git.delta.rocks / jrsonnet / refs/commits / 5dc3b98bcc3b

1use std::{2	cell::RefCell,3	fmt::{self, Debug, Display},4	mem::replace,5	rc::Rc,6};78use jrsonnet_gcmodule::{Cc, Trace};9use jrsonnet_interner::IStr;10use jrsonnet_types::ValType;1112pub use crate::arr::ArrValue;13use crate::{14	error::{Error, ErrorKind::*},15	function::FuncVal,16	gc::{GcHashMap, TraceBox},17	manifest::{ManifestFormat, ToStringFormat},18	tb, throw,19	typed::BoundedUsize,20	ObjValue, Result, Unbound, WeakObjValue,21};2223pub trait ThunkValue: Trace {24	type Output;25	fn get(self: Box<Self>) -> Result<Self::Output>;26}2728#[derive(Trace)]29enum ThunkInner<T: Trace> {30	Computed(T),31	Errored(Error),32	Waiting(TraceBox<dyn ThunkValue<Output = T>>),33	Pending,34}3536/// Lazily evaluated value37#[allow(clippy::module_name_repetitions)]38#[derive(Clone, Trace)]39pub struct Thunk<T: Trace>(Cc<RefCell<ThunkInner<T>>>);4041impl<T: Trace> Thunk<T> {42	pub fn evaluated(val: T) -> Self {43		Self(Cc::new(RefCell::new(ThunkInner::Computed(val))))44	}45	pub fn new(f: impl ThunkValue<Output = T> + 'static) -> Self {46		Self(Cc::new(RefCell::new(ThunkInner::Waiting(tb!(f)))))47	}48	pub fn errored(e: Error) -> Self {49		Self(Cc::new(RefCell::new(ThunkInner::Errored(e))))50	}51}5253impl<T> Thunk<T>54where55	T: Clone + Trace,56{57	pub fn force(&self) -> Result<()> {58		self.evaluate()?;59		Ok(())60	}6162	/// Evaluate thunk, or return cached value63	///64	/// # Errors65	///66	/// - Lazy value evaluation returned error67	/// - This method was called during inner value evaluation68	pub fn evaluate(&self) -> Result<T> {69		match &*self.0.borrow() {70			ThunkInner::Computed(v) => return Ok(v.clone()),71			ThunkInner::Errored(e) => return Err(e.clone()),72			ThunkInner::Pending => return Err(InfiniteRecursionDetected.into()),73			ThunkInner::Waiting(..) => (),74		};75		let ThunkInner::Waiting(value) = replace(&mut *self.0.borrow_mut(), ThunkInner::Pending)76		else {77			unreachable!();78		};79		let new_value = match value.0.get() {80			Ok(v) => v,81			Err(e) => {82				*self.0.borrow_mut() = ThunkInner::Errored(e.clone());83				return Err(e);84			}85		};86		*self.0.borrow_mut() = ThunkInner::Computed(new_value.clone());87		Ok(new_value)88	}89}9091pub trait ThunkMapper<Input>: Trace {92	type Output;93	fn map(self, from: Input) -> Result<Self::Output>;94}95impl<Input> Thunk<Input>96where97	Input: Trace + Clone,98{99	pub fn map<M>(self, mapper: M) -> Thunk<M::Output>100	where101		M: ThunkMapper<Input>,102		M::Output: Trace,103	{104		#[derive(Trace)]105		struct Mapped<Input: Trace, Mapper: Trace> {106			inner: Thunk<Input>,107			mapper: Mapper,108		}109		impl<Input, Mapper> ThunkValue for Mapped<Input, Mapper>110		where111			Input: Trace + Clone,112			Mapper: ThunkMapper<Input>,113		{114			type Output = Mapper::Output;115116			fn get(self: Box<Self>) -> Result<Self::Output> {117				let value = self.inner.evaluate()?;118				let mapped = self.mapper.map(value)?;119				Ok(mapped)120			}121		}122123		Thunk::new(Mapped::<Input, M> {124			inner: self,125			mapper,126		})127	}128}129130impl<T: Trace> From<Result<T>> for Thunk<T> {131	fn from(value: Result<T>) -> Self {132		match value {133			Ok(o) => Self::evaluated(o),134			Err(e) => Self::errored(e),135		}136	}137}138139type CacheKey = (Option<WeakObjValue>, Option<WeakObjValue>);140141#[derive(Trace, Clone)]142pub struct CachedUnbound<I, T>143where144	I: Unbound<Bound = T>,145	T: Trace,146{147	cache: Cc<RefCell<GcHashMap<CacheKey, T>>>,148	value: I,149}150impl<I: Unbound<Bound = T>, T: Trace> CachedUnbound<I, T> {151	pub fn new(value: I) -> Self {152		Self {153			cache: Cc::new(RefCell::new(GcHashMap::new())),154			value,155		}156	}157}158impl<I: Unbound<Bound = T>, T: Clone + Trace> Unbound for CachedUnbound<I, T> {159	type Bound = T;160	fn bind(&self, sup: Option<ObjValue>, this: Option<ObjValue>) -> Result<T> {161		let cache_key = (162			sup.as_ref().map(|s| s.clone().downgrade()),163			this.as_ref().map(|t| t.clone().downgrade()),164		);165		{166			if let Some(t) = self.cache.borrow().get(&cache_key) {167				return Ok(t.clone());168			}169		}170		let bound = self.value.bind(sup, this)?;171172		{173			let mut cache = self.cache.borrow_mut();174			cache.insert(cache_key, bound.clone());175		}176177		Ok(bound)178	}179}180181impl<T: Debug + Trace> Debug for Thunk<T> {182	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {183		write!(f, "Lazy")184	}185}186impl<T: Trace> PartialEq for Thunk<T> {187	fn eq(&self, other: &Self) -> bool {188		Cc::ptr_eq(&self.0, &other.0)189	}190}191192/// Represents a Jsonnet value, which can be sliced or indexed (string or array).193#[allow(clippy::module_name_repetitions)]194pub enum IndexableVal {195	/// String.196	Str(IStr),197	/// Array.198	Arr(ArrValue),199}200impl IndexableVal {201	pub fn to_array(self) -> ArrValue {202		match self {203			IndexableVal::Str(s) => ArrValue::chars(s.chars()),204			IndexableVal::Arr(arr) => arr,205		}206	}207	/// Slice the value.208	///209	/// # Implementation210	///211	/// For strings, will create a copy of specified interval.212	///213	/// For arrays, nothing will be copied on this call, instead [`ArrValue::Slice`] view will be returned.214	pub fn slice(215		self,216		index: Option<BoundedUsize<0, { i32::MAX as usize }>>,217		end: Option<BoundedUsize<0, { i32::MAX as usize }>>,218		step: Option<BoundedUsize<1, { i32::MAX as usize }>>,219	) -> Result<Self> {220		match &self {221			IndexableVal::Str(s) => {222				let index = index.as_deref().copied().unwrap_or(0);223				let end = end.as_deref().copied().unwrap_or(usize::MAX);224				let step = step.as_deref().copied().unwrap_or(1);225226				if index >= end {227					return Ok(Self::Str("".into()));228				}229230				Ok(Self::Str(231					(s.chars()232						.skip(index)233						.take(end - index)234						.step_by(step)235						.collect::<String>())236					.into(),237				))238			}239			IndexableVal::Arr(arr) => {240				let index = index.as_deref().copied().unwrap_or(0);241				let end = end.as_deref().copied().unwrap_or(usize::MAX).min(arr.len());242				let step = step.as_deref().copied().unwrap_or(1);243244				if index >= end {245					return Ok(Self::Arr(ArrValue::empty()));246				}247248				Ok(Self::Arr(249					arr.clone()250						.slice(Some(index), Some(end), Some(step))251						.expect("arguments checked"),252				))253			}254		}255	}256}257258#[derive(Debug, Clone, Trace)]259pub enum StrValue {260	Flat(IStr),261	Tree(Rc<(StrValue, StrValue, usize)>),262}263impl StrValue {264	pub fn concat(a: StrValue, b: StrValue) -> Self {265		// TODO: benchmark for an optimal value, currently just a arbitrary choice266		const STRING_EXTEND_THRESHOLD: usize = 100;267268		if a.is_empty() {269			b270		} else if b.is_empty() {271			a272		} else if a.len() + b.len() < STRING_EXTEND_THRESHOLD {273			Self::Flat(format!