                    ],
+                                },
+                                bindings: [
+                                    (
+                                        ClosureShape {
+                                            captures: [
+                                                Capture(
+                                                    CaptureSlot(
+                                                        0,
+                                                    ),
+                                                ),
+                                            ],
+                                            n_locals: 0,
+                                        },
+                                        Obj(
+                                            StaticMembers(
+                                                LObjStaticMembers {
+                                                    frame_shape: ClosureShape {
+                                                        captures: [
+                                                            Capture(
+                                                                CaptureSlot(
+                                                                    0,
+                                                                ),
                                                             ),
+                                                        ],
+                                                        n_locals: 1,
+                                                    },
+                                                    this: Some(
+                                                        LocalSlot(
+                                                            0,
                                                         ),
-                                                    ],
-                                                    n_locals: 0,
-                                                },
-                                                Obj(
-                                                    MemberList(
-                                                        LObjMembers {
-                                                            frame_shape: ClosureShape {
+                                                    ),
+                                                    set_dollar: false,
+                                                    uses_super: false,
+                                                    locals: [],
+                                                    asserts: None,
+                                                    shape: ObjShape {
+                                                        fields: [
+                                                            ShapeField {
+                                                                name: "c",
+                                                                flags: ObjFieldFlags {
+                                                                    add: false,
+                                                                    visibility: Normal,
+                                                                },
+                                                                location: None,
+                                                                index: FieldIndex(
+                                                                    (),
+                                                                ),
+                                                            },
+                                                            ShapeField {
+                                                                name: "d",
+                                                                flags: ObjFieldFlags {
+                                                                    add: false,
+                                                                    visibility: Normal,
+                                                                },
+                                                                location: None,
+                                                                index: FieldIndex(
+                                                                    (),
+                                                                ),
+                                                            },
+                                                        ],
+                                                    },
+                                                    bindings: [
+                                                        (
+                                                            ClosureShape {
                                                                 captures: [
                                                                     Capture(
                                                                         CaptureSlot(
@@ -110,86 +181,51 @@
                                                                         ),
                                                                     ),
                                                                 ],
-                                                                n_locals: 1,
+                                                                n_locals: 0,
                                                             },
-                                                            this: Some(
-                                                                LocalSlot(
-                                                                    0,
-                                                                ),
-                                                            ),
-                                                            set_dollar: false,
-                                                            uses_super: false,
-                                                            locals: [],
-                                                            asserts: None,
-                                                            fields: [
-                                                                LFieldMember {
-                                                                    name: Fixed(
-                                                                        "c",
+                                                            Index {
+                                                                indexable: Slot(
+                                                                    Capture(
+                                                                        CaptureSlot(
+                                                                            0,
+                                                                        ),
                                                                     ),
-                                                                    plus: false,
-                                                                    visibility: Normal,
-                                                                    value: (
-                                                                        ClosureShape {
-                                                                            captures: [
-                                                                                Capture(
-                                                                                    CaptureSlot(
-                                                                                        0,
-                                                                                    ),
-                                                                                ),
-                                                                            ],
-                                                                            n_locals: 0,
-                                                                        },
-                                                                        Index {
-                                                                            indexable: Slot(
-                                                                                Capture(
-                                                                                    CaptureSlot(
-                                                                                        0,
-                                                                                    ),
