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-rw-r--r--src/eval/mod.rs131
1 files changed, 84 insertions, 47 deletions
diff --git a/src/eval/mod.rs b/src/eval/mod.rs
index bc6c8fc8..be168d63 100644
--- a/src/eval/mod.rs
+++ b/src/eval/mod.rs
@@ -35,7 +35,7 @@ pub use value::*;
use unicode_segmentation::UnicodeSegmentation;
-use crate::diag::{At, Error, StrResult, Trace, Tracepoint, TypResult};
+use crate::diag::{At, Error, StrResult, Trace, Tracepoint, TypError, TypResult};
use crate::geom::{Angle, Fractional, Length, Relative};
use crate::library;
use crate::syntax::ast::*;
@@ -49,13 +49,46 @@ pub trait Eval {
type Output;
/// Evaluate the expression to the output value.
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output>;
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output>;
+}
+
+/// The result type for evaluating a syntactic construct.
+pub type EvalResult<T> = Result<T, Control>;
+
+/// A control flow event that occurred during evaluation.
+#[derive(Clone, Debug, PartialEq)]
+pub enum Control {
+ Break(Span),
+ Continue(Span),
+ Return(Option<Value>, Span),
+ Err(TypError),
+}
+
+impl From<TypError> for Control {
+ fn from(error: TypError) -> Self {
+ Self::Err(error)
+ }
+}
+
+impl From<Control> for TypError {
+ fn from(control: Control) -> Self {
+ match control {
+ Control::Break(span) => Error::boxed(span, "cannot break outside of loop"),
+ Control::Continue(span) => {
+ Error::boxed(span, "cannot continue outside of loop")
+ }
+ Control::Return(_, span) => {
+ Error::boxed(span, "cannot return outside of function")
+ }
+ Control::Err(e) => e,
+ }
+ }
}
impl Eval for Markup {
type Output = Template;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
eval_markup(ctx, scp, &mut self.nodes())
}
}
@@ -65,7 +98,7 @@ fn eval_markup(
ctx: &mut Context,
scp: &mut Scopes,
nodes: &mut impl Iterator<Item = MarkupNode>,
-) -> TypResult<Template> {
+) -> EvalResult<Template> {
let mut seq = Vec::with_capacity(nodes.size_hint().1.unwrap_or_default());
while let Some(node) = nodes.next() {
@@ -93,7 +126,7 @@ fn eval_markup(
impl Eval for MarkupNode {
type Output = Template;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
Ok(match self {
Self::Space => Template::Space,
Self::Linebreak => Template::Linebreak,
@@ -114,7 +147,7 @@ impl Eval for MarkupNode {
impl Eval for StrongNode {
type Output = Template;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
Ok(Template::show(library::StrongNode(
self.body().eval(ctx, scp)?,
)))
@@ -124,7 +157,7 @@ impl Eval for StrongNode {
impl Eval for EmphNode {
type Output = Template;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
Ok(Template::show(library::EmphNode(
self.body().eval(ctx, scp)?,
)))
@@ -134,7 +167,7 @@ impl Eval for EmphNode {
impl Eval for RawNode {
type Output = Template;
- fn eval(&self, _: &mut Context, _: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, _: &mut Context, _: &mut Scopes) -> EvalResult<Self::Output> {
let template = Template::show(library::RawNode {
text: self.text.clone(),
block: self.block,
@@ -149,7 +182,7 @@ impl Eval for RawNode {
impl Eval for MathNode {
type Output = Template;
- fn eval(&self, _: &mut Context, _: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, _: &mut Context, _: &mut Scopes) -> EvalResult<Self::Output> {
Ok(Template::show(library::MathNode {
formula: self.formula.clone(),
display: self.display,
@@ -160,7 +193,7 @@ impl Eval for MathNode {
impl Eval for HeadingNode {
type Output = Template;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
Ok(Template::show(library::HeadingNode {
body: self.body().eval(ctx, scp)?,
level: self.level(),
@@ -171,7 +204,7 @@ impl Eval for HeadingNode {
impl Eval for ListNode {
type Output = Template;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
Ok(Template::List(library::ListItem {
number: None,
body: Box::new(self.body().eval(ctx, scp)?),
@@ -182,7 +215,7 @@ impl Eval for ListNode {
impl Eval for EnumNode {
type Output = Template;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
