eval.sx grows: five new syntactic operators wired via the table-
driven dispatch from Phase 2. lambda creates closures
{:scm-tag :closure :params :rest :body :env} that capture the
static env; scheme-apply-closure binds formals + rest-arg, evaluates
multi-expression body in (extend static-env), returns last value.
Supports lambda formals shapes:
() → no args
(a b c) → fixed arity
args → bare symbol; binds all call-args as a list
Dotted-pair tail (a b . rest) deferred until parser supports it.
define has both flavours:
(define name expr) — direct binding
(define (name . formals) body...) — lambda sugar
set! walks the env chain via refl-env-find-frame, mutates at the
binding's source frame (no shadowing). Raises on unbound name.
24 new tests in lib/scheme/tests/syntax.sx, including:
- Factorial 5 → 120 and 10 → 3628800 (recursion + closures)
- make-counter via closed-over set! state
- Curried (((curry+ 1) 2) 3) → 6
- (lambda args args) rest-arg binding
- Multi-body lambdas with internal define
109 total Scheme tests (62 parse + 23 eval + 24 syntax).
lib/scheme/eval.sx — R7RS evaluator skeleton:
- Self-evaluating: numbers, booleans, characters, vectors, strings
- Symbol lookup: refl-env-lookup
- Lists: syntactic-operator table dispatch, else applicative call
- Table-driven syntactic ops (Phase 2 wires `quote` only; full set
in Phase 3)
- Apply: callable host fn or scheme closure (closure stub for Phase 3)
scheme-make-env / scheme-env-bind! / etc. are THIN ALIASES for the
refl-env-* primitives from lib/guest/reflective/env.sx. No adapter
cfg needed — Scheme's lexical-scope semantics ARE the canonical
wire shape. This is the THIRD CONSUMER for env.sx after Kernel and
Tcl + Smalltalk's variant adapters; the first to use it without
any bridging code. Validates the kit handles canonical-shape
adoption with zero ceremony.
23 tests in lib/scheme/tests/eval.sx cover literals, symbol
lookup with parent-chain shadowing, quote (special form + sugar),
primitive application with nested calls, and an env-as-value
section explicitly demonstrating the kit primitives work on
Scheme envs.
85 total Scheme tests (62 parse + 23 eval).
chisel: consumes-env (third consumer for lib/guest/reflective/env.sx).
