From 52f9ecfc4dac65d305fd920e8c7f748889a0804f Mon Sep 17 00:00:00 2001 From: Nadrieril Date: Mon, 12 Aug 2019 23:24:48 +0200 Subject: Move api into its own crate --- serde_dhall/src/lib.rs | 264 +++++++++++++++++++++++++++++++++++++++++ serde_dhall/src/serde.rs | 70 +++++++++++ serde_dhall/src/static_type.rs | 93 +++++++++++++++ 3 files changed, 427 insertions(+) create mode 100644 serde_dhall/src/lib.rs create mode 100644 serde_dhall/src/serde.rs create mode 100644 serde_dhall/src/static_type.rs (limited to 'serde_dhall/src') diff --git a/serde_dhall/src/lib.rs b/serde_dhall/src/lib.rs new file mode 100644 index 0000000..1dbbf99 --- /dev/null +++ b/serde_dhall/src/lib.rs @@ -0,0 +1,264 @@ +//! [Dhall][dhall] is a programmable configuration language that provides a non-repetitive +//! alternative to JSON and YAML. +//! +//! You can think of Dhall as: JSON + types + imports + functions +//! +//! For a description of the dhall language, examples, tutorials, and more, see the [language +//! website][dhall]. +//! +//! This crate provides support for consuming dhall files the same way you would consume JSON or +//! YAML. It uses the [Serde][serde] serialization library to provide drop-in support for dhall +//! for any datatype that supports serde (and that's a lot of them !). +//! +//! This library is limited to deserializing (reading) dhall values; serializing (writing) +//! values to dhall is not supported for now. +//! +//! # Examples +//! +//! ### Custom datatype +//! +//! If you have a custom datatype for which you derived [serde::Deserialize], chances are +//! you will be able to derive [StaticType][de::StaticType] for it as well. +//! This gives you access to a dhall representation of your datatype that can be outputted +//! to users, and allows easy type-safe deserializing. +//! +//! ```edition2018 +//! use serde::Deserialize; +//! use serde_dhall::de::StaticType; +//! +//! #[derive(Debug, Deserialize, StaticType)] +//! struct Point { +//! x: u64, +//! y: u64, +//! } +//! +//! fn main() { +//! // Some dhall data +//! let data = "{ x = 1, y = 1 + 1 }"; +//! +//! // Convert the dhall string to a Point. +//! let point: Point = +//! serde_dhall::de::from_str_auto_type(&data) +//! .expect("An error ocurred !"); +//! +//! // Prints "point = Point { x: 1, y: 2 }" +//! println!("point = {:?}", point); +//! } +//! ``` +//! +//! ### Loosely typed +//! +//! If you used to consume JSON or YAML in a loosely typed way, you can continue to do so +//! with dhall. You only need to replace [serde_json::from_str] or [serde_yaml::from_str] +//! with [serde_dhall::de::from_str][de::from_str]. +//! More generally, if the [StaticType][de::StaticType] derive doesn't suit your +//! needs, you can still deserialize any valid dhall file that serde can handle. +//! +//! [serde_json::from_str]: https://docs.serde.rs/serde_json/de/fn.from_str.html +//! [serde_yaml::from_str]: https://docs.serde.rs/serde_yaml/fn.from_str.html +//! +//! ```edition2018 +//! use std::collections::BTreeMap; +//! +//! let mut map = BTreeMap::new(); +//! map.insert("x".to_string(), 1); +//! map.insert("y".to_string(), 2); +//! +//! // Some dhall data +//! let data = "{ x = 1, y = 1 + 1 } : { x: Natural, y: Natural }"; +//! +//! // Deserialize it to a Rust type. +//! let deserialized_map: BTreeMap = +//! serde_dhall::de::from_str(&data, None) +//! .expect("Failed reading the data !"); +//! assert_eq!(map, deserialized_map); +//! ``` +//! +//! You can of course specify a dhall type that the input should match. +//! +//! ```edition2018 +//! use std::collections::BTreeMap; +//! +//! let mut map = BTreeMap::new(); +//! map.insert("x".to_string(), 1); +//! map.insert("y".to_string(), 2); +//! +//! // Some dhall data +//! let point_data = "{ x = 1, y = 1 + 1 }"; +//! let point_type_data = "{ x: Natural, y: Natural }"; +//! +//! // Construct a type +//! let point_type = +//! serde_dhall::de::from_str(point_type_data, None) +//! .expect("Could not parse the Point type"); +//! +//! // Deserialize it to a Rust type. +//! let deserialized_map: BTreeMap = +//! serde_dhall::de::from_str(&point_data, Some(&point_type)) +//! .expect("Failed reading the data !"); +//! assert_eq!