[Inter::Frame::] Frames.

To manage frames, which are windows into Inter storage.

@h Frames.

=
typedef struct inter_frame {
	struct inter_repository_segment *repo_segment;
	int index;
	inter_t *data;
	int extent;
} inter_frame;

@ =
inter_frame Inter::Frame::around(inter_repository_segment *IS, int index) {
	inter_frame F;
	F.repo_segment = IS; F.index = index;
	if ((IS) && (index >= 0) && (index < IS->size)) {
		F.data = &(IS->bytecode[index + PREFRAME_SIZE]);
		F.extent = ((int) IS->bytecode[index]) - PREFRAME_SIZE;
	} else {
		F.data = NULL; F.extent = 0;
	}
	return F;
}

int Inter::Frame::valid(inter_frame *F) {
	if ((F == NULL) || (F->repo_segment == NULL) || (F->index < 0) || (F->data == NULL) || (F->extent <= 0)) return FALSE;
	return TRUE;
}

int Inter::Frame::eq(inter_frame *F1, inter_frame *F2) {
	if ((F1 == NULL) || (F2 == NULL)) {
		if (F1 == F2) return TRUE;
		return FALSE;
	}
	if (F1->repo_segment != F2->repo_segment) return FALSE;
	if (F1->index != F2->index) return FALSE;
	return TRUE;
}

@ =
inter_frame Inter::Frame::fill_0(inter_bookmark *IBM, int S, inter_error_location *eloc, inter_t level) {
	inter_frame P = Inter::find_room(IBM->read_into, 2, eloc, Inter::Bookmarks::package(IBM));
	P.data[ID_IFLD] = (inter_t) S;
	P.data[LEVEL_IFLD] = level;
	return P;
}

inter_frame Inter::Frame::fill_1(inter_bookmark *IBM, int S, inter_t V, inter_error_location *eloc, inter_t level) {
	inter_frame P = Inter::find_room(IBM->read_into, 3, eloc, Inter::Bookmarks::package(IBM));
	P.data[ID_IFLD] = (inter_t) S;
	P.data[LEVEL_IFLD] = level;
	P.data[DATA_IFLD] = V;
	return P;
}

inter_frame Inter::Frame::fill_2(inter_bookmark *IBM, int S, inter_t V1, inter_t V2, inter_error_location *eloc, inter_t level) {
	inter_frame P = Inter::find_room(IBM->read_into, 4, eloc, Inter::Bookmarks::package(IBM));
	P.data[ID_IFLD] = (inter_t) S;
	P.data[LEVEL_IFLD] = level;
	P.data[DATA_IFLD] = V1;
	P.data[DATA_IFLD + 1] = V2;
	return P;
}

inter_frame Inter::Frame::fill_3(inter_bookmark *IBM, int S, inter_t V1, inter_t V2, inter_t V3, inter_error_location *eloc, inter_t level) {
	inter_frame P = Inter::find_room(IBM->read_into, 5, eloc, Inter::Bookmarks::package(IBM));
	P.data[ID_IFLD] = (inter_t) S;
	P.data[LEVEL_IFLD] = level;
	P.data[DATA_IFLD] = V1;
	P.data[DATA_IFLD + 1] = V2;
	P.data[DATA_IFLD + 2] = V3;
	return P;
}

inter_frame Inter::Frame::fill_4(inter_bookmark *IBM, int S, inter_t V1, inter_t V2, inter_t V3, inter_t V4, inter_error_location *eloc, inter_t level) {
	inter_frame P = Inter::find_room(IBM->read_into, 6, eloc, Inter::Bookmarks::package(IBM));
	P.data[ID_IFLD] = (inter_t) S;
	P.data[LEVEL_IFLD] = level;
	P.data[DATA_IFLD] = V1;
	P.data[DATA_IFLD + 1] = V2;
	P.data[DATA_IFLD + 2] = V3;
	P.data[DATA_IFLD + 3] = V4;
	return P;
}