Ok(Template::Enum(library::ListItem {
number: self.number(),
body: Box::new(self.body().eval(ctx, scp)?),
@@ -193,7 +226,7 @@ impl Eval for EnumNode {
impl Eval for Expr {
type Output = Value;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
match self {
Self::Lit(v) => v.eval(ctx, scp),
Self::Ident(v) => v.eval(ctx, scp),
@@ -211,6 +244,7 @@ impl Eval for Expr {
Self::Set(_) | Self::Show(_) | Self::Wrap(_) => {
Err("set, show and wrap are only allowed directly in markup")
.at(self.span())
+ .map_err(Into::into)
}
Self::If(v) => v.eval(ctx, scp),
Self::While(v) => v.eval(ctx, scp),
@@ -227,7 +261,7 @@ impl Eval for Expr {
impl Eval for Lit {
type Output = Value;
- fn eval(&self, _: &mut Context, _: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, _: &mut Context, _: &mut Scopes) -> EvalResult<Self::Output> {
Ok(match self.kind() {
LitKind::None => Value::None,
LitKind::Auto => Value::Auto,
@@ -246,7 +280,7 @@ impl Eval for Lit {
impl Eval for Ident {
type Output = Value;
- fn eval(&self, _: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, _: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
match scp.get(self) {
Some(slot) => Ok(slot.read().unwrap().clone()),
None => bail!(self.span(), "unknown variable"),
@@ -257,7 +291,7 @@ impl Eval for Ident {
impl Eval for ArrayExpr {
type Output = Array;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
self.items().map(|expr| expr.eval(ctx, scp)).collect()
}
}
@@ -265,7 +299,7 @@ impl Eval for ArrayExpr {
impl Eval for DictExpr {
type Output = Dict;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
self.items()
.map(|x| Ok((x.name().take(), x.expr().eval(ctx, scp)?)))
.collect()
@@ -275,7 +309,7 @@ impl Eval for DictExpr {
impl Eval for TemplateExpr {
type Output = Template;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
scp.enter();
let template = self.body().eval(ctx, scp)?;
scp.exit();
@@ -286,7 +320,7 @@ impl Eval for TemplateExpr {
impl Eval for GroupExpr {
type Output = Value;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
self.expr().eval(ctx, scp)
}
}
@@ -294,7 +328,7 @@ impl Eval for GroupExpr {
impl Eval for BlockExpr {
type Output = Value;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
scp.enter();
let mut output = Value::None;
@@ -312,21 +346,21 @@ impl Eval for BlockExpr {
impl Eval for UnaryExpr {
type Output = Value;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
let value = self.expr().eval(ctx, scp)?;
let result = match self.op() {
UnOp::Pos => ops::pos(value),
UnOp::Neg => ops::neg(value),
UnOp::Not => ops::not(value),
};
- result.at(self.span())
+ Ok(result.at(self.span())?)
}
}
impl Eval for BinaryExpr {
type Output = Value;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
match self.op() {
BinOp::Add => self.apply(ctx, scp, ops::add),
BinOp::Sub => self.apply(ctx, scp, ops::sub),
@@ -356,7 +390,7 @@ impl BinaryExpr {
ctx: &mut Context,
scp: &mut Scopes,
op: fn(Value, Value) -> StrResult<Value>,
- ) -> TypResult<Value> {
+ ) -> EvalResult<Value> {
let lhs = self.lhs().eval(ctx, scp)?;
// Short-circuit boolean operations.
@@ -367,7 +401,7 @@ impl BinaryExpr {
}
let rhs = self.rhs().eval(ctx, scp)?;
- op(lhs, rhs).at(self.span())
+ Ok(op(lhs, rhs).at(self.span())?)
}
/// Apply an assignment operation.
@@ -376,7 +410,7 @@ impl BinaryExpr {
ctx: &mut Context,
scp: &mut Scopes,
op: fn(Value, Value) -> StrResult<Value>,
- ) -> TypResult<Value> {
+ ) -> EvalResult<Value> {
let rhs = self.rhs().eval(ctx, scp)?;
self.lhs().access(
ctx,
@@ -394,12 +428,12 @@ impl BinaryExpr {
impl Eval for CallExpr {
type Output = Value;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
let span = self.callee().span();
let callee = self.callee().eval(ctx, scp)?;
let args = self.args().eval(ctx, scp)?;
- match callee {
+ Ok(match callee {
Value::Array(array) => {
array.get(args.into_index()?).map(Value::clone).at(self.span())
}
@@ -423,14 +457,14 @@ impl Eval for CallExpr {
"expected callable or collection, found {}",
v.type_name(),
),
- }
+ }?)
