ForceMode

fix-vm/src/instructions/builtins.rs

@@ -5,9 +5,7 @@ use num_enum::TryFromPrimitive as _;
 use smallvec::SmallVec;
 
 use crate::value::*;
-use crate::{
-    BytecodeReader, CallFrame, Step, Vm, VmRuntimeCtx, VmRuntimeCtxExt,
-};
+use crate::{BytecodeReader, CallFrame, Step, Vm, VmRuntimeCtx, VmRuntimeCtxExt};
 
 impl<'gc> Vm<'gc> {
     #[allow(clippy::too_many_lines)]
@@ -34,7 +32,12 @@ impl<'gc> Vm<'gc> {
             FilterCallPred => self.primop_filter_call_pred(reader, mc),
             FilterCheck => self.primop_filter_check(reader, mc),
 
-            _ => todo!("dispatch builtin phase"),
+            ForceResultShallow => self.primop_force_result_shallow(ctx, reader, mc),
+            ForceResultShallowPush => self.primop_force_result_shallow_push(ctx, reader, mc),
+            ForceResultShallowLoop => self.primop_force_result_shallow_loop(reader, mc),
+            ForceResultDeepFinish => self.primop_force_result_deep_finish(ctx, reader, mc),
+
+            phase => todo!("primop phase {phase:?}"),
         }
     }
 
@@ -143,9 +146,7 @@ impl<'gc> Vm<'gc> {
         // stack: [msg] - force msg, then abort with it
         self.force_slot(0, reader, mc)?;
         let msg_val = self.peek_forced(0);
-        let msg = ctx
-            .get_string(msg_val)
-            .unwrap_or("<non-string-value>");
+        let msg = ctx.get_string(msg_val).unwrap_or("<non-string-value>");
         self.finish_err(Error::eval_error(format!(
             "evaluation aborted with the following error message: '{msg}'"
         )))
@@ -222,12 +223,7 @@ impl<'gc> Vm<'gc> {
         self.push(item);
 
         // force item at TOS, resume at DeepSeqLoop after force
-        self.force_slot_to_pc(
-            0,
-            reader,
-            mc,
-            PrimOpPhase::DeepSeqLoop.ip() as usize,
-        )?;
+        self.force_slot_to_pc(0, reader, mc, PrimOpPhase::DeepSeqLoop.ip() as usize)?;
         reader.set_pc(PrimOpPhase::DeepSeqLoop.ip() as usize);
         Step::Continue(())
     }
@@ -281,11 +277,98 @@ impl<'gc> Vm<'gc> {
         Step::Continue(())
     }
 
