static bool
read_collection(SerdReader* reader, ReadContext ctx, Ref* dest)
{
eat_byte_safe(reader, '(');
bool end = peek_delim(reader, ')');
*dest = end ? reader->rdf_nil : blank_id(reader);
if (ctx.subject) {
// subject predicate _:head
*ctx.flags |= (end ? 0 : SERD_LIST_O_BEGIN);
TRY_RET(emit_statement(reader, ctx, *dest, 0, 0));
*ctx.flags |= SERD_LIST_CONT;
} else {
*ctx.flags |= (end ? 0 : SERD_LIST_S_BEGIN);
}
if (end) {
return end_collection(reader, ctx, 0, 0, true);
}
/* The order of node allocation here is necessarily not in stack order,
so we create two nodes and recycle them throughout. */
Ref n1 = push_node_padded(reader, genid_size(reader), SERD_BLANK, "", 0);
Ref n2 = 0;
Ref node = n1;
Ref rest = 0;
ctx.subject = *dest;
while (!(end = peek_delim(reader, ')'))) {
// _:node rdf:first object
ctx.predicate = reader->rdf_first;
bool ate_dot = false;
if (!read_object(reader, ctx, &ate_dot) || ate_dot) {
return end_collection(reader, ctx, n1, n2, false);
}
if (!(end = peek_delim(reader, ')'))) {
/* Give rest a new ID. Done as late as possible to ensure it is
used and > IDs generated by read_object above. */
if (!rest) {
rest = n2 = blank_id(reader); // First pass, push
} else {
set_blank_id(reader, rest, genid_size(reader));
}
}
// _:node rdf:rest _:rest
*ctx.flags |= SERD_LIST_CONT;
ctx.predicate = reader->rdf_rest;
TRY_RET(emit_statement(reader, ctx,
(end ? reader->rdf_nil : rest), 0, 0));
ctx.subject = rest; // _:node = _:rest
rest = node; // _:rest = (old)_:node
node = ctx.subject; // invariant
}
return end_collection(reader, ctx, n1, n2, true);
}
static bool
read_blank(SerdReader* reader, ReadContext ctx, bool subject, Ref* dest, bool* ate_dot)
{
const SerdStatementFlags old_flags = *ctx.flags;
bool empty;
switch (peek_byte(reader)) {
case '_':
return (*dest = read_BLANK_NODE_LABEL(reader, ate_dot));
case '[':
eat_byte_safe(reader, '[');
if ((empty = peek_delim(reader, ']'))) {
*ctx.flags |= (subject) ? SERD_EMPTY_S : SERD_EMPTY_O;
} else {
*ctx.flags |= (subject) ? SERD_ANON_S_BEGIN : SERD_ANON_O_BEGIN;
if (peek_delim(reader, '=')) {
if (!(*dest = read_blankName(reader)) ||
!eat_delim(reader, ';')) {
return false;
}
}
}
if (!*dest) {
*dest = blank_id(reader);
}
if (ctx.subject) {
TRY_RET(emit_statement(reader, ctx, *dest, 0, 0));
}
ctx.subject = *dest;
if (!empty) {
*ctx.flags &= ~(SERD_LIST_CONT);
if (!subject) {
*ctx.flags |= SERD_ANON_CONT;
}
bool ate_dot_in_list = false;
read_predicateObjectList(reader, ctx, &ate_dot_in_list);
if (ate_dot_in_list) {
return r_err(reader, SERD_ERR_BAD_SYNTAX, "`.' inside blank\n");
}
read_ws_star(reader);
if (reader->end_sink) {
reader->end_sink(reader->handle, deref(reader, *dest));
}
*ctx.flags = old_flags;
}
return (eat_byte_check(reader, ']') == ']');
case '(':
return read_collection(reader, ctx, dest);
default: return false; // never reached
}
}