inter_frame Inter::Frame::fill_5(inter_bookmark *IBM, int S, inter_t V1, inter_t V2, inter_t V3, inter_t V4, inter_t V5, inter_error_location *eloc, inter_t level) {
	inter_frame P = Inter::find_room(IBM->read_into, 7, eloc, Inter::Bookmarks::package(IBM));
	P.data[ID_IFLD] = (inter_t) S;
	P.data[LEVEL_IFLD] = level;
	P.data[DATA_IFLD] = V1;
	P.data[DATA_IFLD + 1] = V2;
	P.data[DATA_IFLD + 2] = V3;
	P.data[DATA_IFLD + 3] = V4;
	P.data[DATA_IFLD + 4] = V5;
	return P;
}

inter_frame Inter::Frame::fill_6(inter_bookmark *IBM, int S, inter_t V1, inter_t V2, inter_t V3, inter_t V4, inter_t V5, inter_t V6, inter_error_location *eloc, inter_t level) {
	inter_frame P = Inter::find_room(IBM->read_into, 8, eloc, Inter::Bookmarks::package(IBM));
	P.data[ID_IFLD] = (inter_t) S;
	P.data[LEVEL_IFLD] = level;
	P.data[DATA_IFLD] = V1;
	P.data[DATA_IFLD + 1] = V2;
	P.data[DATA_IFLD + 2] = V3;
	P.data[DATA_IFLD + 3] = V4;
	P.data[DATA_IFLD + 4] = V5;
	P.data[DATA_IFLD + 5] = V6;
	return P;
}

inter_frame Inter::Frame::fill_7(inter_bookmark *IBM, int S, inter_t V1, inter_t V2, inter_t V3, inter_t V4, inter_t V5, inter_t V6, inter_t V7, inter_error_location *eloc, inter_t level) {
	inter_frame P = Inter::find_room(IBM->read_into, 9, eloc, Inter::Bookmarks::package(IBM));
	P.data[ID_IFLD] = (inter_t) S;
	P.data[LEVEL_IFLD] = level;
	P.data[DATA_IFLD] = V1;
	P.data[DATA_IFLD + 1] = V2;
	P.data[DATA_IFLD + 2] = V3;
	P.data[DATA_IFLD + 3] = V4;
	P.data[DATA_IFLD + 4] = V5;
	P.data[DATA_IFLD + 5] = V6;
	P.data[DATA_IFLD + 6] = V7;
	return P;
}

inter_frame Inter::Frame::fill_8(inter_bookmark *IBM, int S, inter_t V1, inter_t V2, inter_t V3, inter_t V4, inter_t V5, inter_t V6, inter_t V7, inter_t V8, inter_error_location *eloc, inter_t level) {
	inter_frame P = Inter::find_room(IBM->read_into, 10, eloc, Inter::Bookmarks::package(IBM));
	P.data[ID_IFLD] = (inter_t) S;
	P.data[LEVEL_IFLD] = level;
	P.data[DATA_IFLD] = V1;
	P.data[DATA_IFLD + 1] = V2;
	P.data[DATA_IFLD + 2] = V3;
	P.data[DATA_IFLD + 3] = V4;
	P.data[DATA_IFLD + 4] = V5;
	P.data[DATA_IFLD + 5] = V6;
	P.data[DATA_IFLD + 6] = V7;
	P.data[DATA_IFLD + 7] = V8;
	return P;
}

@ =
int Inter::Frame::extend(inter_frame *F, inter_t by) {
	if (by == 0) return TRUE;
	if ((F->index + F->extent + PREFRAME_SIZE < F->repo_segment->size) ||
		(F->repo_segment->next_repo_segment)) return FALSE;
	if (F->repo_segment->size + (int) by <= F->repo_segment->capacity) {
		F->repo_segment->bytecode[F->index] += by;
		F->repo_segment->size += by;
		F->extent += by;
		return TRUE;
	}

	int next_size = Inter::enlarge_size(F->repo_segment->capacity, F->extent + PREFRAME_SIZE + (int) by);

	F->repo_segment->next_repo_segment = Inter::create_segment(next_size, F->repo_segment->owning_repo, F->repo_segment);

	inter_frame XF = Inter::find_room_in_segment(F->repo_segment->next_repo_segment, F->extent + (int) by);

	F->repo_segment->size = F->index;
	F->repo_segment->capacity = F->index;

