Clone stack on-demand

maplant · Dec 4, 2024 · 2fb91d9 · 2fb91d9
1 parent 8645a60
commit 2fb91d9
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Showing 3 changed files with 158 additions and 5 deletions.
diff --git a/src/continuation.rs b/src/continuation.rs
@@ -1,4 +1,5 @@
 use async_trait::async_trait;
+use futures::future::BoxFuture;
 use proc_macros::builtin;
 
 use crate::{
@@ -31,6 +32,8 @@ pub trait Resumable: Trace + Send + Sync {
         args: Vec<Gc<Value>>,
         cont: &Option<Arc<Continuation>>,
     ) -> Result<Vec<Gc<Value>>, RuntimeError>;
+
+    async fn clone_stack(&self) -> Arc<dyn Resumable>;
 }
 
 #[derive(Clone, Trace)]
@@ -46,6 +49,19 @@ impl Continuation {
             remaining: remaining.clone(),
         }
     }
+
+    fn clone_stack(&self) -> BoxFuture<'_, Arc<Self>> {
+        Box::pin(async move {
+            Arc::new(Self {
+                resume_point: self.resume_point.clone_stack().await,
+                remaining: if let Some(ref cont) = self.remaining {
+                    Some(cont.clone_stack().await)
+                } else {
+                    None
+                },
+            })
+        })
+    }
 }
 
 #[async_trait]
@@ -63,6 +79,10 @@ impl Resumable for Continuation {
             self.resume_point.resume(args, cont).await
         }
     }
+
+    async fn clone_stack(&self) -> Arc<dyn Resumable> {
+        self.clone_stack().await
+    }
 }
 
 #[async_trait]
@@ -128,7 +148,7 @@ impl Eval for CatchContinuationCall {
     }
 }
 
-#[derive(Trace)]
+#[derive(Trace, Clone)]
 pub struct ResumableBody {
     env: Env,
     remaining: ArcSlice<Arc<dyn Eval>>,
@@ -162,6 +182,19 @@ impl Resumable for ResumableBody {
         }
         last.eval(&self.env, cont).await
     }
+
+    async fn clone_stack(&self) -> Arc<dyn Resumable> {
+        Arc::new(Self {
+            env: self.env.deep_clone().await,
+            remaining: self.remaining.clone(),
+        })
+    }
+
+    /*
+    async fn clone_stack(&self) -> Arc<dyn Resumable> {
+        Arc::new(self.clone())
+    }
+    */
 }
 
 #[derive(Trace)]
@@ -200,6 +233,13 @@ impl Resumable for ResumableSyntaxCase {
             _ => todo!(),
         }
     }
+
+    async fn clone_stack(&self) -> Arc<dyn Resumable> {
+        Arc::new(Self {
+            env: self.env.deep_clone().await,
+            transformer: self.transformer.clone(),
+        })
+    }
 }
 
 #[derive(Trace)]
@@ -236,6 +276,13 @@ impl Resumable for ResumableSet {
             .await = val;
         Ok(vec![Gc::new(Value::Null)])
     }
+
+    async fn clone_stack(&self) -> Arc<dyn Resumable> {
+        Arc::new(Self {
+            env: self.env.deep_clone().await,
+            var: self.var.clone(),
+        })
+    }
 }
 
 #[derive(Trace)]
@@ -287,6 +334,13 @@ impl Resumable for ResumableAnd {
         }
         last.eval(&self.env, cont).await
     }
+
+    async fn clone_stack(&self) -> Arc<dyn Resumable> {
+        Arc::new(Self {
+            env: self.env.deep_clone().await,
+            args: self.args.clone(),
+        })
+    }
 }
 
 #[derive(Trace)]
@@ -338,6 +392,13 @@ impl Resumable for ResumableOr {
         }
         last.eval(&self.env, cont).await
     }
+
+    async fn clone_stack(&self) -> Arc<dyn Resumable> {
+        Arc::new(Self {
+            env: self.env.deep_clone().await,
+            args: self.args.clone(),
+        })
+    }
 }
 
 #[derive(Trace)]
@@ -387,6 +448,15 @@ impl Resumable for ResumableLet {
         }
         self.body.eval(&Env::from(self.scope.clone()), cont).await
     }
+
+    async fn clone_stack(&self) -> Arc<dyn Resumable> {
+        Arc::new(Self {
+            scope: Gc::new(self.scope.read().await.deep_clone().await),
+            curr: self.curr.clone(),
+            remaining_bindings: self.remaining_bindings.clone(),
+            body: self.body.clone(),
+        })
+    }
 }
 
 #[derive(Trace)]
@@ -422,6 +492,14 @@ impl Resumable for ResumableIf {
             Ok(vec![Gc::new(Value::Null)])
         }
     }
+
+    async fn clone_stack(&self) -> Arc<dyn Resumable> {
+        Arc::new(Self {
+            env: self.env.deep_clone().await,
+            success: self.success.clone(),
+            failure: self.failure.clone(),
+        })
+    }
 }
 
