Added support for DROP OPERATOR syntax (#2102)

Co-authored-by: Ifeanyi Ubah <ify1992@yahoo.com>

src/ast/ddl.rs

@@ -4188,3 +4188,62 @@ impl fmt::Display for OperatorPurpose {
         }
     }
 }
+
+/// `DROP OPERATOR` statement
+/// See <https://www.postgresql.org/docs/current/sql-dropoperator.html>
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub struct DropOperator {
+    /// `IF EXISTS` clause
+    pub if_exists: bool,
+    /// One or more operators to drop with their signatures
+    pub operators: Vec<DropOperatorSignature>,
+    /// `CASCADE or RESTRICT`
+    pub drop_behavior: Option<DropBehavior>,
+}
+
+/// Operator signature for a `DROP OPERATOR` statement
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub struct DropOperatorSignature {
+    /// Operator name
+    pub name: ObjectName,
+    /// Left operand type
+    pub left_type: Option<DataType>,
+    /// Right operand type
+    pub right_type: DataType,
+}
+
+impl fmt::Display for DropOperatorSignature {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{} (", self.name)?;
+        if let Some(left_type) = &self.left_type {
+            write!(f, "{}", left_type)?;
+        } else {
+            write!(f, "NONE")?;
+        }
+        write!(f, ", {})", self.right_type)
+    }
+}
+
+impl fmt::Display for DropOperator {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "DROP OPERATOR")?;
+        if self.if_exists {
+            write!(f, " IF EXISTS")?;
+        }
+        write!(f, " {}", display_comma_separated(&self.operators))?;
+        if let Some(drop_behavior) = &self.drop_behavior {
+            write!(f, " {}", drop_behavior)?;
+        }
+        Ok(())
+    }
+}
+
+impl Spanned for DropOperator {
+    fn span(&self) -> Span {
+        Span::empty()
+    }
+}

src/ast/mod.rs

@@ -67,14 +67,15 @@ pub use self::ddl::{
     ColumnPolicyProperty, ConstraintCharacteristics, CreateConnector, CreateDomain,
     CreateExtension, CreateFunction, CreateIndex, CreateOperator, CreateOperatorClass,
     CreateOperatorFamily, CreateTable, CreateTrigger, CreateView, Deduplicate, DeferrableInitial,
-    DropBehavior, DropExtension, DropFunction, DropTrigger, GeneratedAs, GeneratedExpressionMode,
-    IdentityParameters, IdentityProperty, IdentityPropertyFormatKind, IdentityPropertyKind,
-    IdentityPropertyOrder, IndexColumn, IndexOption, IndexType, KeyOrIndexDisplay, Msck,
-    NullsDistinctOption, OperatorArgTypes, OperatorClassItem, OperatorPurpose, Owner, Partition,
-    ProcedureParam, ReferentialAction, RenameTableNameKind, ReplicaIdentity, TagsColumnOption,
-    TriggerObjectKind, Truncate, UserDefinedTypeCompositeAttributeDef,
-    UserDefinedTypeInternalLength, UserDefinedTypeRangeOption, UserDefinedTypeRepresentation,
-    UserDefinedTypeSqlDefinitionOption, UserDefinedTypeStorage, ViewColumnDef,
+    DropBehavior, DropExtension, DropFunction, DropOperator, DropOperatorSignature, DropTrigger,
+    GeneratedAs, GeneratedExpressionMode, IdentityParameters, IdentityProperty,
+    IdentityPropertyFormatKind, IdentityPropertyKind, IdentityPropertyOrder, IndexColumn,
+    IndexOption, IndexType, KeyOrIndexDisplay, Msck, NullsDistinctOption, OperatorArgTypes,
+    OperatorClassItem, OperatorPurpose, Owner, Partition, ProcedureParam, ReferentialAction,
+    RenameTableNameKind, ReplicaIdentity, TagsColumnOption, TriggerObjectKind, Truncate,
+    UserDefinedTypeCompositeAttributeDef, UserDefinedTypeInternalLength,
+    UserDefinedTypeRangeOption, UserDefinedTypeRepresentation, UserDefinedTypeSqlDefinitionOption,
+    UserDefinedTypeStorage, ViewColumnDef,
 };
 pub use self::dml::{Delete, Insert, Update};
 pub use self::operator::{BinaryOperator, UnaryOperator};
@@ -3573,6 +3574,12 @@ pub enum Statement {
     /// <https://www.postgresql.org/docs/current/sql-dropextension.html>
     DropExtension(DropExtension),
     /// ```sql
+    /// DROP OPERATOR [ IF EXISTS ] name ( { left_type | NONE } , right_type ) [, ...] [ CASCADE | RESTRICT ]
+    /// ```
+    /// Note: this is a PostgreSQL-specific statement.
+    /// <https://www.postgresql.org/docs/current/sql-dropoperator.html>
+    DropOperator(DropOperator),
+    /// ```sql
     /// FETCH
     /// ```
     /// Retrieve rows from a query using a cursor
@@ -4836,6 +4843,7 @@ impl fmt::Display for Statement {
             Statement::CreateIndex(create_index) => create_index.fmt(f),
             Statement::CreateExtension(create_extension) => write!(f, "{create_extension}"),
             Statement::DropExtension(drop_extension) => write!(f, "{drop_extension}"),
+            Statement::DropOperator(drop_operator) => write!(f, "{drop_operator}"),
             Statement::CreateRole(create_role) => write!(f, "{create_role}"),
             Statement::CreateSecret {
                 or_replace,

src/ast/spans.rs

@@ -375,6 +375,7 @@ impl Spanned for Statement {
             Statement::CreateRole(create_role) => create_role.span(),
             Statement::CreateExtension(create_extension) => create_extension.span(),
             Statement::DropExtension(drop_extension) => drop_extension.span(),
+            Statement::DropOperator(drop_operator) => drop_operator.span(),
             Statement::CreateSecret { .. } => Span::empty(),
             Statement::CreateServer { .. } => Span::empty(),
             Statement::CreateConnector { .. } => Span::empty(),