Feat: add math associativity simplification

tobymao · May 13, 2023 · 31a82cc · 31a82cc
1 parent 4601831
commit 31a82cc
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Showing 2 changed files with 28 additions and 9 deletions.
diff --git a/sqlglot/optimizer/simplify.py b/sqlglot/optimizer/simplify.py
@@ -388,14 +388,18 @@ def _simplify_binary(expression, a, b):
 
 
 def simplify_parens(expression):
-    if (
-        isinstance(expression, exp.Paren)
-        and not isinstance(expression.this, exp.Select)
-        and (
-            not isinstance(expression.parent, (exp.Condition, exp.Binary))
-            or isinstance(expression.this, exp.Predicate)
-            or not isinstance(expression.this, exp.Binary)
-        )
+    if not isinstance(expression, exp.Paren):
+        return expression
+
+    this = expression.this
+    parent = expression.parent
+
+    if not isinstance(this, exp.Select) and (
+        not isinstance(parent, (exp.Condition, exp.Binary))
+        or isinstance(this, exp.Predicate)
+        or not isinstance(this, exp.Binary)
+        or (isinstance(this, exp.Add) and isinstance(parent, exp.Add))
+        or (isinstance(this, exp.Mul) and isinstance(parent, exp.Mul))
     ):
         return expression.this
     return expression

diff --git a/tests/fixtures/optimizer/simplify.sql b/tests/fixtures/optimizer/simplify.sql
@@ -201,6 +201,21 @@ A AND B AND C AND D;
 (((((A) AND B)) AND C)) AND D;
 A AND B AND C AND D;
 
+(x + 1) + 2;
+x + 3;
+
+x + (1 + 2);
+x + 3;
+
+(x * 2) * 4 + (1 + 3) + 5;
+x * 8 + 9;
+
+(x - 1) - 2;
+(x - 1) - 2;
+
+x - (3 - 2);
+x - 1;
+
 --------------------------------------
 -- Comparison and Pruning
 --------------------------------------
@@ -574,4 +589,4 @@ x > 3;
 TRUE;
 
 x = 2018 OR x <> 2018;
-x <> 2018 OR x = 2018;
+x <> 2018 OR x = 2018;