Box the remaining oversized enum variants and enforce large_enum_variant

Author: LucaCappelletti94

clippy.toml

@@ -0,0 +1 @@
+avoid-breaking-exported-api = false

src/ast/data_type.rs

@@ -39,7 +39,7 @@ pub enum EnumMember {
     /// ClickHouse allows to specify an integer value for each enum value.
     ///
     /// [ClickHouse](https://clickhouse.com/docs/en/sql-reference/data-types/enum)
-    NamedValue(String, Expr),
+    NamedValue(String, Box<Expr>),
 }
 
 /// SQL data types

src/ast/dcl.rs

@@ -19,7 +19,7 @@
 //! (commonly referred to as Data Control Language, or DCL)
 
 #[cfg(not(feature = "std"))]
-use alloc::vec::Vec;
+use alloc::{boxed::Box, vec::Vec};
 use core::fmt;
 
 #[cfg(feature = "serde")]
@@ -122,7 +122,7 @@ pub enum SetConfigValue {
     /// Use the current value (`FROM CURRENT`).
     FromCurrent,
     /// Set to the provided expression value.
-    Value(Expr),
+    Value(Box<Expr>),
 }
 
 /// RESET config option:
@@ -175,7 +175,7 @@ pub enum AlterRoleOperation {
         /// Configuration name to set.
         config_name: ObjectName,
         /// Value to assign to the configuration.
-        config_value: SetConfigValue,
+        config_value: Box<SetConfigValue>,
         /// Optional database scope for the setting.
         in_database: Option<ObjectName>,
     },
@@ -215,7 +215,7 @@ impl fmt::Display for AlterRoleOperation {
                     write!(f, "IN DATABASE {database_name} ")?;
                 }
 
-                match config_value {
+                match config_value.as_ref() {
                     SetConfigValue::Default => write!(f, "SET {config_name} TO DEFAULT"),
                     SetConfigValue::FromCurrent => write!(f, "SET {config_name} FROM CURRENT"),
                     SetConfigValue::Value(expr) => write!(f, "SET {config_name} TO {expr}"),

src/ast/ddl.rs

@@ -561,9 +561,9 @@ pub enum AlterPolicyOperation {
         /// Optional list of owners the policy applies to.
         to: Option<Vec<Owner>>,
         /// Optional `USING` expression for the policy.
-        using: Option<Expr>,
+        using: Option<Box<Expr>>,
         /// Optional `WITH CHECK` expression for the policy.
-        with_check: Option<Expr>,
+        with_check: Option<Box<Expr>>,
     },
 }
 
@@ -1982,7 +1982,7 @@ pub enum ColumnOption {
     /// ```
     /// [MS SQL Server]: https://learn.microsoft.com/en-us/sql/t-sql/statements/create-table-transact-sql-identity-property
     /// [Snowflake]: https://docs.snowflake.com/en/sql-reference/sql/create-table
-    Identity(IdentityPropertyKind),
+    Identity(Box<IdentityPropertyKind>),
     /// SQLite specific: ON CONFLICT option on column definition
     /// <https://www.sqlite.org/lang_conflict.html>
     OnConflict(Keyword),
@@ -2770,7 +2770,7 @@ pub enum Deduplicate {
     /// DEDUPLICATE ALL
     All,
     /// DEDUPLICATE BY expr
-    ByExpression(Expr),
+    ByExpression(Box<Expr>),
 }
 
 impl fmt::Display for Deduplicate {
@@ -3528,7 +3528,7 @@ impl fmt::Display for ForValues {
 #[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
 pub enum PartitionBoundValue {
     /// An expression representing a partition bound value.
-    Expr(Expr),
+    Expr(Box<Expr>),
     /// Represents negative infinity in partition bounds.
     MinValue,
     /// Represents positive infinity in partition bounds.