-                                                                                ),
+                                                                ),
+                                                                parts: [
+                                                                    LIndexPart {
+                                                                        span: virtual:<test>:45-48,
+                                                                        value: Trivial(
+                                                                            Str(
+                                                                                "top",
                                                                             ),
-                                                                            parts: [
-                                                                                LIndexPart {
-                                                                                    span: virtual:<test>:45-48,
-                                                                                    value: Str(
-                                                                                        "top",
-                                                                                    ),
-                                                                                },
-                                                                            ],
-                                                                        },
-                                                                    ),
-                                                                },
-                                                                LFieldMember {
-                                                                    name: Fixed(
-                                                                        "d",
-                                                                    ),
-                                                                    plus: false,
-                                                                    visibility: Normal,
-                                                                    value: (
-                                                                        ClosureShape {
-                                                                            captures: [],
-                                                                            n_locals: 0,
-                                                                        },
-                                                                        Slot(
-                                                                            Local(
-                                                                                LocalSlot(
-                                                                                    0,
-                                                                                ),
-                                                                            ),
                                                                         ),
+                                                                    },
+                                                                ],
+                                                            },
+                                                        ),
+                                                        (
+                                                            ClosureShape {
+                                                                captures: [],
+                                                                n_locals: 0,
+                                                            },
+                                                            Slot(
+                                                                Local(
+                                                                    LocalSlot(
+                                                                        0,
                                                                     ),
-                                                                },
-                                                            ],
-                                                        },
-                                                    ),
-                                                ),
+                                                                ),
+                                                            ),
+                                                        ),
+                                                    ],
+                                                },
                                             ),
-                                        },
-                                    ],
-                                },
-                            ),
+                                        ),
+                                    ),
+                                ],
+                            },
                         ),
                     ),
-                },
+                ),
             ],
         },
     ),
modifiedcrates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@dollar_outside_object.jsonnet.snapdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@dollar_outside_object.jsonnet.snap
+++ b/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@dollar_outside_object.jsonnet.snap
@@ -1,5 +1,6 @@
 ---
 source: crates/jrsonnet-evaluator/src/analyze.rs
+assertion_line: 2175
 expression: rendered
 input_file: crates/jrsonnet-evaluator/src/analysis_tests/dollar_outside_object.jsonnet
 ---
@@ -21,8 +22,10 @@
     parts: [
         LIndexPart {
             span: virtual:<test>:2-3,
-            value: Str(
-                "a",
+            value: Trivial(
+                Str(
+                    "a",
+                ),
             ),
         },
     ],
modifiedcrates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@function_def.jsonnet.snapdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@function_def.jsonnet.snap
+++ b/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@function_def.jsonnet.snap
@@ -1,5 +1,6 @@
 ---
 source: crates/jrsonnet-evaluator/src/analyze.rs
+assertion_line: 2175
 expression: rendered
 input_file: crates/jrsonnet-evaluator/src/analysis_tests/function_def.jsonnet
 ---
@@ -108,11 +109,15 @@
             ),
             args: LArgsDesc {
                 unnamed: [
-                    Num(
-                        1.0,
+                    Trivial(
+                        Num(
+                            1.0,
+                        ),
                     ),
-                    Num(
-                        2.0,
+                    Trivial(
+                        Num(
+                            2.0,
+                        ),
                     ),
                 ],
                 names: [],
modifiedcrates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@hoistable_local.jsonnet.snapdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@hoistable_local.jsonnet.snap
+++ b/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@hoistable_local.jsonnet.snap
@@ -1,5 +1,6 @@
 ---
 source: crates/jrsonnet-evaluator/src/analyze.rs
+assertion_line: 2175
 expression: rendered
 input_file: crates/jrsonnet-evaluator/src/analysis_tests/hoistable_local.jsonnet
 ---
@@ -31,8 +32,10 @@
                     captures: [],
                     n_locals: 0,
                 },
-                value: Num(
-                    1.0,
+                value: Trivial(
+                    Num(
+                        1.0,
+                    ),
                 ),
             },
         ],
@@ -60,12 +63,16 @@
                             n_locals: 0,
                         },
                         value: BinaryOp {
-                            lhs: Num(
-                                10.0,
+                            lhs: Trivial(
+                                Num(
+                                    10.0,
+                                ),
                             ),
                             op: Add,
-                            rhs: Num(
-                                20.0,
+                            rhs: Trivial(
+                                Num(
+                                    20.0,
+                                ),
                             ),
