From 46911b6ea91185fd5c6ffaf070e76709e40fe288 Mon Sep 17 00:00:00 2001 From: Nadrieril Date: Tue, 17 Dec 2019 12:31:37 +0000 Subject: Split binary decoding and encoding into separate files --- dhall/src/syntax/binary/decode.rs | 437 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 437 insertions(+) create mode 100644 dhall/src/syntax/binary/decode.rs (limited to 'dhall/src/syntax/binary/decode.rs') diff --git a/dhall/src/syntax/binary/decode.rs b/dhall/src/syntax/binary/decode.rs new file mode 100644 index 0000000..46c9921 --- /dev/null +++ b/dhall/src/syntax/binary/decode.rs @@ -0,0 +1,437 @@ +use itertools::Itertools; +use serde_cbor::value::value as cbor; +use std::iter::FromIterator; + +use crate::semantics::error::DecodeError; +use crate::semantics::phase::DecodedExpr; +use crate::syntax; +use crate::syntax::{ + Expr, ExprF, FilePath, FilePrefix, Hash, ImportLocation, ImportMode, + Integer, InterpolatedText, Label, Natural, RawExpr, Scheme, Span, URL, V, +}; + +pub(crate) fn decode(data: &[u8]) -> Result { + match serde_cbor::de::from_slice(data) { + Ok(v) => cbor_value_to_dhall(&v), + Err(e) => Err(DecodeError::CBORError(e)), + } +} + +// Should probably rename this +fn rc(x: RawExpr) -> Expr { + Expr::new(x, Span::Decoded) +} + +fn cbor_value_to_dhall(data: &cbor::Value) -> Result { + use cbor::Value::*; + use syntax::{BinOp, Builtin, Const}; + use ExprF::*; + Ok(rc(match data { + String(s) => match Builtin::parse(s) { + Some(b) => ExprF::Builtin(b), + None => match s.as_str() { + "True" => BoolLit(true), + "False" => BoolLit(false), + "Type" => Const(Const::Type), + "Kind" => Const(Const::Kind), + "Sort" => Const(Const::Sort), + _ => Err(DecodeError::WrongFormatError("builtin".to_owned()))?, + }, + }, + U64(n) => Var(V(Label::from("_"), *n as usize)), + F64(x) => DoubleLit((*x).into()), + Bool(b) => BoolLit(*b), + Array(vec) => match vec.as_slice() { + [String(l), U64(n)] => { + if l.as_str() == "_" { + Err(DecodeError::WrongFormatError( + "`_` variable was encoded incorrectly".to_owned(), + ))? + } + let l = Label::from(l.as_str()); + Var(V(l, *n as usize)) + } + [U64(0), f, args @ ..] => { + if args.is_empty() { + Err(DecodeError::WrongFormatError( + "Function application must have at least one argument" + .to_owned(), + ))? + } + let mut f = cbor_value_to_dhall(&f)?; + for a in args { + let a = cbor_value_to_dhall(&a)?; + f = rc(App(f, a)) + } + return Ok(f); + } + [U64(1), x, y] => { + let x = cbor_value_to_dhall(&x)?; + let y = cbor_value_to_dhall(&y)?; + Lam(Label::from("_"), x, y) + } + [U64(1), String(l), x, y] => { + if l.as_str() == "_" { + Err(DecodeError::WrongFormatError( + "`_` variable was encoded incorrectly".to_owned(), + ))? + } + let x = cbor_value_to_dhall(&x)?; + let y = cbor_value_to_dhall(&y)?; + let l = Label::from(l.as_str()); + Lam(l, x, y) + } + [U64(2), x, y] => { + let x = cbor_value_to_dhall(&x)?; + let y = cbor_value_to_dhall(&y)?; + Pi(Label::from("_"), x, y) + } + [U64(2), String(l), x, y] => { + if l.as_str() == "_" { + Err(DecodeError::WrongFormatError( + "`_` variable was encoded incorrectly".to_owned(), + ))? + } + let x = cbor_value_to_dhall(&x)?; + let y = cbor_value_to_dhall(&y)?; + let l = Label::from(l.as_str()); + Pi(l, x, y) + } + [U64(3), U64(n), x, y] => { + let x = cbor_value_to_dhall(&x)?; + let y = cbor_value_to_dhall(&y)?; + use BinOp::*; + let op = match n { + 0 => BoolOr, + 1 => BoolAnd, + 2 => BoolEQ, + 3 => BoolNE, + 4 => NaturalPlus, + 5 => NaturalTimes, + 6 => TextAppend, + 7 => ListAppend, + 8 => RecursiveRecordMerge, + 9 => RightBiasedRecordMerge, + 10 => RecursiveRecordTypeMerge, + 11 => ImportAlt, + 12 => Equivalence, + _ => { + Err(DecodeError::WrongFormatError("binop".to_owned()))? + } + }; + BinOp(op, x, y) + } + [U64(4), t] => { + let t = cbor_value_to_dhall(&t)?; + EmptyListLit(rc(App(rc(ExprF::Builtin(Builtin::List)), t))) + } + [U64(4), Null, rest @ ..] => { + let rest = rest + .iter() + .map(cbor_value_to_dhall) + .collect::, _>>()?; + NEListLit(rest) + } + [U64(5), Null, x] => { + let x = cbor_value_to_dhall(&x)?; + SomeLit(x) + } + // Old-style optional literals + [U64(5), t] => { + let t = cbor_value_to_dhall(&t)?; + App(rc(ExprF::Builtin(Builtin::OptionalNone)), t) + } + [U64(5), t, x] => { + let x = cbor_value_to_dhall(&x)?; + let t = cbor_value_to_dhall(&t)?; + Annot( + rc(SomeLit(x)), + rc(App(rc(ExprF::Builtin(Builtin::Optional)), t)), + ) + } + [U64(6), x, y] => { + let x = cbor_value_to_dhall(&x)?; + let y = cbor_value_to_dhall(&y)?; + Merge(x, y, None) + } + [U64(6), x, y, z] => { + let x = cbor_value_to_dhall(&x)?; + let y = cbor_value_to_dhall(&y)?; + let z = cbor_value_to_dhall(&z)?; + Merge(x, y, Some(z)) + } + [U64(7), Object(map)] => { + let map = cbor_map_to_dhall_map(map)?; + RecordType(map) + } + [U64(8), Object(map)] => { + let map = cbor_map_to_dhall_map(map)?; + RecordLit(map) + } + [U64(9), x, String(l)] => { + let x = cbor_value_to_dhall(&x)?; + let l = Label::from(l.as_str()); + Field(x, l) + } + [U64(10), x, Array(arr)] => { + let x = cbor_value_to_dhall(&x)?; + if let [y] = arr.as_slice() { + let y = cbor_value_to_dhall(&y)?; + ProjectionByExpr(x, y) + } else { + Err(DecodeError::WrongFormatError( + "projection-by-expr".to_owned(), + ))? + } + } + [U64(10), x, rest @ ..] => { + let x = cbor_value_to_dhall(&x)?; + let labels = rest + .iter() + .map(|s| match s { + String(s) => Ok(Label::from(s.as_str())), + _ => Err(DecodeError::WrongFormatError( + "projection".to_owned(), + )), + }) + .collect::>()?; + Projection(x, labels) + } + [U64(11), Object(map)] => { + let map = cbor_map_to_dhall_opt_map(map)?; + UnionType(map) + } + [U64(12), ..] => Err(DecodeError::WrongFormatError( + "Union literals are not supported anymore".to_owned(), + ))?, + [U64(14), x, y, z] => { + let x = cbor_value_to_dhall(&x)?; + let y = cbor_value_to_dhall(&y)?; + let z = cbor_value_to_dhall(&z)?; + BoolIf(x, y, z) + } + [U64(15), U64(x)] => NaturalLit(*x as Natural), + [U64(16), U64(x)] => IntegerLit(*x as Integer), + [U64(16), I64(x)] => IntegerLit(*x as Integer), + [U64(18), String(first), rest @ ..] => { + TextLit(InterpolatedText::from(( + first.clone(), + rest.iter() + .tuples() + .map(|(x, y)| { + let x = cbor_value_to_dhall(&x)?; + let y = match y { + String(s) => s.clone(), + _ => Err(DecodeError::WrongFormatError( + "text".to_owned(), + ))?, + }; + Ok((x, y)) + }) + .collect::>()?, + ))) + } + [U64(19), t] => { + let t = cbor_value_to_dhall(&t)?; + Assert(t) + } + [U64(24), hash, U64(mode), U64(scheme), rest @ ..] => { + let mode = match mode { + 0 => ImportMode::Code, + 1 => ImportMode::RawText, + 2 => ImportMode::Location, + _ => Err(DecodeError::WrongFormatError(format!( + "import/mode/unknown_mode: {:?}", + mode + )))?, + }; + let hash = match hash { + Null => None, + Bytes(bytes) => match bytes.as_slice() { + [18, 32, rest @ ..] => { + Some(Hash::SHA256(rest.to_vec())) + } + _ => Err(DecodeError::WrongFormatError(format!( + "import/hash/unknown_multihash: {:?