//
// Unbind_Values_Core: C
//
// Unbind words in a block, optionally unbinding those which are
// bound to a particular target (if target is NULL, then all
// words will be unbound regardless of their VAL_WORD_CONTEXT).
//
void Unbind_Values_Core(RELVAL *head, REBCTX *context, REBOOL deep)
{
RELVAL *value = head;
for (; NOT_END(value); value++) {
if (
ANY_WORD(value)
&& (
!context
|| (
IS_WORD_BOUND(value)
&& !IS_RELATIVE(value)
&& VAL_WORD_CONTEXT(KNOWN(value)) == context
)
)
) {
UNBIND_WORD(value);
}
else if (ANY_ARRAY(value) && deep)
Unbind_Values_Core(VAL_ARRAY_AT(value), context, TRUE);
}
}
//
// Make_Context_For_Action_Push_Partials: C
//
// This creates a FRAME! context with NULLED cells in the unspecialized slots
// that are available to be filled. For partial refinement specializations
// in the action, it will push the refinement to the stack. In this way it
// retains the ordering information implicit in the partial refinements of an
// action's existing specialization.
//
// It is able to take in more specialized refinements on the stack. These
// will be ordered *after* partial specializations in the function already.
// The caller passes in the stack pointer of the lowest priority refinement,
// which goes up to DSP for the highest of those added specializations.
//
// Since this is walking the parameters to make the frame already--and since
// we don't want to bind to anything specialized out (including the ad-hoc
// refinements added on the stack) we go ahead and collect bindings from the
// frame if needed.
//
REBCTX *Make_Context_For_Action_Push_Partials(
const REBVAL *action, // need ->binding, so can't just be a REBACT*
REBDSP lowest_ordered_dsp, // caller can add refinement specializations
struct Reb_Binder *opt_binder,
REBFLGS prep // cell formatting mask bits, result managed if non-stack
){
REBDSP highest_ordered_dsp = DSP;
REBACT *act = VAL_ACTION(action);
REBCNT num_slots = ACT_NUM_PARAMS(act) + 1; // +1 is for CTX_ARCHETYPE()
REBARR *varlist = Make_Array_Core(num_slots, SERIES_MASK_VARLIST);
REBVAL *rootvar = RESET_CELL(
ARR_HEAD(varlist),
REB_FRAME,
CELL_MASK_CONTEXT
);
INIT_VAL_CONTEXT_VARLIST(rootvar, varlist);
INIT_VAL_CONTEXT_PHASE(rootvar, VAL_ACTION(action));
INIT_BINDING(rootvar, VAL_BINDING(action));
const REBVAL *param = ACT_PARAMS_HEAD(act);
REBVAL *arg = rootvar + 1;
const REBVAL *special = ACT_SPECIALTY_HEAD(act); // of exemplar/paramlist
REBCNT index = 1; // used to bind REFINEMENT! values to parameter slots
REBCTX *exemplar = ACT_EXEMPLAR(act); // may be null
if (exemplar)
assert(special == CTX_VARS_HEAD(exemplar));
else
assert(special == ACT_PARAMS_HEAD(act));
for (; NOT_END(param); ++param, ++arg, ++special, ++index) {
arg->header.bits = prep;
if (Is_Param_Hidden(param)) { // specialized out
assert(GET_CELL_FLAG(special, ARG_MARKED_CHECKED));
Move_Value(arg, special); // doesn't copy ARG_MARKED_CHECKED
SET_CELL_FLAG(arg, ARG_MARKED_CHECKED);
continue_specialized:
assert(not IS_NULLED(arg));
assert(GET_CELL_FLAG(arg, ARG_MARKED_CHECKED));
continue; // Eval_Core() double-checks type in debug build
}
assert(NOT_CELL_FLAG(special, ARG_MARKED_CHECKED));
REBSTR *canon = VAL_PARAM_CANON(param); // for adding to binding
if (not TYPE_CHECK(param, REB_TS_REFINEMENT)) { // nothing to push
continue_unspecialized:
assert(arg->header.bits == prep);
Init_Nulled(arg);
if (opt_binder) {
if (not Is_Param_Unbindable(param))
Add_Binder_Index(opt_binder, canon, index);
}
continue;
}
// Unspecialized refinement slots may have an SYM-WORD! in them that
// reflects a partial that needs to be pushed to the stack. (They
// are in *reverse* order of use.)
assert(
(special == param and IS_PARAM(special))
or (IS_SYM_WORD(special) or IS_NULLED(special))
);
if (IS_SYM_WORD(special)) {
REBCNT partial_index = VAL_WORD_INDEX(special);
Init_Any_Word_Bound( // push a SYM-WORD! to data stack
DS_PUSH(),
REB_SYM_WORD,
VAL_STORED_CANON(special),
exemplar,
partial_index
);
}
// Unspecialized or partially specialized refinement. Check the
// passed-in refinements on the stack for usage.
