Make continuations an optional extension, add special-forms.sx, ellipsis parsing

- Both bootstrappers (JS + Python) now gate shift/reset behind --extensions
  continuations flag. Without it, using reset/shift errors at runtime.
- JS bootstrapper: extracted Continuation/ShiftSignal types, sfReset/sfShift,
  continuation? primitive, and typeOf handling into CONTINUATIONS_JS constant.
  Extension wraps evalList, aserSpecial, and typeOf post-transpilation.
- Python bootstrapper: added special-forms.sx validation cross-check against
  eval.sx dispatch, warns on mismatches.
- Added shared/sx/ref/special-forms.sx: 36 declarative form specs with syntax,
  docs, tail-position, and examples. Used by bootstrappers for validation.
- Added ellipsis (...) support to both parser.py and parser.sx spec.
- Updated continuations essay to reflect optional extension architecture.
- Updated specs page and nav with special-forms.sx entry.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
This commit is contained in:
2026-03-06 01:44:50 +00:00
parent 31ace8768e
commit ca8de3be1a
9 changed files with 799 additions and 138 deletions

View File

@@ -469,7 +469,7 @@ _SPECIAL_FORM_NAMES = frozenset([
"define", "defcomp", "defmacro", "defstyle", "defkeyframes",
"defhandler", "defpage", "defquery", "defaction", "defrelation",
"begin", "do", "quote", "quasiquote",
"->", "set!", "reset", "shift",
"->", "set!",
])
_HO_FORM_NAMES = frozenset([
@@ -632,11 +632,6 @@ def aser_special(name, expr, env):
"defhandler", "defpage", "defquery", "defaction", "defrelation"):
trampoline(eval_expr(expr, env))
return NIL
# reset/shift — evaluate normally in aser mode (they're control flow)
if name == "reset":
return sf_reset(args, env)
if name == "shift":
return sf_shift(args, env)
# Lambda/fn, quote, quasiquote, set!, -> : evaluate normally
result = eval_expr(expr, env)
return trampoline(result)
@@ -869,7 +864,7 @@ trampoline = lambda val: (lambda result: (trampoline(eval_expr(thunk_expr(result
eval_expr = lambda expr, env: _sx_case(type_of(expr), [('number', lambda: expr), ('string', lambda: expr), ('boolean', lambda: expr), ('nil', lambda: NIL), ('symbol', lambda: (lambda name: (env_get(env, name) if sx_truthy(env_has(env, name)) else (get_primitive(name) if sx_truthy(is_primitive(name)) else (True if sx_truthy((name == 'true')) else (False if sx_truthy((name == 'false')) else (NIL if sx_truthy((name == 'nil')) else error(sx_str('Undefined symbol: ', name))))))))(symbol_name(expr))), ('keyword', lambda: keyword_name(expr)), ('dict', lambda: map_dict(lambda k, v: trampoline(eval_expr(v, env)), expr)), ('list', lambda: ([] if sx_truthy(empty_p(expr)) else eval_list(expr, env))), (None, lambda: expr)])
# eval-list
eval_list = lambda expr, env: (lambda head: (lambda args: (map(lambda x: trampoline(eval_expr(x, env)), expr) if sx_truthy((not sx_truthy(((type_of(head) == 'symbol') if sx_truthy((type_of(head) == 'symbol')) else ((type_of(head) == 'lambda') if sx_truthy((type_of(head) == 'lambda')) else (type_of(head) == 'list')))))) else ((lambda name: (sf_if(args, env) if sx_truthy((name == 'if')) else (sf_when(args, env) if sx_truthy((name == 'when')) else (sf_cond(args, env) if sx_truthy((name == 'cond')) else (sf_case(args, env) if sx_truthy((name == 'case')) else (sf_and(args, env) if sx_truthy((name == 'and')) else (sf_or(args, env) if sx_truthy((name == 'or')) else (sf_let(args, env) if sx_truthy((name == 'let')) else (sf_let(args, env) if sx_truthy((name == 'let*')) else (sf_lambda(args, env) if sx_truthy((name == 'lambda')) else (sf_lambda(args, env) if sx_truthy((name == 'fn')) else (sf_define(args, env) if sx_truthy((name == 'define')) else (sf_defcomp(args, env) if sx_truthy((name == 'defcomp')) else (sf_defmacro(args, env) if sx_truthy((name == 'defmacro')) else (sf_defstyle(args, env) if sx_truthy((name == 'defstyle')) else (sf_defkeyframes(args, env) if