-    fn is_value_in_seen(
-        &self,
-        seen: Gc<'gc, List<'gc>>,
-        val: Value<'gc>,
-    ) -> bool {
+    pub(crate) fn primop_force_result_shallow(
+        &mut self,
+        ctx: &mut impl VmRuntimeCtx,
+        reader: &mut BytecodeReader<'_>,
+        mc: &Mutation<'gc>,
+    ) -> Step {
+        self.force_slot(0, reader, mc)?;
+        let val = self.peek_forced(0);
+
+        let (count, has_children) = if let Some(attrs) = val.as_gc::<AttrSet>() {
+            let len = attrs.len();
+            (len, len > 0)
+        } else if let Some(list) = val.as_gc::<List<'gc>>() {
+            let len = list.inner.borrow().len();
+            (len, len > 0)
+        } else {
+            (0, false)
+        };
+
+        if !has_children {
+            let val = self.pop();
+            return self.finish_ok(ctx.convert_value(val));
+        }
+
+        self.push(Value::new_inline(0i32));
+        self.push(Value::new_inline(count as i32));
+        reader.set_pc(PrimOpPhase::ForceResultShallowPush.ip() as usize);
+        Step::Continue(())
+    }
+
+    pub(crate) fn primop_force_result_shallow_push(
+        &mut self,
+        ctx: &mut impl VmRuntimeCtx,
+        reader: &mut BytecodeReader<'_>,
+        mc: &Mutation<'gc>,
+    ) -> Step {
+        #[allow(clippy::unwrap_used)]
+        let idx = self.peek(1).as_inline::<i32>().unwrap();
+        #[allow(clippy::unwrap_used)]
+        let len = self.peek(0).as_inline::<i32>().unwrap();
+
+        if idx == len {
+            let _ = self.pop(); // len
+            let _ = self.pop(); // idx
+            let val = self.pop();
+            return self.finish_ok(ctx.convert_value(val));
+        }
+
+        let val = self.peek_forced(2);
+        let child = if let Some(attrs) = val.as_gc::<AttrSet>() {
+            attrs.get(idx as usize).map(|&(_, v)| v)
+        } else if let Some(list) = val.as_gc::<List<'gc>>() {
+            list.inner.borrow().get(idx as usize).copied()
+        } else {
+            None
+        };
+
+        if let Some(child) = child {
+            self.replace(1, Value::new_inline(idx + 1));
+            self.push(child);
+            self.force_slot_to_pc(
+                0,
+                reader,
+                mc,
+                PrimOpPhase::ForceResultShallowLoop.ip() as usize,
+            )?;
+            reader.set_pc(PrimOpPhase::ForceResultShallowLoop.ip() as usize);
+        }
+        Step::Continue(())
+    }
+
+    pub(crate) fn primop_force_result_shallow_loop(
+        &mut self,
+        reader: &mut BytecodeReader<'_>,
+        _mc: &Mutation<'gc>,
+    ) -> Step {
+        let _ = self.pop(); // forced child
+        reader.set_pc(PrimOpPhase::ForceResultShallowPush.ip() as usize);
+        Step::Continue(())
+    }
+
+    pub(crate) fn primop_force_result_deep_finish(
+        &mut self,
+        ctx: &mut impl VmRuntimeCtx,
+        reader: &mut BytecodeReader<'_>,
+        mc: &Mutation<'gc>,
+    ) -> Step {
+        let val = self.try_force::<StrictValue>(reader, mc)?;
+        self.finish_ok(ctx.convert_value(val.relax()))
+    }
+
+    fn is_value_in_seen(&self, seen: Gc<'gc, List<'gc>>, val: Value<'gc>) -> bool {
         if !is_container(val) {
             return false;
         }
@@ -298,12 +381,7 @@ impl<'gc> Vm<'gc> {
         false
     }
 
-    fn add_value_to_seen(
-        &self,
-        seen: Gc<'gc, List<'gc>>,
-        mc: &Mutation<'gc>,
-        val: Value<'gc>,
-    ) {
+    fn add_value_to_seen(&self, seen: Gc<'gc, List<'gc>>, mc: &Mutation<'gc>, val: Value<'gc>) {
         if is_container(val) {
             seen.unlock(mc).borrow_mut().push(val);
         }

fix-vm/src/instructions/calls.rs

@@ -1,9 +1,11 @@
+use fix_builtins::PrimOpPhase;
 use fix_error::Error;
 use gc_arena::{Gc, Mutation, RefLock};
 
 use crate::value::*;
 use crate::{
-    BytecodeReader, CallFrame, Closure, Env, Step, ThunkState, VmRuntimeCtx, VmRuntimeCtxExt,
+    BytecodeReader, CallFrame, Closure, Env, ForceMode, Step, ThunkState, VmRuntimeCtx,
+    VmRuntimeCtxExt,
 };
 
 impl<'gc> crate::Vm<'gc> {
@@ -112,7 +114,28 @@ impl<'gc> crate::Vm<'gc> {
             with_env,
         }) = self.call_stack.pop()
         else {
-            return self.finish_ok(ctx.convert_value(val.relax()));
+            match self.force_mode {
+                ForceMode::AsIs => return self.finish_ok(ctx.convert_value(val.relax())),
+                ForceMode::Shallow => {
+                    self.push(val.relax());
+                    reader.set_pc(PrimOpPhase::ForceResultShallow.ip() as usize);
+                    return Step::Continue(());
+                }
+                ForceMode::Deep => {
+                    self.push(val.relax());
+                    self.push(val.relax());
+                    self.call_stack.push(CallFrame {
+                        pc: PrimOpPhase::ForceResultDeepFinish.ip() as usize,
+                        stack_depth: 0,
+                        thunk: None,
+                        env: self.env,
+                        with_env: self.with_env,
+                    });
+                    self.call_depth += 1;
+                    reader.set_pc(PrimOpPhase::DeepSeq.ip() as usize);
+                    return Step::Continue(());
+                }
+            }
         };
         reader.set_pc(ret_pc);
         if let Some(outer_thunk) = thunk {

fix-vm/src/lib.rs

@@ -13,7 +13,7 @@ use fix_common::StringId;
 use fix_error::{Error, Result, Source};
 use gc_arena::arena::CollectionPhase;
 use gc_arena::{Arena, Collect, Gc, Mutation, RefLock, Rootable};
-use hashbrown::HashMap;
+use hashbrown::{HashMap, HashSet};
 use num_enum::TryFromPrimitive;
 use smallvec::SmallVec;
 