	XF.repo_segment->bytecode[XF.index + PREFRAME_VERIFICATION_COUNT] = F->repo_segment->bytecode[F->index + PREFRAME_VERIFICATION_COUNT];
	XF.repo_segment->bytecode[XF.index + PREFRAME_ORIGIN] = F->repo_segment->bytecode[F->index + PREFRAME_ORIGIN];
	XF.repo_segment->bytecode[XF.index + PREFRAME_COMMENT] = F->repo_segment->bytecode[F->index + PREFRAME_COMMENT];
	XF.repo_segment->bytecode[XF.index + PREFRAME_PACKAGE] = F->repo_segment->bytecode[F->index + PREFRAME_PACKAGE];

	F->index = XF.index;
	F->repo_segment = XF.repo_segment;
	for (int i=0; i<XF.extent; i++)
		if (i < F->extent)
			XF.data[i] = F->data[i];
		else
			XF.data[i] = 0;
	F->data = XF.data;
	F->extent = XF.extent;

	return TRUE;
}

inter_t Inter::Frame::to_index(inter_frame *F) {
	if ((F->repo_segment == NULL) || (F->index < 0)) internal_error("no index for null frame");
	return (F->repo_segment->index_offset) + (inter_t) (F->index);
}

inter_frame Inter::Frame::from_index(inter_repository *I, inter_t index) {
	inter_repository_segment *seg = I->first_repo_segment;
	while (seg) {
		if (seg->index_offset + (inter_t) seg->capacity > index)
			return Inter::Frame::around(seg, (int) (index - seg->index_offset));
		seg = seg->next_repo_segment;
	}
	internal_error("index not found in repository");
	return Inter::Frame::around(NULL, -1);
}

@

=
int trace_inter_insertion = FALSE;

void Inter::Frame::insert(inter_frame F, inter_bookmark *at) {
	inter_repository *I = F.repo_segment->owning_repo;
	LOGIF(INTER_FRAMES, "I%d: Insert frame %F\n", I->allocation_id, F);
	if (trace_inter_insertion) Inter::Defn::write_construct_text(DL, F);
	inter_t F_level = F.data[LEVEL_IFLD];
	if (F_level == 0) {
		Inter::add_to_frame_list(&(I->global_material), F);
		if ((Inter::Bookmarks::get_placement(at) == AFTER_ICPLACEMENT) ||
			(Inter::Bookmarks::get_placement(at) == IMMEDIATELY_AFTER_ICPLACEMENT))
			Inter::Bookmarks::set_ref(at, F);
	} else {
		if (Inter::Bookmarks::get_placement(at) == NOWHERE_ICPLACEMENT) internal_error("bad wrt");
		if ((Inter::Bookmarks::get_placement(at) == AFTER_ICPLACEMENT) ||
			(Inter::Bookmarks::get_placement(at) == IMMEDIATELY_AFTER_ICPLACEMENT)) {
			while (F_level < Inter::Bookmarks::get_ref(at).data[LEVEL_IFLD]) {
				inter_t PR_index = Inter::Frame::get_parent_index(Inter::Bookmarks::get_ref(at));
				if (PR_index == 0) internal_error("bubbled up out of tree");
				Inter::Bookmarks::set_ref(at, Inter::Frame::from_index(I, PR_index));
			}
			if (F_level > Inter::Bookmarks::get_ref(at).data[LEVEL_IFLD] + 1) internal_error("bubbled down off of tree");
			if (F_level == Inter::Bookmarks::get_ref(at).data[LEVEL_IFLD] + 1) {
				if (Inter::Bookmarks::get_placement(at) == IMMEDIATELY_AFTER_ICPLACEMENT) {
					Inter::Frame::place(F, AS_FIRST_CHILD_OF_ICPLACEMENT, Inter::Bookmarks::get_ref(at));
					Inter::Bookmarks::set_placement(at, AFTER_ICPLACEMENT);
				} else {
					Inter::Frame::place(F, AS_LAST_CHILD_OF_ICPLACEMENT, Inter::Bookmarks::get_ref(at));
				}
			} else {
				Inter::Frame::place(F, AFTER_ICPLACEMENT, Inter::Bookmarks::get_ref(at));
			}
			Inter::Bookmarks::set_ref(at, F);
			return;
		}
		Inter::Frame::place(F, Inter::Bookmarks::get_placement(at), Inter::Bookmarks::get_ref(at));
	}
}

