git.delta.rocks / jrsonnet / refs/commits / cfa49ab1b7b8

1use std::{2	cell::RefCell,3	fmt::{self, Debug, Display},4	hash::Hasher,5	mem::replace,6	rc::Rc,7};89use jrsonnet_gcmodule::{Cc, Trace};10use jrsonnet_interner::IStr;11use jrsonnet_types::ValType;12use rustc_hash::FxHasher;1314pub use crate::arr::{ArrValue, ArrayLike};15use crate::{16	error::{Error, ErrorKind::*},17	function::FuncVal,18	gc::{GcHashMap, TraceBox},19	manifest::{ManifestFormat, ToStringFormat},20	tb, throw,21	typed::BoundedUsize,22	ObjValue, Result, Unbound, WeakObjValue,23};2425pub trait ThunkValue: Trace {26	type Output;27	fn get(self: Box<Self>) -> Result<Self::Output>;28}2930#[derive(Trace)]31enum ThunkInner<T: Trace> {32	Computed(T),33	Errored(Error),34	Waiting(TraceBox<dyn ThunkValue<Output = T>>),35	Pending,36}3738/// Lazily evaluated value39#[allow(clippy::module_name_repetitions)]40#[derive(Clone, Trace)]41pub struct Thunk<T: Trace>(Cc<RefCell<ThunkInner<T>>>);4243impl<T: Trace> Thunk<T> {44	pub fn evaluated(val: T) -> Self {45		Self(Cc::new(RefCell::new(ThunkInner::Computed(val))))46	}47	pub fn new(f: impl ThunkValue<Output = T> + 'static) -> Self {48		Self(Cc::new(RefCell::new(ThunkInner::Waiting(tb!(f)))))49	}50	pub fn errored(e: Error) -> Self {51		Self(Cc::new(RefCell::new(ThunkInner::Errored(e))))52	}53}5455impl<T> Thunk<T>56where57	T: Clone + Trace,58{59	pub fn force(&self) -> Result<()> {60		self.evaluate()?;61		Ok(())62	}6364	/// Evaluate thunk, or return cached value65	///66	/// # Errors67	///68	/// - Lazy value evaluation returned error69	/// - This method was called during inner value evaluation70	pub fn evaluate(&self) -> Result<T> {71		match &*self.0.borrow() {72			ThunkInner::Computed(v) => return Ok(v.clone()),73			ThunkInner::Errored(e) => return Err(e.clone()),74			ThunkInner::Pending => return Err(InfiniteRecursionDetected.into()),75			ThunkInner::Waiting(..) => (),76		};77		let ThunkInner::Waiting(value) = replace(&mut *self.0.borrow_mut(), ThunkInner::Pending)78		else {79			unreachable!();80		};81		let new_value = match value.0.get() {82			Ok(v) => v,83			Err(e) => {84				*self.0.borrow_mut() = ThunkInner::Errored(e.clone());85				return Err(e);86			}87		};88		*self.0.borrow_mut() = ThunkInner::Computed(new_value.clone());89		Ok(new_value)90	}91}9293pub trait ThunkMapper<Input>: Trace {94	type Output;95	fn map(self, from: Input) -> Result<Self::Output>;96}97impl<Input> Thunk<Input>98where99	Input: Trace + Clone,100{101	pub fn map<M>(self, mapper: M) -> Thunk<M::Output>102	where103		M: ThunkMapper<Input>,104		M::Output: Trace,105	{106		#[derive(Trace)]107		struct Mapped<Input: Trace, Mapper: Trace> {108			inner: Thunk<Input>,109			mapper: Mapper,110		}111		impl<Input, Mapper> ThunkValue for Mapped<Input, Mapper>112		where113			Input: Trace + Clone,114			Mapper: ThunkMapper<Input>,115		{116			type Output = Mapper::Output;117118			fn get(self: Box<Self>) -> Result<Self::Output> {119				let value = self.inner.evaluate()?;120				let mapped = self.mapper.map(value)?;121				Ok(mapped)122			}123		}124125		Thunk::new(Mapped::<Input, M> {126			inner: self,127			mapper,128		})129	}130}131132impl<T: Trace> From<Result<T>> for Thunk<T> {133	fn from(value: Result<T>) -> Self {134		match value {135			Ok(o) => Self::evaluated(o),136			Err(e) => Self::errored(e),137		}138	}139}140141impl<T: Trace + Default> Default for Thunk<T> {142	fn default() -> Self {143		Self::evaluated(T::default())144	}145}146147type CacheKey = (Option<WeakObjValue>, Option<WeakObjValue>);148149#[derive(Trace, Clone)]150pub struct CachedUnbound<I, T>151where152	I: Unbound<Bound = T>,153	T: Trace,154{155	cache: Cc<RefCell<GcHashMap<CacheKey, T>>>,156	value: I,157}158impl<I: Unbound<Bound = T>, T: Trace> CachedUnbound<I, T> {159	pub fn new(value: I) -> Self {160		Self {161			cache: Cc::new(RefCell::new(GcHashMap::new())),162			value,163		}164	}165}166impl<I: Unbound<Bound = T>, T: Clone + Trace> Unbound for CachedUnbound<I, T> {167	type Bound = T;168	fn bind(&self, sup: Option<ObjValue>, this: Option<ObjValue>) -> Result<T> {169		let cache_key = (170			sup.as_ref().map(|s| s.clone().downgrade()),171			this.as_ref().map(|t| t.clone().downgrade()),172		);173		{174			if let Some(t) = self.cache.borrow().get(&cache_key) {175				return Ok(t.clone());176			}177		}178		let bound = self.value.bind(sup, this)?;179180		{181			let mut cache = self.cache.borrow_mut();182			cache.insert(cache_key, bound.clone());183		}184185		Ok(bound)186	}187}188189impl<T: Debug + Trace> Debug for Thunk<T> {190	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {191		write!(f, "Lazy")192	}193}194impl<T: Trace> PartialEq for Thunk<T> {195	fn eq(&self, other: &Self) -> bool {196		Cc::ptr_eq(&self.0, &other.0)197	}198}199200/// Represents a Jsonnet value, which can be sliced or indexed (string or array).201#[allow(clippy::module_name_repetitions)]202pub enum IndexableVal {203	/// String.204	Str(IStr),205	/// Array.206	Arr(ArrValue),207}208impl IndexableVal {209	pub fn to_array(self) -> ArrValue {210		match self {211			IndexableVal::Str(s) => ArrValue::chars(s.chars()),212			IndexableVal::Arr(arr) => arr,213		}214	}215	/// Slice the value.216	///217	/// # Implementation218	///219	/// For strings, will create a copy of specified interval.220	///221	/// For arrays, nothing will be copied on this call, instead [`ArrValue::Slice`] view will be returned.222	pub fn slice(223		self,224		index: Option<BoundedUsize<0, { i32::MAX as usize }>>,225		end: Option<BoundedUsize<0, { i32::MAX as usize }>>,226		step: Option<BoundedUsize<1, { i32::MAX as usize }>>,227	) -> Result<Self> {228		match &self {229			IndexableVal::Str(s) => {230				let index = index.as_deref().copied().unwrap_or(0);231				let end = end.as_deref().copied().unwrap_or(usize::MAX);232				let step = step.as_deref().copied().unwrap_or(1);233234				if index >= end {235					return Ok(Self::Str("".into()));236				}237238				Ok(Self::Str(239					(s.chars()240						.skip(index)241						.take(end - index)242						.step_by(step)243						.collect::<String>())244					.into(),245				))246			}247			IndexableVal::Arr(arr) => {248				let index = index.as_deref().copied().unwrap_or(0);249				let end = end.as_deref().copied().unwrap_or(usize::MAX).min(arr.len());250				let step = step.as_deref().copied().unwrap_or(1);251252				if index >= end {253					return Ok(Self::Arr(ArrValue::empty()));254				}255256				Ok(Self::Arr(257					arr.clone()258						.slice(Some(index), Some(end), Some(step))259						.expect("arguments checked"),260				))261			}262		}263	}264}265266#[derive(Debug, Clone, Trace)]267pub enum StrValue {268	Flat(IStr),269	Tree(Rc<(StrValue, StrValue, usize)>),270}271impl StrValue {272	pub fn concat(a: StrValue, b: StrValue) -> Self {273		// TODO: benchmark for an optimal value, currently just a arbitrary choice274		const STRING_EXTEND_THRESHOLD: usize = 100;275276		if a.is_empty() {277			b278		} else if b.is_empty() {279			a280		} else if a.len() + b.len() < STRING_EXTEND_THRESHOLD {281			Self::Flat(format!