mirror of
https://github.com/typst/typst
synced 2025-05-14 04:56:26 +08:00
711 lines
20 KiB
Rust
711 lines
20 KiB
Rust
use std::any::Any;
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use std::cmp::Ordering;
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use std::collections::BTreeMap;
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use std::fmt::{self, Debug, Display, Formatter};
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use std::ops::Deref;
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use std::rc::Rc;
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use super::{EvalContext, NodeMap};
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use crate::color::Color;
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use crate::diag::DiagSet;
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use crate::exec::ExecContext;
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use crate::geom::{Angle, Length, Linear, Relative};
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use crate::syntax::{Span, Spanned, Tree};
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/// A computational value.
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#[derive(Debug, Clone, PartialEq)]
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pub enum Value {
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/// The value that indicates the absence of a meaningful value.
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None,
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/// A boolean: `true, false`.
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Bool(bool),
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/// An integer: `120`.
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Int(i64),
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/// A floating-point number: `1.2`, `10e-4`.
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Float(f64),
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/// A length: `12pt`, `3cm`.
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Length(Length),
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/// An angle: `1.5rad`, `90deg`.
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Angle(Angle),
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/// A relative value: `50%`.
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Relative(Relative),
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/// A combination of an absolute length and a relative value: `20% + 5cm`.
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Linear(Linear),
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/// A color value: `#f79143ff`.
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Color(Color),
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/// A string: `"string"`.
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Str(String),
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/// An array value: `(1, "hi", 12cm)`.
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Array(ArrayValue),
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/// A dictionary value: `(color: #f79143, pattern: dashed)`.
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Dict(DictValue),
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/// A template value: `[*Hi* there]`.
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Template(TemplateValue),
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/// An executable function.
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Func(FuncValue),
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/// Any object.
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Any(AnyValue),
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/// The result of invalid operations.
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Error,
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}
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impl Value {
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/// Create a new template value consisting of a single dynamic node.
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pub fn template<F>(name: impl Into<String>, f: F) -> Self
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where
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F: Fn(&mut ExecContext) + 'static,
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{
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Self::Template(vec![TemplateNode::Func(TemplateFunc::new(name, f))])
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}
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/// Try to cast the value into a specific type.
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pub fn cast<T>(self) -> CastResult<T, Self>
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where
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T: Cast<Value>,
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{
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T::cast(self)
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}
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/// The name of the stored value's type.
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pub fn type_name(&self) -> &'static str {
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match self {
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Self::None => "none",
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Self::Bool(_) => bool::TYPE_NAME,
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Self::Int(_) => i64::TYPE_NAME,
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Self::Float(_) => f64::TYPE_NAME,
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Self::Length(_) => Length::TYPE_NAME,
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Self::Angle(_) => Angle::TYPE_NAME,
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Self::Relative(_) => Relative::TYPE_NAME,
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Self::Linear(_) => Linear::TYPE_NAME,
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Self::Color(_) => Color::TYPE_NAME,
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Self::Str(_) => String::TYPE_NAME,
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Self::Array(_) => ArrayValue::TYPE_NAME,
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Self::Dict(_) => DictValue::TYPE_NAME,
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Self::Template(_) => TemplateValue::TYPE_NAME,
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Self::Func(_) => FuncValue::TYPE_NAME,
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Self::Any(v) => v.type_name(),
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Self::Error => "error",
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}
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}
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/// Recursively compute whether two values are equal.
