git.delta.rocks / jrsonnet / refs/commits / 7a6e8cbd4a25

difftreelog

feat move trace mapping api to evaluator

Лач2020-06-29parent: #8f92008.patch.diff
in: master

4 files changed

deletedcmds/jrsonnet/src/location.rsdiffbeforeafterboth
--- a/cmds/jrsonnet/src/location.rs
+++ /dev/null
@@ -1,99 +0,0 @@
-#[derive(Clone, PartialEq, Debug)]
-pub struct CodeLocation {
-	pub line: usize,
-	pub column: usize,
-
-	pub line_start_offset: usize,
-	pub line_end_offset: usize,
-}
-
-pub fn offset_to_location(file: &str, offsets: &[usize]) -> Vec<CodeLocation> {
-	if offsets.is_empty() {
-		return vec![];
-	}
-	let mut line = 1;
-	let mut column = 0;
-	let max_offset = *offsets.iter().max().unwrap();
-
-	let mut offset_map = offsets
-		.iter()
-		.enumerate()
-		.map(|(pos, offset)| (*offset, pos))
-		.collect::<Vec<_>>();
-	offset_map.sort_by_key(|v| v.0);
-	offset_map.reverse();
-
-	let mut out = vec![
-		CodeLocation {
-			column: 0,
-			line: 0,
-			line_start_offset: 0,
-			line_end_offset: 0
-		};
-		offsets.len()
-	];
-	let mut with_no_known_line_ending = vec![];
-	let mut this_line_offset = 0;
-	for (pos, ch) in file.chars().enumerate() {
-		column += 1;
-		match offset_map.last() {
-			Some(x) if x.0 == pos => {
-				let out_idx = x.1;
-				with_no_known_line_ending.push(out_idx);
-				out[out_idx].line = line;
-				out[out_idx].column = column;
-				out[out_idx].line_start_offset = this_line_offset + 1;
-				offset_map.pop();
-			}
-			_ => {}
-		}
-		if ch == '\n' {
-			line += 1;
-			column = 0;
-
-			for idx in with_no_known_line_ending.drain(..) {
-				out[idx].line_end_offset = pos;
-			}
-			this_line_offset = pos;
-
-			if pos == max_offset + 1 {
-				break;
-			}
-		}
-	}
-	let file_end = file.chars().count();
-	for idx in with_no_known_line_ending {
-		out[idx].line_end_offset = file_end;
-	}
-
-	out
-}
-
-#[cfg(test)]
-pub mod tests {
-	use super::{offset_to_location, CodeLocation};
-
-	#[test]
-	fn test() {
-		assert_eq!(
-			offset_to_location(
-				"hello world\n_______________________________________________________",
-				&[0, 14]
-			),
-			vec![
-				CodeLocation {
-					line: 1,
-					column: 1,
-					line_start_offset: 1,
-					line_end_offset: 11
-				},
-				CodeLocation {
-					line: 2,
-					column: 3,
-					line_start_offset: 12,
-					line_end_offset: 67
-				}
-			]
-		)
-	}
-}
modifiedcmds/jrsonnet/src/main.rsdiffbeforeafterboth
before · cmds/jrsonnet/src/main.rs
1pub mod location;23use clap::Clap;4use jrsonnet_evaluator::{EvaluationState, LocError, StackTrace, Val};5use jrsonnet_parser::{el, Arg, ArgsDesc, Expr, LocExpr, ParserSettings};6use location::{offset_to_location, CodeLocation};7use std::env::current_dir;8use std::{collections::HashMap, path::PathBuf, rc::Rc, str::FromStr};910#[global_allocator]11static GLOBAL: mimallocator::Mimalloc = mimallocator::Mimalloc;1213enum Format {14	None,15	Json,16	Yaml,17}1819impl FromStr for Format {20	type Err = &'static str;21	fn from_str(s: &str) -> Result<Self, Self::Err> {22		Ok(match s {23			"none" => Format::None,24			"json" => Format::Json,25			"yaml" => Format::Yaml,26			_ => return Err("no such format"),27		})28	}29}3031#[derive(PartialEq)]32enum TraceFormat {33	CppJsonnet,34	GoJsonnet,35	Custom,36}37impl FromStr for TraceFormat {38	type Err = &'static str;39	fn from_str(s: &str) -> Result<Self, Self::Err> {40		Ok(match s {41			"cpp" => TraceFormat::CppJsonnet,42			"go" => TraceFormat::GoJsonnet,43			"default" => TraceFormat::Custom,44			