(map, deserialized_map); +//! ``` +//! +//! [dhall]: https://dhall-lang.org/ +//! [serde]: https://docs.serde.rs/serde/ +//! [serde::Deserialize]: https://docs.serde.rs/serde/trait.Deserialize.html + +mod serde; +pub(crate) mod static_type; + +pub use value::Value; + +mod value { + use super::Type; + use dhall::error::Result; + use dhall::phase::{NormalizedSubExpr, Parsed, Typed}; + + // A Dhall value + pub struct Value(Typed); + + impl Value { + pub fn from_str(s: &str, ty: Option<&Type>) -> Result { + let resolved = Parsed::parse_str(s)?.resolve()?; + let typed = match ty { + None => resolved.typecheck()?, + Some(t) => resolved.typecheck_with(&t.to_type())?, + }; + Ok(Value(typed)) + } + pub(crate) fn to_expr(&self) -> NormalizedSubExpr { + self.0.to_expr() + } + pub(crate) fn to_typed(&self) -> Typed { + self.0.clone() + } + } +} + +pub use typ::Type; + +mod typ { + use dhall_syntax::Builtin; + + use dhall::core::thunk::{Thunk, TypeThunk}; + use dhall::core::value::Value; + use dhall::error::Result; + use dhall::phase::{NormalizedSubExpr, Typed}; + + /// A Dhall expression representing a type. + /// + /// This captures what is usually simply called a "type", like + /// `Bool`, `{ x: Integer }` or `Natural -> Text`. + #[derive(Debug, Clone, PartialEq, Eq)] + pub struct Type(Typed); + + impl Type { + pub(crate) fn from_value(v: Value) -> Self { + Type(Typed::from_value_untyped(v)) + } + pub(crate) fn make_builtin_type(b: Builtin) -> Self { + Self::from_value(Value::from_builtin(b)) + } + pub(crate) fn make_optional_type(t: Type) -> Self { + Self::from_value(Value::AppliedBuiltin( + Builtin::Optional, + vec![t.to_thunk()], + )) + } + pub(crate) fn make_list_type(t: Type) -> Self { + Self::from_value(Value::AppliedBuiltin( + Builtin::List, + vec![t.to_thunk()], + )) + } + #[doc(hidden)] + pub fn make_record_type( + kts: impl Iterator, + ) -> Self { + Self::from_value(Value::RecordType( + kts.map(|(k, t)| { + (k.into(), TypeThunk::from_thunk(t.to_thunk())) + }) + .collect(), + )) + } + #[doc(hidden)] + pub fn make_union_type( + kts: impl Iterator)>, + ) -> Self { + Self::from_value(Value::UnionType( + kts.map(|(k, t)| { + (k.into(), t.map(|t| TypeThunk::from_thunk(t.to_thunk()))) + }) + .collect(), + )) + } + + pub(crate) fn to_thunk(&self) -> Thunk { + self.0.to_thunk() + } + #[allow(dead_code)] + pub(crate) fn to_expr(&self) -> NormalizedSubExpr { + self.0.to_expr() + } + pub(crate) fn to_type(&self) -> dhall::phase::Type { + self.0.to_type() + } + } + + impl crate::de::Deserialize for Type { + fn from_dhall(v: &super::Value) -> Result { + Ok(Type(v.to_typed())) + } + } +} + +/// Deserialization of Dhall expressions into Rust +pub mod de { + pub use super::static_type::StaticType; + pub use super::{Type, Value}; + use dhall::error::Result; + #[doc(hidden)] + pub use dhall_proc_macros::StaticType; + + /// A data structure that can be deserialized from a Dhall expression + /// + /// This is automatically implemented for any type that [serde][serde] + /// can deserialize. + /// + /// This trait cannot be implemented manually. + // TODO: seal trait + pub trait Deserialize: Sized { + /// See [dhall::de::from_str][crate::de::from_str] + fn from_dhall(v: &Value) -> Result; + } + + /// Deserialize an instance of type T from a string of Dhall text. + /// + /// This will recursively resolve all imports in the expression, and + /// typecheck it before deserialization. Relative imports will be resolved relative to the + /// provided file. More control over this process is not yet available + /// but will be in a coming version of this crate. + /// + /// If a type is provided, this additionally checks that the provided + /// expression has that type. + pub fn from_str(s: &str, ty: Option<&Type>) -> Result + where + T: Deserialize, + { + T::from_dhall(&Value::from_str(s, ty)?) + } + + /// Deserialize an instance of type T from a string of Dhall text, + /// additionally checking that it matches the type of T. + /// + /// This will recursively resolve all imports in the expression, and + /// typecheck it before deserialization. Relative imports will be resolved relative to the + /// provided file. More control over this process is not yet available + /// but will be in a coming version of this crate. + pub fn from_str_auto_type(s: &str) -> Result + where + T: Deserialize + StaticType, + { + from_str(s, Some(&::static_type())) + } +} diff --git a/serde_dhall/src/serde.rs b/serde_dhall/src/serde.rs new file mode 100644 index 0000000..3dad2d8 --- /dev/null +++ b/serde_dhall/src/serde.rs @@ -0,0 +1,70 @@ +use crate::de::{Deserialize, Value}; +use dhall::error::{Error, Result}; +use dhall_syntax::{ExprF, SubExpr, X}; +use std::borrow::Cow; + +impl<'a, T> Deserialize for T +where + T: serde::Deserialize<'a>, +{ + fn from_dhall(v: &Value) -> Result { + T::deserialize(Deserializer(Cow::Owned(v.to_expr()))) + } +} + +struct Deserializer<'a>(Cow<'a, SubExpr>); + +// impl serde::de::Error for Error { +// fn custom(msg: T) -> Self +// where +// T: std::fmt::Display, +// { +// Error::Deserialize(msg.to_string()) +// } +// } + +impl<'de: 'a, 'a> serde::de::IntoDeserializer<'de, Error> for Deserializer<'a> { + type Deserializer = Deserializer<'a>; + fn into_deserializer(self) -> Self::Deserializer { + self + } +} + +impl<'de: 'a, 'a> serde::Deserializer<'de> for Deserializer<'a> { + type Error = Error; + fn deserialize_any(self, visitor: V) -> Result + where + V: serde::de::Visitor<'de>, + { + use std::convert::TryInto; + use ExprF::*; + match self.0.as_ref().as_ref() { + NaturalLit(n) => match (*n).try_into() { + Ok(n64) => visitor.visit_u64(n64), + Err(_) => match (*n).try_into() { + Ok(n32) => visitor.visit_u32(n32), + Err(_) => unimplemented!(), + }, + }, + IntegerLit(n) => match (*n).try_into() { + Ok(n64) => visitor.visit_i64(n64), + Err(_) => match (*n).try_into() { + Ok(n32) => visitor.visit_i32(n32), + Err(_) => unimplemented!(), + }, + }, + RecordLit(m) => visitor.visit_map( + serde::de::value::MapDeserializer::new(m.iter().map( + |(k, v)| (k.as_ref(), Deserializer(Cow::Borrowed(v))), + )), + ), + _ => unimplemented!(), + } + } + + serde::forward_to_deserialize_any! { + bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string + bytes byte_buf option unit unit_struct newtype_struct seq tuple + tuple_struct map struct enum identifier ignored_any + } +} diff --git a/serde_dhall/src/static_type.rs b/serde_dhall/src/static_type.rs new file mode 100644 index 0000000..13d5d70 --- /dev/null +++ b/serde_dhall/src/static_type.rs @@ -0,0 +1,93 @@ +use dhall_syntax::{Builtin, Integer, Natural}; + +use crate::Type; + +/// A Rust type that can be represented as a Dhall type. +/// +/// A typical example is `Option`, +/// represented by the dhall expression `Optional Bool`. +/// +/// This trait can and should be automatically derived. +/// +/// The representation needs to be independent of the value. +/// For this reason, something like `HashMap` cannot implement +/// [StaticType] because each different value would +/// have a different Dhall record type. +pub trait StaticType { + fn static_type() -> Type; +} + +macro_rules! derive_builtin { + ($ty:ty, $builtin:ident) => { + impl StaticType for $ty { + fn static_type() -> Type { + Type::make_builtin_type(Builtin::$builtin) + } + } + }; +} + +derive_builtin!(bool, Bool); +derive_builtin!(Natural, Natural); +derive_builtin!(u64, Natural); +derive_builtin!(Integer, Integer); +derive_builtin!(String, Text); + +impl StaticType for (A, B) +where + A: StaticType, + B: StaticType, +{ + fn static_type() -> Type { + Type::make_record_type( + vec![ + ("_1".to_owned(), A::static_type()), + ("_2".to_owned(), B::static_type()), + ] + .into_iter(), + ) + } +} + +impl StaticType for std::result::Result +where + T: StaticType, + E: StaticType, +{ + fn static_type() -> Type { + Type::make_union_type( + vec![ + ("Ok".to_owned(), Some(T::static_type())), + ("Err".to_owned(), Some(E::static_type())), + ] + .into_iter(), + ) + } +} + +impl StaticType for Option +where + T: StaticType, +{ + fn static_type() -> Type { + Type::make_optional_type(T::static_type()) + } +} + +impl StaticType for Vec +where + T: StaticType, +{ + fn static_type() -> Type { + Type::make_list_type(T::static_type()) + } +} + +impl<'a, T> StaticType for &'a T +where + T: StaticType, +{ + fn static_type() -> Type { + T::static_type() + } +} -- cgit v1.2.3 From 74bb40e88c71b80ab785f07fd19da22404ab6e95 Mon Sep 17 00:00:00 2001 From: Nadrieril Date: Tue, 13 Aug 2019 15:11:31 +0200 Subject: Add new error type for serde_dhall --- serde_dhall/src/lib.rs | 58 +++++++++++++++++++++++++++++++++++++++++------- serde_dhall/src/serde.rs | 12 +--------- 2 files changed, 51 insertions(+), 19 deletions(-) (limited to 'serde_dhall/src') diff --git a/serde_dhall/src/lib.rs b/serde_dhall/src/lib.rs index 1dbbf99..f8f9ae9 100644 --- a/serde_dhall/src/lib.rs +++ b/serde_dhall/src/lib.rs @@ -1,3 +1,5 @@ +#![feature(non_exhaustive)] + //! [Dhall][dhall] is a programmable configuration language that provides a non-repetitive //! alternative to JSON and YAML. //! @@ -109,8 +111,8 @@ pub(crate) mod static_type; pub use value::Value; mod value { + use super::de::{Error, Result}; use super::Type; - use dhall::error::Result; use dhall::phase::{NormalizedSubExpr, Parsed, Typed}; // A Dhall value @@ -118,6 +120,12 @@ mod value { impl Value { pub fn from_str(s: &str, ty: Option<&Type>) -> Result { + Value::from_str_using_dhall_error_type(s, ty).map_err(Error::Dhall) + } + fn from_str_using_dhall_error_type( + s: &str, + ty: Option<&Type>, + ) -> dhall::error::Result { let resolved = Parsed::parse_str(s)?.resolve()?; let typed = match ty { None => resolved.typecheck()?, @@ -137,12 +145,12 @@ mod value { pub use typ::Type; mod typ { - use dhall_syntax::Builtin; - use dhall::core::thunk::{Thunk, TypeThunk}; use dhall::core::value::Value; - use dhall::error::Result; use dhall::phase::{NormalizedSubExpr, Typed}; + use dhall_syntax::Builtin; + + use super::de::Result; /// A Dhall expression representing a type. /// @@ -205,21 +213,55 @@ mod typ { } } - impl crate::de::Deserialize for Type { + impl super::de::Deserialize for Type { fn from_dhall(v: &super::Value) -> Result { Ok(Type(v.to_typed())) } } } +mod error { + use dhall::error::Error as DhallError; + + pub type Result = std::result::Result; + + #[derive(Debug)] + #[non_exhaustive] + pub enum Error { + Dhall(DhallError), + Deserialize(String), + } + + impl std::fmt::Display for Error { + fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result { + match self { + Error::Dhall(err) => write!(f, "{}", err), + Error::Deserialize(err) => write!(f, "{}", err), + } + } + } + + impl std::error::Error for Error {} + + impl serde::de::Error for Error { + fn custom(msg: T) -> Self + where + T: std::fmt::Display, + { + Error::Deserialize(msg.to_string()) + } + } +} + /// Deserialization of Dhall expressions into Rust pub mod de { - pub use super::static_type::StaticType; - pub use super::{Type, Value}; - use dhall::error::Result; #[doc(hidden)] pub use dhall_proc_macros::StaticType; + pub use super::error::{Error, Result}; + pub use super::static_type::StaticType; + pub use super::{Type, Value}; + /// A data structure that can be deserialized from a Dhall expression /// /// This is automatically implemented for any type that [serde][serde] diff --git a/serde_dhall/src/serde.rs b/serde_dhall/src/serde.rs index 3dad2d8..1f639e6 100644 --- a/serde_dhall/src/serde.rs +++ b/serde_dhall/src/serde.rs @@ -1,5 +1,4 @@ -use crate::de::{Deserialize, Value}; -use dhall::error::{Error, Result}; +use crate::de::{Deserialize, Error, Result, Value}; use dhall_syntax::{ExprF, SubExpr, X}; use std::borrow::Cow; @@ -14,15 +13,6 @@ where struct Deserializer<'a>(Cow<'a, SubExpr>); -// impl serde::de::Error for Error { -// fn custom(msg: T) -> Self -// where -// T: std::fmt::Display, -// { -// Error::Deserialize(msg.to_string()) -// } -// } - impl<'de: 'a, 'a> serde::de::IntoDeserializer<'de, Error> for Deserializer<'a> { type Deserializer = Deserializer<'a>; fn into_deserializer(self) -> Self::Deserializer { -- cgit v1.2.3 From 1ea8b10051d29c634399304273d6ee565d039bc2 Mon Sep 17 00:00:00 2001 From: Nadrieril Date: Tue, 13 Aug 2019 15:25:53 +0200 Subject: Merge `Type` and `Value` in serde_dhall There was no point in separating them --- serde_dhall/src/lib.rs | 87 ++++++++++++++++-------------------------- serde_dhall/src/static_type.rs | 26 ++++++------- 2 files changed, 45 insertions(+), 68 deletions(-) (limited to 'serde_dhall/src') diff --git a/serde_dhall/src/lib.rs b/serde_dhall/src/lib.rs index f8f9ae9..8e1af82 100644 --- a/serde_dhall/src/lib.rs +++ b/serde_dhall/src/lib.rs @@ -106,25 +106,29 @@ //! [serde::Deserialize]: https://docs.serde.rs/serde/trait.Deserialize.html mod serde; -pub(crate) mod static_type; +mod static_type; pub