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pub fn eq(&self, rhs: &Self) -> bool {
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match (self, rhs) {
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(&Self::Int(a), &Self::Float(b)) => a as f64 == b,
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(&Self::Float(a), &Self::Int(b)) => a == b as f64,
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(&Self::Length(a), &Self::Linear(b)) => a == b.abs && b.rel.is_zero(),
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(&Self::Relative(a), &Self::Linear(b)) => a == b.rel && b.abs.is_zero(),
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(&Self::Linear(a), &Self::Length(b)) => a.abs == b && a.rel.is_zero(),
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(&Self::Linear(a), &Self::Relative(b)) => a.rel == b && a.abs.is_zero(),
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(Self::Array(a), Self::Array(b)) => {
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a.len() == b.len() && a.iter().zip(b).all(|(x, y)| x.eq(y))
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}
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(Self::Dict(a), Self::Dict(b)) => {
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a.len() == b.len()
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&& a.iter().all(|(k, x)| b.get(k).map_or(false, |y| x.eq(y)))
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}
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(a, b) => a == b,
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}
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}
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/// Compare a value with another value.
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pub fn cmp(&self, rhs: &Self) -> Option<Ordering> {
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match (self, rhs) {
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(Self::Int(a), Self::Int(b)) => a.partial_cmp(b),
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(Self::Int(a), Self::Float(b)) => (*a as f64).partial_cmp(b),
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(Self::Float(a), Self::Int(b)) => a.partial_cmp(&(*b as f64)),
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(Self::Float(a), Self::Float(b)) => a.partial_cmp(b),
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(Self::Angle(a), Self::Angle(b)) => a.partial_cmp(b),
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(Self::Length(a), Self::Length(b)) => a.partial_cmp(b),
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_ => None,
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}
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}
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}
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impl Default for Value {
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fn default() -> Self {
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Value::None
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}
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}
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/// An array value: `(1, "hi", 12cm)`.
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pub type ArrayValue = Vec<Value>;
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/// A dictionary value: `(color: #f79143, pattern: dashed)`.
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pub type DictValue = BTreeMap<String, Value>;
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/// A template value: `[*Hi* there]`.
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pub type TemplateValue = Vec<TemplateNode>;
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/// One chunk of a template.
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///
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/// Evaluating a template expression creates only a single node. Adding multiple
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/// templates can yield multi-node templates.
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#[derive(Debug, Clone)]
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pub enum TemplateNode {
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/// A template that consists of a syntax tree plus already evaluated
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/// expression.
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Tree {
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/// The syntax tree of the corresponding template expression.
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tree: Rc<Tree>,
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/// The evaluated expressions for the `tree`.
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map: NodeMap,
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},
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/// A template that was converted from a string.
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Str(String),
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/// A function template that can implement custom behaviour.
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Func(TemplateFunc),
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}
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impl PartialEq for TemplateNode {
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fn eq(&self, _: &Self) -> bool {
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// TODO: Figure out what we want here.
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false
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}
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}
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/// A reference-counted dynamic template node that can implement custom
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/// behaviour.
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#[derive(Clone)]
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pub struct TemplateFunc {
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name: String,
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f: Rc<dyn Fn(&mut ExecContext)>,
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}
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impl TemplateFunc {
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/// Create a new function template from a rust function or closure.
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pub fn new<F>(name: impl Into<String>, f: F) -> Self
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where
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F: Fn(&mut ExecContext) + 'static,
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{
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Self { name: name.into(), f: Rc::new(f) }
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}
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/// The name of the template node.
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pub fn name(&self) -> &str {
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&self.name
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}
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}
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impl PartialEq for TemplateFunc {
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fn eq(&self, _: &Self) -> bool {
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// TODO: Figure out what we want here.
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false
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}
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}
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impl Deref for TemplateFunc {
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type Target = dyn Fn(&mut ExecContext);
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fn deref(&self) -> &Self::Target {
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self.f.as_ref()
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}
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}
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impl Debug for TemplateFunc {
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fn fmt(&self, f: &mut Formatter) -> fmt::Result {
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f.debug_struct("TemplateAny").finish()
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}
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}
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/// A wrapper around a reference-counted executable function.
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#[derive(Clone)]
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pub struct FuncValue {
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name: Option<String>,
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f: Rc<dyn Fn(&mut EvalContext, &mut FuncArgs) -> Value>,
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}
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impl FuncValue {
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/// Create a new function value from a rust function or closure.
