diff options
| -rw-r--r-- | tvix/eval/src/builtins/mod.rs | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/tvix/eval/src/builtins/mod.rs b/tvix/eval/src/builtins/mod.rs index 41fa4d4d9992..3ceafa498fcd 100644 --- a/tvix/eval/src/builtins/mod.rs +++ b/tvix/eval/src/builtins/mod.rs @@ -54,6 +54,8 @@ pub fn coerce_value_to_path(v: &Value, vm: &mut VM) -> Result<PathBuf, ErrorKind #[builtins] mod pure_builtins { + use std::collections::VecDeque; + use super::*; #[builtin("abort")] @@ -343,6 +345,51 @@ mod pure_builtins { json.try_into() } + #[builtin("genericClosure")] + fn builtin_generic_closure(vm: &mut VM, input: Value) -> Result<Value, ErrorKind> { + let attrs = input.to_attrs()?; + + // The work set is maintained as a VecDeque because new items + // are popped from the front. + let mut work_set: VecDeque<Value> = attrs + .select_required("startSet")? + .force(vm)? + .to_list()? + .into_iter() + .collect(); + + let operator = attrs.select_required("operator")?; + + let mut res = NixList::new(); + let mut done_keys: Vec<Value> = vec![]; + + let mut insert_key = |k: Value, vm: &mut VM| -> Result<bool, ErrorKind> { + for existing in &done_keys { + if existing.nix_eq(&k, vm)? { + return Ok(false); + } + } + done_keys.push(k); + Ok(true) + }; + + while let Some(val) = work_set.pop_front() { + let attrs = val.force(vm)?.to_attrs()?; + let key = attrs.select_required("key")?; + + if !insert_key(key.clone(), vm)? { + continue; + } + + res.push(val.clone()); + + let op_result = vm.call_with(operator, Some(val))?.force(vm)?.to_list()?; + work_set.extend(op_result.into_iter()); + } + + Ok(Value::List(res)) + } + #[builtin("genList")] fn builtin_gen_list(vm: &mut VM, generator: Value, length: Value) -> Result<Value, ErrorKind> { let len = length.as_int()?; |