From d1a356e7126720c1a357bfc30ff16c6844b9462b Mon Sep 17 00:00:00 2001
From: archibate <1931127624@qq.com>
Date: Mon, 29 Jun 2020 10:05:55 +0800
Subject: [PATCH] [skip ci] revert ti.chain_compare

---
 python/taichi/lang/impl.py | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/python/taichi/lang/impl.py b/python/taichi/lang/impl.py
index 32ebfc8998564..e7308597a21e8 100644
--- a/python/taichi/lang/impl.py
+++ b/python/taichi/lang/impl.py
@@ -102,10 +102,13 @@ def subscript(value, *indices):
 def chain_compare(comparators, ops):
     assert len(comparators) == len(ops) + 1, \
       f'Chain comparison invoked with {len(comparators)} comparators but {len(ops)} operators'
-    ret = True
+    evaluated_comparators = []
+    for i in range(len(comparators)):
+        evaluated_comparators += [expr_init(comparators[i])]
+    ret = expr_init(True)
     for i in range(len(ops)):
-        lhs = comparators[i]
-        rhs = comparators[i + 1]
+        lhs = evaluated_comparators[i]
+        rhs = evaluated_comparators[i + 1]
         if ops[i] == 'Lt':
             now = lhs < rhs
         elif ops[i] == 'LtE':
@@ -120,7 +123,7 @@ def chain_compare(comparators, ops):
             now = lhs != rhs
         else:
             assert False, f'Unknown operator {ops[i]}'
-        ret = logical_and(ret, now)
+        ret = ret.logical_and(now)
     return ret