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-rw-r--r--src/eval/control.rs63
-rw-r--r--src/eval/func.rs2
-rw-r--r--src/eval/mod.rs80
3 files changed, 90 insertions, 55 deletions
diff --git a/src/eval/control.rs b/src/eval/control.rs
new file mode 100644
index 00000000..b310bfb8
--- /dev/null
+++ b/src/eval/control.rs
@@ -0,0 +1,63 @@
+use super::{ops, EvalResult, Value};
+use crate::diag::{At, Error, TypError};
+use crate::syntax::Span;
+
+/// A control flow event that occurred during evaluation.
+#[derive(Clone, Debug, PartialEq)]
+pub enum Control {
+ /// Stop iteration in a loop.
+ Break(Value, Span),
+ /// Skip the remainder of the current iteration in a loop.
+ Continue(Value, Span),
+ /// Stop execution of a function early, returning a value. The bool
+ /// indicates whether this was an explicit return with value.
+ Return(Value, bool, Span),
+ /// Stop the execution because an error occurred.
+ 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,
+ }
+ }
+}
+
+/// Join a value with an evaluated result.
+pub(super) fn join_result(
+ prev: Value,
+ result: EvalResult<Value>,
+ result_span: Span,
+) -> EvalResult<Value> {
+ match result {
+ Ok(value) => Ok(ops::join(prev, value).at(result_span)?),
+ Err(Control::Break(value, span)) => Err(Control::Break(
+ ops::join(prev, value).at(result_span)?,
+ span,
+ )),
+ Err(Control::Continue(value, span)) => Err(Control::Continue(
+ ops::join(prev, value).at(result_span)?,
+ span,
+ )),
+ Err(Control::Return(value, false, span)) => Err(Control::Return(
+ ops::join(prev, value).at(result_span)?,
+ false,
+ span,
+ )),
+ other => other,
+ }
+}
diff --git a/src/eval/func.rs b/src/eval/func.rs
index a7f2a209..451dcbbb 100644
--- a/src/eval/func.rs
+++ b/src/eval/func.rs
@@ -139,7 +139,7 @@ impl Closure {
// Evaluate the body.
let value = match self.body.eval(ctx, &mut scp) {
- Err(Control::Return(value, _)) => value.unwrap_or_default(),
+ Err(Control::Return(value, _, _)) => value,
other => other?,
};
diff --git a/src/eval/mod.rs b/src/eval/mod.rs
index 3686d665..380e9e9d 100644
--- a/src/eval/mod.rs
+++ b/src/eval/mod.rs
@@ -11,6 +11,7 @@ mod styles;
mod capture;
mod class;
mod collapse;
+mod control;
mod func;
mod layout;
mod module;
@@ -23,6 +24,7 @@ pub use array::*;
pub use capture::*;
pub use class::*;
pub use collapse::*;
+pub use control::*;
pub use dict::*;
pub use func::*;
pub use layout::*;
@@ -35,7 +37,7 @@ pub use value::*;
use unicode_segmentation::UnicodeSegmentation;
-use crate::diag::{At, Error, StrResult, Trace, Tracepoint, TypError, TypResult};
+use crate::diag::{At, Error, StrResult, Trace, Tracepoint, TypResult};
use crate::geom::{Angle, Fractional, Length, Relative};
use crate::library;
use crate::syntax::ast::*;
@@ -55,40 +57,6 @@ pub trait Eval {
/// 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 {
- /// Stop iteration in a loop.
- Break(Span),
- /// Skip the remainder of the current iteration in a loop.
- Continue(Span),
- /// Stop execution of a function early, optionally returning a value.
- Return(Option<Value>, Span),
- /// Stop the execution because an error occurred.
- 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;
@@ -337,12 +305,10 @@ impl Eval for BlockExpr {
let mut output = Value::None;
for expr in self.exprs() {
- let value = expr.eval(ctx, scp)?;
- output = ops::join(output, value).at(expr.span())?;
+ output = join_result(output, expr.eval(ctx, scp), expr.span())?;
}
scp.exit();
-
Ok(output)
}
}
@@ -637,12 +603,14 @@ impl Eval for WhileExpr {
let condition = self.condition();
while condition.eval(ctx, scp)?.cast::<bool>().at(condition.span())? {
let body = self.body();
- let value = match body.eval(ctx, scp) {
- Err(Control::Break(_)) => break,
- Err(Control::Continue(_)) => continue,
- other => other?,
- };
- output = ops::join(output, value).at(body.span())?;
+ match join_result(output, body.eval(ctx, scp), body.span()) {
+ Err(Control::Break(value, _)) => {
+ output = value;
+ break;
+ }
+ Err(Control::Continue(value, _)) => output = value,
+ other => output = other?,
+ }
}
Ok(output)
@@ -663,13 +631,14 @@ impl Eval for ForExpr {
$(scp.top.def_mut(&$binding, $value);)*
let body = self.body();
- let value = match body.eval(ctx, scp) {
- Err(Control::Break(_)) => break,
- Err(Control::Continue(_)) => continue,
- other => other?,
- };
-
- output = ops::join(output, value).at(body.span())?;
+ match join_result(output, body.eval(ctx, scp), body.span()) {
+ Err(Control::Break(value, _)) => {
+ output = value;
+ break;
+ }
+ Err(Control::Continue(value, _)) => output = value,
+ other => output = other?,
+ }
}
scp.exit();
@@ -783,7 +752,7 @@ impl Eval for BreakExpr {
type Output = Value;
fn eval(&self, _: &mut Context, _: &mut Scopes) -> EvalResult<Self::Output> {
- Err(Control::Break(self.span()))
+ Err(Control::Break(Value::default(), self.span()))
}
}
@@ -791,7 +760,7 @@ impl Eval for ContinueExpr {
type Output = Value;
fn eval(&self, _: &mut Context, _: &mut Scopes) -> EvalResult<Self::Output> {
- Err(Control::Continue(self.span()))
+ Err(Control::Continue(Value::default(), self.span()))
}
}
@@ -799,8 +768,11 @@ impl Eval for ReturnExpr {
type Output = Value;
fn eval(&self, ctx: &mut Context, scp: &mut Scopes) -> EvalResult<Self::Output> {
+ let value = self.body().map(|body| body.eval(ctx, scp)).transpose()?;
+ let explicit = value.is_some();
Err(Control::Return(
- self.body().map(|body| body.eval(ctx, scp)).transpose()?,
+ value.unwrap_or_default(),
+ explicit,
self.span(),
))
}
generated by cgit v1.2.3 (git 2.25.1) at 2026-03-15 19:25:24 +0000