static value_t lambda_scope_lookup(lambda_scope_o *self, value_t symbol,
binding_info_t *info_out) {
size_t capture_count_before = get_array_buffer_length(self->captures);
// See if we've captured this variable before.
for (size_t i = 0; i < capture_count_before; i++) {
value_t captured = get_array_buffer_at(self->captures, i);
if (value_identity_compare(captured, symbol)) {
// Found it. Record that we did if necessary and return success.
if (info_out != NULL)
binding_info_set(info_out, btLambdaCaptured, i, 0);
return success();
}
}
// We haven't seen this one before so look it up outside.
value_t value = scope_lookup(self->outer, symbol, info_out);
if (info_out != NULL && !in_condition_cause(ccNotFound, value)) {
// We found something and this is a read. Add it to the list of captures.
runtime_t *runtime = self->assembler->runtime;
if (get_array_buffer_length(self->captures) == 0) {
// The first time we add something we have to create a new array buffer
// since all empty capture scopes share the singleton empty buffer.
TRY_SET(self->captures, new_heap_array_buffer(runtime, 2));
}
TRY(add_to_array_buffer(runtime, self->captures, symbol));
binding_info_set(info_out, btLambdaCaptured, capture_count_before, 0);
}
return value;
}
// Returns true iff the given identifier corresponds to a fragment that is
// ready to be bound and hasn't already been bound.
static bool should_fragment_be_bound(binding_context_t *context, value_t schedule,
value_t ident) {
// This fragment is already scheduled so we definitely don't want to bind it
// again.
if (is_fragment_scheduled(schedule, ident))
return false;
// Grab the information we hold about the fragment.
value_t path = get_identifier_path(ident);
value_t stage = get_identifier_stage(ident);
value_t module = get_id_hash_map_at(context->fragment_entry_map, path);
value_t entry = get_id_hash_map_at(module, stage);
value_t imports = get_fragment_entry_imports(entry);
// Check whether all its explicit dependencies are satisfied.
for (size_t i = 0; i < get_array_buffer_length(imports); i++) {
value_t import = get_array_buffer_at(imports, i);
if (!is_fragment_scheduled(schedule, import))
return false;
}
// Check if there is a preceding fragment and whether it has been bound.
value_t entry_before = get_fragment_entry_before(module, stage);
if (in_condition_cause(ccNotFound, entry_before)) {
return true;
} else {
value_t before_ident = get_fragment_entry_identifier(entry_before);
return is_fragment_scheduled(schedule, before_ident);
}
}
value_t build_binding_schedule(binding_context_t *context) {
runtime_t *runtime = get_ambience_runtime(context->ambience);
TRY_DEF(schedule, new_heap_array_buffer(runtime, 16));
TRY_DEF(all_fragments, build_fragment_identifier_array(context));
loop: do {
for (size_t i = 0; i < get_array_buffer_length(all_fragments); i++) {
value_t ident = get_array_buffer_at(all_fragments, i);
if (should_fragment_be_bound(context, schedule, ident)) {
TRY(add_to_array_buffer(runtime, schedule, ident));
goto loop;
}
}
} while (false);
return schedule;
}
// Creates and binds modules and fragments according to the given schedule.
static value_t execute_binding_schedule(binding_context_t *context, value_t schedule) {
runtime_t *runtime = get_ambience_runtime(context->ambience);
for (size_t i = 0; i < get_array_buffer_length(schedule); i++) {
value_t next = get_array_buffer_at(schedule, i);
TOPIC_INFO(Library, "About to bind %v", next);
value_t path = get_identifier_path(next);
value_t stage = get_identifier_stage(next);
// Create the bound module if it doesn't already exist.
value_t bound_module = get_id_hash_map_at(context->bound_module_map, path);
if (in_condition_cause(ccNotFound, bound_module)) {
TRY_SET(bound_module, new_heap_empty_module(runtime, path));
TRY(set_id_hash_map_at(runtime, context->bound_module_map, path,
bound_module));
}
// Create the bound fragment.
value_t bound_fragment = get_module_fragment_at(bound_module, stage);
if (in_condition_cause(ccNotFound, bound_fragment)) {
TRY_SET(bound_fragment, new_empty_module_fragment(runtime, stage,
bound_module));
TRY(add_module_fragment(runtime, bound_module, bound_fragment));
} else {
// An earlier phase needed a reference to this fragment so it has already
// been created but not initialized yet.