}
}
impl Eval for CallArgs {
type Output = Args;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
let mut items = Vec::new();
for arg in self.items() {
@@ -482,7 +516,7 @@ impl Eval for CallArgs {
impl Eval for ClosureExpr {
type Output = Value;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
// The closure's name is defined by its let binding if there's one.
let name = self.name().map(Ident::take);
@@ -529,7 +563,7 @@ impl Eval for ClosureExpr {
impl Eval for WithExpr {
type Output = Value;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
let callee = self.callee();
let func = callee.eval(ctx, scp)?.cast::<Func>().at(callee.span())?;
let args = self.args().eval(ctx, scp)?;
@@ -540,7 +574,7 @@ impl Eval for WithExpr {
impl Eval for LetExpr {
type Output = Value;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
let value = match self.init() {
Some(expr) => expr.eval(ctx, scp)?,
None => Value::None,
@@ -553,18 +587,18 @@ impl Eval for LetExpr {
impl Eval for SetExpr {
type Output = StyleMap;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
let class = self.class();
let class = class.eval(ctx, scp)?.cast::<Class>().at(class.span())?;
let args = self.args().eval(ctx, scp)?;
- class.set(args)
+ Ok(class.set(args)?)
}
}
impl Eval for ShowExpr {
type Output = StyleMap;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
let class = self.class();
let class = class.eval(ctx, scp)?.cast::<Class>().at(class.span())?;
let closure = self.closure();
@@ -578,7 +612,7 @@ impl Eval for ShowExpr {
impl Eval for IfExpr {
type Output = Value;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
let condition = self.condition();
if condition.eval(ctx, scp)?.cast::<bool>().at(condition.span())? {
self.if_body().eval(ctx, scp)
@@ -593,7 +627,7 @@ impl Eval for IfExpr {
impl Eval for WhileExpr {
type Output = Value;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
let mut output = Value::None;
let condition = self.condition();
@@ -610,7 +644,7 @@ impl Eval for WhileExpr {
impl Eval for ForExpr {
type Output = Value;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
macro_rules! iter {
(for ($($binding:ident => $value:ident),*) in $iter:expr) => {{
let mut output = Value::None;
@@ -673,7 +707,7 @@ impl Eval for ForExpr {
impl Eval for ImportExpr {
type Output = Value;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
let span = self.path().span();
let path = self.path().eval(ctx, scp)?.cast::<EcoString>().at(span)?;
let module = import(ctx, &path, span)?;
@@ -702,7 +736,7 @@ impl Eval for ImportExpr {
impl Eval for IncludeExpr {
type Output = Template;
- fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> TypResult<Self::Output> {
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
let span = self.path().span();
let path = self.path().eval(ctx, scp)?.cast::<EcoString>().at(span)?;
let module = import(ctx, &path, span)?;
@@ -735,24 +769,27 @@ fn import(ctx: &mut Context, path: &str, span: Span) -> TypResult<Module> {
impl Eval for BreakExpr {
type Output = Value;
- fn eval(&self, _: &mut Context, _: &mut Scopes) -> TypResult<Self::Output> {
- Err("break is not yet implemented").at(self.span())
+ fn eval(&self, _: &mut Context, _: &mut Scopes) -> EvalResult<Self::Output> {
+ Err(Control::Break(self.span()))
}
}
impl Eval for ContinueExpr {
type Output = Value;
- fn eval(&self, _: &mut Context, _: &mut Scopes) -> TypResult<Self::Output> {
- Err("continue is not yet implemented").at(self.span())
+ fn eval(&self, _: &mut Context, _: &mut Scopes) -> EvalResult<Self::Output> {
+ Err(Control::Continue(self.span()))
}
}
impl Eval for ReturnExpr {
type Output = Value;
- fn eval(&self, _: &mut Context, _: &mut Scopes) -> TypResult<Self::Output> {
- Err("return is not yet implemented").at(self.span())
+ fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
+ Err(Control::Return(
+ self.body().map(|body| body.eval(ctx, scp)).transpose()?,
+ self.span(),
+ ))
}
}
generated by cgit v1.2.3 (git 2.25.1) at 2026-03-15 13:25:24 +0000