Struct GroupPlan 

pub struct GroupPlan {
    pub recursive: bool,
    pub statics: Vec<StaticBinding>,
    pub dynamics: Vec<DynamicBinding>,
    pub inherit_froms: Vec<Expr>,
}

The normalized plan for one binding group — an attrset, a let, a rec, or a legacy let { … }.

Fields

recursive: bool

Effective recursiveness. The FIRST definition’s, never an OR of the two — a later rec is discarded.

★ CORRECTED 2026-08-18. This used to say the discard makes { a = {b=1;}; a = rec {c=2; d=c;}; } “a parse error in nix”. It is not. Measured:

{ a = {b=1;}; a = rec {c=2; d=c;}; }   exit 1  error: undefined variable 'c'
{ a = {b=1;}; a = rec {c=2;};      }   exit 0  { a = { b = 1; c = 2; }; }
{ a = rec {c=2; d=c;}; a = {b=1;}; }   exit 0  { a = { b=1; c=2; d=2; }; }

The MECHANISM was right and the CONSEQUENCE was wrong, which is the dangerous shape: nix accepts the group, splices it, and only then fails to resolve c — at EVAL time, because the discarded rec left no scope for d to find it in. Drop d = c and the same shape is exit 0. Reverse the order and it evaluates fine, because the first declaration’s rec governs.

This matters for the rejection tier: an implementation that read this comment literally would refuse row 2 outright, which nix ACCEPTS. A false reject refuses working code. (The tree-walker was already correct on all three — only the comment was wrong.)

statics: Vec<StaticBinding>

Static bindings after the splice, in nix’s insertion order.

dynamics: Vec<DynamicBinding>

Dynamic-keyed bindings. Collisions among these — and against statics — are an EVAL-time error, and only when forced.

inherit_froms: Vec<Expr>

One entry per inherit (e) …; clause that landed on this group, INCLUDING clauses spliced in from a later side. Referenced by index from Binding::InheritFrom so a clause’s source is evaluated once and shared across its names.

Evaluated in the group’s OWN scope, which is rec-visible when the group is recursive — measured: rec { b = {x=99;}; inherit (b) x; } is x = 99, so the source sees the group it is being bound into.

Trait Implementations

impl Clone for GroupPlan

fn clone(&self) -> GroupPlan

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for GroupPlan

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for GroupPlan

fn default() -> GroupPlan

Returns the “default value” for a type.