Function AST_NewSegment

src/ast/ast.c:432–479

}

AST *AST_NewSegment
(
	AST *master_ast,
	uint start_offset,
	uint end_offset
) {
	AST *ast = rm_malloc(sizeof(AST));

	ast->free_root           = true;
	ast->ref_count           = rm_malloc(sizeof(uint));
	ast->parse_result        = NULL;
	ast->params_parse_result = NULL;
	ast->referenced_entities = NULL;
	ast->anot_ctx_collection = master_ast->anot_ctx_collection;

	uint n = end_offset - start_offset;

	*(ast->ref_count) = 1;
	const cypher_astnode_t *clauses[n];
	for(uint i = 0; i < n; i ++) {
		clauses[i] = cypher_ast_query_get_clause(master_ast->root, i + start_offset);
	}
	struct cypher_input_range range = {0};
	ast->root = cypher_ast_query(NULL, 0, (cypher_astnode_t *const *)clauses, n,
								 (cypher_astnode_t **)clauses, n, range);

	// TODO This overwrites the previously-held AST pointer, which could lead to inconsistencies
	// in the future if we expect the variable to hold a different AST.
	QueryCtx_SetAST(ast);

	// If the segments are split, the next clause is either RETURN or WITH,
	// and its references should be included in this segment's map.
	const cypher_astnode_t *project_clause = NULL;
	uint clause_count = cypher_ast_query_nclauses(master_ast->root);
	if(end_offset == clause_count) end_offset = clause_count - 1;

	project_clause = cypher_ast_query_get_clause(master_ast->root, end_offset);
	// last clause is not necessarily a projection clause
	// [MATCH (a) RETURN a UNION] MATCH (a) RETURN a
	// In this case project_clause = UNION, which is not a projection clause
	cypher_astnode_type_t project_type = cypher_astnode_type(project_clause);
	if(project_type != CYPHER_AST_WITH && project_type != CYPHER_AST_RETURN) project_clause = NULL;

	// Build the map of referenced entities in this AST segment.
	AST_BuildReferenceMap(ast, project_clause);

	return ast;
}

void AST_SetParamsParseResult
(