_ => return Err("no such format"),45		})46	}47}4849#[derive(Clone)]50struct ExtStr {51	name: String,52	value: String,53}54impl FromStr for ExtStr {55	type Err = &'static str;56	fn from_str(s: &str) -> Result<Self, Self::Err> {57		let out: Vec<_> = s.split('=').collect();58		match out.len() {59			1 => Ok(ExtStr {60				name: out[0].to_owned(),61				value: std::env::var(out[0]).or(Err("missing env var"))?,62			}),63			2 => Ok(ExtStr {64				name: out[0].to_owned(),65				value: out[1].to_owned(),66			}),67			_ => Err("bad ext-str syntax"),68		}69	}70}7172#[derive(Clap)]73#[clap(version = "0.1.0", author = "Lach <iam@lach.pw>")]74struct Opts {75	#[clap(long, about = "Disable global std variable")]76	no_stdlib: bool,77	#[clap(long, about = "Add external string")]78	ext_str: Vec<ExtStr>,79	#[clap(long, about = "Add external string from code")]80	ext_code: Vec<ExtStr>,81	#[clap(long, about = "Add TLA")]82	tla_str: Vec<ExtStr>,83	#[clap(long, about = "Add TLA from code")]84	tla_code: Vec<ExtStr>,85	#[clap(long, short = "f", default_value = "json", possible_values = &["none", "json", "yaml"], about = "Output format, wraps resulting value to corresponding std.manifest call")]86	format: Format,87	#[clap(long, default_value = "default", possible_values = &["cpp", "go", "default"], about = "Emulated needed stacktrace display")]88	trace_format: TraceFormat,8990	#[clap(91		long,92		short = "s",93		default_value = "200",94		about = "Number of allowed stack frames"95	)]96	max_stack: usize,97	#[clap(98		long,99		short = "t",100		default_value = "20",101		about = "Max length of stack trace before cropping"102	)]103	max_trace: usize,104105	#[clap(long, short = "J", about = "Library search dir")]106	jpath: Vec<PathBuf>,107108	#[clap(109		long,110		default_value = "3",111		about = "When using --format, this option specifies string to pad output with"112	)]113	line_padding: usize,114115	#[clap(about = "File to compile", index = 1)]116	input: String,117}118119fn main() {120	let opts: Opts = Opts::parse();121	let evaluator = jrsonnet_evaluator::EvaluationState::default();122	evaluator.set_max_trace(opts.max_trace);123	evaluator.set_max_stack(opts.max_stack);124	evaluator.set_import_resolver(Box::new(jrsonnet_evaluator::FileImportResolver {125		library_paths: opts.jpath.clone(),126	}));127	if !opts.no_stdlib {128		evaluator.with_stdlib();129	}130	for ExtStr { name, value } in opts.ext_str.iter().cloned() {131		evaluator.add_ext_var(name.into(), Val::Str(value.into()));132	}133	for ExtStr { name, value } in opts.ext_code.iter().cloned() {134		evaluator.add_ext_var(name.into(), evaluator.parse_evaluate_raw(&value).unwrap());135	}136	let mut input = current_dir().unwrap();137	input.push(opts.input.clone());138	let code_string = String::from_utf8(std::fs::read(opts.input.clone()).unwrap()).unwrap();139	if let Err(e) = evaluator.add_file(Rc::new(input.clone()), code_string.clone().into()) {140		print_syntax_error(e, &input, &code_string);141		std::process::exit(1);142	}143	let result = evaluator.evaluate_file(&input);144	match result {145		Ok(v) => {146			let v = match v {147				Val::Func(f) => {148					let mut desc_map = HashMap::new();149					for ExtStr { name, value } in opts.tla_str.iter().cloned() {150						desc_map.insert(name, el!