Query*
QParser_Expand_Leaf_IMP(QueryParser *self, Query *query) {
QueryParserIVARS *const ivars = QParser_IVARS(self);
LeafQuery *leaf_query = (LeafQuery*)query;
Schema *schema = ivars->schema;
bool is_phrase = false;
bool ambiguous = false;
// Determine whether we can actually process the input.
if (!Query_is_a(query, LEAFQUERY)) { return NULL; }
String *full_text = LeafQuery_Get_Text(leaf_query);
if (!Str_Get_Size(full_text)) { return NULL; }
// If quoted, always generate PhraseQuery.
StringIterator *top = Str_Top(full_text);
StringIterator *tail = Str_Tail(full_text);
StrIter_Skip_Next_Whitespace(top);
StrIter_Skip_Prev_Whitespace(tail);
if (StrIter_Starts_With_Utf8(top, "\"", 1)) {
is_phrase = true;
StrIter_Advance(top, 1);
if (StrIter_Ends_With_Utf8(tail, "\"", 1)
&& !StrIter_Ends_With_Utf8(tail, "\\\"", 2)
) {
StrIter_Recede(tail, 1);
}
}
String *source_text = StrIter_substring(top, tail);
// Either use LeafQuery's field or default to Parser's list.
Vector *fields;
if (LeafQuery_Get_Field(leaf_query)) {
fields = Vec_new(1);
Vec_Push(fields, INCREF(LeafQuery_Get_Field(leaf_query)));
}
else {
fields = (Vector*)INCREF(ivars->fields);
}
CharBuf *unescape_buf = CB_new(Str_Get_Size(source_text));
Vector *queries = Vec_new(Vec_Get_Size(fields));
for (uint32_t i = 0, max = Vec_Get_Size(fields); i < max; i++) {
String *field = (String*)Vec_Fetch(fields, i);
Analyzer *analyzer = ivars->analyzer
? ivars->analyzer
: Schema_Fetch_Analyzer(schema, field);
if (!analyzer) {
Vec_Push(queries,
(Obj*)QParser_Make_Term_Query(self, field,
(Obj*)source_text));
}
else {
// Extract token texts.
String *split_source = S_unescape(self, source_text, unescape_buf);
Vector *maybe_texts = Analyzer_Split(analyzer, split_source);
uint32_t num_maybe_texts = Vec_Get_Size(maybe_texts);
Vector *token_texts = Vec_new(num_maybe_texts);
// Filter out zero-length token texts.
for (uint32_t j = 0; j < num_maybe_texts; j++) {
String *token_text = (String*)Vec_Fetch(maybe_texts, j);
if (Str_Get_Size(token_text)) {
Vec_Push(token_texts, INCREF(token_text));
}
}
if (Vec_Get_Size(token_texts) == 0) {
/* Query might include stop words. Who knows? */
ambiguous = true;
}
// Add either a TermQuery or a PhraseQuery.
if (is_phrase || Vec_Get_Size(token_texts) > 1) {
Vec_Push(queries, (Obj*)
QParser_Make_Phrase_Query(self, field, token_texts));
}
else if (Vec_Get_Size(token_texts) == 1) {
Vec_Push(queries,
(Obj*)QParser_Make_Term_Query(self, field, Vec_Fetch(token_texts, 0)));
}
DECREF(token_texts);
DECREF(maybe_texts);
DECREF(split_source);
}
}
Query *retval;
if (Vec_Get_Size(queries) == 0) {
retval = (Query*)NoMatchQuery_new();
if (ambiguous) {
NoMatchQuery_Set_Fails_To_Match((NoMatchQuery*)retval, false);
}
}
else if (Vec_Get_Size(queries) == 1) {
retval = (Query*)INCREF(Vec_Fetch(queries, 0));
}
else {
retval = QParser_Make_OR_Query(self, queries);
}
// Clean up.
DECREF(unescape_buf);
DECREF(queries);
DECREF(fields);
DECREF(source_text);
DECREF(tail);
DECREF(top);
return retval;
}
// Find an ending boundary before the current position given by the iterator.
// Skip up to max_skip code points plus potential whitespace. Update the
// iterator and return number of code points skipped. Return true if a
// ending edge (sentence) was found.
bool
S_find_ending_boundary(StringIterator *tail, uint32_t max_skip,
uint32_t *num_skipped_ptr) {
int32_t code_point;
// Check if we're at an ending boundary already. Don't check for a word
// boundary because we need space for a trailing ellipsis.
StringIterator *iter = StrIter_Clone(tail);
do {
code_point = StrIter_Next(iter);
if (code_point == STRITER_DONE) {
// Skip remaining whitespace.
*num_skipped_ptr = StrIter_Skip_Prev_Whitespace(tail);
DECREF(iter);
return true;
}
} while (StrHelp_is_whitespace(code_point));
// Keep track of the first word boundary.
StringIterator *word = NULL;
uint32_t word_offset = 0;
StrIter_Assign(iter, tail);
for (uint32_t i = 0;
STRITER_DONE != (code_point = StrIter_Prev(iter));
++i)
{
if (code_point == '.') {
StrIter_Assign(tail, iter);
StrIter_Advance(tail, 1); // Include period.
*num_skipped_ptr = i;
DECREF(word);
DECREF(iter);
return true;
}
if (StrHelp_is_whitespace(code_point)) {
if (word == NULL) {
word = StrIter_Clone(iter);
word_offset = i + 1;
}
}
else if (i >= max_skip) {
// Break only at non-whitespace to allow another sentence
// boundary to be found.
break;
}
}
if (word == NULL) {
// Make space for ellipsis.
*num_skipped_ptr = StrIter_Recede(tail, 1);
}
else {
// Use word boundary if no sentence boundary was found.
StrIter_Assign(tail, word);
// Strip whitespace and punctuation that collides with an ellipsis.
while (STRITER_DONE != (code_point = StrIter_Prev(tail))) {
if (!StrHelp_is_whitespace(code_point)
&& code_point != '.'
&& code_point != ','
&& code_point != ';'
&& code_point != ':'
&& code_point != ':'
&& code_point != '?'
&& code_point != '!'
) {
StrIter_Advance(tail, 1); // Back up.
break;
}
++word_offset;
}
*num_skipped_ptr = word_offset;
}
DECREF(word);
DECREF(iter);
return false;
}