use value::Value; mod value { + use dhall::core::thunk::{Thunk, TypeThunk}; + use dhall::core::value::Value as DhallValue; + use dhall::phase::{NormalizedSubExpr, Parsed, Type, Typed}; + use dhall_syntax::Builtin; + use super::de::{Error, Result}; - use super::Type; - use dhall::phase::{NormalizedSubExpr, Parsed, Typed}; - // A Dhall value + /// A Dhall value + #[derive(Debug, Clone, PartialEq, Eq)] pub struct Value(Typed); impl Value { - pub fn from_str(s: &str, ty: Option<&Type>) -> Result { + pub fn from_str(s: &str, ty: Option<&Value>) -> Result { Value::from_str_using_dhall_error_type(s, ty).map_err(Error::Dhall) } fn from_str_using_dhall_error_type( s: &str, - ty: Option<&Type>, + ty: Option<&Value>, ) -> dhall::error::Result { let resolved = Parsed::parse_str(s)?.resolve()?; let typed = match ty { @@ -136,53 +140,37 @@ mod value { pub(crate) fn to_expr(&self) -> NormalizedSubExpr { self.0.to_expr() } - pub(crate) fn to_typed(&self) -> Typed { - self.0.clone() + pub(crate) fn to_thunk(&self) -> Thunk { + self.0.to_thunk() + } + pub(crate) fn to_type(&self) -> Type { + self.0.to_type() } - } -} - -pub use typ::Type; - -mod typ { - use dhall::core::thunk::{Thunk, TypeThunk}; - use dhall::core::value::Value; - use dhall::phase::{NormalizedSubExpr, Typed}; - use dhall_syntax::Builtin; - - use super::de::Result; - - /// A Dhall expression representing a type. - /// - /// This captures what is usually simply called a "type", like - /// `Bool`, `{ x: Integer }` or `Natural -> Text`. - #[derive(Debug, Clone, PartialEq, Eq)] - pub struct Type(Typed); - impl Type { - pub(crate) fn from_value(v: Value) -> Self { - Type(Typed::from_value_untyped(v)) + pub(crate) fn from_dhall_value(v: DhallValue) -> Self { + Value(Typed::from_value_untyped(v)) } pub(crate) fn make_builtin_type(b: Builtin) -> Self { - Self::from_value(Value::from_builtin(b)) + Self::from_dhall_value(DhallValue::from_builtin(b)) } - pub(crate) fn make_optional_type(t: Type) -> Self { - Self::from_value(Value::AppliedBuiltin( + pub(crate) fn make_optional_type(t: Value) -> Self { + Self::from_dhall_value(DhallValue::AppliedBuiltin( Builtin::Optional, vec![t.to_thunk()], )) } - pub(crate) fn make_list_type(t: Type) -> Self { - Self::from_value(Value::AppliedBuiltin( + pub(crate) fn make_list_type(t: Value) -> Self { + Self::from_dhall_value(DhallValue::AppliedBuiltin( Builtin::List, vec![t.to_thunk()], )) } + // Made public for the StaticType derive macro #[doc(hidden)] pub fn make_record_type( - kts: impl Iterator, + kts: impl Iterator, ) -> Self { - Self::from_value(Value::RecordType( + Self::from_dhall_value(DhallValue::RecordType( kts.map(|(k, t)| { (k.into(), TypeThunk::from_thunk(t.to_thunk())) }) @@ -191,31 +179,20 @@ mod typ { } #[doc(hidden)] pub fn make_union_type( - kts: impl Iterator)>, + kts: impl Iterator)>, ) -> Self { - Self::from_value(Value::UnionType( + Self::from_dhall_value(DhallValue::UnionType( kts.map(|(k, t)| { (k.into(), t.map(|t| TypeThunk::from_thunk(t.to_thunk()))) }) .collect(), )) } - - pub(crate) fn to_thunk(&self) -> Thunk { - self.0.to_thunk() - } - #[allow(dead_code)] - pub(crate) fn to_expr(&self) -> NormalizedSubExpr { - self.0.to_expr() - } - pub(crate) fn to_type(&self) -> dhall::phase::Type { - self.0.to_type() - } } - impl super::de::Deserialize for Type { - fn from_dhall(v: &super::Value) -> Result { - Ok(Type(v.to_typed())) + impl super::de::Deserialize for Value { + fn from_dhall(v: &Value) -> Result { + Ok(v.clone()) } } } @@ -260,7 +237,7 @@ pub mod de { pub use super::error::{Error, Result}; pub use super::static_type::StaticType; - pub use super::{Type, Value}; + pub use super::Value; /// A data structure that can be deserialized from a Dhall expression /// @@ -283,7 +260,7 @@ pub mod de { /// /// If a type is provided, this additionally checks that the provided /// expression has that type. - pub fn from_str(s: &str, ty: Option<&Type>) -> Result + pub fn from_str(s: &str, ty: Option<&Value>) -> Result where T: Deserialize, { diff --git a/serde_dhall/src/static_type.rs b/serde_dhall/src/static_type.rs index 13d5d70..67a7bc4 100644 --- a/serde_dhall/src/static_type.rs +++ b/serde_dhall/src/static_type.rs @@ -1,6 +1,6 @@ use dhall_syntax::{Builtin, Integer, Natural}; -use