@@ -115,6 +115,16 @@ impl<T: VmRuntimeCtx> VmRuntimeCtxExt for T {
     }
 
     fn convert_value(&self, val: Value) -> fix_common::Value {
+        self.convert_value_with_seen(val, &mut HashSet::new())
+    }
+}
+
+trait ConvertValueWithSeen: VmRuntimeCtx {
+    fn convert_value_with_seen(&self, val: Value, seen: &mut HashSet<u64>) -> fix_common::Value;
+}
+
+impl<T: VmRuntimeCtx> ConvertValueWithSeen for T {
+    fn convert_value_with_seen(&self, val: Value, seen: &mut HashSet<u64>) -> fix_common::Value {
         use fix_common::Value;
         if let Some(i) = val.as_inline::<i32>() {
             Value::Int(i as i64)
@@ -132,26 +142,44 @@ impl<T: VmRuntimeCtx> VmRuntimeCtxExt for T {
         } else if let Some(ns) = val.as_gc::<NixString>() {
             Value::String(ns.as_str().to_owned())
         } else if let Some(attrs) = val.as_gc::<AttrSet>() {
+            let bits = val.to_bits();
+            if attrs.is_empty() {
+                return Value::AttrSet(Default::default());
+            }
+            if !seen.insert(bits) {
+                return Value::Repeated;
+            }
             let mut map = std::collections::BTreeMap::new();
             for &(key, val) in attrs.iter() {
                 let key = self.resolve_string(key).to_owned();
-                let converted = self.convert_value(val);
+                let converted = self.convert_value_with_seen(val, seen);
                 map.insert(fix_common::Symbol::from(key), converted);
             }
             Value::AttrSet(fix_common::AttrSet::new(map))
         } else if let Some(list) = val.as_gc::<List>() {
+            let bits = val.to_bits();
+            if list.inner.borrow().is_empty() {
+                return Value::List(Default::default());
+            }
+            if !seen.insert(bits) {
+                return Value::Repeated;
+            }
             let items: Vec<_> = list
                 .inner
                 .borrow()
                 .iter()
                 .copied()
-                .map(|v| self.convert_value(v))
+                .map(|v| self.convert_value_with_seen(v, seen))
                 .collect();
             Value::List(fix_common::List::new(items))
         } else if val.is::<Closure>() {
             Value::Func
-        } else if val.is::<Thunk>() {
-            Value::Thunk
+        } else if let Some(thunk) = val.as_gc::<Thunk>() {
+            if let ThunkState::Evaluated(v) = *thunk.borrow() {
+                self.convert_value_with_seen(v.relax(), seen)
+            } else {
+                Value::Thunk
+            }
         } else if let Some(primop) = val.as_inline::<PrimOp>() {
             let name = fix_builtins::BUILTINS[primop.id as usize].0;
             Value::PrimOp(name.strip_prefix("__").unwrap_or(name))
@@ -278,7 +306,10 @@ fn init_builtins<'gc>(mc: &Mutation<'gc>, ctx: &mut impl VmRuntimeCtx) -> Value<
     entries.sort_by_key(|(k, _)| *k);
 
     let builtins_set = Gc::new(mc, AttrSet::from_sorted_unchecked(entries));
-    Value::new_gc(builtins_set)
+    let builtins_value = Value::new_gc(builtins_set);
+    *self_ref_thunk.borrow_mut(mc) =
+        ThunkState::Evaluated(builtins_value.restrict().expect("builtins is not a thunk"));
+    builtins_value
 }
 
 impl<'gc> Vm<'gc> {

fix-vm/src/value.rs

@@ -506,9 +506,12 @@ pub(crate) struct List<'gc> {
 
 impl<'gc> List<'gc> {
     pub(crate) fn new(mc: &Mutation<'gc>, data: SmallVec<[Value<'gc>; 4]>) -> Gc<'gc, Self> {
-        Gc::new(mc, Self {
-            inner: RefLock::new(data)
-        })
+        Gc::new(
+            mc,
+            Self {
+                inner: RefLock::new(data),
+            },
+        )
     }
 
     pub(crate) fn new_gc(mc: &Mutation<'gc>) -> Gc<'gc, Self> {