("{a}{b}").into())274		} else {275			let len = a.len() + b.len();276			Self::Tree(Rc::new((a, b, len)))277		}278	}279	pub fn into_flat(self) -> IStr {280		#[cold]281		fn write_buf(s: &StrValue, out: &mut String) {282			match s {283				StrValue::Flat(f) => out.push_str(f),284				StrValue::Tree(t) => {285					write_buf(&t.0, out);286					write_buf(&t.1, out);287				}288			}289		}290		match self {291			StrValue::Flat(f) => f,292			StrValue::Tree(_) => {293				let mut buf = String::with_capacity(self.len());294				write_buf(&self, &mut buf);295				buf.into()296			}297		}298	}299	pub fn len(&self) -> usize {300		match self {301			StrValue::Flat(v) => v.len(),302			StrValue::Tree(t) => t.2,303		}304	}305	pub fn is_empty(&self) -> bool {306		match self {307			Self::Flat(v) => v.is_empty(),308			// Can't create non-flat empty string309			Self::Tree(_) => false,310		}311	}312}313impl From<&str> for StrValue {314	fn from(value: &str) -> Self {315		Self::Flat(value.into())316	}317}318impl From<String> for StrValue {319	fn from(value: String) -> Self {320		Self::Flat(value.into())321	}322}323impl From<IStr> for StrValue {324	fn from(value: IStr) -> Self {325		Self::Flat(value)326	}327}328impl Display for StrValue {329	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {330		match self {331			StrValue::Flat(v) => write!(f, "{v}"),332			StrValue::Tree(t) => {333				write!(f, "{}", t.0)?;334				write!(f, "{}", t.1)335			}336		}337	}338}339impl PartialEq for StrValue {340	fn eq(&self, other: &Self) -> bool {341		let a = self.clone().into_flat();342		let b = other.clone().into_flat();343		a == b344	}345}346impl Eq for StrValue {}347impl PartialOrd for StrValue {348	fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {349		let a = self.clone().into_flat();350		let b = other.clone().into_flat();351		Some(a.cmp(&b))352	}353}354impl Ord for StrValue {355	fn cmp(&self, other: &Self) -> std::cmp::Ordering {356		self.partial_cmp(other)357			.expect("partial_cmp always returns Some")358	}359}360361/// Represents any valid Jsonnet value.362#[derive(Debug, Clone, Trace)]363pub enum Val {364	/// Represents a Jsonnet boolean.365	Bool(bool),366	/// Represents a Jsonnet null value.367	Null,368	/// Represents a Jsonnet string.369	Str(StrValue),370	/// Represents a Jsonnet number.371	/// Should be finite, and not NaN372	/// This restriction isn't enforced by enum, as enum field can't be marked as private373	Num(f64),374	/// Experimental bigint375	#[cfg(feature = "exp-bigint")]376	BigInt(#[trace(skip)] Box<num_bigint::BigInt>),377	/// Represents a Jsonnet array.378	Arr(ArrValue),379	/// Represents a Jsonnet object.380	Obj(ObjValue),381	/// Represents a Jsonnet function.382	Func(FuncVal),383}384385#[cfg(target_pointer_width = "64")]386static_assertions::assert_eq_size!(Val, [u8; 24]);387388impl From<IndexableVal> for Val {389	fn from(v: IndexableVal) -> Self {390		match v {391			IndexableVal::Str(s) => Self::Str(StrValue::Flat(s)),392			IndexableVal::Arr(a) => Self::Arr(a),393		}394	}395}396397impl Val {398	pub const fn as_bool(&self) -> Option<bool> {399		match self {400			Self::Bool(v) => Some(*v),401			_ => None,402		}403	}404	pub const fn as_null(&self) -> Option<()> {405		match self {406			Self::Null => Some(()),407			_ => None,408		}409	}410	pub fn as_str(&self) -> Option<IStr> {411		match self {412			Self::Str(s) => Some(s.clone().into_flat()),413			_ => None,414		}415	}416	pub const fn as_num(&self) -> Option<f64> {417		match self {418			Self::Num(n) => Some(*n),419			_ => None,420		}421	}422	pub fn as_arr(&self) -> Option<ArrValue> {423		match self {424			Self::Arr(a) => Some(a.clone()),425			_ => None,426		}427	}428	pub fn as_obj(&self) -> Option<ObjValue> {429		match self {430			Self::Obj(o) => Some(o.clone()),431			_ => None,432		}433	}434	pub fn as_func(&self) -> Option<FuncVal> {435		match self {436			Self::Func(f) => Some(f.clone()),437			_ => None,438		}439	}440441	/// Creates `Val::Num` after checking for numeric overflow.442	/// As numbers are `f64`, we can just check for their finity.443	pub fn new_checked_num(num: f64) -> Result<Self> {444		if num.is_finite() {445			Ok(Self::Num(num))446		} else {447			throw!