//
REBDSP dsp = highest_ordered_dsp;
for (; dsp != lowest_ordered_dsp; --dsp) {
REBVAL *ordered = DS_AT(dsp);
if (VAL_STORED_CANON(ordered) != canon)
continue; // just continuing this loop
assert(not IS_WORD_BOUND(ordered)); // we bind only one
INIT_BINDING(ordered, varlist);
INIT_WORD_INDEX_UNCHECKED(ordered, index);
if (not Is_Typeset_Invisible(param)) // needs argument
goto continue_unspecialized;
// If refinement named on stack takes no arguments, then it can't
// be partially specialized...only fully, and won't be bound:
//
// specialize 'append/only [only: false] ; only not bound
//
Init_Word(arg, VAL_STORED_CANON(ordered));
Refinify(arg);
SET_CELL_FLAG(arg, ARG_MARKED_CHECKED);
goto continue_specialized;
}
goto continue_unspecialized;
}
TERM_ARRAY_LEN(varlist, num_slots);
MISC_META_NODE(varlist) = nullptr; // GC sees this, we must initialize
// !!! Can't pass SERIES_FLAG_STACK_LIFETIME into Make_Array_Core(),
// because TERM_ARRAY_LEN won't let it set stack array lengths.
//
if (prep & CELL_FLAG_STACK_LIFETIME)
SET_SERIES_FLAG(varlist, STACK_LIFETIME);
INIT_CTX_KEYLIST_SHARED(CTX(varlist), ACT_PARAMLIST(act));
return CTX(varlist);
}
//
// Specialize_Action_Throws: C
//
// Create a new ACTION! value that uses the same implementation as another,
// but just takes fewer arguments or refinements. It does this by storing a
// heap-based "exemplar" FRAME! in the specialized action; this stores the
// values to preload in the stack frame cells when it is invoked.
//
// The caller may provide information on the order in which refinements are
// to be specialized, using the data stack. These refinements should be
// pushed in the *reverse* order of their invocation, so append/dup/part
// has /DUP at DS_TOP, and /PART under it. List stops at lowest_ordered_dsp.
//
bool Specialize_Action_Throws(
REBVAL *out,
REBVAL *specializee,
REBSTR *opt_specializee_name,
REBVAL *opt_def, // !!! REVIEW: binding modified directly (not copied)
REBDSP lowest_ordered_dsp
){
assert(out != specializee);
struct Reb_Binder binder;
if (opt_def)
INIT_BINDER(&binder);
REBACT *unspecialized = VAL_ACTION(specializee);
// This produces a context where partially specialized refinement slots
// will be on the stack (including any we are adding "virtually", from
// the current DSP down to the lowest_ordered_dsp).
//
REBCTX *exemplar = Make_Context_For_Action_Push_Partials(
specializee,
lowest_ordered_dsp,
opt_def ? &binder : nullptr,
CELL_MASK_NON_STACK
);
Manage_Array(CTX_VARLIST(exemplar)); // destined to be managed, guarded
if (opt_def) { // code that fills the frame...fully or partially
//
// Bind all the SET-WORD! in the body that match params in the frame
// into the frame. This means `value: value` can very likely have
// `value:` bound for assignments into the frame while `value` refers
// to whatever value was in the context the specialization is running
// in, but this is likely the more useful behavior.
//
// !!! This binds the actual arg data, not a copy of it--following
// OBJECT!'s lead. However, ordinary functions make a copy of the
// body they are passed before rebinding. Rethink.
// See Bind_Values_Core() for explanations of how the binding works.
Bind_Values_Inner_Loop(
&binder,
VAL_ARRAY_AT(opt_def),
exemplar,
FLAGIT_KIND(REB_SET_WORD), // types to bind (just set-word!)