sx_truthy((name == 'defkeyframes')) else (sf_defhandler(args, env) if sx_truthy((name == 'defhandler')) else (sf_defpage(args, env) if sx_truthy((name == 'defpage')) else (sf_defquery(args, env) if sx_truthy((name == 'defquery')) else (sf_defaction(args, env) if sx_truthy((name == 'defaction')) else (sf_begin(args, env) if sx_truthy((name == 'begin')) else (sf_begin(args, env) if sx_truthy((name == 'do')) else (sf_quote(args, env) if sx_truthy((name == 'quote')) else (sf_quasiquote(args, env) if sx_truthy((name == 'quasiquote')) else (sf_thread_first(args, env) if sx_truthy((name == '->')) else (sf_set_bang(args, env) if sx_truthy((name == 'set!')) else (sf_reset(args, env) if sx_truthy((name == 'reset')) else (sf_shift(args, env) if sx_truthy((name == 'shift')) else (ho_map(args, env) if sx_truthy((name == 'map')) else (ho_map_indexed(args, env) if sx_truthy((name == 'map-indexed')) else (ho_filter(args, env) if sx_truthy((name == 'filter')) else (ho_reduce(args, env) if sx_truthy((name == 'reduce')) else (ho_some(args, env) if sx_truthy((name == 'some')) else (ho_every(args, env) if sx_truthy((name == 'every?')) else (ho_for_each(args, env) if sx_truthy((name == 'for-each')) else ((lambda mac: make_thunk(expand_macro(mac, args, env), env))(env_get(env, name)) if sx_truthy((env_has(env, name) if not sx_truthy(env_has(env, name)) else is_macro(env_get(env, name)))) else (render_expr(expr, env) if sx_truthy(is_render_expr(expr)) else eval_call(head, args, env))))))))))))))))))))))))))))))))))))))(symbol_name(head)) if sx_truthy((type_of(head) == 'symbol')) else eval_call(head, args, env))))(rest(expr)))(first(expr))
eval_list = lambda expr, env: (lambda head: (lambda args: (map(lambda x: trampoline(eval_expr(x, env)), expr) if sx_truthy((not sx_truthy(((type_of(head) == 'symbol') if sx_truthy((type_of(head) == 'symbol')) else ((type_of(head) == 'lambda') if sx_truthy((type_of(head) == 'lambda')) else (type_of(head) == 'list')))))) else ((lambda name: (sf_if(args, env) if sx_truthy((name == 'if')) else (sf_when(args, env) if sx_truthy((name == 'when')) else (sf_cond(args, env) if sx_truthy((name == 'cond')) else (sf_case(args, env) if sx_truthy((name == 'case')) else (sf_and(args, env) if sx_truthy((name == 'and')) else (sf_or(args, env) if sx_truthy((name == 'or')) else (sf_let(args, env) if sx_truthy((name == 'let')) else (sf_let(args, env) if sx_truthy((name == 'let*')) else (sf_letrec(args, env) if sx_truthy((name == 'letrec')) else (sf_lambda(args, env) if sx_truthy((name == 'lambda')) else (sf_lambda(args, env) if sx_truthy((name == 'fn')) else (sf_define(args, env) if sx_truthy((name == 'define')) else (sf_defcomp(args, env) if sx_truthy((name == 'defcomp')) else (sf_defmacro(args, env) if sx_truthy((name == 'defmacro')) else (sf_defstyle(args, env) if sx_truthy((name == 'defstyle')) else (sf_defkeyframes(args, env) if sx_truthy((name == 'defkeyframes')) else (sf_defhandler(args, env) if sx_truthy((name == 'defhandler')) else (sf_defpage(args, env) if sx_truthy((name == 'defpage')) else (sf_defquery(args, env) if sx_truthy((name == 'defquery')) else (sf_defaction(args, env) if sx_truthy((name == 'defaction')) else (sf_begin(args, env) if sx_truthy((name == 'begin')) else (sf_begin(args, env) if sx_truthy((name == 'do')) else (sf_quote(args, env) if sx_truthy((name == 'quote')) else (sf_quasiquote(args, env) if sx_truthy((name == 'quasiquote')) else (sf_thread_first(args, env) if sx_truthy((name == '->')) else (sf_set_bang(args, env) if sx_truthy((name == 'set!')) else (sf_dynamic_wind(args, env) if sx_truthy((name == 'dynamic-wind')) else (ho_map(args, env) if sx_truthy((name == 'map')) else (ho_map_indexed(args, env) if sx_truthy((name == 'map-indexed')) else (ho_filter(args, env) if sx_truthy((name == 'filter')) else (ho_reduce(args, env) if sx_truthy((name == 'reduce')) else (ho_some(args, env) if