("overflow")448		}449	}450451	pub const fn value_type(&self) -> ValType {452		match self {453			Self::Str(..) => ValType::Str,454			Self::Num(..) => ValType::Num,455			#[cfg(feature = "exp-bigint")]456			Self::BigInt(..) => ValType::BigInt,457			Self::Arr(..) => ValType::Arr,458			Self::Obj(..) => ValType::Obj,459			Self::Bool(_) => ValType::Bool,460			Self::Null => ValType::Null,461			Self::Func(..) => ValType::Func,462		}463	}464465	pub fn manifest(&self, format: impl ManifestFormat) -> Result<String> {466		fn manifest_dyn(val: &Val, manifest: &dyn ManifestFormat) -> Result<String> {467			manifest.manifest(val.clone())468		}469		manifest_dyn(self, &format)470	}471472	pub fn to_string(&self) -> Result<IStr> {473		Ok(match self {474			Self::Bool(true) => "true".into(),475			Self::Bool(false) => "false".into(),476			Self::Null => "null".into(),477			Self::Str(s) => s.clone().into_flat(),478			_ => self.manifest(ToStringFormat).map(IStr::from)?,479		})480	}481482	pub fn into_indexable(self) -> Result<IndexableVal> {483		Ok(match self {484			Val::Str(s) => IndexableVal::Str(s.into_flat()),485			Val::Arr(arr) => IndexableVal::Arr(arr),486			_ => throw!(ValueIsNotIndexable(self.value_type())),487		})488	}489}490491const fn is_function_like(val: &Val) -> bool {492	matches!(val, Val::Func(_))493}494495/// Native implementation of `std.primitiveEquals`496pub fn primitive_equals(val_a: &Val, val_b: &Val) -> Result<bool> {497	Ok(match (val_a, val_b) {498		(Val::Bool(a), Val::Bool(b)) => a == b,499		(Val::Null, Val::Null) => true,500		(Val::Str(a), Val::Str(b)) => a == b,501		(Val::Num(a), Val::Num(b)) => (a - b).abs() <= f64::EPSILON,502		#[cfg(feature = "exp-bigint")]503		(Val::BigInt(a), Val::BigInt(b)) => a == b,504		(Val::Arr(_), Val::Arr(_)) => {505			throw!("primitiveEquals operates on primitive types, got array")506		}507		(Val::Obj(_), Val::Obj(_)) => {508			throw!("primitiveEquals operates on primitive types, got object")509		}510		(a, b) if is_function_like(a) && is_function_like(b) => {511			throw!("cannot test equality of functions")512		}513		(_, _) => false,514	})515}516517/// Native implementation of `std.equals`518pub fn equals(val_a: &Val, val_b: &Val) -> Result<bool> {519	if val_a.value_type() != val_b.value_type() {520		return Ok(false);521	}522	match (val_a, val_b) {523		(Val::Arr(a), Val::Arr(b)) => {524			if ArrValue::ptr_eq(a, b) {525				return Ok(true);526			}527			if a.len() != b.len() {528				return Ok(false);529			}530			for (a, b) in a.iter().zip(b.iter()) {531				if !equals(&a?, &b?)? {532					return Ok(false);533				}534			}535			Ok(true)536		}537		(Val::Obj(a), Val::Obj(b)) => {538			if ObjValue::ptr_eq(a, b) {539				return Ok(true);540			}541			let fields = a.fields(542				#[cfg(feature = "exp-preserve-order")]543				false,544			);545			if fields546				!= b.fields(547					#[cfg(feature = "exp-preserve-order")]548					false,549				) {550				return Ok(false);551			}552			for field in fields {553				if !equals(554					&a.get(field.clone())?.expect("field exists"),555					&b.get(field)?.expect("field exists"),556				)? {557					return Ok(false);558				}559			}560			Ok(true)561		}562		(a, b) => Ok(primitive_equals(a, b)?),563	}564}