inter_symbols_table *Inter::Frame::global_symbols(inter_frame F) {
	if (Inter::Frame::valid(&F))
		return Inter::get_global_symbols(F.repo_segment->owning_repo);
	return NULL;
}

inter_error_location *Inter::Frame::retrieve_origin(inter_frame *F) {
	if (Inter::Frame::valid(F) == FALSE) return NULL;
	return Inter::retrieve_origin(F->repo_segment->owning_repo, F->repo_segment->bytecode[F->index + PREFRAME_ORIGIN]);
}

inter_error_message *Inter::Frame::error(inter_frame *F, text_stream *err, text_stream *quote) {
	inter_error_message *iem = CREATE(inter_error_message);
	inter_error_location *eloc = Inter::Frame::retrieve_origin(F);
	if (eloc)
		iem->error_at = *eloc;
	else
		iem->error_at = Inter::Errors::file_location(NULL, NULL);
	iem->error_body = err;
	iem->error_quote = quote;
	return iem;
}

inter_t Inter::Frame::get_comment(inter_frame F) {
	if (F.repo_segment) {
		return F.repo_segment->bytecode[F.index + PREFRAME_COMMENT];
	}
	return 0;
}

void Inter::Frame::attach_comment(inter_frame F, inter_t ID) {
	if ((ID) && (F.repo_segment)) {
		F.repo_segment->bytecode[F.index + PREFRAME_COMMENT] = ID;
	}
}

inter_t Inter::Frame::get_package(inter_frame F) {
	if (F.repo_segment) {
		return F.repo_segment->bytecode[F.index + PREFRAME_PACKAGE];
	}
	return 0;
}

inter_t Inter::Frame::get_package_alt(inter_frame F) {
	while (TRUE) {
		inter_t P_index = Inter::Frame::get_parent_index(F);
		if (P_index == 0) break;
		F = Inter::Frame::from_index(F.repo_segment->owning_repo, P_index);
		if (F.data[ID_IFLD] == PACKAGE_IST) {
			return F.data[PID_PACKAGE_IFLD];
		}
	}
	return 0;
}

void Inter::Frame::backtrace(OUTPUT_STREAM, inter_frame F) {
	inter_frame X = F;
	int n = 0;
	while (TRUE) {
		inter_t X_index = Inter::Frame::get_parent_index(X);
		if (X_index == 0) break;
		X = Inter::Frame::from_index(X.repo_segment->owning_repo, X_index);
		n++;
	}
	for (int i = n; i >= 0; i--) {
		inter_frame X = F;
		int m = 0;
		while (TRUE) {
			inter_t X_index = Inter::Frame::get_parent_index(X);
			if (X_index == 0) break;
			if (m == i) {
				WRITE("%2d. ", (n-i));
				if (i == 0) WRITE("** "); else WRITE("   ");
				Inter::Defn::write_construct_text_allowing_nop(OUT, X);
				break;
			}
			X = Inter::Frame::from_index(X.repo_segment->owning_repo, X_index);
			m++;
		}
	}
	LOOP_THROUGH_INTER_CHILDREN(C, F) {
		WRITE("%2d.    ", (n+1));
		Inter::Defn::write_construct_text_allowing_nop(OUT, C);
	}
}		

void Inter::Frame::attach_package(inter_frame F, inter_t ID) {
	if ((ID) && (F.repo_segment)) {
		F.repo_segment->bytecode[F.index + PREFRAME_PACKAGE] = ID;
	}
}

inter_t Inter::Frame::get_first_child_index(inter_frame F) {
	if (F.repo_segment) {
		return F.repo_segment->bytecode[F.index + PREFRAME_FIRST_CHILD];
	}
	return 0;
}

void Inter::Frame::set_first_child_index(inter_frame F, inter_t V) {
	if (F.repo_segment) {
		F.repo_segment->bytecode[F.index + PREFRAME_FIRST_CHILD] = V;
	}
}

inter_t Inter::Frame::get_last_child_index(inter_frame F) {
	if (F.repo_segment) {
		return F.repo_segment->bytecode[F.index + PREFRAME_LAST_CHILD];
	}
	return 0;
}