                         },
                     },
modifiedcrates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@ifelse.jsonnet.snapdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@ifelse.jsonnet.snap
+++ b/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@ifelse.jsonnet.snap
@@ -1,7 +1,8 @@
 ---
 source: crates/jrsonnet-evaluator/src/analyze.rs
+assertion_line: 2175
 expression: rendered
-input_file: crates/jrsonnet-evaluator/src/analyze_tests/ifelse.jsonnet
+input_file: crates/jrsonnet-evaluator/src/analysis_tests/ifelse.jsonnet
 ---
 --- source ---
 if true then 1 else 2
@@ -12,15 +13,21 @@
 --- diagnostics ---
 --- lir ---
 IfElse {
-    cond: Bool(
-        true,
+    cond: Trivial(
+        Bool(
+            true,
+        ),
     ),
-    cond_then: Num(
-        1.0,
+    cond_then: Trivial(
+        Num(
+            1.0,
+        ),
     ),
     cond_else: Some(
-        Num(
-            2.0,
+        Trivial(
+            Num(
+                2.0,
+            ),
         ),
     ),
 }
modifiedcrates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@literal.jsonnet.snapdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@literal.jsonnet.snap
+++ b/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@literal.jsonnet.snap
@@ -1,7 +1,8 @@
 ---
 source: crates/jrsonnet-evaluator/src/analyze.rs
+assertion_line: 2175
 expression: rendered
-input_file: crates/jrsonnet-evaluator/src/analyze_tests/literal.jsonnet
+input_file: crates/jrsonnet-evaluator/src/analysis_tests/literal.jsonnet
 ---
 --- source ---
 42
@@ -11,6 +12,8 @@
 errored: false
 --- diagnostics ---
 --- lir ---
-Num(
-    42.0,
+Trivial(
+    Num(
+        42.0,
+    ),
 )
modifiedcrates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@loop_invariant.jsonnet.snapdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@loop_invariant.jsonnet.snap
+++ b/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@loop_invariant.jsonnet.snap
@@ -1,5 +1,6 @@
 ---
 source: crates/jrsonnet-evaluator/src/analyze.rs
+assertion_line: 2175
 expression: rendered
 input_file: crates/jrsonnet-evaluator/src/analysis_tests/loop_invariant.jsonnet
 ---
@@ -64,19 +65,25 @@
                         parts: [
                             LIndexPart {
                                 span: virtual:<test>:21-26,
-                                value: Str(
-                                    "range",
+                                value: Trivial(
+                                    Str(
+                                        "range",
+                                    ),
                                 ),
                             },
                         ],
                     },
                     args: LArgsDesc {
                         unnamed: [
-                            Num(
-                                1.0,
+                            Trivial(
+                                Num(
+                                    1.0,
+                                ),
                             ),
-                            Num(
-                                1000.0,
+                            Trivial(
+                                Num(
+                                    1000.0,
+                                ),
                             ),
                         ],
                         names: [],
@@ -110,19 +117,25 @@
                         parts: [
                             LIndexPart {
                                 span: virtual:<test>:49-54,
-                                value: Str(
-                                    "range",
+                                value: Trivial(
+                                    Str(
+                                        "range",
+                                    ),
                                 ),
                             },
                         ],
                     },
                     args: LArgsDesc {
                         unnamed: [
-                            Num(
-                                1.0,
+                            Trivial(
+                                Num(
+                                    1.0,
+                                ),
                             ),
-                            Num(
-                                1000.0,
+                            Trivial(
+                                Num(
+                                    1000.0,
+                                ),
                             ),
                         ],
                         names: [],
modifiedcrates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@mutual_recursion.jsonnet.snapdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@mutual_recursion.jsonnet.snap
+++ b/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@mutual_recursion.jsonnet.snap
@@ -1,5 +1,6 @@
 ---
 source: crates/jrsonnet-evaluator/src/analyze.rs
+assertion_line: 2175
 expression: rendered
 input_file: crates/jrsonnet-evaluator/src/analysis_tests/mutual_recursion.jsonnet
 ---
@@ -46,8 +47,10 @@
                     captures: [],
                     n_locals: 0,
                 },
-                value: Num(
-                    1.0,
+                value: Trivial(
+                    Num(
+                        1.0,
+                    ),
                 ),
             },
         ],
@@ -60,8 +63,10 @@
                 ),
             ),
             op: Add,
-            rhs: Num(
-                2.0,
+            rhs: Trivial(
+                Num(
+                    2.0,
+                ),
             ),
         },
     },
modifiedcrates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@nested_object_independent.jsonnet.snapdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@nested_object_independent.jsonnet.snap
+++ b/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@nested_object_independent.jsonnet.snap
@@ -17,8 +17,8 @@
 --- diagnostics ---
 --- lir ---
 Obj(
-    MemberList(
-        LObjMembers {
+    StaticMembers(
+        LObjStaticMembers {
             frame_shape: ClosureShape {
                 captures: [],
                 n_locals: 1,
@@ -28,103 +28,133 @@
             uses_super: false,
             locals: [],
             asserts: None,
-            fields: [
-                LFieldMember {
-                    name: Fixed(
-                        "a",
-                    ),
-                    plus: false,
-                    visibility: Normal,
-                    value: (
-                        ClosureShape {
-                            captures: [],
-                            n_locals: 0,
+            shape: ObjShape {
+                fields: [
+                    ShapeField {
+                        name: "a",
+                        flags: ObjFieldFlags {
+                            add: false,
+                            visibility: Normal,
                         },
+                        location: None,
+                        index: FieldIndex(
+                            (),
+                        ),
+                    },
+                    ShapeField {
+                        name: "b",
+                        flags: ObjFieldFlags {
+                            add: false,
+                            visibility: Normal,
+                        },
+                        location: None,
+                        index: FieldIndex(
+                            (),
+                        ),
+                    },
+                ],
+            },
+            bindings: [
+                (
+                    ClosureShape {
+                        captures: [],
+                        n_locals: 0,
+                    },
+                    Trivial(
                         Num(
                             1.0,
                         ),
                     ),
-                },
-                LFieldMember {
-                    name: Fixed(
-                        "b",
-                    ),
-                    plus: false,
-                    visibility: Normal,
-                    value: (
-                        ClosureShape {
-                            captures: [],
-                            n_locals: 0,
-                        },
-                        Obj(
-                            MemberList(
-                                LObjMembers {
-                                    frame_shape: ClosureShape {
-                                        captures: [],
-                                        n_locals: 1,