sx_truthy((name == 'some')) else (ho_every(args, env) if sx_truthy((name == 'every?')) else (ho_for_each(args, env) if sx_truthy((name == 'for-each')) else ((lambda mac: make_thunk(expand_macro(mac, args, env), env))(env_get(env, name)) if sx_truthy((env_has(env, name) if not sx_truthy(env_has(env, name)) else is_macro(env_get(env, name)))) else (render_expr(expr, env) if sx_truthy(is_render_expr(expr)) else eval_call(head, args, env))))))))))))))))))))))))))))))))))))))(symbol_name(head)) if sx_truthy((type_of(head) == 'symbol')) else eval_call(head, args, env))))(rest(expr)))(first(expr))
# eval-call
eval_call = lambda head, args, env: (lambda f: (lambda evaluated_args: (apply(f, evaluated_args) if sx_truthy((is_callable(f) if not sx_truthy(is_callable(f)) else ((not sx_truthy(is_lambda(f))) if not sx_truthy((not sx_truthy(is_lambda(f)))) else (not sx_truthy(is_component(f)))))) else (call_lambda(f, evaluated_args, env) if sx_truthy(is_lambda(f)) else (call_component(f, args, env) if sx_truthy(is_component(f)) else error(sx_str('Not callable: ', inspect(f)))))))(map(lambda a: trampoline(eval_expr(a, env)), args)))(trampoline(eval_expr(head, env)))
@@ -911,7 +906,13 @@ sf_and = lambda args, env: (True if sx_truthy(empty_p(args)) else (lambda val: (
sf_or = lambda args, env: (False if sx_truthy(empty_p(args)) else (lambda val: (val if sx_truthy(val) else sf_or(rest(args), env)))(trampoline(eval_expr(first(args), env))))
# sf-let
sf_let = lambda args, env: (lambda bindings: (lambda body: (lambda local: _sx_begin((for_each(lambda binding: (lambda vname: _sx_dict_set(local, vname, trampoline(eval_expr(nth(binding, 1), local))))((symbol_name(first(binding)) if sx_truthy((type_of(first(binding)) == 'symbol')) else first(binding))), bindings) if sx_truthy(((type_of(first(bindings)) == 'list') if not sx_truthy((type_of(first(bindings)) == 'list')) else (len(first(bindings)) == 2))) else (lambda i: reduce(lambda acc, pair_idx: (lambda vname: (lambda val_expr: _sx_dict_set(local, vname, trampoline(eval_expr(val_expr, local))))(nth(bindings, ((pair_idx * 2) + 1))))((symbol_name(nth(bindings, (pair_idx * 2))) if sx_truthy((type_of(nth(bindings, (pair_idx * 2))) == 'symbol')) else nth(bindings, (pair_idx * 2)))), NIL, range(0, (len(bindings) / 2))))(0)), for_each(lambda e: trampoline(eval_expr(e, local)), slice(body, 0, (len(body) - 1))), make_thunk(last(body), local)))(env_extend(env)))(rest(args)))(first(args))
sf_let = lambda args, env: (sf_named_let(args, env) if sx_truthy((type_of(first(args)) == 'symbol')) else (lambda bindings: (lambda body: (lambda local: _sx_begin((for_each(lambda binding: (lambda vname: _sx_dict_set(local, vname, trampoline(eval_expr(nth(binding, 1), local))))((symbol_name(first(binding)) if sx_truthy((type_of(first(binding)) == 'symbol')) else first(binding))), bindings) if sx_truthy(((type_of(first(bindings)) == 'list') if not sx_truthy((type_of(first(bindings)) == 'list')) else (len(first(bindings)) == 2))) else (lambda i: reduce(lambda acc, pair_idx: (lambda vname: (lambda val_expr: _sx_dict_set(local, vname, trampoline(eval_expr(val_expr, local))))(nth(bindings, ((pair_idx * 2) + 1))))((symbol_name(nth(bindings, (pair_idx * 2))) if sx_truthy((type_of(nth(bindings, (pair_idx * 2))) == 'symbol')) else nth(bindings, (pair_idx * 2)))), NIL, range(0, (len(bindings) / 2))))(0)), for_each(lambda e: trampoline(eval_expr(e, local)), slice(body, 0, (len(body) - 1))), make_thunk(last(body), local)))(env_extend(env)))(rest(args)))(first(args)))
# sf-named-let
sf_named_let = lambda args, env: (lambda loop_name: (lambda bindings: (lambda body: (lambda params: (lambda inits: _sx_begin((for_each(_sx_fn(lambda binding: (
_sx_append(params, (symbol_name(first(binding)) if sx_truthy((type_of(first(binding)) == 'symbol')) else first(binding))),
_sx_append(inits, nth(binding, 1))
