git.delta.rocks / jrsonnet / refs/commits / ddc0d176fb77

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	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#[allow(clippy::module_name_repetitions)]37#[derive(Clone, Trace)]38pub struct Thunk<T: Trace>(Cc<RefCell<ThunkInner<T>>>);3940impl<T: Trace> Thunk<T> {41	pub fn evaluated(val: T) -> Self {42		Self(Cc::new(RefCell::new(ThunkInner::Computed(val))))43	}44	pub fn new(f: TraceBox<dyn ThunkValue<Output = T>>) -> Self {45		Self(Cc::new(RefCell::new(ThunkInner::Waiting(f))))46	}47	pub fn errored(e: Error) -> Self {48		Self(Cc::new(RefCell::new(ThunkInner::Errored(e))))49	}50}5152impl<T> Thunk<T>53where54	T: Clone + Trace,55{56	pub fn force(&self) -> Result<()> {57		self.evaluate()?;58		Ok(())59	}60	pub fn evaluate(&self) -> Result<T> {61		match &*self.0.borrow() {62			ThunkInner::Computed(v) => return Ok(v.clone()),63			ThunkInner::Errored(e) => return Err(e.clone()),64			ThunkInner::Pending => return Err(InfiniteRecursionDetected.into()),65			ThunkInner::Waiting(..) => (),66		};67		let ThunkInner::Waiting(value) = replace(&mut *self.0.borrow_mut(), ThunkInner::Pending) else {68			unreachable!();69		};70		let new_value = match value.0.get() {71			Ok(v) => v,72			Err(e) => {73				*self.0.borrow_mut() = ThunkInner::Errored(e.clone());74				return Err(e);75			}76		};77		*self.0.borrow_mut() = ThunkInner::Computed(new_value.clone());78		Ok(new_value)79	}80}8182type CacheKey = (Option<WeakObjValue>, Option<WeakObjValue>);8384#[derive(Trace, Clone)]85pub struct CachedUnbound<I, T>86where87	I: Unbound<Bound = T>,88	T: Trace,89{90	cache: Cc<RefCell<GcHashMap<CacheKey, T>>>,91	value: I,92}93impl<I: Unbound<Bound = T>, T: Trace> CachedUnbound<I, T> {94	pub fn new(value: I) -> Self {95		Self {96			cache: Cc::new(RefCell::new(GcHashMap::new())),97			value,98		}99	}100}101impl<I: Unbound<Bound = T>, T: Clone + Trace> Unbound for CachedUnbound<I, T> {102	type Bound = T;103	fn bind(&self, sup: Option<ObjValue>, this: Option<ObjValue>) -> Result<T> {104		let cache_key = (105			sup.as_ref().map(|s| s.clone().downgrade()),106			this.as_ref().map(|t| t.clone().downgrade()),107		);108		{109			if let Some(t) = self.cache.borrow().get(&cache_key) {110				return Ok(t.clone());111			}112		}113		let bound = self.value.bind(sup, this)?;114115		{116			let mut cache = self.cache.borrow_mut();117			cache.insert(cache_key, bound.clone());118		}119120		Ok(bound)121	}122}123124impl<T: Debug + Trace> Debug for Thunk<T> {125	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {126		write!(f, "Lazy")127	}128}129impl<T: Trace> PartialEq for Thunk<T> {130	fn eq(&self, other: &Self) -> bool {131		Cc::ptr_eq(&self.0, &other.0)132	}133}134135/// Represents a Jsonnet value, which can be spliced or indexed (string or array).136#[allow(clippy::module_name_repetitions)]137pub enum IndexableVal {138	/// String.139	Str(IStr),140	/// Array.141	Arr(ArrValue),142}143impl IndexableVal {144	/// Slice the value.145	///146	/// # Implementation147	///148	/// For strings, will create a copy of specified interval.149	///150	/// For arrays, nothing will be copied on this call, instead [`ArrValue::Slice`] view will be returned.151	pub fn slice(152		self,153		index: Option<BoundedUsize<0, { i32::MAX as usize }>>,154		end: Option<BoundedUsize<0, { i32::MAX as usize }>>,155		step: Option<BoundedUsize<1, { i32::MAX as usize }>>,156	) -> Result<Self> {157		match &self {158			IndexableVal::Str(s) => {159				let index = index.as_deref().copied().unwrap_or(0);160				let end = end.as_deref().copied().unwrap_or(usize::MAX);161				let step = step.as_deref().copied().unwrap_or(1);162163				if index >= end {164					return Ok(Self::Str("".into()));165				}166167				Ok(Self::Str(168					(s.chars()169						.skip(index)170						.take(end - index)171						.step_by(step)172						.collect::<String>())173					