void Inter::Frame::set_last_child_index(inter_frame F, inter_t V) {
	if (F.repo_segment) {
		F.repo_segment->bytecode[F.index + PREFRAME_LAST_CHILD] = V;
	}
}

inter_t Inter::Frame::get_parent_index(inter_frame F) {
	if (F.repo_segment) {
		return F.repo_segment->bytecode[F.index + PREFRAME_PARENT];
	}
	return 0;
}

void Inter::Frame::set_parent_index(inter_frame F, inter_t V) {
	if (F.repo_segment) {
		F.repo_segment->bytecode[F.index + PREFRAME_PARENT] = V;
	}
}

inter_t Inter::Frame::get_next_index(inter_frame F) {
	if (F.repo_segment) {
		return F.repo_segment->bytecode[F.index + PREFRAME_NEXT];
	}
	return 0;
}

void Inter::Frame::set_next_index(inter_frame F, inter_t V) {
	if (F.repo_segment) {
		F.repo_segment->bytecode[F.index + PREFRAME_NEXT] = V;
	}
}

inter_t Inter::Frame::get_previous_index(inter_frame F) {
	if (F.repo_segment) {
		return F.repo_segment->bytecode[F.index + PREFRAME_PREVIOUS];
	}
	return 0;
}

void Inter::Frame::set_previous_index(inter_frame F, inter_t V) {
	if (F.repo_segment) {
		F.repo_segment->bytecode[F.index + PREFRAME_PREVIOUS] = V;
	}
}

@d LOOP_THROUGH_INTER_CHILDREN(F, P)
	for (inter_t F##_index = Inter::Frame::get_first_child_index(P);
		F##_index != 0;
		F##_index = Inter::Frame::get_next_index(Inter::Frame::from_index(P.repo_segment->owning_repo, F##_index)))
		for (inter_frame F = Inter::Frame::from_index(P.repo_segment->owning_repo, F##_index); F.repo_segment; F.repo_segment = NULL)

@d PROTECTED_LOOP_THROUGH_INTER_CHILDREN(F, P)
	for (inter_t F##_index = Inter::Frame::get_first_child_index(P), F##_next_index = (F##_index)?(Inter::Frame::get_next_index(Inter::Frame::from_index(P.repo_segment->owning_repo, F##_index))):0;
		F##_index != 0;
		F##_index = F##_next_index, F##_next_index = (F##_next_index)?(Inter::Frame::get_next_index(Inter::Frame::from_index(P.repo_segment->owning_repo, F##_next_index))):0)
		for (inter_frame F = Inter::Frame::from_index(P.repo_segment->owning_repo, F##_index); F.repo_segment; F.repo_segment = NULL)

@

@e BEFORE_ICPLACEMENT from 0
@e AFTER_ICPLACEMENT
@e IMMEDIATELY_AFTER_ICPLACEMENT
@e AS_FIRST_CHILD_OF_ICPLACEMENT
@e AS_LAST_CHILD_OF_ICPLACEMENT
@e NOWHERE_ICPLACEMENT

=
void Inter::Frame::remove_from_tree(inter_frame P) {
	Inter::Frame::place(P, NOWHERE_ICPLACEMENT, Inter::Frame::around(NULL, -1));
}

void Inter::Frame::place(inter_frame C, int how, inter_frame R) {
	inter_t C_index = Inter::Frame::to_index(&C);
	inter_repository *I = C.repo_segment->owning_repo;
	@<Extricate C from its current tree position@>;
	switch (how) {
		case NOWHERE_ICPLACEMENT:
			return;
		case AS_FIRST_CHILD_OF_ICPLACEMENT:
			@<Make C the first child of R@>;
			break;
		case AS_LAST_CHILD_OF_ICPLACEMENT:
			@<Make C the last child of R@>;
			break;
		case AFTER_ICPLACEMENT:
		case IMMEDIATELY_AFTER_ICPLACEMENT:
			@<Insert C after R@>;
			break;
		case BEFORE_ICPLACEMENT:
			@<Insert C before R@>;
			break;
		default:
			internal_error("unimplemented");
	}
}

