From 7eb32146c8afe2b3af1ac940bc176f7e725fd7a7 Mon Sep 17 00:00:00 2001
From: Лач <iam@lach.pw>
Date: Sat, 27 Jun 2020 13:03:10 +0000
Subject: [PATCH] refactor(evaluator): error handling cleanup


---
--- a/crates/jsonnet-evaluator/src/ctx.rs
+++ b/crates/jsonnet-evaluator/src/ctx.rs
@@ -54,11 +54,11 @@
 	}
 
 	pub fn binding(&self, name: Rc<str>) -> Result<LazyVal> {
-		self.0.bindings.get(&name).cloned().ok_or_else(|| {
-			create_error::<()>(Error::UnknownVariable(name))
-				.err()
-				.unwrap()
-		})
+		self.0
+			.bindings
+			.get(&name)
+			.cloned()
+			.ok_or_else(|| create_error(Error::UnknownVariable(name)))
 	}
 	pub fn into_future(self, ctx: FutureContext) -> Context {
 		{
--- a/crates/jsonnet-evaluator/src/evaluate.rs
+++ b/crates/jsonnet-evaluator/src/evaluate.rs
@@ -1,7 +1,7 @@
 use crate::{
-	context_creator, create_error, escape_string_json, future_wrapper, lazy_val, manifest_json_ex,
-	parse_args, push, with_state, Context, ContextCreator, Error, FuncDesc, LazyBinding, LazyVal,
-	ObjMember, ObjValue, Result, Val, ValType,
+	context_creator, create_error, create_error_result, escape_string_json, future_wrapper,
+	lazy_val, manifest_json_ex, parse_args, push, with_state, Context, ContextCreator, Error,
+	FuncDesc, LazyBinding, LazyVal, ObjMember, ObjValue, Result, Val, ValType,
 };
 use closure::closure;
 use jsonnet_parser::{
@@ -74,7 +74,7 @@
 		(UnaryOpType::Not, Val::Bool(v)) => Val::Bool(!v),
 		(UnaryOpType::Minus, Val::Num(n)) => Val::Num(-*n),
 		(UnaryOpType::BitNot, Val::Num(n)) => Val::Num(!(*n as i32) as f64),
-		(op, o) => create_error(Error::UnaryOperatorDoesNotOperateOnType(
+		(op, o) => create_error_result(Error::UnaryOperatorDoesNotOperateOnType(
 			op,
 			o.value_type()?,
 		))?,
@@ -95,7 +95,7 @@
 		(Val::Obj(v1), Val::Obj(v2)) => Val::Obj(v2.with_super(v1.clone())),
 		(Val::Arr(a), Val::Arr(b)) => Val::Arr(Rc::new([&a[..], &b[..]].concat())),
 		(Val::Num(v1), Val::Num(v2)) => Val::Num(v1 + v2),
-		_ => create_error(Error::BinaryOperatorDoesNotOperateOnValues(
+		_ => create_error_result(Error::BinaryOperatorDoesNotOperateOnValues(
 			BinaryOpType::Add,
 			a.value_type()?,
 			b.value_type()?,
@@ -140,7 +140,7 @@
 		(Val::Num(v1), BinaryOpType::Mul, Val::Num(v2)) => Val::Num(v1 * v2),
 		(Val::Num(v1), BinaryOpType::Div, Val::Num(v2)) => {
 			if *v2 <= f64::EPSILON {
-				create_error(crate::Error::DivisionByZero)?
+				create_error_result(crate::Error::DivisionByZero)?
 			}
 			Val::Num(v1 / v2)
 		}
@@ -168,7 +168,7 @@
 			Val::Num(((*v1 as i32) >> (*v2 as i32)) as f64)
 		}
 
-		_ => create_error(Error::BinaryOperatorDoesNotOperateOnValues(
+		_ => create_error_result(Error::BinaryOperatorDoesNotOperateOnValues(
 			op,
 			a.value_type()?,
 			b.value_type()?,
@@ -367,7 +367,7 @@
 							},
 						);
 					}
-					v => create_error(Error::FieldMustBeStringGot(v.value_type()?))?,
+					v => create_error_result(Error::FieldMustBeStringGot(v.value_type()?))?,
 				}
 			}
 
@@ -423,10 +423,10 @@
 					} else if let Some(Val::Str(n)) = v.get("__intristic_namespace__".into())? {
 						Val::Intristic(n, s)
 					} else {
-						create_error(crate::Error::NoSuchField(s))?
+						create_error_result(crate::Error::NoSuchField(s))?
 					}
 				}
-				(Val::Obj(_), n) => create_error(crate::Error::ValueIndexMustBeTypeGot(
+				(Val::Obj(_), n) => create_error_result(crate::Error::ValueIndexMustBeTypeGot(
 					ValType::Obj,
 					ValType::Str,
 					n.value_type()?,
@@ -434,17 +434,19 @@
 