(Expr::Str(value.into())));151					}152					for ExtStr { name, value } in opts.tla_code.iter().cloned() {153						desc_map.insert(154							name,155							jrsonnet_parser::parse(156								&value,157								&ParserSettings {158									file_name: Rc::new(PathBuf::new()),159									loc_data: false,160								},161							)162							.unwrap(),163						);164					}165					evaluator.add_global("__tmp__tlf__".into(), Val::Func(f));166					evaluator167						.evaluate_raw(el!(Expr::Apply(168							el!(Expr::Var("__tmp__tlf__".into())),169							ArgsDesc(desc_map.into_iter().map(|(k, v)| Arg(Some(k), v)).collect()),170							false,171						)))172						.unwrap()173				}174				v => v,175			};176			let v = evaluator.run_in_state(|| match opts.format {177				Format::Json => Ok(Val::Str(v.into_json(opts.line_padding)?)),178				Format::Yaml => {179					evaluator.add_global("__tmp__to_yaml__".into(), v);180					evaluator.parse_evaluate_raw("std.manifestYamlDoc(__tmp__to_yaml__, \"  \")")181				}182				_ => Ok(v),183			});184			let v = match v {185				Ok(v) => v,186				Err(err) => {187					print_error(&err, evaluator, &opts);188					std::process::exit(1);189				}190			};191			match v {192				Val::Str(s) => println!("{}", s),193				Val::Num(n) => println!("{}", n),194				_v => eprintln!(195					"jsonnet output is not a string.\nDid you forgot to set --format, or wrap your data with std.manifestJson?"196				),197			}198		}199		Err(err) => {200			print_error(&err, evaluator, &opts);201			std::process::exit(1);202		}203	}204}205206fn print_error(err: &LocError, evaluator: EvaluationState, opts: &Opts) {207	println!("Error: {:?}", err.0);208	print_trace(&(err.1), evaluator, &opts);209}210211fn print_syntax_error(error: jrsonnet_parser::ParseError, file: &PathBuf, code: &str) {212	use annotate_snippets::{213		display_list::{DisplayList, FormatOptions},214		snippet::{Annotation, AnnotationType, Slice, Snippet, SourceAnnotation},215	};216	//&("Expected: ".to_owned() + error.expected)217	let origin = file.to_str().unwrap();218	let error_message = format!("Expected: {}", error.expected);219	let snippet = Snippet {220		opt: FormatOptions {221			color: true,222			..Default::default()223		},224		title: Some(Annotation {225			label: Some(&error_message),226			id: None,227			annotation_type: AnnotationType::Error,228		}),229		footer: vec![],230		slices: vec![Slice {231			source: &code,232			line_start: 1,233			origin: Some(origin),234			fold: false,235			annotations: vec![SourceAnnotation {236				label: "At this position",237				annotation_type: AnnotationType::Error,238				range: (error.location.offset, error.location.offset + 1),239			}],240		}],241	};242243	let dl = DisplayList::from(snippet);244	println!("{}", dl);245}246247fn print_trace(trace: &StackTrace, evaluator: EvaluationState, opts: &Opts) {248	use annotate_snippets::{249		display_list::{DisplayList, FormatOptions},250		snippet::{Annotation, AnnotationType, Slice, Snippet, SourceAnnotation},251	};252	for item in trace.0.iter() {253		let desc = &item.1;254		let source = item.0.clone();255		let code = evaluator.get_source(&source.0);256		if code.is_none() {257			continue;258		}259		let code = code.unwrap();260		let start_end = offset_to_location(&code, &[source.1, source.2]);261		if opts.trace_format == TraceFormat::Custom {262			let source_fragment: String = code263				.chars()264				.skip(start_end[0].line_start_offset)265				.take(start_end[1].line_end_offset - start_end[0].line_start_offset)266				.collect();267			let snippet = Snippet {268				opt: FormatOptions {269					color: true,270					..Default::default()271				},272				title: Some(Annotation {273					label: Some(&item.1),274					id: None,275					annotation_type: AnnotationType::Error,276				}),277				footer: vec![],278				slices: vec![Slice {279					source: &source_fragment,280					line_start: start_end[0].line,281					origin: Some(&source.0.to_str().unwrap()),282					fold: false,283					annotations: vec![SourceAnnotation {284						label: desc,285						annotation_type: AnnotationType::Error,286						range: (287							source.1 - start_end[0].line_start_offset,288							source.2 - start_end[0].line_start_offset,289						),290					}],291				}],292			};293294			let dl = DisplayList::from(snippet);295			println!("{}", dl);296		} else {297			print_jsonnet_pair(298				source.0.to_str().unwrap(),299				&start_end[0],300				&start_end[1],301				opts.trace_format == TraceFormat::GoJsonnet,302			);303		}304	}305}306307fn print_jsonnet_pair(file: &str, start: &CodeLocation, end: &CodeLocation, is_go: bool) {308	if is_go {309		print!("        ");310	} else {311		print!("  ");312	}313	print!("{}:", file);314	if start.line == end.line {315		// IDK why, but this is the behavior original jsonnet cpp impl shows316		if start.column == end.column || !is_go && start.column + 1 == end.column {317			println!("{}:{}", start.line, end.column)318		} else {319			println!("{}:{}-{}", start.line, start.column, end.column);320		}321	} else {322		println!(323			"({}:{})-({}:{})",324			start.line, end.column, start.line, end.column325		);326	}327}
after · cmds/jrsonnet/src/main.rs
1use clap::Clap;2use jrsonnet_evaluator::{trace::CodeLocation, EvaluationState, LocError, StackTrace, Val};3use jrsonnet_parser::{el, Arg, ArgsDesc, Expr, LocExpr, ParserSettings};4use std::env::current_dir;5use std::{collections::HashMap, path::PathBuf, rc::Rc, str::FromStr};67#[global_allocator]8static GLOBAL: mimallocator::Mimalloc = mimallocator::Mimalloc;910enum Format {11	None,12	Json,13	Yaml,14}1516impl FromStr for Format {17	type Err = &'static str;18	fn from_str(s: &str) -> Result<Self, Self::Err> {19		Ok(match s {20			"none" => Format::None,21			"json" => Format::Json,22			"yaml" => Format::Yaml,23			_ => return Err("no such format"),24		})25	}26}2728#[derive(PartialEq)]29enum TraceFormat {30	CppJsonnet,31	GoJsonnet,32	Custom,33}34impl FromStr for TraceFormat {35	type Err = &'static str;36	fn from_str(s: &str) -> Result<Self, Self::Err> {37		Ok(match s {38			"cpp" => TraceFormat::CppJsonnet,39			"go" => TraceFormat::GoJsonnet,40			"default" => TraceFormat::Custom,41			_ => return Err("no such format"),42		})43	}44}4546#[derive(Clone)]47struct ExtStr {48	name: String,49	value: String,50}51impl FromStr for ExtStr {52	type Err = &'static str;53	fn from_str(s: &str) -> Result<Self, Self::Err> {54		let out: Vec<_> = s.split('=').collect();55		match out.len() {56			1 => Ok(ExtStr {57				name: out[0].to_owned(),58				value: std::env::var(out[0]).or(Err("missing env var"))?,59			}),60			2 => Ok(ExtStr {61				name: out[0].to_owned(),62				value: out[1].to_owned(),63			}),64			_ => Err("bad ext-str syntax"),65		}66	}67}6869#[derive(Clap)]70#[clap(version = "0.1.0", author = "Lach <iam@lach.pw>")]71struct Opts {72	#[clap(long, about = "Disable global std variable")]73	no_stdlib: bool,74	#[clap(long, about = "Add external string")]75	ext_str: Vec<ExtStr>,76	#[clap(long, about = "Add external string from code")]77	ext_code: Vec<ExtStr>,78	#[clap(long, about = "Add TLA")]79	tla_str: Vec<ExtStr>,80	#[clap(long, about = "Add TLA from code")]81	tla_code: Vec<ExtStr>,82	