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-rw-r--r--src/eval/cast.rs316
1 files changed, 0 insertions, 316 deletions
diff --git a/src/eval/cast.rs b/src/eval/cast.rs
deleted file mode 100644
index 917972ed..00000000
--- a/src/eval/cast.rs
+++ /dev/null
@@ -1,316 +0,0 @@
-pub use typst_macros::{cast, Cast};
-
-use std::fmt::Write;
-use std::ops::Add;
-
-use ecow::EcoString;
-
-use super::Value;
-use crate::diag::{At, SourceResult, StrResult};
-use crate::syntax::{Span, Spanned};
-use crate::util::separated_list;
-
-/// Determine details of a type.
-///
-/// Type casting works as follows:
-/// - [`Reflect for T`](Reflect) describes the possible Typst values for `T`
-/// (for documentation and autocomplete).
-/// - [`IntoValue for T`](IntoValue) is for conversion from `T -> Value`
-/// (infallible)
-/// - [`FromValue for T`](FromValue) is for conversion from `Value -> T`
-/// (fallible).
-///
-/// We can't use `TryFrom<Value>` due to conflicting impls. We could use
-/// `From<T> for Value`, but that inverses the impl and leads to tons of
-/// `.into()` all over the place that become hard to decipher.
-pub trait Reflect {
- /// Describe the acceptable values for this type.
- fn describe() -> CastInfo;
-
- /// Whether the given value can be converted to `T`.
- ///
- /// This exists for performance. The check could also be done through the
- /// [`CastInfo`], but it would be much more expensive (heap allocation +
- /// dynamic checks instead of optimized machine code for each type).
- fn castable(value: &Value) -> bool;
-
- /// Produce an error message for an inacceptable value.
- ///
- /// ```
- /// # use typst::eval::{Int, Reflect, Value};
- /// assert_eq!(
- /// <Int as Reflect>::error(Value::None),
- /// "expected integer, found none",
- /// );
- /// ```
- fn error(found: &Value) -> EcoString {
- Self::describe().error(found)
- }
-}
-
-impl Reflect for Value {
- fn describe() -> CastInfo {
- CastInfo::Any
- }
-
- fn castable(_: &Value) -> bool {
- true
- }
-}
-
-impl<T: Reflect> Reflect for Spanned<T> {
- fn describe() -> CastInfo {
- T::describe()
- }
-
- fn castable(value: &Value) -> bool {
- T::castable(value)
- }
-}
-
-impl<T: Reflect> Reflect for StrResult<T> {
- fn describe() -> CastInfo {
- T::describe()
- }
-
- fn castable(value: &Value) -> bool {
- T::castable(value)
- }
-}
-
-impl<T: Reflect> Reflect for SourceResult<T> {
- fn describe() -> CastInfo {
- T::describe()
- }
-
- fn castable(value: &Value) -> bool {
- T::castable(value)
- }
-}
-
-impl<T: Reflect> Reflect for &T {
- fn describe() -> CastInfo {
- T::describe()
- }
-
- fn castable(value: &Value) -> bool {
- T::castable(value)
- }
-}
-
-impl<T: Reflect> Reflect for &mut T {
- fn describe() -> CastInfo {
- T::describe()
- }
-
- fn castable(value: &Value) -> bool {
- T::castable(value)
- }
-}
-
-/// Cast a Rust type into a Typst [`Value`].
-///
-/// See also: [`Reflect`].
-pub trait IntoValue {
- /// Cast this type into a value.
- fn into_value(self) -> Value;
-}
-
-impl IntoValue for Value {
- fn into_value(self) -> Value {
- self
- }
-}
-
-impl<T: IntoValue> IntoValue for Spanned<T> {
- fn into_value(self) -> Value {
- self.v.into_value()
- }
-}
-
-/// Cast a Rust type or result into a [`SourceResult<Value>`].
-///
-/// Converts `T`, [`StrResult<T>`], or [`SourceResult<T>`] into
-/// [`SourceResult<Value>`] by `Ok`-wrapping or adding span information.
-pub trait IntoResult {
- /// Cast this type into a value.
- fn into_result(self, span: Span) -> SourceResult<Value>;
-}
-
-impl<T: IntoValue> IntoResult for T {
- fn into_result(self, _: Span) -> SourceResult<Value> {
- Ok(self.into_value())
- }
-}
-
-impl<T: IntoValue> IntoResult for StrResult<T> {
- fn into_result(self, span: Span) -> SourceResult<Value> {
- self.map(IntoValue::into_value).at(span)
- }
-}
-
-impl<T: IntoValue> IntoResult for SourceResult<T> {
- fn into_result(self, _: Span) -> SourceResult<Value> {
- self.map(IntoValue::into_value)
- }
-}
-
-/// Try to cast a Typst [`Value`] into a Rust type.