("{a}{b}").into())282		} else {283			let len = a.len() + b.len();284			Self::Tree(Rc::new((a, b, len)))285		}286	}287	pub fn into_flat(self) -> IStr {288		#[cold]289		fn write_buf(s: &StrValue, out: &mut String) {290			match s {291				StrValue::Flat(f) => out.push_str(f),292				StrValue::Tree(t) => {293					write_buf(&t.0, out);294					write_buf(&t.1, out);295				}296			}297		}298		match self {299			StrValue::Flat(f) => f,300			StrValue::Tree(_) => {301				let mut buf = String::with_capacity(self.len());302				write_buf(&self, &mut buf);303				buf.into()304			}305		}306	}307	pub fn len(&self) -> usize {308		match self {309			StrValue::Flat(v) => v.len(),310			StrValue::Tree(t) => t.2,311		}312	}313	pub fn is_empty(&self) -> bool {314		match self {315			Self::Flat(v) => v.is_empty(),316			// Can't create non-flat empty string317			Self::Tree(_) => false,318		}319	}320}321impl From<&str> for StrValue {322	fn from(value: &str) -> Self {323		Self::Flat(value.into())324	}325}326impl From<String> for StrValue {327	fn from(value: String) -> Self {328		Self::Flat(value.into())329	}330}331impl From<IStr> for StrValue {332	fn from(value: IStr) -> Self {333		Self::Flat(value)334	}335}336impl Display for StrValue {337	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {338		match self {339			StrValue::Flat(v) => write!(f, "{v}"),340			StrValue::Tree(t) => {341				write!(f, "{}", t.0)?;342				write!(f, "{}", t.1)343			}344		}345	}346}347impl PartialEq for StrValue {348	fn eq(&self, other: &Self) -> bool {349		let a = self.clone().into_flat();350		let b = other.clone().into_flat();351		a == b352	}353}354impl Eq for StrValue {}355impl PartialOrd for StrValue {356	fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {357		Some(self.cmp(other))358	}359}360impl Ord for StrValue {361	fn cmp(&self, other: &Self) -> std::cmp::Ordering {362		let a = self.clone().into_flat();363		let b = other.clone().into_flat();364		a.cmp(&b)365	}366}367368/// Represents any valid Jsonnet value.369#[derive(Debug, Clone, Trace, Default)]370pub enum Val {371	/// Represents a Jsonnet boolean.372	Bool(bool),373	/// Represents a Jsonnet null value.374	#[default]375	Null,376	/// Represents a Jsonnet string.377	Str(StrValue),378	/// Represents a Jsonnet number.379	/// Should be finite, and not NaN380	/// This restriction isn't enforced by enum, as enum field can't be marked as private381	Num(f64),382	/// Experimental bigint383	#[cfg(feature = "exp-bigint")]384	BigInt(#[trace(skip)] Box<num_bigint::BigInt>),385	/// Represents a Jsonnet array.386	Arr(ArrValue),387	/// Represents a Jsonnet object.388	Obj(ObjValue),389	/// Represents a Jsonnet function.390	Func(FuncVal),391}392393#[cfg(target_pointer_width = "64")]394static_assertions::assert_eq_size!(Val, [u8; 24]);395396impl From<IndexableVal> for Val {397	fn from(v: IndexableVal) -> Self {398		match v {399			IndexableVal::Str(s) => Self::Str(StrValue::Flat(s)),400			IndexableVal::Arr(a) => Self::Arr(a),401		}402	}403}404405impl Val {406	pub const fn as_bool(&self) -> Option<bool> {407		match self {408			Self::Bool(v) => Some(*v),409			_ => None,410		}411	}412	pub const fn as_null(&self) -> Option<()> {413		match self {414			Self::Null => Some(()),415			_ => None,416		}417	}418	pub fn as_str(&self) -> Option<IStr> {419		match self {420			Self::Str(s) => Some(s.clone().into_flat()),421			_ => None,422		}423	}424	pub const fn as_num(&self) -> Option<f64> {425		match self {426			Self::Num(n) => Some(*n),427			_ => None,428		}429	}430	pub fn as_arr(&self) -> Option<ArrValue> {431		match self {432			Self::Arr(a) => Some(a.clone()),433			_ => None,434		}435	}436	pub fn as_obj(&self) -> Option<ObjValue> {437		match self {438			Self::Obj(o) => Some(o.clone()),439			_ => None,440		}441	}442	pub fn as_func(&self) -> Option<FuncVal> {443		match self {444			Self::Func(f) => Some(f.clone()),445			_ => None,446		}447	}448449	/// Creates `Val::Num` after checking for numeric overflow.450	/// As numbers are `f64`, we can just check for their finity.451	pub fn new_checked_num(num: f64) -> Result<Self> {452		if num.is_finite() {453			Ok(Self::Num(num))454		} else {455			throw!