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mod serde;
pub(crate) mod static_type;
pub use value::Value;
mod value {
use super::Type;
use crate::error::Result;
use crate::phase::{NormalizedSubExpr, Parsed, Typed};
// A Dhall value
pub struct Value(Typed);
impl Value {
pub fn from_str(s: &str, ty: Option<&Type>) -> Result<Self> {
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 crate::core::thunk::{Thunk, TypeThunk};
use crate::core::value::Value;
use crate::error::Result;
use crate::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<Item = (String, Type)>,
) -> 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<Item = (String, Option<Type>)>,
) -> 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) -> crate::phase::Type {
self.0.to_type()
}
}
impl crate::de::Deserialize for Type {
fn from_dhall(v: &crate::api::Value) -> Result<Self> {
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 crate::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<Self>;
}
/// 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<T>(s: &str, ty: Option<&Type>) -> Result<T>
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<T>(s: &str) -> Result<T>
where
T: Deserialize + StaticType,
{
from_str(s, Some(&<T as StaticType>::static_type()))
}
}
|