src/ast/dml.rs

@@ -934,7 +934,7 @@ pub struct MultiTableInsertValues {
 #[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
 pub enum MultiTableInsertValue {
     /// A column reference or expression from the source
-    Expr(Expr),
+    Expr(Box<Expr>),
     /// The DEFAULT keyword
     Default,
 }

src/ast/mod.rs

@@ -1440,9 +1440,9 @@ pub enum Subscript {
         /// Optional lower bound for the slice (inclusive).
         lower_bound: Option<Expr>,
         /// Optional upper bound for the slice (inclusive).
-        upper_bound: Option<Expr>,
+        upper_bound: Option<Box<Expr>>,
         /// Optional stride for the slice (step size).
-        stride: Option<Expr>,
+        stride: Option<Box<Expr>>,
     },
 }
 
@@ -1474,14 +1474,17 @@ impl fmt::Display for Subscript {
 
 /// An element of a [`Expr::CompoundFieldAccess`].
 /// It can be an expression or a subscript.
+// Dot(Expr) cannot be boxed: it is used in deeply-nested patterns such as
+// `AccessExpr::Dot(Expr::Function(..))` and as a fn-pointer via `.map(AccessExpr::Dot)`.
+#[allow(clippy::large_enum_variant)]
 #[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
 pub enum AccessExpr {
     /// Accesses a field using dot notation, e.g. `foo.bar.baz`.
     Dot(Expr),
     /// Accesses a field or array element using bracket notation, e.g. `foo['bar']`.
-    Subscript(Subscript),
+    Subscript(Box<Subscript>),
 }
 
 impl fmt::Display for AccessExpr {
@@ -2588,7 +2591,7 @@ impl fmt::Display for CommentObject {
 /// Password specification variants used in user-related statements.
 pub enum Password {
     /// A concrete password expression.
-    Password(Expr),
+    Password(Box<Expr>),
     /// Represents a `NULL` password.
     NullPassword,
 }
@@ -6813,7 +6816,7 @@ pub enum MinMaxValue {
     /// NO MINVALUE / NO MAXVALUE.
     None,
     /// `MINVALUE <expr>` / `MAXVALUE <expr>`.
-    Some(Expr),
+    Some(Box<Expr>),
 }
 
 #[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
@@ -6825,7 +6828,7 @@ pub enum OnInsert {
     /// ON DUPLICATE KEY UPDATE (MySQL when the key already exists, then execute an update instead)
     DuplicateKeyUpdate(Vec<Assignment>),
     /// ON CONFLICT is a PostgreSQL and Sqlite extension
-    OnConflict(OnConflict),
+    OnConflict(Box<OnConflict>),
 }
 
 #[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
@@ -6878,7 +6881,7 @@ pub enum OnConflictAction {
     /// Do nothing on conflict.
     DoNothing,
     /// Perform an update on conflict.
-    DoUpdate(DoUpdate),
+    DoUpdate(Box<DoUpdate>),
 }
 
 #[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
@@ -9343,7 +9346,7 @@ pub enum ShowStatementFilter {
     /// Filter using ILIKE pattern.
     ILike(String),
     /// Filter using a WHERE expression.
-    Where(Expr),
+    Where(Box<Expr>),
     /// Filter provided without a keyword (raw string).
     NoKeyword(String),
 }
@@ -10333,7 +10336,7 @@ pub enum CreateFunctionBody {
         /// AS 'MODULE_PATHNAME', 'cas_in_wrapper'
         /// ```
         /// [PostgreSQL]: https://www.postgresql.org/docs/current/sql-createfunction.html
-        link_symbol: Option<Expr>,
+        link_symbol: Option<Box<Expr>>,
     },
     /// A function body expression using the 'AS' keyword and shows up
     /// after any `OPTIONS` clause.
@@ -10397,7 +10400,7 @@ pub enum CreateFunctionBody {
     /// ```
     ///
     /// [MsSql]: https://learn.microsoft.com/en-us/sql/t-sql/statements/create-function-transact-sql?view=sql-server-ver16#select_stmt
-    AsReturnSelect(Select),
+    AsReturnSelect(Box<Select>),
 }
 