)[-1]), bindings) if sx_truthy(((type_of(first(bindings)) == 'list') if not sx_truthy((type_of(first(bindings)) == 'list')) else (len(first(bindings)) == 2))) else reduce(lambda acc, pair_idx: _sx_begin(_sx_append(params, (symbol_name(nth(bindings, (pair_idx * 2))) if sx_truthy((type_of(nth(bindings, (pair_idx * 2))) == 'symbol')) else nth(bindings, (pair_idx * 2)))), _sx_append(inits, nth(bindings, ((pair_idx * 2) + 1)))), NIL, range(0, (len(bindings) / 2)))), (lambda loop_body: (lambda loop_fn: _sx_begin(_sx_set_attr(loop_fn, 'name', loop_name), _sx_dict_set(lambda_closure(loop_fn), loop_name, loop_fn), (lambda init_vals: call_lambda(loop_fn, init_vals, env))(map(lambda e: trampoline(eval_expr(e, env)), inits))))(make_lambda(params, loop_body, env)))((first(body) if sx_truthy((len(body) == 1)) else cons(make_symbol('begin'), body)))))([]))([]))(slice(args, 2)))(nth(args, 1)))(symbol_name(first(args)))
# sf-lambda
sf_lambda = lambda args, env: (lambda params_expr: (lambda body: (lambda param_names: make_lambda(param_names, body, env))(map(lambda p: (symbol_name(p) if sx_truthy((type_of(p) == 'symbol')) else p), params_expr)))(nth(args, 1)))(first(args))
@@ -980,6 +981,12 @@ sf_thread_first = lambda args, env: (lambda val: reduce(lambda result, form: ((l
# sf-set!
sf_set_bang = lambda args, env: (lambda name: (lambda value: _sx_begin(_sx_dict_set(env, name, value), value))(trampoline(eval_expr(nth(args, 1), env))))(symbol_name(first(args)))
# sf-letrec
sf_letrec = lambda args, env: (lambda bindings: (lambda body: (lambda local: (lambda names: (lambda val_exprs: _sx_begin((for_each(lambda binding: (lambda vname: _sx_begin(_sx_append(names, vname), _sx_append(val_exprs, nth(binding, 1)), _sx_dict_set(local, vname, NIL)))((symbol_name(first(binding)) if sx_truthy((type_of(first(binding)) == 'symbol')) else first(binding))), bindings) if sx_truthy(((type_of(first(bindings)) == 'list') if not sx_truthy((type_of(first(bindings)) == 'list')) else (len(first(bindings)) == 2))) else reduce(lambda acc, pair_idx: (lambda vname: (lambda val_expr: _sx_begin(_sx_append(names, vname), _sx_append(val_exprs, val_expr), _sx_dict_set(local, vname, NIL)))(nth(bindings, ((pair_idx * 2) + 1))))((symbol_name(nth(bindings, (pair_idx * 2))) if sx_truthy((type_of(nth(bindings, (pair_idx * 2))) == 'symbol')) else nth(bindings, (pair_idx * 2)))), NIL, range(0, (len(bindings) / 2)))), (lambda values: _sx_begin(for_each(lambda pair: _sx_dict_set(local, first(pair), nth(pair, 1)), zip(names, values)), for_each(lambda val: (for_each(lambda n: _sx_dict_set(lambda_closure(val), n, env_get(local, n)), names) if sx_truthy(is_lambda(val)) else NIL), values)))(map(lambda e: trampoline(eval_expr(e, local)), val_exprs)), for_each(lambda e: trampoline(eval_expr(e, local)), slice(body, 0, (len(body) - 1))), make_thunk(last(body), local)))([]))([]))(env_extend(env)))(rest(args)))(first(args))
# sf-dynamic-wind
sf_dynamic_wind = lambda args, env: (lambda before: (lambda body: (lambda after: _sx_begin(call_thunk(before, env), push_wind_b(before, after), (lambda result: _sx_begin(pop_wind_b(), call_thunk(after, env), result))(call_thunk(body, env))))(trampoline(eval_expr(nth(args, 2), env))))(trampoline(eval_expr(nth(args, 1), env))))(trampoline(eval_expr(first(args), env)))
# expand-macro
expand_macro = lambda mac, raw_args, env: (lambda local: _sx_begin(for_each(lambda pair: _sx_dict_set(local, first(pair), (nth(raw_args, nth(pair, 1)) if sx_truthy((nth(pair, 1) < len(raw_args))) else NIL)), map_indexed(lambda i, p: [p, i], macro_params(mac))), (_sx_dict_set(local, macro_rest_param(mac), slice(raw_args, len(macro_params(mac)))) if sx_truthy(macro_rest_param(mac)) else NIL), trampoline(eval_expr(macro_body(mac), local))))(env_merge(macro_closure(mac), env))
@@ -1108,38 +1115,6 @@ aser_fragment = lambda children, env: (lambda parts: ('' if sx_truthy(empty_p(pa
