cast_f32_to_string impl

Signed-off-by: Petros Angelatos <petrosagg@gmail.com>

src/expr/src/scalar/func.rs

@@ -273,12 +273,6 @@ fn cast_int64_to_string<'a>(a: Datum<'a>, temp_storage: &'a RowArena) -> Datum<'
     Datum::String(temp_storage.push_string(buf))
 }
 
-fn cast_float32_to_string<'a>(a: Datum<'a>, temp_storage: &'a RowArena) -> Datum<'a> {
-    let mut buf = String::new();
-    strconv::format_float32(&mut buf, a.unwrap_float32());
-    Datum::String(temp_storage.push_string(buf))
-}
-
 fn cast_float32_to_numeric<'a>(a: Datum<'a>, scale: Option<u8>) -> Result<Datum<'a>, EvalError> {
     let a = a.unwrap_float32();
     if a.is_infinite() {
@@ -3451,7 +3445,7 @@ pub enum UnaryFunc {
     CastFloat32ToInt32(CastFloat32ToInt32),
     CastFloat32ToInt64(CastFloat32ToInt64),
     CastFloat32ToFloat64(CastFloat32ToFloat64),
-    CastFloat32ToString,
+    CastFloat32ToString(CastFloat32ToString),
     CastFloat32ToNumeric(Option<u8>),
     CastFloat64ToNumeric(Option<u8>),
     CastFloat64ToInt16(CastFloat64ToInt16),
@@ -3640,7 +3634,8 @@ derive_unary!(
     CastFloat64ToInt32,
     CastFloat64ToInt64,
     CastFloat32ToFloat64,
-    CastFloat64ToFloat32
+    CastFloat64ToFloat32,
+    CastFloat32ToString
 );
 
 impl UnaryFunc {
@@ -3675,6 +3670,7 @@ impl UnaryFunc {
             | CastFloat64ToInt32(_)
             | CastFloat64ToInt64(_)
             | CastFloat64ToFloat32(_)
+            | CastFloat32ToString(_)
             | CastFloat32ToFloat64(_) => unreachable!(),
             IsNull => Ok(is_null(a)),
             NegInt16 => Ok(neg_int16(a)),
@@ -3716,7 +3712,6 @@ impl UnaryFunc {
             CastInt64ToFloat32 => Ok(cast_int64_to_float32(a)),
             CastInt64ToFloat64 => Ok(cast_int64_to_float64(a)),
             CastInt64ToString => Ok(cast_int64_to_string(a, temp_storage)),
-            CastFloat32ToString => Ok(cast_float32_to_string(a, temp_storage)),
             CastFloat64ToString => Ok(cast_float64_to_string(a, temp_storage)),
             CastStringToBool => cast_string_to_bool(a),
             CastStringToBytes => cast_string_to_bytes(a, temp_storage),
@@ -3872,6 +3867,7 @@ impl UnaryFunc {
             | CastFloat64ToInt32(_)
             | CastFloat64ToInt64(_)
             | CastFloat64ToFloat32(_)
+            | CastFloat32ToString(_)
             | CastFloat32ToFloat64(_) => unreachable!(),
             IsNull => ScalarType::Bool.nullable(nullable),
 
@@ -3894,7 +3890,6 @@ impl UnaryFunc {
             | CastInt16ToString
             | CastInt32ToString
             | CastInt64ToString
-            | CastFloat32ToString
             | CastFloat64ToString
             | CastNumericToString
             | CastDateToString
@@ -4073,6 +4068,7 @@ impl UnaryFunc {
             | CastFloat64ToInt32(_)
             | CastFloat64ToInt64(_)
             | CastFloat64ToFloat32(_)
+            | CastFloat32ToString(_)
             | CastFloat32ToFloat64(_) => unreachable!(),
             // These return null when their input is SQL null.
             CastJsonbToString | CastJsonbToInt16 | CastJsonbToInt32 | CastJsonbToInt64
@@ -4105,7 +4101,6 @@ impl UnaryFunc {
             | CastInt16ToString
             | CastInt32ToString
             | CastInt64ToString
-            | CastFloat32ToString
             | CastFloat64ToString
             | CastNumericToString
             | CastDateToString
@@ -4196,6 +4191,7 @@ impl UnaryFunc {
             | CastFloat64ToInt32(_)
             | CastFloat64ToInt64(_)
             | CastFloat64ToFloat32(_)
+            | CastFloat32ToString(_)
             | CastFloat32ToFloat64(_) => unreachable!(),
             NegInt16
             | NegInt32
@@ -4212,7 +4208,6 @@ impl UnaryFunc {
             | CastInt32ToInt64
             | CastInt32ToString
             | CastInt64ToString
-            | CastFloat32ToString
             | CastFloat64ToString
             | CastStringToBytes
             | CastDateToTimestamp
@@ -4245,6 +4240,7 @@ impl UnaryFunc {
             | CastFloat64ToInt32(_)
             | CastFloat64ToInt64(_)
             | CastFloat64ToFloat32(_)
+            | CastFloat32ToString(_)
             | CastFloat32ToFloat64(_) => unreachable!(),
             IsNull => f.write_str("isnull"),
             NegInt16 => f.write_str("-"),
@@ -4284,7 +4280,6 @@ impl UnaryFunc {
             CastInt64ToFloat32 => f.write_str("i64tof32"),
             CastInt64ToFloat64 => f.write_str("i64tof64"),
             CastInt64ToString => f.write_str("i64tostr"),
-            CastFloat32ToString => f.write_str("f32tostr"),
             CastFloat32ToNumeric(_) => f.write_str("f32tonumeric"),
             CastFloat64ToString => f.write_str("f64tostr"),
             CastFloat64ToNumeric(_) => f.write_str("f32tonumeric"),

src/expr/src/scalar/func/impls/float.rs

@@ -8,6 +8,7 @@
 // by the Apache License, Version 2.0.
 
 use crate::EvalError;
+use repr::strconv;
 
 sqlfunc!(
     #[sqlname = "-"]
@@ -199,3 +200,12 @@ sqlfunc!(
         a.into()
     }
 );
+
+sqlfunc!(
+    #[sqlname = "f32tostr"]
+    fn cast_float32_to_string(a: f32) -> String {
+        let mut s = String::new();
+        strconv::format_float32(&mut s, a);
+        s
+    }
+);

src/sql/src/plan/typeconv.rs

@@ -183,7 +183,7 @@ lazy_static! {
                 let s = to_type.unwrap_numeric_scale();
                 Some(move |e: HirScalarExpr| e.call_unary(CastFloat32ToNumeric(s)))
             }),
-            (Float32, String) => Assignment: CastFloat32ToString,
+            (Float32, String) => Assignment: CastFloat32ToString(func::CastFloat32ToString),
 
             // FLOAT64
             (Float64, Int16) => Assignment: CastFloat64ToInt16(func::CastFloat64ToInt16),