}", + bytes + )))?, + }, + _ => Err(DecodeError::WrongFormatError( + "import/hash/should_be_bytes".to_owned(), + ))?, + }; + let mut rest = rest.iter(); + let location = match scheme { + 0 | 1 => { + let scheme = match scheme { + 0 => Scheme::HTTP, + _ => Scheme::HTTPS, + }; + let headers = match rest.next() { + Some(Null) => None, + Some(x) => { + let x = cbor_value_to_dhall(&x)?; + Some(x) + } + _ => Err(DecodeError::WrongFormatError( + "import/remote/headers".to_owned(), + ))?, + }; + let authority = match rest.next() { + Some(String(s)) => s.to_owned(), + _ => Err(DecodeError::WrongFormatError( + "import/remote/authority".to_owned(), + ))?, + }; + let query = match rest.next_back() { + Some(Null) => None, + Some(String(s)) => Some(s.to_owned()), + _ => Err(DecodeError::WrongFormatError( + "import/remote/query".to_owned(), + ))?, + }; + let file_path = rest + .map(|s| match s.as_string() { + Some(s) => Ok(s.clone()), + None => Err(DecodeError::WrongFormatError( + "import/remote/path".to_owned(), + )), + }) + .collect::>()?; + let path = FilePath { file_path }; + ImportLocation::Remote(URL { + scheme, + authority, + path, + query, + headers, + }) + } + 2 | 3 | 4 | 5 => { + let prefix = match scheme { + 2 => FilePrefix::Absolute, + 3 => FilePrefix::Here, + 4 => FilePrefix::Parent, + 5 => FilePrefix::Home, + _ => Err(DecodeError::WrongFormatError( + "import/local/prefix".to_owned(), + ))?, + }; + let file_path = rest + .map(|s| match s.as_string() { + Some(s) => Ok(s.clone()), + None => Err(DecodeError::WrongFormatError( + "import/local/path".to_owned(), + )), + }) + .collect::>()?; + let path = FilePath { file_path }; + ImportLocation::Local(prefix, path) + } + 6 => { + let env = match rest.next() { + Some(String(s)) => s.to_owned(), + _ => Err(DecodeError::WrongFormatError( + "import/env".to_owned(), + ))?, + }; + ImportLocation::Env(env) + } + 7 => ImportLocation::Missing, + _ => Err(DecodeError::WrongFormatError( + "import/type".to_owned(), + ))?, + }; + Import(syntax::Import { + mode, + hash, + location, + }) + } + [U64(25), bindings @ ..] => { + let mut tuples = bindings.iter().tuples(); + let bindings = (&mut tuples) + .map(|(x, t, v)| { + let x = x.as_string().ok_or_else(|| { + DecodeError::WrongFormatError( + "let/label".to_owned(), + ) + })?; + let x = Label::from(x.as_str()); + let t = match t { + Null => None, + t => Some(cbor_value_to_dhall(&t)?), + }; + let v = cbor_value_to_dhall(&v)?; + Ok((x, t, v)) + }) + .collect::, _>>()?; + let expr = tuples.into_buffer().next().ok_or_else(|| { + DecodeError::WrongFormatError("let/expr".to_owned()) + })?; + let expr = cbor_value_to_dhall(expr)?; + return Ok(bindings + .into_iter() + .rev() + .fold(expr, |acc, (x, t, v)| rc(Let(x, t, v, acc)))); + } + [U64(26), x, y] => { + let x = cbor_value_to_dhall(&x)?; + let y = cbor_value_to_dhall(&y)?; + Annot(x, y) + } + [U64(27), x] => { + let x = cbor_value_to_dhall(&x)?; + ToMap(x, None) + } + [U64(27), x, y] => { + let x = cbor_value_to_dhall(&x)?; + let y = cbor_value_to_dhall(&y)?; + ToMap(x, Some(y)) + } + [U64(28), x] => { + let x = cbor_value_to_dhall(&x)?; + EmptyListLit(x) + } + _ => Err(DecodeError::WrongFormatError(format!("{:?}", data)))?, + }, + _ => Err(DecodeError::WrongFormatError(format!("{:?}", data)))?, + })) +} + +fn cbor_map_to_dhall_map<'a, T>( + map: impl IntoIterator, +) -> Result +where + T: FromIterator<(Label, DecodedExpr)>, +{ + map.into_iter() + .map(|(k, v)| -> Result<(_, _), _> { + let k = k.as_string().ok_or_else(|| { + DecodeError::WrongFormatError("map/key".to_owned()) + })?; + let v = cbor_value_to_dhall(v)?; + Ok((Label::from(k.as_ref()), v)) + }) + .collect::>() +} + +fn cbor_map_to_dhall_opt_map<'a, T>( + map: impl IntoIterator, +) -> Result +where + T: FromIterator<(Label, Option)>, +{ + map.into_iter() + .map(|(k, v)| -> Result<(_, _), _> { + let k = k.as_string().ok_or_else(|| { + DecodeError::WrongFormatError("map/key".to_owned()) + })?; + let v = match v { + cbor::Value::Null => None, + _ => Some(cbor_value_to_dhall(v)?), + }; + Ok((Label::from(k.as_ref()), v)) + }) + .collect::>() +} -- cgit v1.2.3