diff options
Diffstat (limited to 'tvix/eval/src/value/thunk.rs')
| -rw-r--r-- | tvix/eval/src/value/thunk.rs | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/tvix/eval/src/value/thunk.rs b/tvix/eval/src/value/thunk.rs index 1acb50a94b..9c048d40b4 100644 --- a/tvix/eval/src/value/thunk.rs +++ b/tvix/eval/src/value/thunk.rs @@ -27,6 +27,7 @@ use std::{ use crate::{ errors::ErrorKind, + opcode::OpCode, spans::LightSpan, upvalues::Upvalues, value::Closure, @@ -124,6 +125,36 @@ impl Thunk { ))))) } + /// Helper function to create a [`Thunk`] that calls a function given as the + /// [`Value`] `callee` with the argument `arg` when it is forced. This is + /// particularly useful in builtin implementations if the result of calling + /// a function does not need to be forced immediately, because e.g. it is + /// stored in an attribute set. + pub fn new_suspended_call(callee: Value, arg: Value, light_span: LightSpan) -> Self { + let mut lambda = Lambda::default(); + let span = light_span.span(); + + let arg_idx = lambda.chunk().push_constant(arg); + let f_idx = lambda.chunk().push_constant(callee); + + // This is basically a recreation of compile_apply(): + // We need to push the argument onto the stack and then the function. + // The function (not the argument) needs to be forced before calling. + lambda.chunk.push_op(OpCode::OpConstant(arg_idx), span); + lambda.chunk().push_op(OpCode::OpConstant(f_idx), span); + lambda.chunk.push_op(OpCode::OpForce, span); + lambda.chunk.push_op(OpCode::OpCall, span); + + // Inform the VM that the chunk has ended + lambda.chunk.push_op(OpCode::OpReturn, span); + + Thunk(Rc::new(RefCell::new(ThunkRepr::Suspended { + upvalues: Rc::new(Upvalues::with_capacity(0)), + lambda: Rc::new(lambda), + light_span, + }))) + } + fn prepare_blackhole(&self, forced_at: LightSpan) -> ThunkRepr { match &*self.0.borrow() { ThunkRepr::Suspended { |