crate::Type; +use crate::Value; /// A Rust type that can be represented as a Dhall type. /// @@ -14,14 +14,14 @@ use crate::Type; /// [StaticType] because each different value would /// have a different Dhall record type. pub trait StaticType { - fn static_type() -> Type; + fn static_type() -> Value; } macro_rules! derive_builtin { ($ty:ty, $builtin:ident) => { impl StaticType for $ty { - fn static_type() -> Type { - Type::make_builtin_type(Builtin::$builtin) + fn static_type() -> Value { + Value::make_builtin_type(Builtin::$builtin) } } }; @@ -38,8 +38,8 @@ where A: StaticType, B: StaticType, { - fn static_type() -> Type { - Type::make_record_type( + fn static_type() -> Value { + Value::make_record_type( vec![ ("_1".to_owned(), A::static_type()), ("_2".to_owned(), B::static_type()), @@ -54,8 +54,8 @@ where T: StaticType, E: StaticType, { - fn static_type() -> Type { - Type::make_union_type( + fn static_type() -> Value { + Value::make_union_type( vec![ ("Ok".to_owned(), Some(T::static_type())), ("Err".to_owned(), Some(E::static_type())), @@ -69,8 +69,8 @@ impl StaticType for Option where T: StaticType, { - fn static_type() -> Type { - Type::make_optional_type(T::static_type()) + fn static_type() -> Value { + Value::make_optional_type(T::static_type()) } } @@ -78,8 +78,8 @@ impl StaticType for Vec where T: StaticType, { - fn static_type() -> Type { - Type::make_list_type(T::static_type()) + fn static_type() -> Value { + Value::make_list_type(T::static_type()) } } @@ -87,7 +87,7 @@ impl<'a, T> StaticType for &'a T where T: StaticType, { - fn static_type() -> Type { + fn static_type() -> Value { T::static_type() } } -- cgit v1.2.3 From bf5d33f3ba991afe398d58fb4fed38ec72d6f4c7 Mon Sep 17 00:00:00 2001 From: Nadrieril Date: Tue, 13 Aug 2019 16:31:41 +0200 Subject: Rework API to resemble that of serde_json --- serde_dhall/src/lib.rs | 200 ++++++++++++++++++++++++++--------------------- serde_dhall/src/serde.rs | 3 +- 2 files changed, 111 insertions(+), 92 deletions(-) (limited to 'serde_dhall/src') diff --git a/serde_dhall/src/lib.rs b/serde_dhall/src/lib.rs index 8e1af82..19aabec 100644 --- a/serde_dhall/src/lib.rs +++ b/serde_dhall/src/lib.rs @@ -5,28 +5,27 @@ //! //! You can think of Dhall as: JSON + types + imports + functions //! -//! For a description of the dhall language, examples, tutorials, and more, see the [language +//! For a description of the Dhall language, examples, tutorials, and more, see the [language //! website][dhall]. //! -//! This crate provides support for consuming dhall files the same way you would consume JSON or -//! YAML. It uses the [Serde][serde] serialization library to provide drop-in support for dhall +//! This crate provides support for consuming Dhall files the same way you would consume JSON or +//! YAML. It uses the [Serde][serde] serialization library to provide drop-in support for Dhall //! for any datatype that supports serde (and that's a lot of them !). //! -//! This library is limited to deserializing (reading) dhall values; serializing (writing) -//! values to dhall is not supported for now. +//! This library is limited to deserializing (reading) Dhall values; serializing (writing) +//! values to Dhall is not supported for now. //! //! # Examples //! //! ### Custom datatype //! //! If you have a custom datatype for which you derived [serde::Deserialize], chances are -//! you will be able to derive [StaticType][de::StaticType] for it as well. -//! This gives you access to a dhall representation of your datatype that can be outputted -//! to users, and allows easy type-safe deserializing. +//! you will be able to derive [StaticType] for it as well. +//! This allows easy type-safe deserializing. //! //! ```edition2018 //! use serde::Deserialize; -//! use serde_dhall::de::StaticType; +//! use serde_dhall::{de::Error, StaticType}; //! //! #[derive(Debug, Deserialize, StaticType)] //! struct Point { @@ -34,71 +33,78 @@ //! y: u64, //! } //! -//! fn main() { -//! // Some dhall data +//! fn main() -> Result<(), Error> { +//! // Some Dhall data //! let data = "{ x = 1, y = 1 + 1 }"; //! -//! // Convert the dhall string to a Point. -//! let point: Point = -//! serde_dhall::de::from_str_auto_type(&data) -//! .expect("An error ocurred !"); +//! // Convert the Dhall string to a Point. +//! let point: Point = serde_dhall::from_str_auto_type(data)?; +//! assert_eq!