 				(Val::Arr(v), Val::Num(n)) => {
 					if n.fract() > f64::EPSILON {
-						create_error(crate::Error::FractionalIndex)?
+						create_error_result(crate::Error::FractionalIndex)?
 					}
 					v.get(n as usize)
-						.unwrap_or_else(|| panic!("out of bounds"))
+						.ok_or_else(|| {
+							create_error(crate::Error::ArrayBoundsError(n as usize, v.len()))
+						})?
 						.clone()
 						.unwrap_if_lazy()?
 				}
 				(Val::Arr(_), Val::Str(n)) => {
-					create_error(crate::Error::AttemptedIndexAnArrayWithString(n))?
+					create_error_result(crate::Error::AttemptedIndexAnArrayWithString(n))?
 				}
-				(Val::Arr(_), n) => create_error(crate::Error::ValueIndexMustBeTypeGot(
+				(Val::Arr(_), n) => create_error_result(crate::Error::ValueIndexMustBeTypeGot(
 					ValType::Arr,
 					ValType::Num,
 					n.value_type()?,
@@ -457,13 +459,13 @@
 						.collect::<String>()
 						.into(),
 				),
-				(Val::Str(_), n) => create_error(crate::Error::ValueIndexMustBeTypeGot(
+				(Val::Str(_), n) => create_error_result(crate::Error::ValueIndexMustBeTypeGot(
 					ValType::Str,
 					ValType::Num,
 					n.value_type()?,
 				))?,
 
-				(v, _) => create_error(crate::Error::CantIndexInto(v.value_type()?))?,
+				(v, _) => create_error_result(crate::Error::CantIndexInto(v.value_type()?))?,
 			}
 		}
 		LocalExpr(bindings, returned) => {
@@ -623,11 +625,7 @@
 						0, x: [Val::Str]!!Val::Str, vec![ValType::Str];
 					], {
 						with_state(|s| s.0.ext_vars.borrow().get(&x).cloned()).ok_or_else(
-							|| {
-								create_error::<()>(crate::Error::UndefinedExternalVariable(x))
-									.err()
-									.unwrap()
-							},
+							|| create_error(crate::Error::UndefinedExternalVariable(x)),
 						)?
 					}),
 					("std", "filter") => parse_args!(context, "std.filter", args, 2, [
@@ -728,7 +726,7 @@
 							Val::Str(manifest_json_ex(&value, &indent)?.into())
 						})
 					}
-					(ns, name) => create_error(crate::error::Error::IntristicNotFound(
+					(ns, name) => create_error_result(crate::Error::IntristicNotFound(
 						ns.into(),
 						name.into(),
 					))?,
@@ -741,7 +739,7 @@
 						push(loc, "function call", body)?
 					}
 				}
-				v => create_error(crate::error::Error::OnlyFunctionsCanBeCalledGot(
+				v => create_error_result(crate::Error::OnlyFunctionsCanBeCalledGot(
 					v.value_type()?,
 				))?,
 			}
@@ -764,7 +762,7 @@
 				panic!("assertion failed ({:?}): no message", value);
 			}
 		}
-		Error(e) => create_error(crate::Error::RuntimeError(
+		Error(e) => create_error_result(crate::Error::RuntimeError(
 			evaluate(context, e)?.try_cast_str("error text should be string")?,
 		))?,
 		IfElse {
@@ -801,6 +799,8 @@
 			import_location.pop();
 			Val::Str(with_state(|s| s.import_file_str(&import_location, path))?)
 		}
-		Literal(LiteralType::Super) => return create_error(crate::error::Error::StandaloneSuper),
+		Literal(LiteralType::Super) => {
+			return create_error_result(crate::Error::StandaloneSuper)
+		}
 	})
 }
--- a/crates/jsonnet-evaluator/src/function.rs
+++ b/crates/jsonnet-evaluator/src/function.rs
@@ -1,4 +1,7 @@
-use crate::{create_error, evaluate, lazy_val, resolved_lazy_val, Context, Error, Result, Val};
+use crate::{
+	create_error, create_error_result, evaluate, lazy_val, resolved_lazy_val, Context, Error,
+	Result, Val,
+};
 use closure::closure;
 use jsonnet_parser::{ArgsDesc, ParamsDesc};
 use std::collections::HashMap;
@@ -21,20 +24,19 @@
 	let mut positioned_args = vec![None; params.0.len()];
 	for (id, arg) in args.iter().enumerate() {
 		let idx = if let Some(name) = &arg.0 {
-			params.iter().position(|p| *p.0 == *name).ok_or_else(|| {
-				create_error::<()>(Error::UnknownFunctionParameter(name.clone()))
-					.err()
-					.unwrap()
-			})?
+			params
+				.iter()
+				.position(|p| *p.0 == *name)
+				.ok_or_else(|| create_error(Error::UnknownFunctionParameter(name.clone())))?
 		} else {
 			id
 		};
 
