refactor: add CastError for cast function

src/frontend/src/binder/expr/mod.rs

@@ -40,6 +40,7 @@ impl Binder {
             Expr::TypedString { data_type, value } => {
                 let s: ExprImpl = self.bind_string(value)?.into();
                 s.cast_explicit(bind_data_type(&data_type)?)
+                    .map_err(Into::into)
             }
             Expr::Row(exprs) => self.bind_row(exprs),
             // input ref
@@ -430,7 +431,7 @@ impl Binder {
             return self.bind_array_cast(expr.clone(), data_type);
         }
         let lhs = self.bind_expr(expr)?;
-        lhs.cast_explicit(data_type)
+        lhs.cast_explicit(data_type).map_err(Into::into)
     }
 }
 

src/frontend/src/binder/expr/value.rs

@@ -130,7 +130,7 @@ impl Binder {
                 },
             )
             .into();
-            return lhs.cast_explicit(ty);
+            return lhs.cast_explicit(ty).map_err(Into::into);
         }
         let inner_type = if let DataType::List { datatype } = &ty {
             *datatype.clone()

src/frontend/src/binder/insert.rs

@@ -247,7 +247,7 @@ impl Binder {
                 return exprs
                     .into_iter()
                     .zip_eq_fast(expected_types)
-                    .map(|(e, t)| e.cast_assign(t.clone()))
+                    .map(|(e, t)| e.cast_assign(t.clone()).map_err(Into::into))
                     .try_collect();
             }
             std::cmp::Ordering::Less => "INSERT has more expressions than target columns",

src/frontend/src/expr/function_call.rs

@@ -14,10 +14,11 @@
 
 use itertools::Itertools;
 use risingwave_common::catalog::Schema;
-use risingwave_common::error::{ErrorCode, Result};
+use risingwave_common::error::{ErrorCode, Result as RwResult, RwError};
 use risingwave_common::types::DataType;
 use risingwave_common::util::iter_util::ZipEqFast;
 use risingwave_expr::vector_op::cast::literal_parsing;
+use thiserror::Error;
 
 use super::{cast_ok, infer_some_all, infer_type, CastContext, Expr, ExprImpl, Literal};
 use crate::expr::{ExprDisplay, ExprType};
@@ -99,7 +100,7 @@ impl FunctionCall {
     // The functions listed here are all variadic.  Type signatures of functions that take a fixed
     // number of arguments are checked
     // [elsewhere](crate::expr::type_inference::build_type_derive_map).
-    pub fn new(func_type: ExprType, mut inputs: Vec<ExprImpl>) -> Result<Self> {
+    pub fn new(func_type: ExprType, mut inputs: Vec<ExprImpl>) -> RwResult<Self> {
         let return_type = infer_type(func_type, &mut inputs)?;
         Ok(Self {
             func_type,
@@ -109,12 +110,16 @@ impl FunctionCall {
     }
 
     /// Create a cast expr over `child` to `target` type in `allows` context.
-    pub fn new_cast(child: ExprImpl, target: DataType, allows: CastContext) -> Result<ExprImpl> {
+    pub fn new_cast(
+        child: ExprImpl,
+        target: DataType,
+        allows: CastContext,
+    ) -> Result<ExprImpl, CastError> {
         if is_row_function(&child) {
             // Row function will have empty fields in Datatype::Struct at this point. Therefore,
             // we will need to take some special care to generate the cast types. For normal struct
             // types, they will be handled in `cast_ok`.
-            return Self::cast_nested(child, target, allows);
+            return Self::cast_row_expr(child, target, allows);
         }
         if child.is_unknown() {
             // `is_unknown` makes sure `as_literal` and `as_utf8` will never panic.
@@ -146,46 +151,51 @@ impl FunctionCall {
             }
             .into())
         } else {
-            Err(ErrorCode::BindError(format!(
+            Err(CastError(format!(
                 "cannot cast type \"{}\" to \"{}\" in {:?} context",
                 source, target, allows
-            ))
-            .into())
+            )))
         }
     }
 
