Merging upstream version 18.7.0.

Signed-off-by: Daniel Baumann <daniel@debian.org>

sqlglot/expressions.py

@@ -664,16 +664,6 @@ class Expression(metaclass=_Expression):
 
         return load(obj)
 
-
-IntoType = t.Union[
-    str,
-    t.Type[Expression],
-    t.Collection[t.Union[str, t.Type[Expression]]],
-]
-ExpOrStr = t.Union[str, Expression]
-
-
-class Condition(Expression):
     def and_(
         self,
         *expressions: t.Optional[ExpOrStr],
@@ -762,11 +752,19 @@ class Condition(Expression):
             return klass(this=other, expression=this)
         return klass(this=this, expression=other)
 
-    def __getitem__(self, other: ExpOrStr | t.Tuple[ExpOrStr]):
+    def __getitem__(self, other: ExpOrStr | t.Tuple[ExpOrStr]) -> Bracket:
         return Bracket(
             this=self.copy(), expressions=[convert(e, copy=True) for e in ensure_list(other)]
         )
 
+    def __iter__(self) -> t.Iterator:
+        if "expressions" in self.arg_types:
+            return iter(self.args.get("expressions") or [])
+        # We define this because __getitem__ converts Expression into an iterable, which is
+        # problematic because one can hit infinite loops if they do "for x in some_expr: ..."
+        # See: https://peps.python.org/pep-0234/
+        raise TypeError(f"'{self.__class__.__name__}' object is not iterable")
+
     def isin(
         self,
         *expressions: t.Any,
@@ -886,6 +884,18 @@ class Condition(Expression):
         return not_(self.copy())
 
 
+IntoType = t.Union[
+    str,
+    t.Type[Expression],
+    t.Collection[t.Union[str, t.Type[Expression]]],
+]
+ExpOrStr = t.Union[str, Expression]
+
+
+class Condition(Expression):
+    """Logical conditions like x AND y, or simply x"""
+
+
 class Predicate(Condition):
     """Relationships like x = y, x > 1, x >= y."""
 
@@ -1045,6 +1055,10 @@ class Describe(Expression):
     arg_types = {"this": True, "kind": False, "expressions": False}
 
 
+class Kill(Expression):
+    arg_types = {"this": True, "kind": False}
+
+
 class Pragma(Expression):
     pass
 
@@ -1161,7 +1175,7 @@ class Column(Condition):
             if self.args.get(part)
         ]
 
-    def to_dot(self) -> Dot:
+    def to_dot(self) -> Dot | Identifier:
         """Converts the column into a dot expression."""
         parts = self.parts
         parent = self.parent
@@ -1171,7 +1185,7 @@ class Column(Condition):
                 parts.append(parent.expression)
             parent = parent.parent
 
-        return Dot.build(deepcopy(parts))
+        return Dot.build(deepcopy(parts)) if len(parts) > 1 else parts[0]
 
 
 class ColumnPosition(Expression):
@@ -1607,6 +1621,7 @@ class Index(Expression):
         "primary": False,
         "amp": False,  # teradata
         "partition_by": False,  # teradata
+        "where": False,  # postgres partial indexes
     }
 
 
@@ -1917,7 +1932,7 @@ class Sort(Order):
 
 
 class Ordered(Expression):
-    arg_types = {"this": True, "desc": True, "nulls_first": True}
+    arg_types = {"this": True, "desc": False, "nulls_first": True}
 
 
 class Property(Expression):
@@ -2569,7 +2584,6 @@ class Intersect(Union):
 class Unnest(UDTF):
     arg_types = {
         "expressions": True,
-        "ordinality": False,
         "alias": False,
         "offset": False,
     }
@@ -2862,6 +2876,7 @@ class Select(Subqueryable):
             prefix="LIMIT",
             dialect=dialect,
             copy=copy,
+            into_arg="expression",
             **opts,
         )
 
@@ -4007,6 +4022,10 @@ class TimeUnit(Expression):
 
         super().__init__(**args)
 
+    @property
+    def unit(self) -> t.Optional[Var]:
+        return self.args.get("unit")
+
 
 # https://www.oracletutorial.com/oracle-basics/oracle-interval/
 # https://trino.io/docs/current/language/types.html#interval-day-to-second
@@ -4018,10 +4037,6 @@ class IntervalSpan(Expression):
 class Interval(TimeUnit):
     arg_types = {"this": False, "unit": False}
 
-    @property
-    def unit(self) -> t.Optional[Var]:
-        return self.args.get("unit")
-
 
 class IgnoreNulls(Expression):
     pass
@@ -4327,6 +4342,10 @@ class DateDiff(Func, TimeUnit):
 class DateTrunc(Func):
     arg_types = {"unit": True, "this": True, "zone": False}
 
+    @property
+    def unit(self) -> Expression:
+        return self.args["unit"]
+
 
 class DatetimeAdd(Func, TimeUnit):
     arg_types = {"this": True, "expression": True, "unit": False}
@@ -4427,7 +4446,8 @@ class DateToDi(Func):
 
 # https://cloud.google.com/bigquery/docs/reference/standard-sql/date_functions#date
 class Date(Func):
-    arg_types = {"this": True, "zone": False}
+    arg_types = {"this": False, "zone": False, "expressions": False}
+    is_var_len_args = True
 
 
 class Day(Func):
@@ -5131,10 +5151,11 @@ def _apply_builder(
     prefix=None,
     into=None,
     dialect=None,
+    into_arg="this",
     **opts,
 ):
     if _is_wrong_expression(expression, into):
-        expression = into(this=expression)
+        expression = into(**{into_arg: expression})
     instance = maybe_copy(instance, copy)
     expression = maybe_parse(
         sql_or_expression=expression,
@@ -5926,7 +5947,10 @@ def cast(expression: ExpOrStr, to: str | DataType | DataType.Type, **opts) -> Ca
         The new Cast instance.
     """
     expression = maybe_parse(expression, **opts)
-    return Cast(this=expression, to=DataType.build(to, **opts))
+    data_type = DataType.build(to, **opts)
+    expression = Cast(this=expression, to=data_type)
+    expression.type = data_type
+    return expression
 
 
 def table_(