git.delta.rocks / jrsonnet / refs/commits / ac5b435d4caa

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crates/jrsonnet-evaluator/src/function/mod.rs6.8 KiBsourcehistory
1use std::{fmt::Debug, rc::Rc};23pub use arglike::{ArgLike, ArgsLike, TlaArg};4use educe::Educe;5use jrsonnet_gcmodule::{Cc, Trace};6use jrsonnet_interner::IStr;7pub use jrsonnet_macros::builtin;8use jrsonnet_parser::{Destruct, Expr, ExprParams, Span, Spanned};910use self::{11	arglike::OptionalContext,12	builtin::{Builtin, StaticBuiltin},13	native::NativeDesc,14	parse::{parse_default_function_call, parse_function_call},15};16use crate::{17	bail, error::ErrorKind::*, evaluate, evaluate_trivial, function::builtin::BuiltinFunc, Context,18	ContextBuilder, Result, Thunk, Val,19};2021pub mod arglike;22pub mod builtin;23pub mod native;24pub mod parse;25pub mod prepared;2627pub use jrsonnet_parser::function::*;2829/// Function callsite location.30/// Either from other jsonnet code, specified by expression location, or from native (without location).31#[derive(Clone, Copy)]32pub struct CallLocation<'l>(pub Option<&'l Span>);33impl<'l> CallLocation<'l> {34	/// Construct new location for calls coming from specified jsonnet expression location.35	pub const fn new(loc: &'l Span) -> Self {36		Self(Some(loc))37	}38}39impl CallLocation<'static> {40	/// Construct new location for calls coming from native code.41	pub const fn native() -> Self {42		Self(None)43	}44}4546/// Represents Jsonnet function defined in code.47#[derive(Trace, Educe)]48#[educe(Debug, PartialEq)]49pub struct FuncDesc {50	/// # Example51	///52	/// In expressions like this, deducted to `a`, unspecified otherwise.53	/// ```jsonnet54	/// local a = function() ...55	/// local a() ...56	/// { a: function() ... }57	/// { a() = ... }58	/// ```59	pub name: IStr,60	/// Context, in which this function was evaluated.61	///62	/// # Example63	/// In64	/// ```jsonnet65	/// local a = 2;66	/// function() ...67	/// ```68	/// context will contain `a`.69	pub ctx: Context,7071	/// Function parameter definition72	pub params: ExprParams,73	/// Function body74	pub body: Rc<Spanned<Expr>>,75}76impl FuncDesc {77	/// Create body context, but fill arguments without defaults with lazy error78	pub fn default_body_context(&self) -> Result<Context> {79		parse_default_function_call(self.ctx.clone(), &self.params)80	}8182	/// Create context, with which body code will run83	pub fn call_body_context(84		&self,85		call_ctx: Context,86		args: &dyn ArgsLike,87		tailstrict: bool,88	) -> Result<Context> {89		parse_function_call(call_ctx, self.ctx.clone(), &self.params, args, tailstrict)90	}9192	pub fn evaluate_trivial(&self) -> Option<Val> {93		evaluate_trivial(&self.body)94	}95}9697/// Represents a Jsonnet function value, including plain functions and user-provided builtins.98#[allow(clippy::module_name_repetitions)]99#[derive(Trace, Clone)]100pub enum FuncVal {101	/// Identity function, kept this way for comparsions.102	Id,103	/// Plain function implemented in jsonnet.104	Normal(Cc<FuncDesc>),105	/// Function without arguments works just as a fancy thunk value.106	Thunk(Thunk<Val>),107	/// Standard library function.108	StaticBuiltin(#[trace(skip)] &'static dyn StaticBuiltin),109	/// User-provided function.110	Builtin(BuiltinFunc),111}112113impl Debug for FuncVal {114	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {115		match self {116			Self::Id => f.debug_tuple("Id").finish(),117			Self::Thunk(arg0) => f.debug_tuple("Thunk").field(arg0).finish(),118			Self::Normal(arg0) => f.debug_tuple("Normal").field(arg0).finish(),119			Self::StaticBuiltin(arg0) => {120				f.debug_tuple("StaticBuiltin").field(&arg0.name()).finish()121			}122			Self::Builtin(arg0) => f.debug_tuple("Builtin").field(&arg0.name()).finish(),123		}124	