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pub fn new<F>(name: Option<String>, f: F) -> Self
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where
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F: Fn(&mut EvalContext, &mut FuncArgs) -> Value + 'static,
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{
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Self { name, f: Rc::new(f) }
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}
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/// The name of the function.
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pub fn name(&self) -> Option<&str> {
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self.name.as_deref()
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}
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}
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impl PartialEq for FuncValue {
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fn eq(&self, _: &Self) -> bool {
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// TODO: Figure out what we want here.
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false
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}
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}
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impl Deref for FuncValue {
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type Target = dyn Fn(&mut EvalContext, &mut FuncArgs) -> Value;
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fn deref(&self) -> &Self::Target {
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self.f.as_ref()
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}
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}
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impl Debug for FuncValue {
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fn fmt(&self, f: &mut Formatter) -> fmt::Result {
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f.debug_struct("ValueFunc").field("name", &self.name).finish()
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}
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}
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/// Evaluated arguments to a function.
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#[derive(Debug, Clone, PartialEq)]
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pub struct FuncArgs {
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/// The span of the whole argument list.
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pub span: Span,
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/// The arguments.
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pub items: Vec<FuncArg>,
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}
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impl FuncArgs {
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/// Find and remove the first convertible positional argument.
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pub fn find<T>(&mut self, ctx: &mut EvalContext) -> Option<T>
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where
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T: Cast<Spanned<Value>>,
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{
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(0 .. self.items.len()).find_map(move |i| self.try_take(&mut ctx.diags, i))
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}
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/// Find and remove the first convertible positional argument, producing an
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/// error if no match was found.
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pub fn require<T>(&mut self, ctx: &mut EvalContext, what: &str) -> Option<T>
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where
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T: Cast<Spanned<Value>>,
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{
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let found = self.find(ctx);
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if found.is_none() {
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ctx.diag(error!(self.span, "missing argument: {}", what));
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}
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found
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}
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/// Filter out and remove all convertible positional arguments.
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pub fn filter<'a, T>(
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&'a mut self,
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ctx: &'a mut EvalContext,
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) -> impl Iterator<Item = T> + 'a
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where
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T: Cast<Spanned<Value>>,
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{
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let diags = &mut ctx.diags;
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let mut i = 0;
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std::iter::from_fn(move || {
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while i < self.items.len() {
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if let Some(val) = self.try_take(diags, i) {
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return Some(val);
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}
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i += 1;
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}
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None
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})
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}
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/// Convert and remove the value for the given named argument, producing an
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/// error if the conversion fails.
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pub fn get<T>(&mut self, ctx: &mut EvalContext, name: &str) -> Option<T>
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where
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T: Cast<Spanned<Value>>,
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{
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let index = self
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.items
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.iter()
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.position(|arg| arg.name.as_ref().map(|s| s.v.as_str()) == Some(name))?;
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let value = self.items.remove(index).value;
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self.cast(ctx, value)
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}
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/// Produce "unexpected argument" errors for all remaining arguments.
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pub fn finish(self, ctx: &mut EvalContext) {
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for arg in &self.items {
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if arg.value.v != Value::Error {
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ctx.diag(error!(arg.span(), "unexpected argument"));
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}
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}
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}
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/// Cast the value into `T`, generating an error if the conversion fails.
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fn cast<T>(&self, ctx: &mut EvalContext, value: Spanned<Value>) -> Option<T>
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where
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T: Cast<Spanned<Value>>,
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{
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let span = value.span;
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match T::cast(value) {
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CastResult::Ok(t) => Some(t),
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CastResult::Warn(t, m) => {
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ctx.diag(warning!(span, "{}", m));
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Some(t)
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}
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CastResult::Err(value) => {
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ctx.diag(error!(
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span,
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"expected {}, found {}",
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T::TYPE_NAME,
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value.v.type_name()
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));
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None
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}
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}
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}
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/// Try to take and cast a positional argument in the i'th slot into `T`,
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/// putting it back if the conversion fails.