.into(),174				))175			}176			IndexableVal::Arr(arr) => {177				let index = index.as_deref().copied().unwrap_or(0);178				let end = end.as_deref().copied().unwrap_or(usize::MAX).min(arr.len());179				let step = step.as_deref().copied().unwrap_or(1);180181				if index >= end {182					return Ok(Self::Arr(ArrValue::empty()));183				}184185				Ok(Self::Arr(186					arr.clone()187						.slice(Some(index), Some(end), Some(step))188						.expect("arguments checked"),189				))190			}191		}192	}193}194195#[derive(Debug, Clone, Trace)]196pub enum StrValue {197	Flat(IStr),198	Tree(Rc<(StrValue, StrValue, usize)>),199}200impl StrValue {201	pub fn concat(a: StrValue, b: StrValue) -> Self {202		// TODO: benchmark for an optimal value, currently just a arbitrary choice203		const STRING_EXTEND_THRESHOLD: usize = 100;204205		if a.is_empty() {206			b207		} else if b.is_empty() {208			a209		} else if a.len() + b.len() < STRING_EXTEND_THRESHOLD {210			Self::Flat(format!("{a}{b}").into())211		} else {212			let len = a.len() + b.len();213			Self::Tree(Rc::new((a, b, len)))214		}215	}216	pub fn into_flat(self) -> IStr {217		#[cold]218		fn write_buf(s: &StrValue, out: &mut String) {219			match s {220				StrValue::Flat(f) => out.push_str(f),221				StrValue::Tree(t) => {222					write_buf(&t.0, out);223					write_buf(&t.1, out);224				}225			}226		}227		match self {228			StrValue::Flat(f) => f,229			StrValue::Tree(_) => {230				let mut buf = String::with_capacity(self.len());231				write_buf(&self, &mut buf);232				buf.into()233			}234		}235	}236	pub fn len(&self) -> usize {237		match self {238			StrValue::Flat(v) => v.len(),239			StrValue::Tree(t) => t.2,240		}241	}242	pub fn is_empty(&self) -> bool {243		match self {244			Self::Flat(v) => v.is_empty(),245			// Can't create non-flat empty string246			Self::Tree(_) => false,247		}248	}249}250impl Display for StrValue {251	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {252		match self {253			StrValue::Flat(v) => write!(f, "{v}"),254			StrValue::Tree(t) => {255				write!(f, "{}", t.0)?;256				write!(f, "{}", t.1)257			}258		}259	}260}261impl PartialEq for StrValue {262	fn eq(&self, other: &Self) -> bool {263		let a = self.clone().into_flat();264		let b = other.clone().into_flat();265		a == b266	}267}268impl Eq for StrValue {}269impl PartialOrd for StrValue {270	fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {271		let a = self.clone().into_flat();272		let b = other.clone().into_flat();273		Some(a.cmp(&b))274	}275}276impl Ord for StrValue {277	fn cmp(&self, other: &Self) -> std::cmp::Ordering {278		self.partial_cmp(other)279			.expect("partial_cmp always returns Some")280	}281}282283/// Represents any valid Jsonnet value.284#[derive(Debug, Clone, Trace)]285pub enum Val {286	/// Represents a Jsonnet boolean.287	Bool(bool),288	/// Represents a Jsonnet null value.289	Null,290	/// Represents a Jsonnet string.291	Str(StrValue),292	/// Represents a Jsonnet number.293	/// Should be finite, and not NaN294	/// This restriction isn't enforced by enum, as enum field can't be marked as private295	Num(f64),296	/// Represents a Jsonnet array.297	Arr(ArrValue),298	/// Represents a Jsonnet object.299	Obj(ObjValue),300	/// Represents a Jsonnet function.301	Func(FuncVal),302}303304static_assertions::assert_eq_size!