// // Val_Init_Context: C // // Common routine for initializing OBJECT, MODULE!, PORT!, and ERROR! // // A fully constructed context can reconstitute the ANY-CONTEXT! REBVAL that // is its canon form from a single pointer...the REBVAL sitting in the 0 slot // of the context's varlist. // void Val_Init_Context(REBVAL *out, enum Reb_Kind kind, REBCTX *context) { // // In a debug build we check to make sure the type of the embedded value // matches the type of what is intended (so someone who thinks they are // initializing a REB_OBJECT from a CONTEXT does not accidentally get a // REB_ERROR, for instance.) It's a point for several other integrity // checks as well. // #if !defined(NDEBUG) REBVAL *value = CTX_VALUE(context); assert(ANY_CONTEXT(value)); assert(CTX_TYPE(context) == kind); assert(VAL_CONTEXT(value) == context); if (!CTX_KEYLIST(context)) { Debug_Fmt("Context found with no keylist set"); Panic_Context(context); } assert(GET_ARR_FLAG(CTX_VARLIST(context), ARRAY_FLAG_CONTEXT_VARLIST)); // !!! Historically spec is a frame of an object for a "module spec", // may want to use another word of that and make a block "spec" // if (IS_FRAME(CTX_VALUE(context))) { assert(IS_FUNCTION(FUNC_VALUE(CTX_FRAME_FUNC(context)))); } else assert( NOT(CTX_SPEC(context)) || ANY_CONTEXT(CTX_VALUE(CTX_SPEC(context))) ); #endif // Some contexts (stack frames in particular) start out unmanaged, and // then check to see if an operation like Val_Init_Context set them to // managed. If not, they will free the context. This avoids the need // for the garbage collector to have to deal with the series if there's // no reason too. // // Here is a case of where we mark the context as having an extant usage, // so that at minimum this value must become unreachable from the root GC // set before they are GC'd. For another case, see INIT_WORD_CONTEXT(), // where an ANY-WORD! can mark a context as in use. // ENSURE_ARRAY_MANAGED(CTX_VARLIST(context)); // Keylists are different, because they may-or-may-not-be-reused by some // operations. There needs to be a uniform policy on their management, // or certain routines would return "sometimes managed, sometimes not" // keylist series...a bad invariant. // ASSERT_ARRAY_MANAGED(CTX_KEYLIST(context)); *out = *CTX_VALUE(context); }
// // 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 }