Function _add_first_clause

src/ast/ast_rewrite_call_subquery.c:200–254

adds a leading WITH clause to the query, projecting all bound vars (names) to their internal representation (inter_names)

// adds a leading WITH clause to the query, projecting all bound vars (names) to
// their internal representation (inter_names)
static void _add_first_clause
(
	cypher_astnode_t *callsubquery,     // call subquery ast-node
	uint callsubquery_ind,              // index of the call subquery node
	uint first_ind,                     // the index in which to plant the clause
	char **names,                       // original bound vars
	char **inter_names                  // internal representation of bound vars
) {
	uint n_names = array_len(names);
	uint n_inter_names = array_len(inter_names);

	uint n_projections = n_inter_names;
	uint proj_idx = 0;
	cypher_astnode_t *projections[n_projections];

	// -------------------------------------------------------------------------
	// create projections for bound vars
	// -------------------------------------------------------------------------
	proj_idx = _add_projections(projections, proj_idx, names, inter_names,
		true);

	// -------------------------------------------------------------------------
	// prepare additional arguments
	//--------------------------------------------------------------------------

	struct cypher_input_range range = {0};

	// build the replacement clause
	cypher_astnode_t *new_clause;
	new_clause = cypher_ast_with(false, false, projections, n_projections,
		NULL, NULL, NULL, NULL, projections, n_projections, range);

	// -------------------------------------------------------------------------
	// replace original clause with fully populated one
	// -------------------------------------------------------------------------

	cypher_astnode_t *query = cypher_ast_call_subquery_get_query(callsubquery);

	uint n_clauses = cypher_ast_query_nclauses(query);
	cypher_astnode_t *clauses[n_clauses + 1];
	for(uint i = 0; i < first_ind; i++) {
		clauses[i] = cypher_ast_clone(cypher_ast_query_get_clause(query, i));
	}

	clauses[first_ind] = new_clause;

	for(uint i = first_ind; i < n_clauses; i++) {
		clauses[i + 1] = cypher_ast_clone(cypher_ast_query_get_clause(query, i));
	}

	cypher_astnode_t *q = cypher_ast_query(NULL, 0, clauses, n_clauses + 1,
		clauses, n_clauses + 1, range);

	cypher_ast_call_subquery_replace_query(callsubquery, q);
}

// replace all intermediate WITH clauses in the query with new WITH clauses,
// containing projections from the internal representation of bound vars to