0, // types to "add midstream" to binding as we go (nothing)
BIND_DEEP
);
// !!! Only one binder can be in effect, and we're calling arbitrary
// code. Must clean up now vs. in loop we do at the end. :-(
//
RELVAL *key = CTX_KEYS_HEAD(exemplar);
REBVAL *var = CTX_VARS_HEAD(exemplar);
for (; NOT_END(key); ++key, ++var) {
if (Is_Param_Unbindable(key))
continue; // !!! is this flag still relevant?
if (Is_Param_Hidden(key)) {
assert(GET_CELL_FLAG(var, ARG_MARKED_CHECKED));
continue;
}
if (GET_CELL_FLAG(var, ARG_MARKED_CHECKED))
continue; // may be refinement from stack, now specialized out
Remove_Binder_Index(&binder, VAL_KEY_CANON(key));
}
SHUTDOWN_BINDER(&binder);
// Run block and ignore result (unless it is thrown)
//
PUSH_GC_GUARD(exemplar);
bool threw = Do_Any_Array_At_Throws(out, opt_def, SPECIFIED);
DROP_GC_GUARD(exemplar);
if (threw) {
DS_DROP_TO(lowest_ordered_dsp);
return true;
}
}
REBVAL *rootkey = CTX_ROOTKEY(exemplar);
// Build up the paramlist for the specialized function on the stack.
// The same walk used for that is used to link and process REB_X_PARTIAL
// arguments for whether they become fully specialized or not.
REBDSP dsp_paramlist = DSP;
Move_Value(DS_PUSH(), ACT_ARCHETYPE(unspecialized));
REBVAL *param = rootkey + 1;
REBVAL *arg = CTX_VARS_HEAD(exemplar);
REBDSP ordered_dsp = lowest_ordered_dsp;
for (; NOT_END(param); ++param, ++arg) {
if (TYPE_CHECK(param, REB_TS_REFINEMENT)) {
if (IS_NULLED(arg)) {
//
// A refinement that is nulled is a candidate for usage at the
// callsite. Hence it must be pre-empted by our ordered
// overrides. -but- the overrides only apply if their slot
// wasn't filled by the user code. Yet these values we are
// putting in disrupt that detection (!), so use another
// flag (PUSH_PARTIAL) to reflect this state.
//
while (ordered_dsp != dsp_paramlist) {
++ordered_dsp;
REBVAL *ordered = DS_AT(ordered_dsp);
if (not IS_WORD_BOUND(ordered)) // specialize 'print/asdf
fail (Error_Bad_Refine_Raw(ordered));
REBVAL *slot = CTX_VAR(exemplar, VAL_WORD_INDEX(ordered));
if (
IS_NULLED(slot) or GET_CELL_FLAG(slot, PUSH_PARTIAL)
){
// It's still partial, so set up the pre-empt.
//
Init_Any_Word_Bound(
arg,
REB_SYM_WORD,
VAL_STORED_CANON(ordered),
exemplar,
VAL_WORD_INDEX(ordered)
);
SET_CELL_FLAG(arg, PUSH_PARTIAL);
goto unspecialized_arg;
}
// Otherwise the user filled it in, so skip to next...
}
goto unspecialized_arg; // ran out...no pre-empt needed
}
if (GET_CELL_FLAG(arg, ARG_MARKED_CHECKED)) {
assert(
IS_BLANK(arg)
or (
IS_REFINEMENT(arg)
and (
VAL_REFINEMENT_SPELLING(arg)
== VAL_PARAM_SPELLING(param)
)
)
);
}
else
Typecheck_Refinement_And_Canonize(param, arg);
goto specialized_arg_no_typecheck;
}
switch (VAL_PARAM_CLASS(param)) {
case REB_P_RETURN:
case REB_P_LOCAL:
assert(IS_NULLED(arg)); // no bindings, you can't set these
goto unspecialized_arg;
default:
break;
}
// It's an argument, either a normal one or a refinement arg.
if (not IS_NULLED(arg))
goto specialized_arg_with_check;
unspecialized_arg:
assert(NOT_CELL_FLAG(arg, ARG_MARKED_CHECKED));
assert(
IS_NULLED(arg)
or (IS_SYM_WORD(arg) and TYPE_CHECK(param, REB_TS_REFINEMENT))
);
Move_Value(DS_PUSH(), param);
continue;
specialized_arg_with_check:
// !!! If argument was previously specialized, should have been type
// checked already... don't type check again (?)