CHECK_EQ("Unexpected phase", get_module_fragment_epoch(bound_fragment),
feUninitialized);
TRY(init_empty_module_fragment(runtime, bound_fragment));
set_module_fragment_epoch(bound_fragment, feUnbound);
}
if (is_present_core(runtime, next)) {
// TODO: this is a hack, there should be some other mechanism for
// identifying the core module. This way of binding it also means it
// gets bound at a time that's not particularly well-defined which is
// also an issue.
TOPIC_INFO(Library, "Binding present core to %v", bound_fragment);
set_ambience_present_core_fragment(context->ambience, bound_fragment);
}
// Grab the unbound fragment we'll use to create the bound fragment.
value_t module_entries = get_id_hash_map_at(context->fragment_entry_map, path);
value_t fragment_entry = get_id_hash_map_at(module_entries, stage);
// Bind the fragment based on the data from the entry.
TRY(bind_module_fragment(context, fragment_entry, bound_fragment));
TOPIC_INFO(Library, "Done binding %v", next);
}
return success();
}
static value_t find_best_match(runtime_t *runtime, value_t current,
value_t target, value_t current_score, value_t space, value_t *score_out) {
if (value_identity_compare(current, target)) {
*score_out = current_score;
return success();
} else {
TRY_DEF(parents, get_type_parents(runtime, space, current));
int64_t length = get_array_buffer_length(parents);
value_t score = new_no_match_score();
for (int64_t i = 0; i < length; i++) {
value_t parent = get_array_buffer_at(parents, i);
value_t next_score = whatever();
TRY(find_best_match(runtime, parent, target, get_score_successor(current_score),
space, &next_score));
score = best_score(score, next_score);
}
*score_out = score;
return success();
}
}
// Adds mappings in the namespace and imports in the methodspace for everything
// imported by the given fragment.
static value_t bind_module_fragment_imports(binding_context_t *context,
value_t imports, value_t bound_fragment) {
// Import the modules spaces into this fragment and create bindings in the
// importspace.
value_t methodspace = get_module_fragment_methodspace(bound_fragment);
value_t importspace = get_module_fragment_imports(bound_fragment);
runtime_t *runtime = get_ambience_runtime(context->ambience);
for (size_t i = 0; i < get_array_buffer_length(imports); i++) {
// Look up the imported module.
value_t import_ident = get_array_buffer_at(imports, i);
value_t import_path = get_identifier_path(import_ident);
value_t import_head = get_path_head(import_path);
value_t import_stage = get_identifier_stage(import_ident);
value_t import_module = get_id_hash_map_at(context->bound_module_map, import_path);
value_t import_fragment = get_module_fragment_at(import_module, import_stage);
CHECK_TRUE("import not bound", is_module_fragment_bound(import_fragment));
value_t import_methods = get_module_fragment_methodspace(import_fragment);
TRY(add_methodspace_import(runtime, methodspace, import_methods));
TRY(set_id_hash_map_at(runtime, importspace, import_head,
import_fragment));
}
return success();
}
// Given an array of modules map builds a two-level map from paths to stages to
// fragment entries.