(point.x, 1); +//! assert_eq!(point.y, 2); //! -//! // Prints "point = Point { x: 1, y: 2 }" -//! println!("point = {:?}", point); +//! // Invalid data fails the type validation +//! let invalid_data = "{ x = 1, z = 0.3 }"; +//! assert!(serde_dhall::from_str_auto_type::(invalid_data).is_err()); +//! +//! Ok(()) //! } //! ``` //! //! ### Loosely typed //! //! If you used to consume JSON or YAML in a loosely typed way, you can continue to do so -//! with dhall. You only need to replace [serde_json::from_str] or [serde_yaml::from_str] -//! with [serde_dhall::de::from_str][de::from_str]. -//! More generally, if the [StaticType][de::StaticType] derive doesn't suit your -//! needs, you can still deserialize any valid dhall file that serde can handle. +//! with Dhall. You only need to replace [serde_json::from_str] or [serde_yaml::from_str] +//! with [serde_dhall::from_str][from_str]. +//! More generally, if the [StaticType] derive doesn't suit your +//! needs, you can still deserialize any valid Dhall file that serde can handle. //! //! [serde_json::from_str]: https://docs.serde.rs/serde_json/de/fn.from_str.html //! [serde_yaml::from_str]: https://docs.serde.rs/serde_yaml/fn.from_str.html //! //! ```edition2018 +//! # fn main() -> serde_dhall::de::Result<()> { //! use std::collections::BTreeMap; //! -//! let mut map = BTreeMap::new(); -//! map.insert("x".to_string(), 1); -//! map.insert("y".to_string(), 2); -//! -//! // Some dhall data +//! // Some Dhall data //! let data = "{ x = 1, y = 1 + 1 } : { x: Natural, y: Natural }"; //! //! // Deserialize it to a Rust type. -//! let deserialized_map: BTreeMap = -//! serde_dhall::de::from_str(&data, None) -//! .expect("Failed reading the data !"); -//! assert_eq!(map, deserialized_map); +//! let deserialized_map: BTreeMap = serde_dhall::from_str(data)?; +//! +//! let mut expected_map = BTreeMap::new(); +//! expected_map.insert("x".to_string(), 1); +//! expected_map.insert("y".to_string(), 2); +//! +//! assert_eq!(deserialized_map, expected_map); +//! # Ok(()) +//! # } //! ``` //! -//! You can of course specify a dhall type that the input should match. +//! You can alternatively specify a Dhall type that the input should match. //! //! ```edition2018 +//! # fn main() -> serde_dhall::de::Result<()> { //! use std::collections::BTreeMap; //! -//! let mut map = BTreeMap::new(); -//! map.insert("x".to_string(), 1); -//! map.insert("y".to_string(), 2); +//! // Parse a Dhall type +//! let point_type_str = "{ x: Natural, y: Natural }"; +//! let point_type = serde_dhall::from_str(point_type_str)?; //! -//! // Some dhall data +//! // Some Dhall data //! let point_data = "{ x = 1, y = 1 + 1 }"; -//! let point_type_data = "{ x: Natural, y: Natural }"; -//! -//! // Construct a type -//! let point_type = -//! serde_dhall::de::from_str(point_type_data, None) -//! .expect("Could not parse the Point type"); //! -//! // Deserialize it to a Rust type. +//! // Deserialize the data to a Rust type. This ensures that +//! // the data matches the point type. //! let deserialized_map: BTreeMap = -//! serde_dhall::de::from_str(&point_data, Some(&point_type)) -//! .expect("Failed reading the data !"); -//! assert_eq!(map, deserialized_map); +//! serde_dhall::from_str_check_type(point_data, &point_type)?; +//! +//! let mut expected_map = BTreeMap::new(); +//! expected_map.insert("x".to_string(), 1); +//! expected_map.insert("y".to_string(), 2); +//! +//! assert_eq!(deserialized_map, expected_map); +//! # Ok(()) +//! # } //! ``` //! //! [dhall]: https://dhall-lang.org/ @@ -108,9 +114,16 @@ mod serde; mod static_type; +#[doc(inline)] +pub use de::{from_str, from_str_auto_type, from_str_check_type}; +#[doc(hidden)] +pub use dhall_proc_macros::StaticType; +pub use static_type::StaticType; +#[doc(inline)] pub use value::Value; -mod value { +// A Dhall value. +pub mod value { use dhall::core::thunk::{Thunk, TypeThunk}; use dhall::core::value::Value as DhallValue; use dhall::phase::{NormalizedSubExpr, Parsed, Type, Typed}; @@ -197,47 +210,44 @@ mod value { } } -mod error { - use dhall::error::Error as DhallError; +/// Deserialize Dhall data to a Rust data structure. +pub mod de { + use super::StaticType; + use super::Value; + pub use error::{Error, Result}; - pub type Result = std::result::Result; + mod error { + use dhall::error::Error as DhallError; - #[derive(Debug)] - #[non_exhaustive] - pub enum Error { - Dhall(DhallError), - Deserialize(String), - } + pub type Result = std::result::Result; - impl std::fmt::Display for Error { - fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result { - match self { - Error::Dhall(err) => write!