scm-match-list now detects `<pat> ...` at the END of a pattern list
and binds <pat> (must be a symbol — single-variable rest) to the
remaining forms as a list. Nested-list patterns under ellipsis and
middle-of-list ellipses are NOT supported yet (rare in practice;
deferred).
scm-instantiate-list mirrors: when it encounters `<var> ... `
inside a list template, it splices the list-valued binding of <var>
in place. Internal list-append-all helper for the splice.
Removes the `(length pat) = (length form)` strict-equality check
in scm-match-step's list case — that gate blocked ellipsis. The
length-1-or-more relaxed check now lives in scm-match-list itself.
8 ellipsis tests cover:
- Empty rest (my-list)
- Non-empty rest (my-list 1 2 3 4)
- my-when with multi-body
- Variadic sum-em via fold-left
- Recursive my-and pattern (short-circuit AND defined as macro)
257 total Scheme tests (62 + 23 + 49 + 78 + 25 + 20).
Phase 6c (proper hygiene) is the next step and will be the
**second consumer for lib/guest/reflective/hygiene.sx** — the
deferred research-grade kit from the kernel-on-sx loop.
eval.sx adds macro infrastructure:
- {:scm-tag :macro :literals (LIT...) :rules ((PAT TMPL)...) :env E}
- scheme-macro? predicate
- scm-match / scm-match-list — pattern matching against literals,
pattern variables, and structural list shapes
- scm-instantiate — template substitution with bindings
- scm-expand-rules — try each rule in order
- (syntax-rules (LITS) (PAT TMPL)...) → macro value
- (define-syntax NAME FORM) → bind macro in env
- scheme-eval: when head looks up to a macro, expand and re-eval
Pattern matching supports:
- _ → match anything, no bind
- literal symbols from the LITERALS list → must equal-match
- other symbols → pattern variables, bind to matched form
- list patterns → must be same length, each element matches
NO ellipsis (`...`) support yet — that's Phase 6b. NO hygiene
yet (introduced symbols can shadow caller bindings) — that's
Phase 6c, which will be the second consumer for
lib/guest/reflective/hygiene.sx.
12 tests cover: simple substitution, multi-rule selection,
nested macro use, swap-idiom (state mutation via set!), control-
flow wrappers, literal-keyword pattern matching, macros inside
lambdas.
249 total Scheme tests now (62 + 23 + 49 + 78 + 25 + 12).