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fn try_take<T>(&mut self, diags: &mut DiagSet, i: usize) -> Option<T>
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where
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T: Cast<Spanned<Value>>,
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{
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let slot = &mut self.items[i];
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if slot.name.is_some() {
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return None;
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}
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let value = std::mem::replace(&mut slot.value, Spanned::zero(Value::None));
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let span = value.span;
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match T::cast(value) {
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CastResult::Ok(t) => {
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self.items.remove(i);
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Some(t)
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}
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CastResult::Warn(t, m) => {
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self.items.remove(i);
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diags.insert(warning!(span, "{}", m));
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Some(t)
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}
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CastResult::Err(value) => {
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slot.value = value;
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None
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}
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}
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}
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}
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/// An argument to a function call: `12` or `draw: false`.
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#[derive(Debug, Clone, PartialEq)]
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pub struct FuncArg {
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/// The name of the argument (`None` for positional arguments).
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pub name: Option<Spanned<String>>,
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/// The value of the argument.
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pub value: Spanned<Value>,
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}
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impl FuncArg {
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/// The source code location.
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pub fn span(&self) -> Span {
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match &self.name {
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Some(name) => name.span.join(self.value.span),
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None => self.value.span,
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}
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}
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}
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/// A wrapper around a dynamic value.
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pub struct AnyValue(Box<dyn Bounds>);
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impl AnyValue {
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/// Create a new instance from any value that satisifies the required bounds.
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pub fn new<T>(any: T) -> Self
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where
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T: Type + Debug + Display + Clone + PartialEq + 'static,
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{
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Self(Box::new(any))
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}
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/// Whether the wrapped type is `T`.
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pub fn is<T: 'static>(&self) -> bool {
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self.0.as_any().is::<T>()
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}
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/// Try to downcast to a specific type.
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pub fn downcast<T: 'static>(self) -> Result<T, Self> {
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if self.is::<T>() {
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Ok(*self.0.into_any().downcast().unwrap())
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} else {
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Err(self)
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}
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}
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/// Try to downcast to a reference to a specific type.
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pub fn downcast_ref<T: 'static>(&self) -> Option<&T> {
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self.0.as_any().downcast_ref()
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}
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/// The name of the stored value's type.
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pub fn type_name(&self) -> &'static str {
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self.0.dyn_type_name()
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}
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}
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impl Clone for AnyValue {
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fn clone(&self) -> Self {
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Self(self.0.dyn_clone())
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}
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}
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impl PartialEq for AnyValue {
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fn eq(&self, other: &Self) -> bool {
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self.0.dyn_eq(other)
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}
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}
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impl Debug for AnyValue {
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fn fmt(&self, f: &mut Formatter) -> fmt::Result {
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f.debug_tuple("ValueAny").field(&self.0).finish()
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}
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}
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impl Display for AnyValue {
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fn fmt(&self, f: &mut Formatter) -> fmt::Result {
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Display::fmt(&self.0, f)
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}
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}
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trait Bounds: Debug + Display + 'static {
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fn as_any(&self) -> &dyn Any;
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fn into_any(self: Box<Self>) -> Box<dyn Any>;
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fn dyn_eq(&self, other: &AnyValue) -> bool;
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fn dyn_clone(&self) -> Box<dyn Bounds>;
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fn dyn_type_name(&self) -> &'static str;
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}
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impl<T> Bounds for T
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where
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T: Type + Debug + Display + Clone + PartialEq + 'static,
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{
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fn as_any(&self) -> &dyn Any {
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self
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}
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fn into_any(self: Box<Self>) -> Box<dyn Any> {
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self
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}
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fn dyn_eq(&self, other: &AnyValue) -> bool {
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if let Some(other) = other.downcast_ref::<Self>() {
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self == other
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} else {
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false
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}
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}
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fn dyn_clone(&self) -> Box<dyn Bounds> {
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Box::new(self.clone())
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}
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fn dyn_type_name(&self) -> &'static str {
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T::TYPE_NAME
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}
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}
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/// Types that can be stored in values.