-                                    },
-                                    this: Some(
-                                        LocalSlot(
-                                            0,
-                                        ),
+                ),
+                (
+                    ClosureShape {
+                        captures: [],
+                        n_locals: 0,
+                    },
+                    Obj(
+                        StaticMembers(
+                            LObjStaticMembers {
+                                frame_shape: ClosureShape {
+                                    captures: [],
+                                    n_locals: 1,
+                                },
+                                this: Some(
+                                    LocalSlot(
+                                        0,
                                     ),
-                                    set_dollar: false,
-                                    uses_super: false,
-                                    locals: [],
-                                    asserts: None,
+                                ),
+                                set_dollar: false,
+                                uses_super: false,
+                                locals: [],
+                                asserts: None,
+                                shape: ObjShape {
                                     fields: [
-                                        LFieldMember {
-                                            name: Fixed(
-                                                "c",
+                                        ShapeField {
+                                            name: "c",
+                                            flags: ObjFieldFlags {
+                                                add: false,
+                                                visibility: Normal,
+                                            },
+                                            location: None,
+                                            index: FieldIndex(
+                                                (),
                                             ),
-                                            plus: false,
-                                            visibility: Normal,
-                                            value: (
-                                                ClosureShape {
-                                                    captures: [],
-                                                    n_locals: 0,
-                                                },
-                                                Num(
-                                                    2.0,
-                                                ),
+                                        },
+                                        ShapeField {
+                                            name: "d",
+                                            flags: ObjFieldFlags {
+                                                add: false,
+                                                visibility: Normal,
+                                            },
+                                            location: None,
+                                            index: FieldIndex(
+                                                (),
                                             ),
                                         },
-                                        LFieldMember {
-                                            name: Fixed(
-                                                "d",
+                                    ],
+                                },
+                                bindings: [
+                                    (
+                                        ClosureShape {
+                                            captures: [],
+                                            n_locals: 0,
+                                        },
+                                        Trivial(
+                                            Num(
+                                                2.0,
                                             ),
-                                            plus: false,
-                                            visibility: Normal,
-                                            value: (
-                                                ClosureShape {
-                                                    captures: [],
-                                                    n_locals: 0,
-                                                },
-                                                Index {
-                                                    indexable: Slot(
-                                                        Local(
-                                                            LocalSlot(
-                                                                0,
-                                                            ),
+                                        ),
+                                    ),
+                                    (
+                                        ClosureShape {
+                                            captures: [],
+                                            n_locals: 0,
+                                        },
+                                        Index {
+                                            indexable: Slot(
+                                                Local(
+                                                    LocalSlot(
+                                                        0,
+                                                    ),
+                                                ),
+                                            ),
+                                            parts: [
+                                                LIndexPart {
+                                                    span: virtual:<test>:35-36,
+                                                    value: Trivial(
+                                                        Str(
+                                                            "c",
                                                         ),
                                                     ),
-                                                    parts: [
-                                                        LIndexPart {
-                                                            span: virtual:<test>:35-36,
-                                                            value: Str(
-                                                                "c",
-                                                            ),
-                                                        },
-                                                    ],
                                                 },
-                                            ),
+                                            ],
                                         },
-                                    ],
-                                },
-                            ),
+                                    ),
+                                ],
+                            },
                         ),
                     ),
-                },
+                ),
             ],
         },
     ),
modifiedcrates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@object_comp.jsonnet.snapdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@object_comp.jsonnet.snap
+++ b/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@object_comp.jsonnet.snap
@@ -1,5 +1,6 @@
 ---
 source: crates/jrsonnet-evaluator/src/analyze.rs
+assertion_line: 2175
 expression: rendered
 input_file: crates/jrsonnet-evaluator/src/analysis_tests/object_comp.jsonnet
 ---
@@ -71,12 +72,8 @@
                             0,
                         ),
                     ),
-                    over: Arr {
-                        shape: ClosureShape {
-                            captures: [],
-                            n_locals: 0,
-                        },
-                        items: [
+                    over: ArrConst(
+                        [
                             Str(
                                 "a",
                             ),
@@ -84,7 +81,7 @@
                                 "b",
                             ),
                         ],
-                    },
+                    ),
                     loop_invariant: true,
                 },
             ],