 #[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
@@ -10464,7 +10467,7 @@ impl fmt::Display for MacroArg {
 /// Definition for a DuckDB macro: either an expression or a table-producing query.
 pub enum MacroDefinition {
     /// The macro is defined as an expression.
-    Expr(Expr),
+    Expr(Box<Expr>),
     /// The macro is defined as a table (query).
     Table(Box<Query>),
 }
@@ -11206,7 +11209,7 @@ pub enum TableObject {
     /// INSERT INTO TABLE FUNCTION remote('localhost', default.simple_table)
     /// ```
     /// [Clickhouse](https://clickhouse.com/docs/en/sql-reference/table-functions)
-    TableFunction(Function),
+    TableFunction(Box<Function>),
 
     /// Table specified through a sub-query
     /// Example:

src/ast/query.rs

@@ -854,7 +854,7 @@ pub enum SelectItemQualifiedWildcardKind {
     ObjectName(ObjectName),
     /// Select star on an arbitrary expression.
     /// e.g. `STRUCT<STRING>('foo').*`
-    Expr(Expr),
+    Expr(Box<Expr>),
 }
 
 /// One item of the comma-separated list following `SELECT`
@@ -1139,7 +1139,7 @@ impl fmt::Display for ExceptSelectItem {
 #[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
 pub struct ReplaceSelectItem {
     /// List of replacement elements contained in the `REPLACE(...)` clause.
-    pub items: Vec<Box<ReplaceSelectElement>>,
+    pub items: Vec<ReplaceSelectElement>,
 }
 
 impl fmt::Display for ReplaceSelectItem {
@@ -1482,7 +1482,7 @@ pub enum TableFactor {
         with_hints: Vec<Expr>,
         /// Optional version qualifier to facilitate table time-travel, as
         /// supported by BigQuery and MSSQL.
-        version: Option<TableVersion>,
+        version: Option<Box<TableVersion>>,
         //  Optional table function modifier to generate the ordinality for column.
         /// For example, `SELECT * FROM generate_series(1, 10) WITH ORDINALITY AS t(a, b);`
         /// [WITH ORDINALITY](https://www.postgresql.org/docs/current/functions-srf.html), supported by Postgres.
@@ -2649,9 +2649,9 @@ pub enum TableVersion {
         /// The `CHANGES(INFORMATION => ...)` function-call expression.
         changes: Expr,
         /// The `AT(TIMESTAMP => ...)` function-call expression.
-        at: Expr,
+        at: Box<Expr>,
         /// The optional `END(TIMESTAMP => ...)` function-call expression.
-        end: Option<Expr>,
+        end: Option<Box<Expr>>,
     },
 }
 
@@ -2866,9 +2866,9 @@ pub enum JoinOperator {
     /// See <https://docs.snowflake.com/en/sql-reference/constructs/asof-join>.
     AsOf {
         /// Condition used to match records in the `ASOF` join.
-        match_condition: Expr,
+        match_condition: Box<Expr>,
         /// Additional constraint applied to the `ASOF` join.
-        constraint: JoinConstraint,
+        constraint: Box<JoinConstraint>,
     },
     /// `STRAIGHT_JOIN` (MySQL non-standard behavior)
     ///
@@ -2890,7 +2890,7 @@ pub enum JoinOperator {
 /// Represents how two tables are constrained in a join: `ON`, `USING`, `NATURAL`, or none.
 pub enum JoinConstraint {
     /// `ON <expr>` join condition.
-    On(Expr),
+    On(Box<Expr>),
     /// `USING(...)` list of column names.
     Using(Vec<ObjectName>),
     /// `NATURAL` join (columns matched automatically).
@@ -3396,7 +3396,7 @@ pub enum PipeOperator {
     /// Syntax: `|> [JOIN_TYPE] JOIN <table> [alias] ON <condition>` or `|> [JOIN_TYPE] JOIN <table> [alias] USING (<columns>)`
     ///
     /// See more at <https://cloud.google.com/bigquery/docs/reference/standard-sql/pipe-syntax#join_pipe_operator>
-    Join(Join),
+    Join(Box<Join>),
 }
 
