change simplify signature

Signed-off-by: jayzhan211 <jayzhan211@gmail.com>

datafusion/core/tests/user_defined/user_defined_scalar_functions.rs

@@ -24,14 +24,16 @@ use arrow_schema::{DataType, Field, Schema};
 use datafusion::prelude::*;
 use datafusion::{execution::registry::FunctionRegistry, test_util};
 use datafusion_common::cast::as_float64_array;
-use datafusion_common::DFSchemaRef;
+use datafusion_common::DFSchema;
 use datafusion_common::{
     assert_batches_eq, assert_batches_sorted_eq, cast::as_int32_array, not_impl_err,
     plan_err, DataFusionError, ExprSchema, Result, ScalarValue,
 };
+use datafusion_expr::simplify::Simplified;
+use datafusion_expr::simplify::SimplifyInfo;
 use datafusion_expr::{
     create_udaf, create_udf, Accumulator, ColumnarValue, ExprSchemable,
-    LogicalPlanBuilder, ScalarUDF, ScalarUDFImpl, Signature, Simplified, Volatility,
+    LogicalPlanBuilder, ScalarUDF, ScalarUDFImpl, Signature, Volatility,
 };
 
 use rand::{thread_rng, Rng};
@@ -529,8 +531,9 @@ impl ScalarUDFImpl for CastToI64UDF {
         Ok(DataType::Int64)
     }
     // Wrap with Expr::Cast() to Int64
-    fn simplify(&self, args: &[Expr], schema: DFSchemaRef) -> Result<Simplified> {
+    fn simplify(&self, args: &[Expr], info: &dyn SimplifyInfo) -> Result<Simplified> {
         let e = args[0].to_owned();
+        let schema = info.schema().unwrap_or_else(|| DFSchema::empty().into());
         let casted_expr = e.cast_to(&DataType::Int64, schema.as_ref())?;
         Ok(Simplified::Rewritten(casted_expr))
     }

datafusion/expr/src/lib.rs

@@ -83,7 +83,7 @@ pub use signature::{
 };
 pub use table_source::{TableProviderFilterPushDown, TableSource, TableType};
 pub use udaf::{AggregateUDF, AggregateUDFImpl};
-pub use udf::{ScalarUDF, ScalarUDFImpl, Simplified};
+pub use udf::{ScalarUDF, ScalarUDFImpl};
 pub use udwf::{WindowUDF, WindowUDFImpl};
 pub use window_frame::{WindowFrame, WindowFrameBound, WindowFrameUnits};
 

datafusion/expr/src/simplify.rs

@@ -140,3 +140,12 @@ impl<'a> SimplifyInfo for SimplifyContext<'a> {
         self.props
     }
 }
+
+/// Was the expression simplified?
+pub enum Simplified {
+    /// The function call was simplified to an entirely new Expr
+    Rewritten(Expr),
+    /// the function call could not be simplified, and the arguments
+    /// are return unmodified
+    Original,
+}

datafusion/expr/src/udf.rs

@@ -17,29 +17,20 @@
 
 //! [`ScalarUDF`]: Scalar User Defined Functions
 
+use crate::simplify::{Simplified, SimplifyInfo};
 use crate::ExprSchemable;
 use crate::{
     ColumnarValue, Expr, FuncMonotonicity, ReturnTypeFunction,
     ScalarFunctionImplementation, Signature,
 };
 use arrow::datatypes::DataType;
-use datafusion_common::{DFSchemaRef, ExprSchema, Result};
+use datafusion_common::{ExprSchema, Result};
 use std::any::Any;
 use std::fmt;
 use std::fmt::Debug;
 use std::fmt::Formatter;
 use std::sync::Arc;
 
-// TODO(In this PR): Move to simplify.rs
-/// Was the expression simplified?
-pub enum Simplified {
-    /// The function call was simplified to an entirely new Expr
-    Rewritten(Expr),
-    /// the function call could not be simplified, and the arguments
-    /// are return unmodified
-    Original,
-}
-
 /// Logical representation of a Scalar User Defined Function.
 ///
 /// A scalar function produces a single row output for each row of input. This
@@ -173,8 +164,8 @@ impl ScalarUDF {
     /// Do the function rewrite
     ///
     /// See [`ScalarUDFImpl::simplify`] for more details.
-    pub fn simplify(&self, args: &[Expr], schema: DFSchemaRef) -> Result<Simplified> {
-        self.inner.simplify(args, schema)
+    pub fn simplify(&self, args: &[Expr], info: &dyn SimplifyInfo) -> Result<Simplified> {
+        self.inner.simplify(args, info)
     }
 
     /// Invoke the function on `args`, returning the appropriate result.
@@ -358,7 +349,7 @@ pub trait ScalarUDFImpl: Debug + Send + Sync {
     // Do the function rewrite.
     // 'args': The arguments of the function
     // 'schema': The schema of the function
-    fn simplify(&self, _args: &[Expr], _schema: DFSchemaRef) -> Result<Simplified> {
+    fn simplify(&self, _args: &[Expr], _info: &dyn SimplifyInfo) -> Result<Simplified> {
         Ok(Simplified::Original)
     }
 }

datafusion/optimizer/src/simplify_expressions/function_simplifier.rs

@@ -18,9 +18,9 @@
 //! This module implements a rule that do function simplification.
 
 use datafusion_common::tree_node::TreeNodeRewriter;
-use datafusion_common::{DFSchema, Result};
+use datafusion_common::Result;
+use datafusion_expr::simplify::Simplified;
 use datafusion_expr::simplify::SimplifyInfo;
-use datafusion_expr::Simplified;
 use datafusion_expr::{expr::ScalarFunction, Expr, ScalarFunctionDefinition};
 
 pub(super) struct FunctionSimplifier<'a, S> {
@@ -42,12 +42,7 @@ impl<'a, S: SimplifyInfo> TreeNodeRewriter for FunctionSimplifier<'a, S> {
             args,
         }) = &expr
         {
-            let schema = self
-                .info
-                .schema()
-                .unwrap_or_else(|| DFSchema::empty().into());
-
-            let simplified_expr = udf.simplify(args, schema)?;
+            let simplified_expr = udf.simplify(args, self.info)?;
             match simplified_expr {
                 Simplified::Original => Ok(expr),
                 Simplified::Rewritten(expr) => Ok(expr),