Fix NOT operator precedence with parenthesized expressions

When NOT is followed by a parenthesized expression, use UNARY precedence
so binary operators after the group don't continue as part of the NOT
operand. This ensures:
- NOT (0) + 1 parses as (NOT(0)) + 1
- NOT 0 + 1 parses as NOT(0 + 1)

Enables test 02920_unary_operators_functions.

Author: claude

parser/expression.go

@@ -809,7 +809,15 @@ func (p *Parser) parseNot() ast.Expression {
 		Op:       "NOT",
 	}
 	p.nextToken()
-	expr.Operand = p.parseExpression(NOT_PREC)
+	// When NOT is followed by a parenthesized expression, use UNARY precedence
+	// so that binary operators after the group don't continue as part of the NOT operand.
+	// e.g., NOT (0) + 1 should parse as (NOT(0)) + 1, not NOT((0) + 1)
+	// But NOT 0 + 1 should parse as NOT(0 + 1)
+	if p.currentIs(token.LPAREN) {
+		expr.Operand = p.parseExpression(UNARY)
+	} else {
+		expr.Operand = p.parseExpression(NOT_PREC)
+	}
 	return expr
 }
 

parser/testdata/02920_unary_operators_functions/metadata.json

@@ -1 +1 @@
-{"todo": true}
+{}