#[clap(long, short = "f", default_value = "json", possible_values = &["none", "json", "yaml"], about = "Output format, wraps resulting value to corresponding std.manifest call")]83	format: Format,84	#[clap(long, default_value = "default", possible_values = &["cpp", "go", "default"], about = "Emulated needed stacktrace display")]85	trace_format: TraceFormat,8687	#[clap(88		long,89		short = "s",90		default_value = "200",91		about = "Number of allowed stack frames"92	)]93	max_stack: usize,94	#[clap(95		long,96		short = "t",97		default_value = "20",98		about = "Max length of stack trace before cropping"99	)]100	max_trace: usize,101102	#[clap(long, short = "J", about = "Library search dir")]103	jpath: Vec<PathBuf>,104105	#[clap(106		long,107		default_value = "3",108		about = "When using --format, this option specifies string to pad output with"109	)]110	line_padding: usize,111112	#[clap(about = "File to compile", index = 1)]113	input: String,114}115116fn main() {117	let opts: Opts = Opts::parse();118	let evaluator = jrsonnet_evaluator::EvaluationState::default();119	evaluator.set_max_trace(opts.max_trace);120	evaluator.set_max_stack(opts.max_stack);121	evaluator.set_import_resolver(Box::new(jrsonnet_evaluator::FileImportResolver {122		library_paths: opts.jpath.clone(),123	}));124	if !opts.no_stdlib {125		evaluator.with_stdlib();126	}127	for ExtStr { name, value } in opts.ext_str.iter().cloned() {128		evaluator.add_ext_var(name.into(), Val::Str(value.into()));129	}130	for ExtStr { name, value } in opts.ext_code.iter().cloned() {131		evaluator.add_ext_var(name.into(), evaluator.parse_evaluate_raw(&value).unwrap());132	}133	let mut input = current_dir().unwrap();134	input.push(opts.input.clone());135	let code_string = String::from_utf8(std::fs::read(opts.input.clone()).unwrap()).unwrap();136	if let Err(e) = evaluator.add_file(Rc::new(input.clone()), code_string.clone().into()) {137		print_syntax_error(e, &input, &code_string);138		std::process::exit(1);139	}140	let result = evaluator.evaluate_file(&input);141	match result {142		Ok(v) => {143			let v = match v {144				Val::Func(f) => {145					let mut desc_map = HashMap::new();146					for ExtStr { name, value } in opts.tla_str.iter().cloned() {147						desc_map.insert(name, el!(Expr::Str(value.into())));148					}149					for ExtStr { name, value } in opts.tla_code.iter().cloned() {150						desc_map.insert(151							name,152							jrsonnet_parser::parse(153								&value,154								&ParserSettings {155									file_name: Rc::new(PathBuf::new()),156									loc_data: false,157								},158							)159							.unwrap(),160						);161					}162					evaluator.add_global("__tmp__tlf__".into(), Val::Func(f));163					evaluator164						.evaluate_raw(el!(Expr::Apply(165							el!(Expr::Var("__tmp__tlf__".into())),166							ArgsDesc(desc_map.into_iter().map(|(k, v)| Arg(Some(k), v)).collect()),167							false,168						)))169						.unwrap()170				}171				v => v,172			};173			let v = evaluator.run_in_state(|| match opts.format {174				Format::Json => Ok(Val::Str(v.into_json(opts.line_padding)?)),175				Format::Yaml => {176					evaluator.add_global("__tmp__to_yaml__".into(), v);177					evaluator.parse_evaluate_raw("std.manifestYamlDoc(__tmp__to_yaml__, \"  \")")178				}179				_ => Ok(v),180			});181			let v = match v {182				Ok(v) => v,183				Err(err) => {184					print_error(&err, evaluator, &opts);185					std::process::exit(1);186				}187			};188			match v {189				Val::Str(s) => println!