@<Extricate C from its current tree position@> =
	inter_t OP_index = Inter::Frame::get_parent_index(C);
	if (OP_index != 0) {
		inter_frame OP = Inter::Frame::from_index(I, OP_index);
		if (Inter::Frame::get_first_child_index(OP) == C_index)
			Inter::Frame::set_first_child_index(OP, Inter::Frame::get_next_index(C));
		if (Inter::Frame::get_last_child_index(OP) == C_index)
			Inter::Frame::set_last_child_index(OP, Inter::Frame::get_previous_index(C));
	}
	inter_t OB_index = Inter::Frame::get_previous_index(C);
	inter_t OD_index = Inter::Frame::get_next_index(C);
	if (OB_index != 0) {
		inter_frame OB = Inter::Frame::from_index(I, OB_index);
		Inter::Frame::set_next_index(OB, OD_index);
	}
	if (OD_index != 0) {
		inter_frame OD = Inter::Frame::from_index(I, OD_index);
		Inter::Frame::set_previous_index(OD, OB_index);
	}
	Inter::Frame::set_parent_index(C, 0);
	Inter::Frame::set_previous_index(C, 0);
	Inter::Frame::set_next_index(C, 0);

@<Make C the first child of R@> =
	inter_t R_index = Inter::Frame::to_index(&R);
	Inter::Frame::set_parent_index(C, R_index);
	inter_t D_index = Inter::Frame::get_first_child_index(R);
	if (D_index == 0) {
		Inter::Frame::set_last_child_index(R, C_index);
		Inter::Frame::set_next_index(C, 0);
	} else {
		inter_frame D = Inter::Frame::from_index(I, D_index);
		Inter::Frame::set_previous_index(D, C_index);
		Inter::Frame::set_next_index(C, D_index);
	}
	Inter::Frame::set_first_child_index(R, C_index);

@<Make C the last child of R@> =
	inter_t R_index = Inter::Frame::to_index(&R);
	Inter::Frame::set_parent_index(C, R_index);
	inter_t B_index = Inter::Frame::get_last_child_index(R);
	if (B_index == 0) {
		Inter::Frame::set_first_child_index(R, C_index);
		Inter::Frame::set_previous_index(C, 0);
	} else {
		inter_frame B = Inter::Frame::from_index(I, B_index);
		Inter::Frame::set_next_index(B, C_index);
		Inter::Frame::set_previous_index(C, B_index);
	}
	Inter::Frame::set_last_child_index(R, C_index);

@<Insert C after R@> =
	inter_t P_index = Inter::Frame::get_parent_index(R);
	inter_t R_index = Inter::Frame::to_index(&R);
	if (P_index == 0) internal_error("can't move C after R when R is nowhere");
	Inter::Frame::set_parent_index(C, P_index);
	inter_frame P = Inter::Frame::from_index(I, P_index);
	if (Inter::Frame::get_last_child_index(P) == R_index)
		Inter::Frame::set_last_child_index(P, C_index);
	else {
		inter_t D_index = Inter::Frame::get_next_index(R);
		if (D_index == 0) internal_error("inter tree broken");
		inter_frame D = Inter::Frame::from_index(I, D_index);
		Inter::Frame::set_next_index(C, D_index);
		Inter::Frame::set_previous_index(D, C_index);
	}
	Inter::Frame::set_next_index(R, C_index);
	Inter::Frame::set_previous_index(C, R_index);

@<Insert C before R@> =
	inter_t P_index = Inter::Frame::get_parent_index(R);
	inter_t R_index = Inter::Frame::to_index(&R);
	if (P_index == 0) internal_error("can't move C before R when R is nowhere");
	Inter::Frame::set_parent_index(C, P_index);
	inter_frame P = Inter::Frame::from_index(I, P_index);
	if (Inter::Frame::get_first_child_index(P) == R_index)
		Inter::Frame::set_first_child_index(P, C_index);
	else {
		inter_t B_index = Inter::Frame::get_previous_index(R);
		if (B_index == 0) internal_error("inter tree broken");
		inter_frame B = Inter::Frame::from_index(I, B_index);
		Inter::Frame::set_previous_index(C, B_index);
		Inter::Frame::set_next_index(B, C_index);
	}
	Inter::Frame::set_next_index(C, R_index);
	Inter::Frame::set_previous_index(R, C_index);