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pub trait Type {
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/// The name of the type.
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const TYPE_NAME: &'static str;
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}
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impl<T> Type for Spanned<T>
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where
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T: Type,
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{
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const TYPE_NAME: &'static str = T::TYPE_NAME;
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}
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/// Cast from a value to a specific type.
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pub trait Cast<V>: Type + Sized {
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/// Try to cast the value into an instance of `Self`.
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fn cast(value: V) -> CastResult<Self, V>;
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}
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/// The result of casting a value to a specific type.
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#[derive(Debug, Clone, Eq, PartialEq)]
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pub enum CastResult<T, V> {
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/// The value was cast successfully.
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Ok(T),
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/// The value was cast successfully, but with a warning message.
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Warn(T, String),
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/// The value could not be cast into the specified type.
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Err(V),
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}
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impl<T, V> CastResult<T, V> {
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/// Access the conversion result, discarding a possibly existing warning.
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pub fn ok(self) -> Option<T> {
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match self {
|
|
CastResult::Ok(t) | CastResult::Warn(t, _) => Some(t),
|
|
CastResult::Err(_) => None,
|
|
}
|
|
}
|
|
}
|
|
|
|
impl Type for Value {
|
|
const TYPE_NAME: &'static str = "value";
|
|
}
|
|
|
|
impl Cast<Value> for Value {
|
|
fn cast(value: Value) -> CastResult<Self, Value> {
|
|
CastResult::Ok(value)
|
|
}
|
|
}
|
|
|
|
impl<T> Cast<Spanned<Value>> for T
|
|
where
|
|
T: Cast<Value>,
|
|
{
|
|
fn cast(value: Spanned<Value>) -> CastResult<Self, Spanned<Value>> {
|
|
let span = value.span;
|
|
match T::cast(value.v) {
|
|
CastResult::Ok(t) => CastResult::Ok(t),
|
|
CastResult::Warn(t, m) => CastResult::Warn(t, m),
|
|
CastResult::Err(v) => CastResult::Err(Spanned::new(v, span)),
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<T> Cast<Spanned<Value>> for Spanned<T>
|
|
where
|
|
T: Cast<Value>,
|
|
{
|
|
fn cast(value: Spanned<Value>) -> CastResult<Self, Spanned<Value>> {
|
|
let span = value.span;
|
|
match T::cast(value.v) {
|
|
CastResult::Ok(t) => CastResult::Ok(Spanned::new(t, span)),
|
|
CastResult::Warn(t, m) => CastResult::Warn(Spanned::new(t, span), m),
|
|
CastResult::Err(v) => CastResult::Err(Spanned::new(v, span)),
|
|
}
|
|
}
|
|
}
|
|
|
|
macro_rules! primitive {
|
|
($type:ty:
|
|
$type_name:literal,
|
|
$variant:path
|
|
$(, $pattern:pat => $out:expr)* $(,)?
