inform7/inter/pipeline-module/Chapter 5/Rules.w

[SynopticRules::] Rules.

To compile the main/synoptic/rules and main/synoptic/rulebooks submodules.

@ Our inventory |inv| already contains a list |inv->rulebook_nodes| of all packages
in the tree with type |_rulebook|, and similarly for |inv->rule_nodes|.

For reasons going back to the very cramped memory of the Z-machine VM, once
Inform's main compilation target, the following code can run in "memory economy"
mode, which diverts functionality from arrays to functions (giving up execution
speed for reduced array memory usage). This is specified by the presence of the
|^memory_economy| metadata symbol, left in the Inter tree by the //inform7//
compiler.

=
void SynopticRules::compile(inter_tree *I, pipeline_step *step, tree_inventory *inv) {
	if (InterNodeList::array_len(inv->rulebook_nodes) > 0) @<Assign unique rulebook ID numbers@>;
	int economy = FALSE;
	inter_symbol *me_s = InterSymbolsTable::URL_to_symbol(I,
		I"/main/completion/basics/^memory_economy");
	if (me_s) economy = Inter::Symbols::evaluate_to_int(me_s);
	@<Define NUMBER_RULEBOOKS_CREATED@>;
	@<Define RulebookNames array@>;
	if (economy) @<Define SlowLookup function@>
	else @<Define rulebook_var_creators array@>;
	@<Define rulebooks_array array@>;
	@<Define RULEPRINTINGRULE function@>;
}

@ Each rulebook package contains a numeric constant with the symbol name |rulebook_id|.
We want to ensure that these ID numbers are contiguous from 0 and never duplicated,
so we change the values of these constants accordingly.

@<Assign unique rulebook ID numbers@> =
	InterNodeList::array_sort(inv->rulebook_nodes, MakeSynopticModuleStage::module_order);
	for (int i=0; i<InterNodeList::array_len(inv->rulebook_nodes); i++) {
		inter_package *pack =
			InterPackage::at_this_head(inv->rulebook_nodes->list[i].node);
		inter_tree_node *D = Synoptic::get_definition(pack, I"rulebook_id");
		D->W.instruction[DATA_CONST_IFLD+1] = (inter_ti) i;
	}

@<Define NUMBER_RULEBOOKS_CREATED@> =
	inter_name *iname = HierarchyLocations::iname(I, NUMBER_RULEBOOKS_CREATED_HL);
	Produce::numeric_constant(I, iname, K_value,
		(inter_ti) (InterNodeList::array_len(inv->rulebook_nodes)));

@<Define RulebookNames array@> =
	inter_name *iname = HierarchyLocations::iname(I, RULEBOOKNAMES_HL);
	Synoptic::begin_array(I, step, iname);
	if (economy) {
		Synoptic::numeric_entry(0);
		Synoptic::numeric_entry(0);
	} else {
		for (int i=0; i<InterNodeList::array_len(inv->rulebook_nodes); i++) {
			inter_package *pack =
				InterPackage::at_this_head(inv->rulebook_nodes->list[i].node);
			text_stream *name = Metadata::read_textual(pack, I"^printed_name");
			Synoptic::textual_entry(name);
		}
	}
	Synoptic::end_array(I);

@<Define rulebook_var_creators array@> =
	inter_name *iname = HierarchyLocations::iname(I, RULEBOOK_VAR_CREATORS_HL);
	Synoptic::begin_array(I, step, iname);
	for (int i=0; i<InterNodeList::array_len(inv->rulebook_nodes); i++) {
		inter_package *pack = InterPackage::at_this_head(inv->rulebook_nodes->list[i].node);
		inter_symbol *vc_s = Metadata::read_optional_symbol(pack, I"^var_creator");
		if (vc_s) Synoptic::symbol_entry(vc_s);
		else Synoptic::numeric_entry(0);
	}
	Synoptic::end_array(I);

@<Define rulebooks_array array@> =
	inter_name *iname = HierarchyLocations::iname(I, RULEBOOKS_ARRAY_HL);
	Synoptic::begin_array(I, step, iname);
	for (int i=0; i<InterNodeList::array_len(inv->rulebook_nodes); i++) {
		inter_package *pack = InterPackage::at_this_head(inv->rulebook_nodes->list[i].node);
		inter_symbol *fn_s = Metadata::read_symbol(pack, I"^run_fn");
		Synoptic::symbol_entry(fn_s);
	}
	Synoptic::numeric_entry(0);
	Synoptic::end_array(I);

@<Define SlowLookup function@> =
	inter_name *iname = HierarchyLocations::iname(I, SLOW_LOOKUP_HL);
	Synoptic::begin_function(I, iname);
	inter_symbol *rb_s = Synoptic::local(I, I"rb", NULL);

