Function collect_aliases_in_scope

src/ast/ast_shared.c:389–440

collect aliases defined in a scope bounded by scope_start and scope_end

// collect aliases defined in a scope bounded by scope_start and scope_end
void collect_aliases_in_scope
(
	const cypher_astnode_t *root,  // the query root
	uint scope_start,              // start index of scope
	uint scope_end,                // end index of scope
	rax *identifiers               // rax to populate with identifiers
) {
	ASSERT(scope_start != scope_end);
	ASSERT(identifiers != NULL);

	for(uint i = scope_start; i < scope_end; i ++) {
		const cypher_astnode_t *clause = cypher_astnode_type(root) ==
										 CYPHER_AST_QUERY ?
			cypher_ast_query_get_clause(root, i) :
			cypher_ast_query_get_clause(
				cypher_ast_call_subquery_get_query(root), i);
		cypher_astnode_type_t type = cypher_astnode_type(clause);

		if(type == CYPHER_AST_WITH) {
			// the WITH clause contains either
			// aliases or its own STAR projection
			_collect_with_projections(clause, identifiers);
		} else if(type == CYPHER_AST_MATCH) {
			// the MATCH clause contains one pattern of N paths
			const cypher_astnode_t *pattern =
				cypher_ast_match_get_pattern(clause);
			_collect_aliases_in_pattern(pattern, identifiers);
		} else if(type == CYPHER_AST_CREATE) {
			// the CREATE clause contains one pattern of N paths
			const cypher_astnode_t *pattern =
				cypher_ast_create_get_pattern(clause);
			_collect_aliases_in_pattern(pattern, identifiers);
		} else if(type == CYPHER_AST_MERGE) {
			// the MERGE clause contains one path
			const cypher_astnode_t *path =
				cypher_ast_merge_get_pattern_path(clause);
			_collect_aliases_in_path(path, identifiers);
		} else if(type == CYPHER_AST_UNWIND) {
			// the UNWIND clause introduces one alias
			const cypher_astnode_t *unwind_alias =
				cypher_ast_unwind_get_alias(clause);
			const char *identifier =
				cypher_ast_identifier_get_name(unwind_alias);
			raxTryInsert(identifiers, (unsigned char *)identifier,
				strlen(identifier), (void *)unwind_alias, NULL);
		} else if(type == CYPHER_AST_CALL) {
			_collect_call_projections(clause, identifiers);
		} else if(type == CYPHER_AST_CALL_SUBQUERY) {
			_collect_call_subquery_projections(clause, identifiers);
		}
	}
}