-///
-/// See also: [`Reflect`].
-pub trait FromValue<V = Value>: Sized + Reflect {
- /// Try to cast the value into an instance of `Self`.
- fn from_value(value: V) -> StrResult<Self>;
-}
-
-impl FromValue for Value {
- fn from_value(value: Value) -> StrResult<Self> {
- Ok(value)
- }
-}
-
-impl<T: FromValue> FromValue<Spanned<Value>> for T {
- fn from_value(value: Spanned<Value>) -> StrResult<Self> {
- T::from_value(value.v)
- }
-}
-
-impl<T: FromValue> FromValue<Spanned<Value>> for Spanned<T> {
- fn from_value(value: Spanned<Value>) -> StrResult<Self> {
- let span = value.span;
- T::from_value(value.v).map(|t| Spanned::new(t, span))
- }
-}
-
-/// Describes a possible value for a cast.
-#[derive(Debug, Clone, Hash, PartialEq, PartialOrd)]
-pub enum CastInfo {
- /// Any value is okay.
- Any,
- /// A specific value, plus short documentation for that value.
- Value(Value, &'static str),
- /// Any value of a type.
- Type(&'static str),
- /// Multiple alternatives.
- Union(Vec<Self>),
-}
-
-impl CastInfo {
- /// Produce an error message describing what was expected and what was
- /// found.
- pub fn error(&self, found: &Value) -> EcoString {
- fn accumulate(
- info: &CastInfo,
- found: &Value,
- parts: &mut Vec<EcoString>,
- matching_type: &mut bool,
- ) {
- match info {
- CastInfo::Any => parts.push("anything".into()),
- CastInfo::Value(value, _) => {
- parts.push(value.repr().into());
- if value.type_name() == found.type_name() {
- *matching_type = true;
- }
- }
- CastInfo::Type(ty) => parts.push((*ty).into()),
- CastInfo::Union(options) => {
- for option in options {
- accumulate(option, found, parts, matching_type);
- }
- }
- }
- }
-
- let mut matching_type = false;
- let mut parts = vec![];
- accumulate(self, found, &mut parts, &mut matching_type);
-
- let mut msg = String::from("expected ");
- if parts.is_empty() {
- msg.push_str(" nothing");
- }
-
- msg.push_str(&separated_list(&parts, "or"));
-
- if !matching_type {
- msg.push_str(", found ");
- msg.push_str(found.type_name());
- }
- if_chain::if_chain! {
- if let Value::Int(i) = found;
- if parts.iter().any(|p| p == "length");
- if !matching_type;
- then {
- write!(msg, ": a length needs a unit - did you mean {i}pt?").unwrap();
- }
- };
-
- msg.into()
- }
-}
-
-impl Add for CastInfo {
- type Output = Self;
-
- fn add(self, rhs: Self) -> Self {
- Self::Union(match (self, rhs) {
- (Self::Union(mut lhs), Self::Union(rhs)) => {
- for cast in rhs {
- if !lhs.contains(&cast) {
- lhs.push(cast);
- }
- }
- lhs
- }
- (Self::Union(mut lhs), rhs) => {
- if !lhs.contains(&rhs) {
- lhs.push(rhs);
- }
- lhs
- }
- (lhs, Self::Union(mut rhs)) => {
- if !rhs.contains(&lhs) {
- rhs.insert(0, lhs);
- }
- rhs
- }
- (lhs, rhs) => vec![lhs, rhs],
- })
- }
-}
-
-/// A container for a variadic argument.
-pub trait Variadics {
- /// The contained type.
- type Inner;
-}
-
-impl<T> Variadics for Vec<T> {
- type Inner = T;
-}
-
-/// An uninhabitable type.
-pub enum Never {}
-
-impl Reflect for Never {
- fn describe() -> CastInfo {
- CastInfo::Union(vec![])
- }
-
- fn castable(_: &Value) -> bool {
- false
- }
-}
-
-impl IntoValue for Never {
- fn into_value(self) -> Value {
- match self {}
- }
-}
-
-impl FromValue for Never {
- fn from_value(value: Value) -> StrResult<Self> {
- Err(Self::error(&value))
- }
-}
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