("{}", s),190				Val::Num(n) => println!("{}", n),191				_v => eprintln!(192					"jsonnet output is not a string.\nDid you forgot to set --format, or wrap your data with std.manifestJson?"193				),194			}195		}196		Err(err) => {197			print_error(&err, evaluator, &opts);198			std::process::exit(1);199		}200	}201}202203fn print_error(err: &LocError, evaluator: EvaluationState, opts: &Opts) {204	println!("Error: {:?}", err.0);205	print_trace(&(err.1), evaluator, &opts);206}207208fn print_syntax_error(error: jrsonnet_parser::ParseError, file: &PathBuf, code: &str) {209	use annotate_snippets::{210		display_list::{DisplayList, FormatOptions},211		snippet::{Annotation, AnnotationType, Slice, Snippet, SourceAnnotation},212	};213	//&("Expected: ".to_owned() + error.expected)214	let origin = file.to_str().unwrap();215	let error_message = format!("Expected: {}", error.expected);216	let snippet = Snippet {217		opt: FormatOptions {218			color: true,219			..Default::default()220		},221		title: Some(Annotation {222			label: Some(&error_message),223			id: None,224			annotation_type: AnnotationType::Error,225		}),226		footer: vec![],227		slices: vec![Slice {228			source: &code,229			line_start: 1,230			origin: Some(origin),231			fold: false,232			annotations: vec![SourceAnnotation {233				label: "At this position",234				annotation_type: AnnotationType::Error,235				range: (error.location.offset, error.location.offset + 1),236			}],237		}],238	};239240	let dl = DisplayList::from(snippet);241	println!("{}", dl);242}243244fn print_trace(trace: &StackTrace, evaluator: EvaluationState, opts: &Opts) {245	use annotate_snippets::{246		display_list::{DisplayList, FormatOptions},247		snippet::{Annotation, AnnotationType, Slice, Snippet, SourceAnnotation},248	};249	for item in trace.0.iter() {250		let desc = &item.1;251		let source = item.0.clone();252		let start_end = evaluator.map_source_locations(&source.0, &[source.1, source.2]);253		if opts.trace_format == TraceFormat::Custom {254			let source_fragment: String = evaluator255				.get_source(&source.0)256				.unwrap()257				.chars()258				.skip(start_end[0].line_start_offset)259				.take(start_end[1].line_end_offset - start_end[0].line_start_offset)260				.collect();261			let snippet = Snippet {262				opt: FormatOptions {263					color: true,264					..Default::default()265				},266				title: Some(Annotation {267					label: Some(&item.1),268					id: None,269					annotation_type: AnnotationType::Error,270				}),271				footer: vec![],272				slices: vec![Slice {273					source: &source_fragment,274					line_start: start_end[0].line,275					origin: Some(&source.0.to_str().unwrap()),276					fold: false,277					annotations: vec![SourceAnnotation {278						label: desc,279						annotation_type: AnnotationType::Error,280						range: (281							source.1 - start_end[0].line_start_offset,282							source.2 - start_end[0].line_start_offset,283						),284					}],285				}],286			};287288			let dl = DisplayList::from(snippet);289			println!("{}", dl);290		} else {291			print_jsonnet_pair(292				source.0.to_str().unwrap(),293				&start_end[0],294				&start_end[1],295				opts.trace_format == TraceFormat::GoJsonnet,296			);297		}298	}299}300301fn print_jsonnet_pair(file: &str, start: &CodeLocation, end: &CodeLocation, is_go: bool) {302	if is_go {303		print!("        ");304	} else {305		print!("  ");306	}307	print!("{}:", file);308	if start.line == end.line {309		// IDK why, but this is the behavior original jsonnet cpp impl shows310		if start.column == end.column || !is_go && start.column + 1 == end.column {311			println!("{}:{}", start.line, end.column)312		} else {313			println!("{}:{}-{}", start.line, start.column, end.column);314		}315	} else {316		println!(317			"({}:{})-({}:{})",318			start.line, end.column, start.line, end.column319		);320	}321}