("overflow")456		}457	}458459	pub const fn value_type(&self) -> ValType {460		match self {461			Self::Str(..) => ValType::Str,462			Self::Num(..) => ValType::Num,463			#[cfg(feature = "exp-bigint")]464			Self::BigInt(..) => ValType::BigInt,465			Self::Arr(..) => ValType::Arr,466			Self::Obj(..) => ValType::Obj,467			Self::Bool(_) => ValType::Bool,468			Self::Null => ValType::Null,469			Self::Func(..) => ValType::Func,470		}471	}472473	pub fn manifest(&self, format: impl ManifestFormat) -> Result<String> {474		fn manifest_dyn(val: &Val, manifest: &dyn ManifestFormat) -> Result<String> {475			manifest.manifest(val.clone())476		}477		manifest_dyn(self, &format)478	}479480	pub fn to_string(&self) -> Result<IStr> {481		Ok(match self {482			Self::Bool(true) => "true".into(),483			Self::Bool(false) => "false".into(),484			Self::Null => "null".into(),485			Self::Str(s) => s.clone().into_flat(),486			_ => self.manifest(ToStringFormat).map(IStr::from)?,487		})488	}489490	pub fn into_indexable(self) -> Result<IndexableVal> {491		Ok(match self {492			Val::Str(s) => IndexableVal::Str(s.into_flat()),493			Val::Arr(arr) => IndexableVal::Arr(arr),494			_ => throw!(ValueIsNotIndexable(self.value_type())),495		})496	}497}498499const fn is_function_like(val: &Val) -> bool {500	matches!(val, Val::Func(_))501}502503/// Native implementation of `std.primitiveEquals`504pub fn primitive_equals(val_a: &Val, val_b: &Val) -> Result<bool> {505	Ok(match (val_a, val_b) {506		(Val::Bool(a), Val::Bool(b)) => a == b,507		(Val::Null, Val::Null) => true,508		(Val::Str(a), Val::Str(b)) => a == b,509		(Val::Num(a), Val::Num(b)) => (a - b).abs() <= f64::EPSILON,510		#[cfg(feature = "exp-bigint")]511		(Val::BigInt(a), Val::BigInt(b)) => a == b,512		(Val::Arr(_), Val::Arr(_)) => {513			throw!("primitiveEquals operates on primitive types, got array")514		}515		(Val::Obj(_), Val::Obj(_)) => {516			throw!("primitiveEquals operates on primitive types, got object")517		}518		(a, b) if is_function_like(a) && is_function_like(b) => {519			throw!("cannot test equality of functions")520		}521		(_, _) => false,522	})523}524525/// Native implementation of `std.equals`526pub fn equals(val_a: &Val, val_b: &Val) -> Result<bool> {527	if val_a.value_type() != val_b.value_type() {528		return Ok(false);529	}530	match (val_a, val_b) {531		(Val::Arr(a), Val::Arr(b)) => {532			if ArrValue::ptr_eq(a, b) {533				return Ok(true);534			}535			if a.len() != b.len() {536				return Ok(false);537			}538			for (a, b) in a.iter().zip(b.iter()) {539				if !equals(&a?, &b?)? {540					return Ok(false);541				}542			}543			Ok(true)544		}545		(Val::Obj(a), Val::Obj(b)) => {546			if ObjValue::ptr_eq(a, b) {547				return Ok(true);548			}549			let fields = a.fields(550				#[cfg(feature = "exp-preserve-order")]551				false,552			);553			if fields554				!= b.fields(555					#[cfg(feature = "exp-preserve-order")]556					false,557				) {558				return Ok(false);559			}560			for field in fields {561				if !equals(562					&a.get(field.clone())?.expect("field exists"),563					&b.get(field)?.expect("field exists"),564				)? {565					return Ok(false);566				}567			}568			Ok(true)569		}570		(a, b) => Ok(primitive_equals(a, b)?),571	}572}