static value_t build_real_fragment_entries(binding_context_t *context,
value_t modules) {
runtime_t *runtime = get_ambience_runtime(context->ambience);
for (size_t mi = 0; mi < get_array_buffer_length(modules); mi++) {
value_t module = get_array_buffer_at(modules, mi);
value_t path = get_unbound_module_path(module);
value_t fragments = get_unbound_module_fragments(module);
for (size_t fi = 0; fi < get_array_length(fragments); fi++) {
value_t fragment = get_array_at(fragments, fi);
value_t stage = get_unbound_module_fragment_stage(fragment);
bool dummy = false;
TRY_DEF(entry, binding_context_ensure_fragment_entry(context, stage,
path, fragment, &dummy));
value_t imports = get_fragment_entry_imports(entry);
value_t fragment_imports = get_unbound_module_fragment_imports(fragment);
for (size_t ii = 0; ii < get_array_length(fragment_imports); ii++) {
value_t import = get_array_at(fragment_imports, ii);
TRY_DEF(ident, new_heap_identifier(runtime, present_stage(), import));
TRY(ensure_array_buffer_contains(runtime, imports, ident));
}
}
}
return success();
}
// Add synthetic fragment entries corresponding to imported fragments where
// there is no real fragment to import the fragment into.
static value_t build_synthetic_fragment_entries(binding_context_t *context) {
// Keep adding synthetic modules as long as changes are being made to the
// map. We'll scan through the fragments currently in the map, then scan
// through their imports, and for each check that the fragment that should
// receive the import exists. If it doesn't it is created.
loop: do {
id_hash_map_iter_t module_iter;
id_hash_map_iter_init(&module_iter, context->fragment_entry_map);
while (id_hash_map_iter_advance(&module_iter)) {
value_t module_path;
value_t module_fragments;
// Scan through the fragments.
id_hash_map_iter_get_current(&module_iter, &module_path, &module_fragments);
id_hash_map_iter_t fragment_iter;
id_hash_map_iter_init(&fragment_iter, module_fragments);
while (id_hash_map_iter_advance(&fragment_iter)) {
value_t stage;
value_t entry;
id_hash_map_iter_get_current(&fragment_iter, &stage, &entry);
value_t unbound_fragment = get_fragment_entry_fragment(entry);
// If there is no fragment associated with this entry it is synthetic
// and hence we're done.
if (is_nothing(unbound_fragment))
continue;
// Scan through the fragment's imports and ensure that their import
// targets have been created.
value_t imports = get_fragment_entry_imports(entry);
for (size_t i = 0; i < get_array_buffer_length(imports); i++) {
value_t import = get_array_buffer_at(imports, i);
value_t import_fragment_stage = get_identifier_stage(import);
if (!value_identity_compare(import_fragment_stage, present_stage()))
// We'll record past imports but ignore them for the purposes of
// closing the import map since they're redundant.
continue;
value_t import_module_path = get_identifier_path(import);
value_t import_module = get_id_hash_map_at(context->fragment_entry_map,
import_module_path);
// Scan through the fragments of the imported module.
id_hash_map_iter_t imported_fragment_iter;
id_hash_map_iter_init(&imported_fragment_iter, import_module);
bool has_changed_anything = false;
while (id_hash_map_iter_advance(&imported_fragment_iter)) {
value_t import_stage;
value_t import_entry;
id_hash_map_iter_get_current(&imported_fragment_iter,
&import_stage, &import_entry);
value_t target_stage = add_stage_offsets(import_stage, stage);
// Ensure that there is a target entry to add the import to. If it
// already exists this is a no-op, if it doesn't a synthetic entry
// is created.
TRY_DEF(target_entry, binding_context_ensure_fragment_entry(
context, target_stage, module_path, nothing(),
&has_changed_anything));
value_t target_imports = get_fragment_entry_imports(target_entry);
value_t import_ident = get_fragment_entry_identifier(import_entry);
if (!in_array_buffer(target_imports, import_ident)) {
has_changed_anything = true;
TRY(add_to_array_buffer(get_ambience_runtime(context->ambience),
target_imports, import_ident));
}
}
// If any changes were made we have to start over.
if (has_changed_anything)
goto loop;
}
}
}
} while (false);
return success();
}