modifiedcrates/jrsonnet-evaluator/src/lib.rsdiffbeforeafterboth
--- a/crates/jrsonnet-evaluator/src/lib.rs
+++ b/crates/jrsonnet-evaluator/src/lib.rs
@@ -16,6 +16,7 @@
 mod map;
 mod obj;
 mod val;
+pub mod trace;
 
 pub use ctx::*;
 pub use dynamic::*;
@@ -27,6 +28,7 @@
 pub use obj::*;
 use std::{cell::{Ref, RefCell, RefMut}, collections::HashMap, fmt::Debug, path::PathBuf, rc::Rc};
 pub use val::*;
+use trace::{offset_to_location, CodeLocation};
 
 type BindableFn = dyn Fn(Option<ObjValue>, Option<ObjValue>) -> Result<LazyVal>;
 #[derive(Clone)]
@@ -187,6 +189,10 @@
 		let ro_map = &self.data().files;
 		ro_map.get(name).map(|value| value.0.clone())
 	}
+	pub fn map_source_locations(&self, file: &PathBuf, locs: &[usize]) -> Vec<CodeLocation> {
+		offset_to_location(&self.get_source(file).unwrap(), locs)
+	}
+
 	pub fn evaluate_file(&self, name: &PathBuf) -> Result<Val> {
 		self.run_in_state(|| {
 			let expr: LocExpr = {
addedcrates/jrsonnet-evaluator/src/trace.rsdiffbeforeafterboth
--- /dev/null
+++ b/crates/jrsonnet-evaluator/src/trace.rs
@@ -0,0 +1,99 @@
+#[derive(Clone, PartialEq, Debug)]
+pub struct CodeLocation {
+	pub line: usize,
+	pub column: usize,
+
+	pub line_start_offset: usize,
+	pub line_end_offset: usize,
+}
+
+pub fn offset_to_location(file: &str, offsets: &[usize]) -> Vec<CodeLocation> {
+	if offsets.is_empty() {
+		return vec![];
+	}
+	let mut line = 1;
+	let mut column = 0;
+	let max_offset = *offsets.iter().max().unwrap();
+
+	let mut offset_map = offsets
+		.iter()
+		.enumerate()
+		.map(|(pos, offset)| (*offset, pos))
+		.collect::<Vec<_>>();
+	offset_map.sort_by_key(|v| v.0);
+	offset_map.reverse();
+
+	let mut out = vec![
+		CodeLocation {
+			column: 0,
+			line: 0,
+			line_start_offset: 0,
+			line_end_offset: 0
+		};
+		offsets.len()
+	];
+	let mut with_no_known_line_ending = vec![];
+	let mut this_line_offset = 0;
+	for (pos, ch) in file.chars().enumerate() {
+		column += 1;
+		match offset_map.last() {
+			Some(x) if x.0 == pos => {
+				let out_idx = x.1;
+				with_no_known_line_ending.push(out_idx);
+				out[out_idx].line = line;
+				out[out_idx].column = column;
+				out[out_idx].line_start_offset = this_line_offset + 1;
+				offset_map.pop();
+			}
+			_ => {}
+		}
+		if ch == '\n' {
+			line += 1;
+			column = 0;
+
+			for idx in with_no_known_line_ending.drain(..) {
+				out[idx].line_end_offset = pos;
+			}
+			this_line_offset = pos;
+
+			if pos == max_offset + 1 {
+				break;
+			}
+		}
+	}
+	let file_end = file.chars().count();
+	for idx in with_no_known_line_ending {
+		out[idx].line_end_offset = file_end;
+	}
+
+	out
+}
+
+#[cfg(test)]
+pub mod tests {
+	use super::{offset_to_location, CodeLocation};
+
+	#[test]
+	fn test() {
+		assert_eq!(
+			offset_to_location(
+				"hello world\n_______________________________________________________",
+				&[0, 14]
+			),
+			vec![
+				CodeLocation {
+					line: 1,
+					column: 1,
+					line_start_offset: 1,
+					line_end_offset: 11
+				},
+				CodeLocation {
+					line: 2,
+					column: 3,
+					line_start_offset: 12,
+					line_end_offset: 67
+				}
+			]
+		)
+	}
+}