Function _replace_delete_clause

src/ast/ast_rewrite_same_clauses.c:123–166

compresses multiple consecutive DELETE clauses into a single DELETE clause

// compresses multiple consecutive DELETE clauses into a single DELETE clause
static void _replace_delete_clause
(
	cypher_astnode_t *root,      // ast root
	cypher_astnode_t **clauses,  // clause being replaced
	int scope_start,             // beginning of scope
	int scope_end,               // ending of scope
	replace_func replace         // replace function pointer
) {
	uint count = array_len(clauses);

	struct cypher_input_range range = cypher_astnode_range(clauses[0]);
	cypher_astnode_t **exps = array_new(cypher_astnode_t *, count);
	rax *identifiers = raxNew();

	// collect expressions
	for (uint i = 0; i < count; i++) {
		uint nexps = cypher_ast_delete_nexpressions(clauses[i]);
		for(uint j = 0; j < nexps; j++) {
			const cypher_astnode_t *exp =
				cypher_ast_delete_get_expression(clauses[i], j);
			
			// do not aggregate multiple appearances of an identifier
			if(cypher_astnode_type(exp) == CYPHER_AST_IDENTIFIER) {
				const char *identifier = cypher_ast_identifier_get_name(exp);
				if(raxTryInsert(identifiers, (unsigned char *)identifier, strlen(identifier), NULL, NULL)) {
					array_append(exps, cypher_ast_clone(exp));
				}
			} else {
				// "MATCH p1=(n:N), p2=(m:M) DELETE nodes(p1)[0] DELETE nodes(p2)[0]"
				array_append(exps, cypher_ast_clone(exp));
			}
		}
	}
	raxFree(identifiers);

	// build the replacement clause
	cypher_astnode_t *new_clause = cypher_ast_delete(false, exps,
			array_len(exps), exps, array_len(exps), range);

	// replace original clause with the new one
	replace(root, new_clause, scope_start, scope_end);
	
	array_free(exps);
}

// compresses multiple consecutive SET clauses into a single SET clause
static void _replace_set_clause