ForceMode

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 {