continue

datafusion/expr/src/built_in_window_function.rs

@@ -17,115 +17,12 @@
 
 //! Built-in functions module contains all the built-in functions definitions.
 
-use std::fmt;
-use std::str::FromStr;
-
-use crate::type_coercion::functions::data_types;
-use crate::utils;
-use crate::{Signature, Volatility};
-use datafusion_common::{plan_datafusion_err, plan_err, DataFusionError, Result};
-
-use arrow::datatypes::DataType;
-
 use strum_macros::EnumIter;
 
-impl fmt::Display for BuiltInWindowFunction {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "{}", self.name())
-    }
-}
-
 /// A [window function] built in to DataFusion
 ///
 /// [Window Function]: https://en.wikipedia.org/wiki/Window_function_(SQL)
 #[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Hash, EnumIter)]
 pub enum BuiltInWindowFunction {
-    /// returns value evaluated at the row that is the first row of the window frame
-    FirstValue,
-    /// Returns value evaluated at the row that is the last row of the window frame
-    LastValue,
-    /// Returns value evaluated at the row that is the nth row of the window frame (counting from 1); returns null if no such row
-    NthValue,
-}
-
-impl BuiltInWindowFunction {
-    pub fn name(&self) -> &str {
-        use BuiltInWindowFunction::*;
-        match self {
-            FirstValue => "first_value",
-            LastValue => "last_value",
-            NthValue => "NTH_VALUE",
-        }
-    }
-}
-
-impl FromStr for BuiltInWindowFunction {
-    type Err = DataFusionError;
-    fn from_str(name: &str) -> Result<BuiltInWindowFunction> {
-        Ok(match name.to_uppercase().as_str() {
-            "FIRST_VALUE" => BuiltInWindowFunction::FirstValue,
-            "LAST_VALUE" => BuiltInWindowFunction::LastValue,
-            "NTH_VALUE" => BuiltInWindowFunction::NthValue,
-            _ => return plan_err!("There is no built-in window function named {name}"),
-        })
-    }
-}
-
-/// Returns the datatype of the built-in window function
-impl BuiltInWindowFunction {
-    pub fn return_type(&self, input_expr_types: &[DataType]) -> Result<DataType> {
-        // Note that this function *must* return the same type that the respective physical expression returns
-        // or the execution panics.
-
-        // Verify that this is a valid set of data types for this function
-        data_types(input_expr_types, &self.signature())
-            // Original errors are all related to wrong function signature
-            // Aggregate them for better error message
-            .map_err(|_| {
-                plan_datafusion_err!(
-                    "{}",
-                    utils::generate_signature_error_msg(
-                        &format!("{self}"),
-                        self.signature(),
-                        input_expr_types,
-                    )
-                )
-            })?;
-
-        match self {
-            BuiltInWindowFunction::FirstValue
-            | BuiltInWindowFunction::LastValue
-            | BuiltInWindowFunction::NthValue => Ok(input_expr_types[0].clone()),
-        }
-    }
-
-    /// The signatures supported by the built-in window function `fun`.
-    pub fn signature(&self) -> Signature {
-        // Note: The physical expression must accept the type returned by this function or the execution panics.
-        match self {
-            BuiltInWindowFunction::FirstValue | BuiltInWindowFunction::LastValue => {
-                Signature::any(1, Volatility::Immutable)
-            }
-            BuiltInWindowFunction::NthValue => Signature::any(2, Volatility::Immutable),
-        }
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use strum::IntoEnumIterator;
-    #[test]
-    // Test for BuiltInWindowFunction's Display and from_str() implementations.
-    // For each variant in BuiltInWindowFunction, it converts the variant to a string
-    // and then back to a variant. The test asserts that the original variant and
-    // the reconstructed variant are the same. This assertion is also necessary for
-    // function suggestion. See https://github.com/apache/datafusion/issues/8082
-    fn test_display_and_from_str() {
-        for func_original in BuiltInWindowFunction::iter() {
-            let func_name = func_original.to_string();
-            let func_from_str = BuiltInWindowFunction::from_str(&func_name).unwrap();
-            assert_eq!(func_from_str, func_original);
-        }
-    }
+    Stub,
 }

datafusion/functions-window/src/lib.rs

@@ -22,6 +22,9 @@
 //!
 //! [DataFusion]: https://crates.io/crates/datafusion
 //!
+
+extern crate core;
+
 use std::sync::Arc;
 
 use log::debug;