     /// Cast a `ROW` expression to the target type. We intentionally disallow casting arbitrary
     /// expressions, like `ROW(1)::STRUCT<i INTEGER>` to `STRUCT<VARCHAR>`, although an integer
     /// is castible to VARCHAR. It's to simply the casting rules.
-    fn cast_nested(expr: ExprImpl, target_type: DataType, allows: CastContext) -> Result<ExprImpl> {
+    fn cast_row_expr(
+        expr: ExprImpl,
+        target_type: DataType,
+        allows: CastContext,
+    ) -> Result<ExprImpl, CastError> {
         let func = *expr.into_function_call().unwrap();
         let (fields, field_names) = if let DataType::Struct(t) = &target_type {
             (t.fields.clone(), t.field_names.clone())
         } else {
-            return Err(ErrorCode::BindError(format!(
-                "column is of type '{}' but expression is of type record",
-                target_type
-            ))
-            .into());
+            return Err(CastError(format!(
+                "cannot cast type \"{}\" to \"{}\" in {:?} context",
+                func.return_type(),
+                target_type,
+                allows
+            )));
         };
         let (func_type, inputs, _) = func.decompose();
-        let msg = match fields.len().cmp(&inputs.len()) {
+        match fields.len().cmp(&inputs.len()) {
             std::cmp::Ordering::Equal => {
                 let inputs = inputs
                     .into_iter()
                     .zip_eq_fast(fields.to_vec())
                     .map(|(e, t)| Self::new_cast(e, t, allows))
-                    .collect::<Result<Vec<_>>>()?;
+                    .collect::<Result<Vec<_>, CastError>>()?;
                 let return_type = DataType::new_struct(
                     inputs.iter().map(|i| i.return_type()).collect_vec(),
                     field_names,
                 );
-                return Ok(FunctionCall::new_unchecked(func_type, inputs, return_type).into());
+                Ok(FunctionCall::new_unchecked(func_type, inputs, return_type).into())
             }
-            std::cmp::Ordering::Less => "Input has too few columns.",
-            std::cmp::Ordering::Greater => "Input has too many columns.",
-        };
-        Err(ErrorCode::BindError(format!("cannot cast record to {} ({})", target_type, msg)).into())
+            std::cmp::Ordering::Less => Err(CastError("Input has too few columns.".to_string())),
+            std::cmp::Ordering::Greater => {
+                Err(CastError("Input has too many columns.".to_string()))
+            }
+        }
     }
 
     /// Construct a `FunctionCall` expr directly with the provided `return_type`, bypassing type
@@ -205,7 +215,7 @@ impl FunctionCall {
     pub fn new_binary_op_func(
         mut func_types: Vec<ExprType>,
         mut inputs: Vec<ExprImpl>,
-    ) -> Result<ExprImpl> {
+    ) -> RwResult<ExprImpl> {
         let expr_type = func_types.remove(0);
         match expr_type {
             ExprType::Some | ExprType::All => {
@@ -274,7 +284,7 @@ impl FunctionCall {
         function_call: &risingwave_pb::expr::FunctionCall,
         expr_type: ExprType,
         ret_type: DataType,
-    ) -> Result<Self> {
+    ) -> RwResult<Self> {
         let inputs: Vec<_> = function_call
             .get_children()
             .iter()
@@ -419,3 +429,19 @@ pub fn is_row_function(expr: &ExprImpl) -> bool {
     }
     false
 }
+
+#[derive(Debug, Error)]
+#[error("{0}")]
+pub struct CastError(String);
+
+impl From<CastError> for ErrorCode {
+    fn from(value: CastError) -> Self {
+        ErrorCode::BindError(value.to_string())
+    }
+}
+
+impl From<CastError> for RwError {
+    fn from(value: CastError) -> Self {
+        ErrorCode::from(value).into()
+    }
+}

src/frontend/src/expr/mod.rs

@@ -16,7 +16,7 @@ use enum_as_inner::EnumAsInner;
 use fixedbitset::FixedBitSet;
 use paste::paste;
 use risingwave_common::array::ListValue;
-use risingwave_common::error::Result;
+use risingwave_common::error::Result as RwResult;
 use risingwave_common::types::{DataType, Datum, Scalar};
 use risingwave_expr::expr::{build_from_prost, AggKind};
 use risingwave_pb::expr::expr_node::RexNode;
@@ -177,22 +177,22 @@ impl ExprImpl {
     }
 