aser_call = lambda name, args, env: (lambda parts: _sx_begin(reduce(lambda state, arg: (lambda skip: (assoc(state, 'skip', False, 'i', (get(state, 'i') + 1)) if sx_truthy(skip) else ((lambda val: _sx_begin((_sx_begin(_sx_append(parts, sx_str(':', keyword_name(arg))), _sx_append(parts, serialize(val))) if sx_truthy((not sx_truthy(is_nil(val)))) else NIL), assoc(state, 'skip', True, 'i', (get(state, 'i') + 1))))(aser(nth(args, (get(state, 'i') + 1)), env)) if sx_truthy(((type_of(arg) == 'keyword') if not sx_truthy((type_of(arg) == 'keyword')) else ((get(state, 'i') + 1) < len(args)))) else (lambda val: _sx_begin((_sx_append(parts, serialize(val)) if sx_truthy((not sx_truthy(is_nil(val)))) else NIL), assoc(state, 'i', (get(state, 'i') + 1))))(aser(arg, env)))))(get(state, 'skip')), {'i': 0, 'skip': False}, args), sx_str('(', join(' ', parts), ')')))([name])
# =========================================================================
# Delimited continuations (shift/reset)
# =========================================================================
_RESET_RESUME = [] # stack of resume values; empty = not resuming
def sf_reset(args, env):
"""(reset body) -- establish a continuation delimiter."""
body = first(args)
try:
return trampoline(eval_expr(body, env))
except _ShiftSignal as sig:
def cont_fn(value=NIL):
_RESET_RESUME.append(value)
try:
return trampoline(eval_expr(body, env))
finally:
_RESET_RESUME.pop()
k = Continuation(cont_fn)
sig_env = dict(sig.env)
sig_env[sig.k_name] = k
return trampoline(eval_expr(sig.body, sig_env))
def sf_shift(args, env):
"""(shift k body) -- capture continuation to nearest reset."""
if _RESET_RESUME:
return _RESET_RESUME[-1]
k_name = symbol_name(first(args))
body = nth(args, 1)
raise _ShiftSignal(k_name, body, env)
# =========================================================================
# Fixups -- wire up render adapter dispatch
# =========================================================================
@@ -1172,6 +1147,64 @@ def _wrap_aser_outputs():
aser_fragment = _aser_fragment_wrapped
# =========================================================================
# Extension: delimited continuations (shift/reset)
# =========================================================================
_RESET_RESUME = [] # stack of resume values; empty = not resuming
_SPECIAL_FORM_NAMES = _SPECIAL_FORM_NAMES | frozenset(["reset", "shift"])
def sf_reset(args, env):
"""(reset body) -- establish a continuation delimiter."""
body = first(args)
try:
return trampoline(eval_expr(body, env))
except _ShiftSignal as sig:
def cont_fn(value=NIL):
_RESET_RESUME.append(value)
try:
return trampoline(eval_expr(body, env))
finally:
_RESET_RESUME.pop()
k = Continuation(cont_fn)
sig_env = dict(sig.env)
sig_env[sig.k_name] = k
return trampoline(eval_expr(sig.body, sig_env))
def sf_shift(args, env):
"""(shift k body) -- capture continuation to nearest reset."""
if _RESET_RESUME:
return _RESET_RESUME[-1]
k_name = symbol_name(first(args))
body = nth(args, 1)
raise _ShiftSignal(k_name, body, env)
# Wrap eval_list to inject shift/reset dispatch
_base_eval_list = eval_list
def _eval_list_with_continuations(expr, env):
head = first(expr)
if type_of(head) == "symbol":
name = symbol_name(head)
args = rest(expr)
if name == "reset":
return sf_reset(args, env)
if name == "shift":
return sf_shift(args, env)
return _base_eval_list(expr, env)
eval_list = _eval_list_with_continuations
# Inject into aser_special
_base_aser_special = aser_special
def _aser_special_with_continuations(name, expr, env):
if name == "reset":
return sf_reset(expr[1:], env)
if name == "shift":
return sf_shift(expr[1:], env)
return _base_aser_special(name, expr, env)
aser_special = _aser_special_with_continuations
# =========================================================================
# Public API
# =========================================================================