git.delta.rocks / jrsonnet / refs/commits / a05afd32cebc

1use std::borrow::Cow;23use jrsonnet_gcmodule::Trace;45use super::{arglike::ArgsLike, parse::parse_builtin_call, CallLocation};6use crate::{error::Result, gc::TraceBox, tb, Context, Val};78pub type BuiltinParamName = Cow<'static, str>;910#[derive(Clone, Trace)]11pub struct BuiltinParam {12	/// Parameter name for named call parsing13	pub name: Option<BuiltinParamName>,14	/// Is implementation allowed to return empty value15	pub has_default: bool,16}1718/// Description of function defined by native code19///20/// Prefer to use #[builtin] macro, instead of manual implementation of this trait21pub trait Builtin: Trace {22	/// Function name to be used in stack traces23	fn name(&self) -> &str;24	/// Parameter names for named calls25	fn params(&self) -> &[BuiltinParam];26	/// Call the builtin27	fn call(&self, ctx: Context, loc: CallLocation<'_>, args: &dyn ArgsLike) -> Result<Val>;28}2930pub trait StaticBuiltin: Builtin + Send + Sync31where32	Self: 'static,33{34	// In impl, to make it object safe:35	// const INST: &'static Self;36}3738#[derive(Trace)]39pub struct NativeCallback {40	pub(crate) params: Vec<BuiltinParam>,41	handler: TraceBox<dyn NativeCallbackHandler>,42}43impl NativeCallback {44	#[deprecated = "prefer using builtins directly, use this interface only for bindings"]45	pub fn new(params: Vec<Cow<'static, str>>, handler: impl NativeCallbackHandler) -> Self {46		Self {47			params: params48				.into_iter()49				.map(|n| BuiltinParam {50					name: Some(n),51					has_default: false,52				})53				.collect(),54			handler: tb!(handler),55		}56	}57}5859impl Builtin for NativeCallback {60	fn name(&self) -> &str {61		// TODO: standard natives gets their names from definition62		// But builitins should already have them63		"<native>"64	}6566	fn params(&self) -> &[BuiltinParam] {67		&self.params68	}6970	fn call(&self, ctx: Context, _loc: CallLocation<'_>, args: &dyn ArgsLike) -> Result<Val> {71		let args = parse_builtin_call(ctx, &self.params, args, true)?;72		let args = args73			.into_iter()74			.map(|a| a.expect("legacy natives have no default params"))75			.map(|a| a.evaluate())76			.collect::<Result<Vec<Val>>>()?;77		self.handler.call(&args)78	}79}8081pub trait NativeCallbackHandler: Trace {82	fn call(&self, args: &[Val]) -> Result<Val>;83}