modifiedcrates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@object_dollar.jsonnet.snapdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@object_dollar.jsonnet.snap
+++ b/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@object_dollar.jsonnet.snap
@@ -12,8 +12,8 @@
 --- diagnostics ---
 --- lir ---
 Obj(
-    MemberList(
-        LObjMembers {
+    StaticMembers(
+        LObjStaticMembers {
             frame_shape: ClosureShape {
                 captures: [],
                 n_locals: 1,
@@ -27,95 +27,119 @@
             uses_super: false,
             locals: [],
             asserts: None,
-            fields: [
-                LFieldMember {
-                    name: Fixed(
-                        "a",
-                    ),
-                    plus: false,
-                    visibility: Normal,
-                    value: (
-                        ClosureShape {
-                            captures: [],
-                            n_locals: 0,
+            shape: ObjShape {
+                fields: [
+                    ShapeField {
+                        name: "a",
+                        flags: ObjFieldFlags {
+                            add: false,
+                            visibility: Normal,
                         },
+                        location: None,
+                        index: FieldIndex(
+                            (),
+                        ),
+                    },
+                    ShapeField {
+                        name: "b",
+                        flags: ObjFieldFlags {
+                            add: false,
+                            visibility: Normal,
+                        },
+                        location: None,
+                        index: FieldIndex(
+                            (),
+                        ),
+                    },
+                ],
+            },
+            bindings: [
+                (
+                    ClosureShape {
+                        captures: [],
+                        n_locals: 0,
+                    },
+                    Trivial(
                         Num(
                             1.0,
                         ),
                     ),
-                },
-                LFieldMember {
-                    name: Fixed(
-                        "b",
-                    ),
-                    plus: false,
-                    visibility: Normal,
-                    value: (
-                        ClosureShape {
-                            captures: [],
-                            n_locals: 0,
-                        },
-                        Obj(
-                            MemberList(
-                                LObjMembers {
-                                    frame_shape: ClosureShape {
-                                        captures: [
-                                            Local(
-                                                LocalSlot(
-                                                    0,
-                                                ),
+                ),
+                (
+                    ClosureShape {
+                        captures: [],
+                        n_locals: 0,
+                    },
+                    Obj(
+                        StaticMembers(
+                            LObjStaticMembers {
+                                frame_shape: ClosureShape {
+                                    captures: [
+                                        Local(
+                                            LocalSlot(
+                                                0,
                                             ),
-                                        ],
-                                        n_locals: 1,
-                                    },
-                                    this: None,
-                                    set_dollar: false,
-                                    uses_super: false,
-                                    locals: [],
-                                    asserts: None,
+                                        ),
+                                    ],
+                                    n_locals: 1,
+                                },
+                                this: None,
+                                set_dollar: false,
+                                uses_super: false,
+                                locals: [],
+                                asserts: None,
+                                shape: ObjShape {
                                     fields: [
-                                        LFieldMember {
-                                            name: Fixed(
-                                                "c",
+                                        ShapeField {
+                                            name: "c",
+                                            flags: ObjFieldFlags {
+                                                add: false,
+                                                visibility: Normal,
+                                            },
+                                            location: None,
+                                            index: FieldIndex(
+                                                (),
                                             ),
-                                            plus: false,
-                                            visibility: Normal,
-                                            value: (
-                                                ClosureShape {
-                                                    captures: [
-                                                        Capture(
-                                                            CaptureSlot(
-                                                                0,
-                                                            ),
-                                                        ),
-                                                    ],
-                                                    n_locals: 0,
-                                                },
-                                                Index {
-                                                    indexable: Slot(
-                                                        Capture(
-                                                            CaptureSlot(
-                                                                0,
-                                                            ),
+                                        },
+                                    ],
+                                },
+                                bindings: [
+                                    (
+                                        ClosureShape {
+                                            captures: [
+                                                Capture(
+                                                    CaptureSlot(
+                                                        0,
+                                                    ),
+                                                ),
+                                            ],
+                                            n_locals: 0,
+                                        },
+                                        Index {
+                                            indexable: Slot(
+                                                Capture(
+                                                    CaptureSlot(
+                                                        0,
+                                                    ),
+                                                ),
+                                            ),
+                                            parts: [
+                                                LIndexPart {
+                                                    span: virtual:<test>:18-19,
+                                                    value: Trivial(
+                                                        Str(
+                                                            "a",
                                                         ),
                                                     ),
-                                                    parts: [
-                                                        LIndexPart {
-                                                            span: virtual:<test>:18-19,
-                                                            value: Str(