|
|
) => {
|
|
impl Type for $type {
|
|
const TYPE_NAME: &'static str = $type_name;
|
|
}
|
|
|
|
impl From<$type> for Value {
|
|
fn from(v: $type) -> Self {
|
|
$variant(v)
|
|
}
|
|
}
|
|
|
|
impl Cast<Value> for $type {
|
|
fn cast(value: Value) -> CastResult<Self, Value> {
|
|
match value {
|
|
$variant(v) => CastResult::Ok(v),
|
|
$($pattern => CastResult::Ok($out),)*
|
|
v => CastResult::Err(v),
|
|
}
|
|
}
|
|
}
|
|
};
|
|
}
|
|
|
|
primitive! { bool: "boolean", Value::Bool }
|
|
primitive! { i64: "integer", Value::Int }
|
|
primitive! {
|
|
f64: "float",
|
|
Value::Float,
|
|
Value::Int(v) => v as f64,
|
|
}
|
|
primitive! { Length: "length", Value::Length }
|
|
primitive! { Angle: "angle", Value::Angle }
|
|
primitive! { Relative: "relative", Value::Relative }
|
|
primitive! {
|
|
Linear: "linear",
|
|
Value::Linear,
|
|
Value::Length(v) => v.into(),
|
|
Value::Relative(v) => v.into(),
|
|
}
|
|
primitive! { Color: "color", Value::Color }
|
|
primitive! { String: "string", Value::Str }
|
|
primitive! { ArrayValue: "array", Value::Array }
|
|
primitive! { DictValue: "dictionary", Value::Dict }
|
|
primitive! {
|
|
TemplateValue: "template",
|
|
Value::Template,
|
|
Value::Str(v) => vec![TemplateNode::Str(v)],
|
|
}
|
|
primitive! { FuncValue: "function", Value::Func }
|
|
|
|
impl From<usize> for Value {
|
|
fn from(v: usize) -> Self {
|
|
Self::Int(v as i64)
|
|
}
|
|
}
|
|
|
|
impl From<&str> for Value {
|
|
fn from(v: &str) -> Self {
|
|
Self::Str(v.to_string())
|
|
}
|
|
}
|
|
|
|
impl From<AnyValue> for Value {
|
|
fn from(v: AnyValue) -> Self {
|
|
Self::Any(v)
|
|
}
|
|
}
|
|
|
|
/// Make a type usable as a [`Value`].
|
|
///
|
|
/// Given a type `T`, this implements the following traits:
|
|
/// - [`Type`] for `T`,
|
|
/// - [`Cast<Value>`](Cast) for `T`.
|
|
///
|
|
/// # Example
|
|
/// Allow a type `FontFamily` to be cast from:
|
|
/// - a [`Value::Any`] variant already containing a `FontFamily`
|
|
/// - a string, producing a `FontFamiliy::Named(..)`.
|
|
/// ```
|
|
/// # use typst::typify;
|
|
/// # enum FontFamily { Named(String) }
|
|
/// typify! {
|
|
/// FontFamily: "font family",
|
|
/// Value::Str(string) => Self::Named(string.to_lowercase())
|
|
/// }
|
|
/// ```
|
|
#[macro_export]
|
|
macro_rules! typify {
|
|
($type:ty:
|
|
$type_name:literal
|
|
$(, $pattern:pat => $out:expr)*
|
|
$(, #($anyvar:ident: $anytype:ty) => $anyout:expr)*
|
|
$(,)?
|
|
) => {
|
|
impl $crate::eval::Type for $type {
|
|
const TYPE_NAME: &'static str = $type_name;
|
|
}
|
|
|
|
impl $crate::eval::Cast<$crate::eval::Value> for $type {
|
|
fn cast(
|
|
value: $crate::eval::Value,
|
|
) -> $crate::eval::CastResult<Self, $crate::eval::Value> {
|
|
use $crate::eval::*;
|
|
|
|
#[allow(unreachable_code)]
|
|
match value {
|
|
$($pattern => CastResult::Ok($out),)*
|
|
Value::Any(mut any) => {
|
|
any = match any.downcast::<Self>() {
|
|
Ok(t) => return CastResult::Ok(t),
|
|
Err(any) => any,
|
|
};
|
|
|
|
$(any = match any.downcast::<$anytype>() {
|
|
Ok($anyvar) => return CastResult::Ok($anyout),
|
|
Err(any) => any,
|
|
};)*
|
|
|
|
CastResult::Err(Value::Any(any))
|
|
},
|
|
v => CastResult::Err(v),
|
|
}
|
|
}
|
|
}
|
|
};
|
|
}
|