}125}126127#[allow(clippy::unnecessary_wraps)]128#[builtin]129const fn builtin_id(x: Val) -> Val {130	x131}132static ID: &builtin_id = &builtin_id {};133134impl FuncVal {135	pub fn builtin(builtin: impl Builtin) -> Self {136		Self::Builtin(BuiltinFunc::new(builtin))137	}138	pub fn static_builtin(static_builtin: &'static dyn StaticBuiltin) -> Self {139		Self::StaticBuiltin(static_builtin)140	}141142	pub fn params(&self) -> FunctionSignature {143		match self {144			Self::Id => ID.params(),145			Self::StaticBuiltin(i) => i.params(),146			Self::Builtin(i) => i.params(),147			Self::Normal(p) => p.params.signature.clone(),148			Self::Thunk(_) => FunctionSignature::empty(),149		}150	}151	/// Amount of non-default required arguments152	pub fn params_len(&self) -> usize {153		self.params().iter().filter(|p| !p.has_default()).count()154	}155	/// Function name, as defined in code.156	pub fn name(&self) -> IStr {157		match self {158			Self::Id => "id".into(),159			Self::Normal(normal) => normal.name.clone(),160			Self::StaticBuiltin(builtin) => builtin.name().into(),161			Self::Builtin(builtin) => builtin.name().into(),162			Self::Thunk(_) => "thunk".into(),163		}164	}165	/// Call function using arguments evaluated in specified `call_ctx` [`Context`].166	///167	/// If `tailstrict` is specified - then arguments will be evaluated before being passed to function body.168	pub fn evaluate(169		&self,170		call_ctx: Context,171		loc: CallLocation<'_>,172		args: &dyn ArgsLike,173		tailstrict: bool,174	) -> Result<Val> {175		match self {176			Self::Id => ID.call(call_ctx, loc, args),177			Self::Normal(func) => {178				let body_ctx = func.call_body_context(call_ctx, args, tailstrict)?;179				evaluate(body_ctx, &func.body)180			}181			Self::Thunk(thunk) => {182				if !args.is_empty() {183					bail!(TooManyArgsFunctionHas(0, FunctionSignature::empty()))184				}185				thunk.evaluate()186			}187			Self::StaticBuiltin(b) => b.call(call_ctx, loc, args),188			Self::Builtin(b) => b.call(call_ctx, loc, args),189		}190	}191	pub fn evaluate_simple<A: ArgsLike + OptionalContext>(192		&self,193		args: &A,194		tailstrict: bool,195	) -> Result<Val> {196		self.evaluate(197			ContextBuilder::new().build(),198			CallLocation::native(),199			args,200			tailstrict,201		)202	}203	/// Convert jsonnet function to plain `Fn` value.204	pub fn into_native<D: NativeDesc>(self) -> D::Value {205		D::into_native(self)206	}207208	/// Is this function an indentity function.209	///210	/// Currently only works for builtin `std.id`, aka `Self::Id` value, and `function(x) x`.211	///212	/// This function should only be used for optimization, not for the conditional logic, i.e code should work with syntetic identity function too213	pub fn is_identity(&self) -> bool {214		match self {215			Self::Id => true,216			Self::Normal(desc) => {217				if desc.params.len() != 1 {218					return false;219				}220				let param = &desc.params.exprs[0];221				if param.default.is_some() {222					return false;223				}224225				#[allow(clippy::infallible_destructuring_match)]226				let id = match &param.destruct {227					Destruct::Full(id) => id,228					#[cfg(feature = "exp-destruct")]229					_ => return false,230				};231				**desc.body == Expr::Var(id.clone())232			}233			_ => false,234		}235	}236	/// Identity function value.237	pub const fn identity() -> Self {238		Self::Id239	}240241	pub fn evaluate_trivial(&self) -> Option<Val> {242		match self {243			Self::Normal(n) => n.evaluate_trivial(),244			_ => None,245		}246	}247}248249impl<T> From<T> for FuncVal250where251	T: Builtin,252{253	fn from(value: T) -> Self {254		Self::builtin(value)255	}256}257impl From<&'static dyn StaticBuiltin> for FuncVal {258	fn from(value: &'static dyn StaticBuiltin) -> Self {259		Self::static_builtin(value)260	}261}