 		if idx >= params.len() {
-			create_error(Error::TooManyArgsFunctionHas(params.len()))?;
+			create_error_result(Error::TooManyArgsFunctionHas(params.len()))?;
 		}
 		if positioned_args[idx].is_some() {
-			create_error(Error::BindingParameterASecondTime(params[idx].0.clone()))?;
+			create_error_result(Error::BindingParameterASecondTime(params[idx].0.clone()))?;
 		}
 		positioned_args[idx] = Some(arg.1.clone());
 	}
@@ -50,7 +52,7 @@
 				default,
 			)
 		} else {
-			create_error(Error::FunctionParameterNotBoundInCall(p.0.clone()))?;
+			create_error_result(Error::FunctionParameterNotBoundInCall(p.0.clone()))?;
 			unreachable!()
 		};
 		let val = if tailstrict {
@@ -74,7 +76,7 @@
 	let mut positioned_args = vec![None; params.0.len()];
 	for (id, arg) in args.iter().enumerate() {
 		if id >= params.len() {
-			create_error(Error::TooManyArgsFunctionHas(params.len()))?;
+			create_error_result(Error::TooManyArgsFunctionHas(params.len()))?;
 		}
 		positioned_args[id] = Some(arg);
 	}
@@ -85,7 +87,7 @@
 		} else if let Some(default) = &p.1 {
 			evaluate(ctx.clone(), default)?
 		} else {
-			create_error(Error::FunctionParameterNotBoundInCall(p.0.clone()))?;
+			create_error_result(Error::FunctionParameterNotBoundInCall(p.0.clone()))?;
 			unreachable!()
 		};
 		out.insert(p.0.clone(), resolved_lazy_val!(val));
@@ -99,31 +101,31 @@
 	($ctx: expr, $fn_name: expr, $args: expr, $total_args: expr, [
 		$($id: expr, $name: ident $(: [$($p: path)|+] $(!! $a: path)?)?, $nt: expr);+ $(;)?
 	], $handler:block) => {{
-		use crate::error::Error;
+		use crate::Error;
 		let args = $args;
 		if args.len() > $total_args {
-			create_error(Error::TooManyArgsFunctionHas($total_args))?;
+			create_error_result(Error::TooManyArgsFunctionHas($total_args))?;
 		}
 		$(
 			if args.len() <= $id {
-				create_error(Error::FunctionParameterNotBoundInCall(stringify!($name).into()))?;
+				create_error_result(Error::FunctionParameterNotBoundInCall(stringify!($name).into()))?;
 			}
 			let $name = &args[$id];
 			if $name.0.is_some() {
 				if $name.0.as_ref().unwrap() != stringify!($name) {
-					create_error(Error::IntristicArgumentReorderingIsNotSupportedYet)?;
+					create_error_result(Error::IntristicArgumentReorderingIsNotSupportedYet)?;
 				}
 			}
 			let $name = evaluate($ctx.clone(), &$name.1)?;
 			$(
 				match $name {
 					$($p(_))|+ => {},
-					_ => create_error(Error::TypeMismatch(concat!($fn_name, " ", stringify!($id), "nd argument"), $nt, $name.value_type()?))?,
+					_ => create_error_result(Error::TypeMismatch(concat!($fn_name, " ", stringify!($id), "nd argument"), $nt, $name.value_type()?))?,
 				};
 				$(
 					let $name = match $name {
 						$a(v) => v,
-						_ => create_error(Error::TypeMismatch(concat!($fn_name, " ", stringify!($id), "nd argument"), $nt, $name.value_type()?))?,
+						_ => create_error_result(Error::TypeMismatch(concat!($fn_name, " ", stringify!($id), "nd argument"), $nt, $name.value_type()?))?,
 					};
 				)*
 			)*
--- a/crates/jsonnet-evaluator/src/import.rs
+++ b/crates/jsonnet-evaluator/src/import.rs
@@ -1,5 +1,8 @@
-use crate::create_error;
-use crate::error::{Error, Result};
+use crate::create_error_result;
+use crate::{
+	create_error,
+	error::{Error, Result},
+};
 use fs::File;
 use std::fs;
 use std::io::Read;
@@ -13,7 +16,7 @@
 pub struct DummyImportResolver;