     /// Shorthand to create cast expr to `target` type in implicit context.
-    pub fn cast_implicit(self, target: DataType) -> Result<ExprImpl> {
+    pub fn cast_implicit(self, target: DataType) -> Result<ExprImpl, CastError> {
         FunctionCall::new_cast(self, target, CastContext::Implicit)
     }
 
     /// Shorthand to create cast expr to `target` type in assign context.
-    pub fn cast_assign(self, target: DataType) -> Result<ExprImpl> {
+    pub fn cast_assign(self, target: DataType) -> Result<ExprImpl, CastError> {
         FunctionCall::new_cast(self, target, CastContext::Assign)
     }
 
     /// Shorthand to create cast expr to `target` type in explicit context.
-    pub fn cast_explicit(self, target: DataType) -> Result<ExprImpl> {
+    pub fn cast_explicit(self, target: DataType) -> Result<ExprImpl, CastError> {
         FunctionCall::new_cast(self, target, CastContext::Explicit)
     }
 
     /// Shorthand to enforce implicit cast to boolean
-    pub fn enforce_bool_clause(self, clause: &str) -> Result<ExprImpl> {
+    pub fn enforce_bool_clause(self, clause: &str) -> RwResult<ExprImpl> {
         if self.is_unknown() {
             let inner = self.cast_implicit(DataType::Boolean)?;
             return Ok(inner);
@@ -218,26 +218,27 @@ impl ExprImpl {
     /// References in `PostgreSQL`:
     /// * [cast](https://github.com/postgres/postgres/blob/a3ff08e0b08dbfeb777ccfa8f13ebaa95d064c04/src/include/catalog/pg_cast.dat#L437-L444)
     /// * [impl](https://github.com/postgres/postgres/blob/27b77ecf9f4d5be211900eda54d8155ada50d696/src/backend/utils/adt/bool.c#L204-L209)
-    pub fn cast_output(self) -> Result<ExprImpl> {
+    pub fn cast_output(self) -> RwResult<ExprImpl> {
         if self.return_type() == DataType::Boolean {
             return Ok(FunctionCall::new(ExprType::BoolOut, vec![self])?.into());
         }
         // Use normal cast for other types. Both `assign` and `explicit` can pass the castability
         // check and there is no difference.
         self.cast_assign(DataType::Varchar)
+            .map_err(|err| err.into())
     }
 
     /// Evaluate the expression on the given input.
     ///
     /// TODO: This is a naive implementation. We should avoid proto ser/de.
     /// Tracking issue: <https://github.com/risingwavelabs/risingwave/issues/3479>
-    fn eval_row(&self, input: &OwnedRow) -> Result<Datum> {
+    fn eval_row(&self, input: &OwnedRow) -> RwResult<Datum> {
         let backend_expr = build_from_prost(&self.to_expr_proto())?;
         backend_expr.eval_row(input).map_err(Into::into)
     }
 
     /// Evaluate a constant expression.
-    pub fn eval_row_const(&self) -> Result<Datum> {
+    pub fn eval_row_const(&self) -> RwResult<Datum> {
         assert!(self.is_const());
         self.eval_row(&OwnedRow::empty())
     }
@@ -728,7 +729,7 @@ impl ExprImpl {
         }
     }
 
-    pub fn from_expr_proto(proto: &ExprNode) -> Result<Self> {
+    pub fn from_expr_proto(proto: &ExprNode) -> RwResult<Self> {
         let rex_node = proto.get_rex_node()?;
         let ret_type = proto.get_return_type()?.into();
         let expr_type = proto.get_expr_type()?;
@@ -892,6 +893,7 @@ use risingwave_common::bail;
 use risingwave_common::catalog::Schema;
 use risingwave_common::row::OwnedRow;
 
+use self::function_call::CastError;
 use crate::binder::BoundSetExpr;
 use crate::utils::Condition;
 

src/frontend/src/expr/table_function.rs

@@ -20,7 +20,7 @@ use risingwave_common::types::{unnested_list_type, DataType, ScalarImpl};
 use risingwave_pb::expr::table_function::Type;
 use risingwave_pb::expr::TableFunction as TableFunctionProst;
 
-use super::{Expr, ExprImpl, ExprRewriter, Result};
+use super::{Expr, ExprImpl, ExprRewriter, RwResult};
 
 /// A table function takes a row as input and returns a table. It is also known as Set-Returning
 /// Function.
@@ -85,7 +85,7 @@ impl FromStr for TableFunctionType {
 impl TableFunction {
     /// Create a `TableFunction` expr with the return type inferred from `func_type` and types of
     /// `inputs`.
-    pub fn new(func_type: TableFunctionType, args: Vec<ExprImpl>) -> Result<Self> {
+    pub fn new(func_type: TableFunctionType, args: Vec<ExprImpl>) -> RwResult<Self> {
         // TODO: refactor into sth like FunctionCall::new.
         // Current implementation is copied from legacy code.
 