-                                                                "a",
-                                                            ),
-                                                        },
-                                                    ],
                                                 },
-                                            ),
+                                            ],
                                         },
-                                    ],
-                                },
-                            ),
+                                    ),
+                                ],
+                            },
                         ),
                     ),
-                },
+                ),
             ],
         },
     ),
modifiedcrates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@object_self.jsonnet.snapdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@object_self.jsonnet.snap
+++ b/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@object_self.jsonnet.snap
@@ -12,8 +12,8 @@
 --- diagnostics ---
 --- lir ---
 Obj(
-    MemberList(
-        LObjMembers {
+    StaticMembers(
+        LObjStaticMembers {
             frame_shape: ClosureShape {
                 captures: [],
                 n_locals: 1,
@@ -27,53 +27,69 @@
             uses_super: false,
             locals: [],
             asserts: None,
-            fields: [
-                LFieldMember {
-                    name: Fixed(
-                        "a",
-                    ),
-                    plus: false,
-                    visibility: Normal,
-                    value: (
-                        ClosureShape {
-                            captures: [],
-                            n_locals: 0,
+            shape: ObjShape {
+                fields: [
+                    ShapeField {
+                        name: "a",
+                        flags: ObjFieldFlags {
+                            add: false,
+                            visibility: Normal,
+                        },
+                        location: None,
+                        index: FieldIndex(
+                            (),
+                        ),
+                    },
+                    ShapeField {
+                        name: "b",
+                        flags: ObjFieldFlags {
+                            add: false,
+                            visibility: Normal,
                         },
+                        location: None,
+                        index: FieldIndex(
+                            (),
+                        ),
+                    },
+                ],
+            },
+            bindings: [
+                (
+                    ClosureShape {
+                        captures: [],
+                        n_locals: 0,
+                    },
+                    Trivial(
                         Num(
                             1.0,
                         ),
                     ),
-                },
-                LFieldMember {
-                    name: Fixed(
-                        "b",
-                    ),
-                    plus: false,
-                    visibility: Normal,
-                    value: (
-                        ClosureShape {
-                            captures: [],
-                            n_locals: 0,
-                        },
-                        Index {
-                            indexable: Slot(
-                                Local(
-                                    LocalSlot(
-                                        0,
-                                    ),
+                ),
+                (
+                    ClosureShape {
+                        captures: [],
+                        n_locals: 0,
+                    },
+                    Index {
+                        indexable: Slot(
+                            Local(
+                                LocalSlot(
+                                    0,
                                 ),
                             ),
-                            parts: [
-                                LIndexPart {
-                                    span: virtual:<test>:16-17,
-                                    value: Str(
+                        ),
+                        parts: [
+                            LIndexPart {
+                                span: virtual:<test>:16-17,
+                                value: Trivial(
+                                    Str(
                                         "a",
                                     ),
-                                },
-                            ],
-                        },
-                    ),
-                },
+                                ),
+                            },
+                        ],
+                    },
+                ),
             ],
         },
     ),
modifiedcrates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@object_with_locals.jsonnet.snapdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@object_with_locals.jsonnet.snap
+++ b/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@object_with_locals.jsonnet.snap
@@ -16,8 +16,8 @@
 --- diagnostics ---
 --- lir ---
 Obj(
-    MemberList(
-        LObjMembers {
+    StaticMembers(
+        LObjStaticMembers {
             frame_shape: ClosureShape {
                 captures: [],
                 n_locals: 2,
@@ -36,59 +36,75 @@
                         captures: [],
                         n_locals: 0,
                     },
-                    value: Num(
-                        10.0,
+                    value: Trivial(
+                        Num(
+                            10.0,
+                        ),
                     ),
                 },
             ],
             asserts: None,
-            fields: [
-                LFieldMember {
-                    name: Fixed(
-                        "a",
+            shape: ObjShape {
+                fields: [
+                    ShapeField {
+                        name: "a",
+                        flags: ObjFieldFlags {
+                            add: false,
+                            visibility: Normal,
+                        },
+                        location: None,
+                        index: FieldIndex(
+                            (),
+                        ),
+                    },
+                    ShapeField {
+                        name: "b",
+                        flags: ObjFieldFlags {
+                            add: false,
+                            visibility: Normal,
+                        },
+                        location: None,
+                        index: FieldIndex(
+                            (),
+                        ),
+                    },
+                ],
+            },
+            bindings: [
+                (
+                    ClosureShape {
+                        captures: [],
+                        n_locals: 0,
+                    },
+                    Slot(
+                        Local(
+                            LocalSlot(
+                                1,
+                            ),
+                        ),
                     ),
-                    plus: false,
-                    visibility: Normal,
-                    value: (
-                        ClosureShape {
-                            captures: [],
-                            n_locals: 0,
-                        },
-                        Slot(
+                ),
+                (
+                    ClosureShape {
+                        captures: [],
+                        n_locals: 0,
+                    },
+                    BinaryOp {
+                        lhs: Slot(
                             Local(
                                 LocalSlot(
                                     1,
                                 ),
                             ),
                         ),
-                    ),
-                },
-                LFieldMember {
-                    name: Fixed(
-                        "b",
-                    ),
-                    plus: false,
-                    visibility: Normal,
-                    value: (
-                        ClosureShape {
-                            captures: [],
-                            n_locals: 0,
-                        },
-                        BinaryOp {
-                            lhs: Slot(
-                                Local(
-                                    LocalSlot(
