<?php
echo substr("abc", [1,2]);
% phan -a test.php
AST_STMT_LIST @ 1
0: AST_STMT_LIST @ 2
0: AST_ECHO @ 2
0: AST_CALL @ 2
0: AST_NAME @ 2
flags: NAME_NOT_FQ (1)
0: "substr"
1: AST_ARG_LIST @ 2
0: "abc"
1: AST_ARRAY @ 2
0: AST_ARRAY_ELEM @ 2
flags: 0
0: 1
1: null
1: AST_ARRAY_ELEM @ 2
flags: 0
0: 2
1: null
% phan test.php
test.php:2 TypeError arg#2(start) is int[] but substr() takes int