 impl fmt::Display for PipeOperator {
@@ -3680,7 +3680,7 @@ pub struct Top {
 /// Quantity used in a `TOP` clause: either an expression or a constant.
 pub enum TopQuantity {
     /// A parenthesized expression (MSSQL syntax: `TOP (expr)`).
-    Expr(Expr),
+    Expr(Box<Expr>),
     /// An unparenthesized integer constant: `TOP 10`.
     Constant(u64),
 }
@@ -3788,7 +3788,7 @@ pub enum GroupByWithModifier {
     /// Hive supports GROUPING SETS syntax, e.g. `GROUP BY GROUPING SETS(...)`.
     ///
     /// [Hive]: <https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=30151323#EnhancedAggregation,Cube,GroupingandRollup-GROUPINGSETSclause>
-    GroupingSets(Expr),
+    GroupingSets(Box<Expr>),
 }
 
 impl fmt::Display for GroupByWithModifier {
@@ -4061,7 +4061,7 @@ impl fmt::Display for ForJson {
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub enum JsonTableColumn {
     /// A named column with a JSON path
-    Named(JsonTableNamedColumn),
+    Named(Box<JsonTableNamedColumn>),
     /// The FOR ORDINALITY column, which is a special column that returns the index of the current row in a JSON array.
     ForOrdinality(Ident),
     /// A set of nested columns, which extracts data from a nested JSON array.
@@ -4268,9 +4268,9 @@ pub enum XmlTableColumnOption {
         /// The type of the column to be extracted.
         r#type: DataType,
         /// The path to the column to be extracted. If None, defaults to the column name.
-        path: Option<Expr>,
+        path: Option<Box<Expr>>,
         /// Default value if path does not match
-        default: Option<Expr>,
+        default: Option<Box<Expr>>,
         /// Whether the column is nullable (NULL=true, NOT NULL=false)
         nullable: bool,
     },

src/dialect/snowflake.rs

@@ -418,12 +418,15 @@ impl Dialect for SnowflakeDialect {
             let with = parser.parse_keyword(Keyword::WITH);
 
             if parser.parse_keyword(Keyword::IDENTITY) {
-                Ok(parse_identity_property(parser)
-                    .map(|p| Some(ColumnOption::Identity(IdentityPropertyKind::Identity(p)))))
+                Ok(parse_identity_property(parser).map(|p| {
+                    Some(ColumnOption::Identity(Box::new(
+                        IdentityPropertyKind::Identity(p),
+                    )))
+                }))
             } else if parser.parse_keyword(Keyword::AUTOINCREMENT) {
                 Ok(parse_identity_property(parser).map(|p| {
-                    Some(ColumnOption::Identity(IdentityPropertyKind::Autoincrement(
-                        p,
+                    Some(ColumnOption::Identity(Box::new(
+                        IdentityPropertyKind::Autoincrement(p),
                     )))
                 }))
             } else if parser.parse_keywords(&[Keyword::MASKING, Keyword::POLICY]) {
@@ -1943,7 +1946,7 @@ fn parse_multi_table_insert_value(
     if parser.parse_keyword(Keyword::DEFAULT) {
         Ok(MultiTableInsertValue::Default)
     } else {
-        Ok(MultiTableInsertValue::Expr(parser.parse_expr()?))
+        Ok(MultiTableInsertValue::Expr(Box::new(parser.parse_expr()?)))
     }
 }
 

src/lib.rs

@@ -149,10 +149,9 @@
 
 #![cfg_attr(not(feature = "std"), no_std)]
 #![allow(clippy::upper_case_acronyms)]
-// Permit large enum variants to keep a unified, expressive AST.
-// Splitting complex nodes (expressions, statements, types) into separate types
-// would bloat the API and hide intent. Extra memory is a worthwhile tradeoff.
-#![allow(clippy::large_enum_variant)]
+// `avoid-breaking-exported-api = false` in clippy.toml exists to catch oversized
+// enum variants; it also unmutes naming lints on the public API, which are not wanted.
+#![allow(clippy::enum_variant_names)]
 #![forbid(clippy::unreachable)]
 #![forbid(missing_docs)]