	Produce::inv_primitive(I, SWITCH_BIP);
	Produce::down(I);
		Produce::val_symbol(I, K_value, rb_s);
		Produce::code(I);
		Produce::down(I);
		for (int i=0; i<InterNodeList::array_len(inv->rulebook_nodes); i++) {
			inter_package *pack = InterPackage::at_this_head(inv->rulebook_nodes->list[i].node);
			inter_symbol *vc_s = Metadata::read_optional_symbol(pack, I"^var_creator");
			if (vc_s) {
				Produce::inv_primitive(I, CASE_BIP);
				Produce::down(I);
					Produce::val(I, K_value, LITERAL_IVAL, (inter_ti) i);
					Produce::code(I);
					Produce::down(I);
						Produce::inv_primitive(I, RETURN_BIP);
						Produce::down(I);
							Produce::val_symbol(I, K_value, vc_s);
						Produce::up(I);
					Produce::up(I);
				Produce::up(I);
			}
		}
		Produce::up(I);
	Produce::up(I);
	Produce::inv_primitive(I, RETURN_BIP);
	Produce::down(I);
		Produce::val(I, K_value, LITERAL_IVAL, 0);
	Produce::up(I);
	Synoptic::end_function(I, step, iname);

@<Define RULEPRINTINGRULE function@> =
	inter_name *iname = HierarchyLocations::iname(I, RULEPRINTINGRULE_HL);
	Synoptic::begin_function(I, iname);
	inter_symbol *R_s = Synoptic::local(I, I"R", NULL);

	Produce::inv_primitive(I, IFELSE_BIP);
	Produce::down(I);
		Produce::inv_primitive(I, AND_BIP);
		Produce::down(I);
			Produce::inv_primitive(I, GE_BIP);
			Produce::down(I);
				Produce::val_symbol(I, K_value, R_s);
				Produce::val(I, K_value, LITERAL_IVAL, 0);
			Produce::up(I);
			Produce::inv_primitive(I, LT_BIP);
			Produce::down(I);
				Produce::val_symbol(I, K_value, R_s);
				Produce::val(I, K_value, LITERAL_IVAL, (inter_ti) InterNodeList::array_len(inv->rulebook_nodes));
			Produce::up(I);
		Produce::up(I);
		Produce::code(I);
		Produce::down(I);
			@<Print a rulebook name@>;
		Produce::up(I);
		Produce::code(I);
		Produce::down(I);
			@<Print a rule name@>;
		Produce::up(I);
	Produce::up(I);
	Synoptic::end_function(I, step, iname);

@<Print a rulebook name@> =
	if (economy) {
		Produce::inv_primitive(I, PRINT_BIP);
		Produce::down(I);
			Produce::val_text(I, I"(rulebook ");
		Produce::up(I);
		Produce::inv_primitive(I, PRINTNUMBER_BIP);
		Produce::down(I);
			Produce::val_symbol(I, K_value, R_s);
		Produce::up(I);
		Produce::inv_primitive(I, PRINT_BIP);
		Produce::down(I);
			Produce::val_text(I, I")");
		Produce::up(I);
	} else {
		Produce::inv_primitive(I, PRINTSTRING_BIP);
		Produce::down(I);
			Produce::inv_primitive(I, LOOKUP_BIP);
			Produce::down(I);
				Produce::val_iname(I, K_value, HierarchyLocations::iname(I, RULEBOOKNAMES_HL));
				Produce::val_symbol(I, K_value, R_s);
			Produce::up(I);
		Produce::up(I);
	}

@<Print a rule name@> =
	if (economy) {
		Produce::inv_primitive(I, PRINT_BIP);
		Produce::down(I);
			Produce::val_text(I, I"(rule at address ");
		Produce::up(I);
		Produce::inv_primitive(I, PRINTNUMBER_BIP);
		Produce::down(I);
			Produce::val_symbol(I, K_value, R_s);
		Produce::up(I);
		Produce::inv_primitive(I, PRINT_BIP);
		Produce::down(I);
			Produce::val_text(I, I")");
		Produce::up(I);
	} else {
		for (int i=0; i<InterNodeList::array_len(inv->rule_nodes); i++) {
			inter_package *pack = InterPackage::at_this_head(inv->rule_nodes->list[i].node);
			text_stream *name = Metadata::read_textual(pack, I"^printed_name");
			inter_symbol *rule_s = Metadata::read_symbol(pack, I"^value");
			if (Str::len(name) == 0) continue;
			Produce::inv_primitive(I, IF_BIP);
			Produce::down(I);
				Produce::inv_primitive(I, EQ_BIP);
				Produce::down(I);
					Produce::val_symbol(I, K_value, R_s);
					Produce::val_symbol(I, K_value, rule_s);
				Produce::up(I);
				Produce::code(I);
				Produce::down(I);
					Produce::inv_primitive(I, PRINT_BIP);
					Produce::down(I);
						Produce::val_text(I, name);
					Produce::up(I);
					Produce::rtrue(I);
				Produce::up(I);
			Produce::up(I);
		}
		Produce::inv_primitive(I, PRINT_BIP);
		Produce::down(I);
			Produce::val_text(I, I"(nameless rule at address ");
		Produce::up(I);
		Produce::inv_primitive(I, PRINTNUMBER_BIP);
		Produce::down(I);
			Produce::val_symbol(I, K_value, R_s);
		Produce::up(I);
		Produce::inv_primitive(I, PRINT_BIP);
		Produce::down(I);
			Produce::val_text(I, I")");
		Produce::up(I);
	}