 #[derive(Trace)]
@@ -450,6 +528,13 @@ impl Resumable for ResumableDefineVar {
         self.env.def_var(&self.name, arg).await;
         Ok(vec![Gc::new(Value::Null)])
     }
+
+    async fn clone_stack(&self) -> Arc<dyn Resumable> {
+        Arc::new(Self {
+            env: self.env.deep_clone().await,
+            name: self.name.clone(),
+        })
+    }
 }
 
 #[derive(Trace)]
@@ -516,6 +601,16 @@ impl Resumable for ResumableCall {
             .eval(cont)
             .await
     }
+
+    async fn clone_stack(&self) -> Arc<dyn Resumable> {
+        Arc::new(Self {
+            env: self.env.deep_clone().await,
+            collected: self.collected.clone(),
+            remaining: self.remaining.clone(),
+            proc_name: self.proc_name.clone(),
+            location: self.location.clone(),
+        })
+    }
 }
 
 #[derive(Trace)]
@@ -602,6 +697,25 @@ impl Resumable for ResumableApply {
             .eval(cont)
             .await
     }
+
+    async fn clone_stack(&self) -> Arc<dyn Resumable> {
+        Arc::new(Self {
+            env: self.env.deep_clone().await,
+            collected: self.collected.clone(),
+            remaining: self.remaining.clone(),
+            rest_args: self.rest_args.clone(),
+            proc_name: self.proc_name.clone(),
+            location: self.location.clone(),
+        })
+    }
+}
+
+async fn clone_cont_stack(cont: &Option<Arc<Continuation>>) -> Option<Arc<Continuation>> {
+    if let Some(ref cont) = cont {
+        Some(cont.clone_stack().await)
+    } else {
+        None
+    }
 }
 
 #[builtin("call/cc")]
@@ -615,13 +729,16 @@ pub async fn call_cc(
             .ok_or_else(|| RuntimeError::invalid_type("procedure", proc.type_name()))?
     };
     callable
-        .call(vec![Gc::new(Value::Continuation(cont.clone()))], cont)
+        .call(
+            vec![Gc::new(Value::Continuation(clone_cont_stack(cont).await))],
+            cont,
+        )
         .await?
         .eval(cont)
         .await
 }
 
-#[derive(Trace)]
+#[derive(Trace, Clone)]
 pub struct CallWithValues {
     min_args: usize,
     max_args: Option<usize>,
@@ -649,6 +766,10 @@ impl Resumable for CallWithValues {
         };
         callable.call(args, cont).await?.eval(cont).await
     }
+
+    async fn clone_stack(&self) -> Arc<dyn Resumable> {
+        Arc::new(self.clone())
+    }
 }
 
 #[builtin("call-with-values")]
@@ -673,7 +794,7 @@ pub async fn call_with_values(
             max_args: consumer_callable.max_args(),
             consumer: consumer.clone(),
         }),
-        cont,
+        &clone_cont_stack(cont).await,
     ));
 
     let producer_result = producer_callable

diff --git a/src/env.rs b/src/env.rs
@@ -72,6 +72,16 @@ impl LexicalContour {
         }
         self.macros.insert(ident.clone(), value);
     }
+
+    pub fn deep_clone(&self) -> BoxFuture<'_, Self> {
+        Box::pin(async move {
+            Self {
+                up: self.up.deep_clone().await,
+                vars: self.vars.clone(),
+                macros: self.macros.clone(),
+            }
+        })
+    }
 }
 
 #[derive(derive_more::Debug, Trace)]
@@ -124,6 +134,16 @@ impl ExpansionContext {
             }
         })
     }
+
+    pub fn deep_clone(&self) -> BoxFuture<'_, Self> {
+        Box::pin(async move {
+            Self {
+                up: self.up.deep_clone().await,
+                mark: self.mark,
+                macro_env: self.macro_env.deep_clone().await,
+            }
+        })
+    }
 }
 
 #[derive(Clone, Trace, derive_more::Debug)]
@@ -219,6 +239,18 @@ impl Env {
         })
     }
 
+    pub async fn deep_clone(&self) -> Self {
+        match self {
+            Self::Top => Self::Top,
+            Self::Expansion(expansion) => {
+                Self::Expansion(Gc::new(expansion.read().await.deep_clone().await))
+            }
+            Self::LexicalContour(env) => {
+                Self::LexicalContour(Gc::new(env.read().await.deep_clone().await))
+            }
+        }
+    }
+
     /// Evaluate a string, returning all of the results in a Vec
     pub async fn eval<'e>(&self, exprs: &'e str) -> Result<Vec<Vec<Gc<Value>>>, EvalError<'e>> {
         let tokens = Token::tokenize_str(exprs)?;

diff --git a/src/value.rs b/src/value.rs
@@ -360,6 +360,6 @@ pub async fn disp(
     _cont: &Option<Arc<Continuation>>,
     arg: &Gc<Value>,
 ) -> Result<Vec<Gc<Value>>, RuntimeError> {
-    println!("{}", arg.read().await.fmt().await);
+    print!("{}", arg.read().await.fmt().await);
     Ok(vec![Gc::new(Value::Null)])
 }