Refactor: move simplify_expression.rs and expr_simplifier.rs to a new mod simplify_expressions

datafusion-examples/examples/expr_api.rs

@@ -17,7 +17,7 @@
 
 use datafusion::arrow::datatypes::{DataType, Field, Schema, TimeUnit};
 use datafusion::error::Result;
-use datafusion::optimizer::expr_simplifier::{ExprSimplifier, SimplifyContext};
+use datafusion::optimizer::simplify_expressions::{ExprSimplifier, SimplifyContext};
 use datafusion::physical_expr::execution_props::ExecutionProps;
 use datafusion::prelude::*;
 use datafusion_common::{ScalarValue, ToDFSchema};

datafusion/core/tests/simplification.rs

@@ -21,7 +21,7 @@ use arrow::datatypes::{DataType, Field, Schema};
 use datafusion::common::DFSchema;
 use datafusion::{error::Result, execution::context::ExecutionProps, prelude::*};
 use datafusion_expr::{Expr, ExprSchemable};
-use datafusion_optimizer::expr_simplifier::{ExprSimplifier, SimplifyInfo};
+use datafusion_optimizer::simplify_expressions::{ExprSimplifier, SimplifyInfo};
 
 /// In order to simplify expressions, DataFusion must have information
 /// about the expressions.

datafusion/expr/src/lib.rs

@@ -56,7 +56,9 @@ pub use accumulator::{Accumulator, AggregateState};
 pub use aggregate_function::AggregateFunction;
 pub use built_in_function::BuiltinScalarFunction;
 pub use columnar_value::{ColumnarValue, NullColumnarValue};
-pub use expr::{Between, BinaryExpr, Case, Expr, GetIndexedField, GroupingSet, Like};
+pub use expr::{
+    Between, BinaryExpr, Case, Cast, Expr, GetIndexedField, GroupingSet, Like,
+};
 pub use expr_fn::*;
 pub use expr_schema::ExprSchemable;
 pub use function::{

datafusion/optimizer/src/lib.rs

@@ -20,7 +20,6 @@ pub mod decorrelate_where_exists;
 pub mod decorrelate_where_in;
 pub mod eliminate_filter;
 pub mod eliminate_limit;
-pub mod expr_simplifier;
 pub mod filter_null_join_keys;
 pub mod filter_push_down;
 pub mod inline_table_scan;