-                                        1,
-                                    ),
-                                ),
-                            ),
-                            op: Mul,
-                            rhs: Num(
+                        op: Mul,
+                        rhs: Trivial(
+                            Num(
                                 2.0,
                             ),
-                        },
-                    ),
-                },
+                        ),
+                    },
+                ),
             ],
         },
     ),
modifiedcrates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@redeclared_local.jsonnet.snapdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@redeclared_local.jsonnet.snap
+++ b/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@redeclared_local.jsonnet.snap
@@ -1,5 +1,6 @@
 ---
 source: crates/jrsonnet-evaluator/src/analyze.rs
+assertion_line: 2175
 expression: rendered
 input_file: crates/jrsonnet-evaluator/src/analysis_tests/redeclared_local.jsonnet
 ---
@@ -31,8 +32,10 @@
                     captures: [],
                     n_locals: 0,
                 },
-                value: Num(
-                    1.0,
+                value: Trivial(
+                    Num(
+                        1.0,
+                    ),
                 ),
             },
         ],
modifiedcrates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@shadowing.jsonnet.snapdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@shadowing.jsonnet.snap
+++ b/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@shadowing.jsonnet.snap
@@ -1,5 +1,6 @@
 ---
 source: crates/jrsonnet-evaluator/src/analyze.rs
+assertion_line: 2175
 expression: rendered
 input_file: crates/jrsonnet-evaluator/src/analysis_tests/shadowing.jsonnet
 ---
@@ -32,8 +33,10 @@
                     captures: [],
                     n_locals: 0,
                 },
-                value: Num(
-                    1.0,
+                value: Trivial(
+                    Num(
+                        1.0,
+                    ),
                 ),
             },
         ],
@@ -54,8 +57,10 @@
                             captures: [],
                             n_locals: 0,
                         },
-                        value: Num(
-                            2.0,
+                        value: Trivial(
+                            Num(
+                                2.0,
+                            ),
                         ),
                     },
                 ],
modifiedcrates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@simple_local.jsonnet.snapdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@simple_local.jsonnet.snap
+++ b/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@simple_local.jsonnet.snap
@@ -1,5 +1,6 @@
 ---
 source: crates/jrsonnet-evaluator/src/analyze.rs
+assertion_line: 2175
 expression: rendered
 input_file: crates/jrsonnet-evaluator/src/analysis_tests/simple_local.jsonnet
 ---
@@ -28,8 +29,10 @@
                     captures: [],
                     n_locals: 0,
                 },
-                value: Num(
-                    1.0,
+                value: Trivial(
+                    Num(
+                        1.0,
+                    ),
                 ),
             },
         ],
@@ -42,8 +45,10 @@
                 ),
             ),
             op: Add,
-            rhs: Num(
-                2.0,
+            rhs: Trivial(
+                Num(
+                    2.0,
+                ),
             ),
         },
     },
modifiedcrates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@slice.jsonnet.snapdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@slice.jsonnet.snap
+++ b/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@slice.jsonnet.snap
@@ -1,6 +1,6 @@
 ---
 source: crates/jrsonnet-evaluator/src/analyze.rs
-assertion_line: 2017
+assertion_line: 2175
 expression: rendered
 input_file: crates/jrsonnet-evaluator/src/analysis_tests/slice.jsonnet
 ---
@@ -14,12 +14,8 @@
 --- lir ---
 Slice(
     LSliceExpr {
-        value: Arr {
-            shape: ClosureShape {
-                captures: [],
-                n_locals: 0,
-            },
-            items: [
+        value: ArrConst(
+            [
                 Num(
                     1.0,
                 ),
@@ -36,15 +32,19 @@
                     5.0,
                 ),
             ],
-        },
+        ),
         start: Some(
-            Num(
-                1.0,
+            Trivial(
+                Num(
+                    1.0,
+                ),
             ),
         ),
         end: Some(
-            Num(
-                3.0,
+            Trivial(
+                Num(
+                    3.0,
+                ),
             ),
         ),
         step: None,
modifiedcrates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@super_outside_object.jsonnet.snapdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@super_outside_object.jsonnet.snap
+++ b/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@super_outside_object.jsonnet.snap
@@ -1,5 +1,6 @@
 ---
 source: crates/jrsonnet-evaluator/src/analyze.rs
+assertion_line: 2175
 expression: rendered
 input_file: crates/jrsonnet-evaluator/src/analysis_tests/super_outside_object.jsonnet
 ---
@@ -21,8 +22,10 @@
     parts: [
         LIndexPart {
             span: virtual:<test>:6-7,
-            value: Str(
-                "a",
+            value: Trivial(
+                Str(
+                    "a",
+                ),
             ),
         },
     ],
modifiedcrates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@super_usage.jsonnet.snapdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@super_usage.jsonnet.snap
+++ b/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@super_usage.jsonnet.snap
@@ -13,8 +13,8 @@
 --- lir ---
 BinaryOp {
     lhs: Obj(
-        MemberList(
-            LObjMembers {
+        StaticMembers(
+            LObjStaticMembers {
                 frame_shape: ClosureShape {
                     captures: [],
                     n_locals: 1,
@@ -24,47 +24,63 @@
                 uses_super: false,
                 locals: [],
                 asserts: None,
-                fields: [
-                    LFieldMember {
-                        name: Fixed(
-                            "a",
-                        ),
-                        plus: false,
-                        visibility: Normal,
-                        value: (
-                            ClosureShape {
-                                captures: [],
-                                n_locals: 0,
+                shape: ObjShape {
+                    fields: [
+                        ShapeField {
+                            name: "a",
+                            flags: ObjFieldFlags {
+                                add: false,
+                                visibility: Normal,
                             },
+                            location: None,
+                            index: FieldIndex(
+                                (),
+                            ),
+                        },
+                        ShapeField {
+                            name: "b",
+                            flags: ObjFieldFlags {
+                                add: false,
+                                visibility: Normal,
+                            },
+                            location: None,
+                            index: FieldIndex(
+                                (),
+                            ),
+                        },
+                    ],
+                },
+                bindings: [
+                    (
+                        ClosureShape {
+                            captures: [],
+                            n_locals: 0,
+                        },
+                        Trivial(
                             Num(
                                 1.0,
                             ),
                         ),
-                    },
-                    LFieldMember {
-                        name: Fixed(
-                            "b",
-                        ),
-                        plus: false,
-                        visibility: Normal,
-                        value: (
-                            ClosureShape {
-                                captures: [],
-                                n_locals: 0,
-                            },
+                    ),
+                    (