 impl ImportResolver for DummyImportResolver {
 	fn resolve_file(&self, from: &PathBuf, path: &PathBuf) -> Result<Rc<PathBuf>> {
-		create_error(Error::ImportNotSupported(from.clone(), path.clone()))
+		create_error_result(Error::ImportNotSupported(from.clone(), path.clone()))
 	}
 	fn load_file_contents(&self, _resolved: &PathBuf) -> Result<Rc<str>> {
 		// Can be only caused by library direct consumer, not by supplied jsonnet
@@ -43,21 +46,15 @@
 					return Ok(Rc::new(cloned));
 				}
 			}
-			create_error(Error::ImportFileNotFound(from.clone(), path.clone()))
+			create_error_result(Error::ImportFileNotFound(from.clone(), path.clone()))
 		}
 	}
 	fn load_file_contents(&self, id: &PathBuf) -> Result<Rc<str>> {
-		let mut file = File::open(id).map_err(|_e| {
-			create_error::<()>(Error::ResolvedFileNotFound(id.clone()))
-				.err()
-				.unwrap()
-		})?;
+		let mut file =
+			File::open(id).map_err(|_e| create_error(Error::ResolvedFileNotFound(id.clone())))?;
 		let mut out = String::new();
-		file.read_to_string(&mut out).map_err(|_e| {
-			create_error::<()>(Error::ImportBadFileUtf8(id.clone()))
-				.err()
-				.unwrap()
-		})?;
+		file.read_to_string(&mut out)
+			.map_err(|_e| create_error(Error::ImportBadFileUtf8(id.clone())))?;
 		Ok(out.into())
 	}
 }
--- a/crates/jsonnet-evaluator/src/lib.rs
+++ b/crates/jsonnet-evaluator/src/lib.rs
@@ -87,9 +87,12 @@
 pub(crate) fn with_state<T>(f: impl FnOnce(&EvaluationState) -> T) -> T {
 	EVAL_STATE.with(|s| f(s.borrow().as_ref().unwrap()))
 }
-pub(crate) fn create_error<T>(err: Error) -> Result<T> {
+pub(crate) fn create_error(err: Error) -> LocError {
 	with_state(|s| s.error(err))
 }
+pub(crate) fn create_error_result<T>(err: Error) -> Result<T> {
+	Err(with_state(|s| s.error(err)))
+}
 pub(crate) fn push<T>(
 	e: &Option<ExprLocation>,
 	comment: &str,
@@ -187,9 +190,7 @@
 		}
 		let contents = self.0.import_resolver.load_file_contents(&file_path)?;
 		self.add_file(file_path.clone(), contents).map_err(|e| {
-			create_error::<()>(Error::ImportSyntaxError(e))
-				.err()
-				.unwrap()
+			create_error(Error::ImportSyntaxError(e))
 		})?;
 		self.evaluate_file(&file_path)
 	}
@@ -292,7 +293,7 @@
 			let mut stack = self.0.stack.borrow_mut();
 			if stack.len() > self.0.settings.max_stack_frames {
 				drop(stack);
-				return self.error(Error::StackOverflow);
+				return Err(self.error(Error::StackOverflow));
 			} else {
 				stack.push(StackTraceElement(e, comment));
 			}
@@ -318,8 +319,8 @@
 				.collect(),
 		)
 	}
-	pub fn error<T>(&self, err: Error) -> Result<T> {
-		Err(LocError(err, self.stack_trace()))
+	pub fn error(&self, err: Error) -> LocError {
+		LocError(err, self.stack_trace())
 	}
 
 	pub fn run_in_state<T>(&self, f: impl FnOnce() -> T) -> T {
--- a/crates/jsonnet-evaluator/src/val.rs
+++ b/crates/jsonnet-evaluator/src/val.rs
@@ -1,5 +1,5 @@
 use crate::{
-	create_error, evaluate,
+	create_error_result, evaluate,
 	function::{parse_function_call, place_args},
 	Context, Error, ObjValue, Result,
 };
@@ -137,7 +137,7 @@
 	pub fn assert_type(&self, context: &'static str, val_type: ValType) -> Result<()> {
 		let this_type = self.value_type()?;
 		if this_type != val_type {
-			create_error(Error::TypeMismatch(context, vec![val_type], this_type))
+			create_error_result(Error::TypeMismatch(context, vec![val_type], this_type))
 		} else {
 			Ok(())
 		}

-- 
gitstuff