//
if (Is_Param_Variadic(param))
fail ("Cannot currently SPECIALIZE variadic arguments.");
if (TYPE_CHECK(param, REB_TS_DEQUOTE_REQUOTE) and IS_QUOTED(arg)) {
//
// Have to leave the quotes on, but still want to type check.
if (not TYPE_CHECK(param, CELL_KIND(VAL_UNESCAPED(arg))))
fail (arg); // !!! merge w/Error_Invalid_Arg()
}
else if (not TYPE_CHECK(param, VAL_TYPE(arg)))
fail (arg); // !!! merge w/Error_Invalid_Arg()
SET_CELL_FLAG(arg, ARG_MARKED_CHECKED);
specialized_arg_no_typecheck:
// Specialized-out arguments must still be in the parameter list,
// for enumeration in the evaluator to line up with the frame values
// of the underlying function.
assert(GET_CELL_FLAG(arg, ARG_MARKED_CHECKED));
Move_Value(DS_PUSH(), param);
TYPE_SET(DS_TOP, REB_TS_HIDDEN);
continue;
}
REBARR *paramlist = Pop_Stack_Values_Core(
dsp_paramlist,
SERIES_MASK_PARAMLIST
| (SER(unspecialized)->header.bits & PARAMLIST_MASK_INHERIT)
);
Manage_Array(paramlist);
RELVAL *rootparam = ARR_HEAD(paramlist);
VAL_ACT_PARAMLIST_NODE(rootparam) = NOD(paramlist);
// Everything should have balanced out for a valid specialization
//
while (ordered_dsp != DSP) {
++ordered_dsp;
REBVAL *ordered = DS_AT(ordered_dsp);
if (not IS_WORD_BOUND(ordered)) // specialize 'print/asdf
fail (Error_Bad_Refine_Raw(ordered));
REBVAL *slot = CTX_VAR(exemplar, VAL_WORD_INDEX(ordered));
assert(not IS_NULLED(slot) and NOT_CELL_FLAG(slot, PUSH_PARTIAL));
UNUSED(slot);
}
DS_DROP_TO(lowest_ordered_dsp);
// See %sysobj.r for `specialized-meta:` object template
REBVAL *example = Get_System(SYS_STANDARD, STD_SPECIALIZED_META);
REBCTX *meta = Copy_Context_Shallow_Managed(VAL_CONTEXT(example));
Init_Nulled(CTX_VAR(meta, STD_SPECIALIZED_META_DESCRIPTION)); // default
Move_Value(
CTX_VAR(meta, STD_SPECIALIZED_META_SPECIALIZEE),
specializee
);
if (not opt_specializee_name)
Init_Nulled(CTX_VAR(meta, STD_SPECIALIZED_META_SPECIALIZEE_NAME));
else
Init_Word(
CTX_VAR(meta, STD_SPECIALIZED_META_SPECIALIZEE_NAME),
opt_specializee_name
);
MISC_META_NODE(paramlist) = NOD(meta);
REBACT *specialized = Make_Action(
paramlist,
&Specializer_Dispatcher,
ACT_UNDERLYING(unspecialized), // same underlying action as this
exemplar, // also provide a context of specialization values
1 // details array capacity
);
assert(CTX_KEYLIST(exemplar) == ACT_PARAMLIST(unspecialized));
assert(
GET_ACTION_FLAG(specialized, IS_INVISIBLE)
== GET_ACTION_FLAG(unspecialized, IS_INVISIBLE)
);
// The "body" is the FRAME! value of the specialization. It takes on the
// binding we want to use (which we can't put in the exemplar archetype,
// that binding has to be UNBOUND). It also remembers the original
// action in the phase, so Specializer_Dispatcher() knows what to call.
//
RELVAL *body = ARR_HEAD(ACT_DETAILS(specialized));
Move_Value(body, CTX_ARCHETYPE(exemplar));
INIT_BINDING(body, VAL_BINDING(specializee));
INIT_VAL_CONTEXT_PHASE(body, unspecialized);
Init_Action_Unbound(out, specialized);
return false; // code block did not throw
}