@@ -94,7 +94,7 @@ impl TableFunction {
                 // generate_series ( start timestamp, stop timestamp, step interval ) or
                 // generate_series ( start i32, stop i32, step i32 )
 
-                fn type_check(exprs: &[ExprImpl]) -> Result<DataType> {
+                fn type_check(exprs: &[ExprImpl]) -> RwResult<DataType> {
                     let mut exprs = exprs.iter();
                     let (start, stop, step) = exprs.next_tuple().unwrap();
                     match (start.return_type(), stop.return_type(), step.return_type()) {

src/frontend/src/expr/type_inference/cast.rs

@@ -115,9 +115,11 @@ pub fn align_array_and_element(
         .enumerate()
         .map(|(idx, input)| {
             if idx == array_idx {
-                input.cast_implicit(array_type.clone())
+                input.cast_implicit(array_type.clone()).map_err(Into::into)
             } else {
-                input.cast_implicit(common_ele_type.clone())
+                input
+                    .cast_implicit(common_ele_type.clone())
+                    .map_err(Into::into)
             }
         })
         .try_collect();

src/frontend/src/expr/type_inference/func.rs

@@ -14,7 +14,7 @@
 
 use itertools::Itertools as _;
 use num_integer::Integer as _;
-use risingwave_common::error::{ErrorCode, Result};
+use risingwave_common::error::{ErrorCode, Result, RwError};
 use risingwave_common::types::struct_type::StructType;
 use risingwave_common::types::{DataType, DataTypeName, ScalarImpl};
 use risingwave_common::util::iter_util::ZipEqFast;
@@ -48,7 +48,7 @@ pub fn infer_type(func_type: ExprType, inputs: &mut Vec<ExprImpl>) -> Result<Dat
         .map(|(expr, t)| {
             if DataTypeName::from(expr.return_type()) != *t {
                 if t.is_scalar() {
-                    return expr.cast_implicit((*t).into());
+                    return expr.cast_implicit((*t).into()).map_err(Into::into);
                 } else {
                     return Err(ErrorCode::BindError(format!(
                         "Cannot implicitly cast '{:?}' to polymorphic type {:?}",
@@ -59,7 +59,7 @@ pub fn infer_type(func_type: ExprType, inputs: &mut Vec<ExprImpl>) -> Result<Dat
             }
             Ok(expr)
         })
-        .try_collect()?;
+        .try_collect::<_, _, RwError>()?;
     Ok(sig.ret_type.into())
 }
 
@@ -318,7 +318,7 @@ fn infer_type_for_special(
                 .enumerate()
                 .map(|(i, input)| match i {
                     // 0-th arg must be string
-                    0 => input.cast_implicit(DataType::Varchar),
+                    0 => input.cast_implicit(DataType::Varchar).map_err(Into::into),
                     // subsequent can be any type, using the output format
                     _ => input.cast_output(),
                 })

src/frontend/src/expr/window_function.rs

@@ -19,7 +19,7 @@ use parse_display::Display;
 use risingwave_common::error::ErrorCode;
 use risingwave_common::types::DataType;
 
-use super::{Expr, ExprImpl, OrderBy, Result};
+use super::{Expr, ExprImpl, OrderBy, RwResult};
 
 /// A window function performs a calculation across a set of table rows that are somehow related to
 /// the current row, according to the window spec `OVER (PARTITION BY .. ORDER BY ..)`.
@@ -79,7 +79,7 @@ impl WindowFunction {
         partition_by: Vec<ExprImpl>,
         order_by: OrderBy,
         args: Vec<ExprImpl>,
-    ) -> Result<Self> {
+    ) -> RwResult<Self> {
         if !args.is_empty() {
             return Err(ErrorCode::BindError(format!(
                 "the length of args of {function_type} function should be 0"