+                        ClosureShape {
+                            captures: [],
+                            n_locals: 0,
+                        },
+                        Trivial(
                             Num(
                                 2.0,
                             ),
                         ),
-                    },
+                    ),
                 ],
             },
         ),
     ),
     op: Add,
     rhs: Obj(
-        MemberList(
-            LObjMembers {
+        StaticMembers(
+            LObjStaticMembers {
                 frame_shape: ClosureShape {
                     captures: [],
                     n_locals: 1,
@@ -78,67 +94,85 @@
                 uses_super: true,
                 locals: [],
                 asserts: None,
-                fields: [
-                    LFieldMember {
-                        name: Fixed(
-                            "a",
-                        ),
-                        plus: false,
-                        visibility: Normal,
-                        value: (
-                            ClosureShape {
-                                captures: [],
-                                n_locals: 0,
+                shape: ObjShape {
+                    fields: [
+                        ShapeField {
+                            name: "a",
+                            flags: ObjFieldFlags {
+                                add: false,
+                                visibility: Normal,
+                            },
+                            location: None,
+                            index: FieldIndex(
+                                (),
+                            ),
+                        },
+                        ShapeField {
+                            name: "c",
+                            flags: ObjFieldFlags {
+                                add: false,
+                                visibility: Normal,
                             },
-                            BinaryOp {
-                                lhs: Index {
-                                    indexable: Super,
-                                    parts: [
-                                        LIndexPart {
-                                            span: virtual:<test>:28-29,
-                                            value: Str(
+                            location: None,
+                            index: FieldIndex(
+                                (),
+                            ),
+                        },
+                    ],
+                },
+                bindings: [
+                    (
+                        ClosureShape {
+                            captures: [],
+                            n_locals: 0,
+                        },
+                        BinaryOp {
+                            lhs: Index {
+                                indexable: Super,
+                                parts: [
+                                    LIndexPart {
+                                        span: virtual:<test>:28-29,
+                                        value: Trivial(
+                                            Str(
                                                 "a",
                                             ),
-                                        },
-                                    ],
-                                },
-                                op: Add,
-                                rhs: Num(
+                                        ),
+                                    },
+                                ],
+                            },
+                            op: Add,
+                            rhs: Trivial(
+                                Num(
                                     10.0,
                                 ),
-                            },
-                        ),
-                    },
-                    LFieldMember {
-                        name: Fixed(
-                            "c",
-                        ),
-                        plus: false,
-                        visibility: Normal,
-                        value: (
-                            ClosureShape {
-                                captures: [],
-                                n_locals: 0,
-                            },
-                            Index {
-                                indexable: Slot(
-                                    Local(
-                                        LocalSlot(
-                                            0,
-                                        ),
+                            ),
+                        },
+                    ),
+                    (
+                        ClosureShape {
+                            captures: [],
+                            n_locals: 0,
+                        },
+                        Index {
+                            indexable: Slot(
+                                Local(
+                                    LocalSlot(
+                                        0,
                                     ),
                                 ),
-                                parts: [
-                                    LIndexPart {
-                                        span: virtual:<test>:44-45,
-                                        value: Str(
+                            ),
+                            parts: [
+                                LIndexPart {
+                                    span: virtual:<test>:44-45,
+                                    value: Trivial(
+                                        Str(
                                             "b",
                                         ),
-                                    },
-                                ],
-                            },
-                        ),
-                    },
+                                    ),
+                                },
+                            ],
+                        },
+                    ),
                 ],
             },
         ),
modifiedcrates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@undefined_var.jsonnet.snapdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@undefined_var.jsonnet.snap
+++ b/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@undefined_var.jsonnet.snap
@@ -1,5 +1,6 @@
 ---
 source: crates/jrsonnet-evaluator/src/analyze.rs
+assertion_line: 2175
 expression: rendered
 input_file: crates/jrsonnet-evaluator/src/analysis_tests/undefined_var.jsonnet
 ---
@@ -19,7 +20,9 @@
         "ref",
     ),
     op: Add,
-    rhs: Num(
-        1.0,
+    rhs: Trivial(
+        Num(
+            1.0,
+        ),
     ),
 }
modifiedcrates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@unused_local.jsonnet.snapdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@unused_local.jsonnet.snap
+++ b/crates/jrsonnet-evaluator/src/snapshots/jrsonnet_evaluator__analyze__tests__snapshots@unused_local.jsonnet.snap
@@ -1,5 +1,6 @@
 ---
 source: crates/jrsonnet-evaluator/src/analyze.rs
+assertion_line: 2175
 expression: rendered
 input_file: crates/jrsonnet-evaluator/src/analysis_tests/unused_local.jsonnet
 ---
@@ -31,13 +32,17 @@
                     captures: [],
                     n_locals: 0,
                 },
-                value: Num(
-                    1.0,
+                value: Trivial(
+                    Num(
+                        1.0,
+                    ),
                 ),
             },
         ],
-        body: Num(
-            2.0,
+        body: Trivial(
+            Num(
+                2.0,
+            ),
         ),
     },
 )
modifiedcrates/jrsonnet-evaluator/src/tla.rsdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/tla.rs
+++ b/crates/jrsonnet-evaluator/src/tla.rs
@@ -5,7 +5,7 @@
 use jrsonnet_ir::{SourceFifo, SourcePath};
 
 use crate::{
-	Result, Thunk, Val,
+	Result, Thunk, Val, ensure_sufficient_stack,
 	function::{CallLocation, PreparedFuncVal},
 	in_description_frame, with_state,
 };
@@ -21,7 +21,7 @@
 }
 impl TlaArg {
 	pub fn evaluate_tailstrict(&self) -> Result<Val> {
-		match self {
+		ensure_sufficient_stack(|| match self {
 			Self::String(s) => Ok(Val::string(s.clone())),
 			Self::Val(val) => Ok(val.clone()),
 			Self::Lazy(lazy) => Ok(lazy.evaluate()?),
@@ -38,7 +38,7 @@
 					SourcePath::new(SourceFifo("<inline code>".to_owned(), p.as_bytes().into()));
 				s.import_resolved(resolved)
 			}),
-		}
+		})
 	}
 	pub fn evaluate(&self) -> Result<Thunk<Val>> {
 		match self {