Module core 

Core data types: expressions (Exp), values (Val), and environments (Env).

The floor language is λ↑↓ as defined by base.scm in namin/pink (Amin & Rompf, Collapsing Towers of Interpreters, POPL 2018): a unary lambda calculus with pairs, staging operators, and a small set of effects. The representation is nameless — the parser resolves every identifier to an environment slot, so variables are Exp::Var indices and binders carry no names. This module holds only the data: the CK machine that evaluates it lives in crate::eval, the reader in crate::parse.

Enums

Exp

A floor expression, after parsing and sugar expansion.

Val

A runtime value.

Functions

code

Wrap an expression tree as a Val::Code staged-code value.

count_nodes

Count Exp tree nodes — used by Val::Display for #<code N nodes>, and by tests that need to bound compiled-ANF size.

env_new

An empty environment.

env_push

Push a value onto a borrowed environment, returning a new Env.

env_push_owned

Push a value onto an owned environment, returning a new Env.

rc_exp

Wrap an expression as a shared child node.

rc_val

Wrap a value as a shared child node.

tup

Cons two values into a Val::Tup pair.

Type Aliases

Env

A persistent, copy-on-write environment: Rc<Vec<Val>>.

RcExp

Shared expression node. See the note above on why Rc and not Box.

RcVal

Shared value node.