(f, "{}", err), - Error::Deserialize(err) => write!(f, "{}", err), + #[derive(Debug)] + #[non_exhaustive] + pub enum Error { + Dhall(DhallError), + Deserialize(String), + } + + impl std::fmt::Display for Error { + fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result { + match self { + Error::Dhall(err) => write!(f, "{}", err), + Error::Deserialize(err) => write!(f, "{}", err), + } } } - } - impl std::error::Error for Error {} + impl std::error::Error for Error {} - impl serde::de::Error for Error { - fn custom(msg: T) -> Self - where - T: std::fmt::Display, - { - Error::Deserialize(msg.to_string()) + impl serde::de::Error for Error { + fn custom(msg: T) -> Self + where + T: std::fmt::Display, + { + Error::Deserialize(msg.to_string()) + } } } -} - -/// Deserialization of Dhall expressions into Rust -pub mod de { - #[doc(hidden)] - pub use dhall_proc_macros::StaticType; - - pub use super::error::{Error, Result}; - pub use super::static_type::StaticType; - pub use super::Value; /// A data structure that can be deserialized from a Dhall expression /// @@ -247,37 +257,45 @@ pub mod de { /// This trait cannot be implemented manually. // TODO: seal trait pub trait Deserialize: Sized { - /// See [dhall::de::from_str][crate::de::from_str] + /// See [serde_dhall::from_str][crate::from_str] fn from_dhall(v: &Value) -> Result; } - /// Deserialize an instance of type T from a string of Dhall text. + /// Deserialize an instance of type `T` from a string of Dhall text. /// /// This will recursively resolve all imports in the expression, and /// typecheck it before deserialization. Relative imports will be resolved relative to the /// provided file. More control over this process is not yet available /// but will be in a coming version of this crate. + pub fn from_str(s: &str) -> Result + where + T: Deserialize, + { + T::from_dhall(&Value::from_str(s, None)?) + } + + /// Deserialize an instance of type `T` from a string of Dhall text, + /// additionally checking that it matches the supplied type. /// - /// If a type is provided, this additionally checks that the provided - /// expression has that type. - pub fn from_str(s: &str, ty: Option<&Value>) -> Result + /// Like [from_str], but this additionally checks that + /// the type of the provided expression matches the supplied type. + pub fn from_str_check_type(s: &str, ty: &Value) -> Result where T: Deserialize, { - T::from_dhall(&Value::from_str(s, ty)?) + T::from_dhall(&Value::from_str(s, Some(ty))?) } - /// Deserialize an instance of type T from a string of Dhall text, - /// additionally checking that it matches the type of T. + /// Deserialize an instance of type `T` from a string of Dhall text, + /// additionally checking that it matches the type of `T`. /// - /// This will recursively resolve all imports in the expression, and - /// typecheck it before deserialization. Relative imports will be resolved relative to the - /// provided file. More control over this process is not yet available - /// but will be in a coming version of this crate. + /// Like [from_str], but this additionally checks that + /// the type of the provided expression matches the output type `T`. The [StaticType] trait + /// captures Rust types that are valid Dhall types. pub fn from_str_auto_type(s: &str) -> Result where T: Deserialize + StaticType, { - from_str(s, Some(&::static_type())) + from_str_check_type(s, &::static_type()) } } diff --git a/serde_dhall/src/serde.rs b/serde_dhall/src/serde.rs index 1f639e6..10d5a17 100644 --- a/serde_dhall/src/serde.rs +++ b/serde_dhall/src/serde.rs @@ -1,4 +1,5 @@ -use crate::de::{Deserialize, Error, Result, Value}; +use crate::de::{Deserialize, Error, Result}; +use crate::Value; use dhall_syntax::{ExprF, SubExpr, X}; use std::borrow::Cow; -- cgit v1.2.3