(Val, [u8; 24]);305306impl From<IndexableVal> for Val {307	fn from(v: IndexableVal) -> Self {308		match v {309			IndexableVal::Str(s) => Self::Str(StrValue::Flat(s)),310			IndexableVal::Arr(a) => Self::Arr(a),311		}312	}313}314315impl Val {316	pub const fn as_bool(&self) -> Option<bool> {317		match self {318			Self::Bool(v) => Some(*v),319			_ => None,320		}321	}322	pub const fn as_null(&self) -> Option<()> {323		match self {324			Self::Null => Some(()),325			_ => None,326		}327	}328	pub fn as_str(&self) -> Option<IStr> {329		match self {330			Self::Str(s) => Some(s.clone().into_flat()),331			_ => None,332		}333	}334	pub const fn as_num(&self) -> Option<f64> {335		match self {336			Self::Num(n) => Some(*n),337			_ => None,338		}339	}340	pub fn as_arr(&self) -> Option<ArrValue> {341		match self {342			Self::Arr(a) => Some(a.clone()),343			_ => None,344		}345	}346	pub fn as_obj(&self) -> Option<ObjValue> {347		match self {348			Self::Obj(o) => Some(o.clone()),349			_ => None,350		}351	}352	pub fn as_func(&self) -> Option<FuncVal> {353		match self {354			Self::Func(f) => Some(f.clone()),355			_ => None,356		}357	}358359	/// Creates `Val::Num` after checking for numeric overflow.360	/// As numbers are `f64`, we can just check for their finity.361	pub fn new_checked_num(num: f64) -> Result<Self> {362		if num.is_finite() {363			Ok(Self::Num(num))364		} else {365			throw!("overflow")366		}367	}368369	pub const fn value_type(&self) -> ValType {370		match self {371			Self::Str(..) => ValType::Str,372			Self::Num(..) => ValType::Num,373			Self::Arr(..) => ValType::Arr,374			Self::Obj(..) => ValType::Obj,375			Self::Bool(_) => ValType::Bool,376			Self::Null => ValType::Null,377			Self::Func(..) => ValType::Func,378		}379	}380381	pub fn manifest(&self, format: impl ManifestFormat) -> Result<String> {382		fn manifest_dyn(val: &Val, manifest: &dyn ManifestFormat) -> Result<String> {383			manifest.manifest(val.clone())384		}385		manifest_dyn(self, &format)386	}387388	pub fn to_string(&self) -> Result<IStr> {389		Ok(match self {390			Self::Bool(true) => "true".into(),391			Self::Bool(false) => "false".into(),392			Self::Null => "null".into(),393			Self::Str(s) => s.clone().into_flat(),394			_ => self.manifest(ToStringFormat).map(IStr::from)?,395		})396	}397398	pub fn into_indexable(self) -> Result<IndexableVal> {399		Ok(match self {400			Val::Str(s) => IndexableVal::Str(s.into_flat()),401			Val::Arr(arr) => IndexableVal::Arr(arr),402			_ => throw!(ValueIsNotIndexable(self.value_type())),403		})404	}405}406407const fn is_function_like(val: &Val) -> bool {408	matches!(val, Val::Func(_))409}410411/// Native implementation of `std.primitiveEquals`412pub fn primitive_equals(val_a: &Val, val_b: &Val) -> Result<bool> {413	Ok(match (val_a, val_b) {414		(Val::Bool(a), Val::Bool(b)) => a == b,415		(Val::Null, Val::Null) => true,416		(Val::Str(a), Val::Str(b)) => a == b,417		(Val::Num(a), Val::Num(b)) => (a - b).abs() <= f64::EPSILON,418		(Val::Arr(_), Val::Arr(_)) => {419			throw!("primitiveEquals operates on primitive types, got array")420		}421		(Val::Obj(_), Val::Obj(_)) => {422			throw!("primitiveEquals operates on primitive types, got object")423		}424		(a, b) if is_function_like(a) && is_function_like(b) => {425			throw!("cannot test equality of functions")426		}427		(_, _) => false,428	})429}430431/// Native implementation of `std.equals`432pub fn equals(val_a: &Val, val_b: &Val) -> Result<bool> {433	if val_a.value_type() != val_b.value_type() {434		return Ok(false);435	}436	match (val_a, val_b) {437		(Val::Arr(a), Val::Arr(b)) => {438			if ArrValue::ptr_eq(a, b) {439				return Ok(true);440			}441			if a.len() != b.len() {442				return Ok(false);443			}444			for (a, b) in a.iter().zip(b.iter()) {445				if !equals(&a?, &b?)? {446					return Ok(false);447				}448			}449			Ok(true)450		}451		(Val::Obj(a), Val::Obj(b)) => {452			if ObjValue::ptr_eq(a, b) {453				return Ok(true);454			}455			let fields = a.fields(456				#[cfg(feature = "exp-preserve-order")]457				false,458			);459			if fields460				!= b.fields(461					#[cfg(feature = "exp-preserve-order")]462					false,463				) {464				return Ok(false);465			}466			for field in fields {467				if !equals(468					&a.get(field.clone())?.expect("field exists"),469					&b.get(field)?.expect("field exists"),470				)? {471					return Ok(false);472				}473			}474			Ok(true)475		}476		(a, b) => Ok(primitive_equals(a, b)?),477	}478}