Rewrite Postgres array type handling

sqlx-core/src/postgres/mod.rs

@@ -37,6 +37,7 @@ pub use row::PgRow;
 pub use statement::PgStatement;
 pub use transaction::PgTransactionManager;
 pub use type_info::{PgTypeInfo, PgTypeKind};
+pub use types::PgHasArrayType;
 pub use value::{PgValue, PgValueFormat, PgValueRef};
 
 /// An alias for [`Pool`][crate::pool::Pool], specialized for Postgres.

sqlx-core/src/postgres/types/array.rs

@@ -7,29 +7,49 @@ use crate::postgres::type_info::PgType;
 use crate::postgres::{PgArgumentBuffer, PgTypeInfo, PgValueFormat, PgValueRef, Postgres};
 use crate::types::Type;
 
-impl<T> Type<Postgres> for [Option<T>]
+pub trait PgHasArrayType {
+    fn array_type_info() -> PgTypeInfo;
+    fn array_compatible(ty: &PgTypeInfo) -> bool {
+        *ty == Self::array_type_info()
+    }
+}
+
+impl<T> PgHasArrayType for Option<T>
+where
+    T: PgHasArrayType,
+{
+    fn array_type_info() -> PgTypeInfo {
+        T::array_type_info()
+    }
+
+    fn array_compatible(ty: &PgTypeInfo) -> bool {
+        T::array_compatible(ty)
+    }
+}
+
+impl<T> Type<Postgres> for [T]
 where
-    [T]: Type<Postgres>,
+    T: PgHasArrayType,
 {
     fn type_info() -> PgTypeInfo {
-        <[T] as Type<Postgres>>::type_info()
+        T::array_type_info()
     }
 
     fn compatible(ty: &PgTypeInfo) -> bool {
-        <[T] as Type<Postgres>>::compatible(ty)
+        T::array_compatible(ty)
     }
 }
 
-impl<T> Type<Postgres> for Vec<Option<T>>
+impl<T> Type<Postgres> for Vec<T>
 where
-    Vec<T>: Type<Postgres>,
+    T: PgHasArrayType,
 {
     fn type_info() -> PgTypeInfo {
-        <Vec<T> as Type<Postgres>>::type_info()
+        T::array_type_info()
     }
 
     fn compatible(ty: &PgTypeInfo) -> bool {
-        <Vec<T> as Type<Postgres>>::compatible(ty)
+        T::array_compatible(ty)
     }
 }
 

sqlx-core/src/postgres/types/bigdecimal.rs

@@ -8,7 +8,9 @@ use crate::decode::Decode;
 use crate::encode::{Encode, IsNull};
 use crate::error::BoxDynError;
 use crate::postgres::types::numeric::{PgNumeric, PgNumericSign};
-use crate::postgres::{PgArgumentBuffer, PgTypeInfo, PgValueFormat, PgValueRef, Postgres};
+use crate::postgres::{
+    PgArgumentBuffer, PgHasArrayType, PgTypeInfo, PgValueFormat, PgValueRef, Postgres,
+};
 use crate::types::Type;
 
 impl Type<Postgres> for BigDecimal {
@@ -17,18 +19,12 @@ impl Type<Postgres> for BigDecimal {
     }
 }
 
-impl Type<Postgres> for [BigDecimal] {
-    fn type_info() -> PgTypeInfo {
+impl PgHasArrayType for BigDecimal {
+    fn array_type_info() -> PgTypeInfo {
         PgTypeInfo::NUMERIC_ARRAY
     }
 }
 
-impl Type<Postgres> for Vec<BigDecimal> {
-    fn type_info() -> PgTypeInfo {
-        <[BigDecimal] as Type<Postgres>>::type_info()
-    }
-}
-
 impl TryFrom<PgNumeric> for BigDecimal {
     type Error = BoxDynError;
 

sqlx-core/src/postgres/types/bit_vec.rs

@@ -2,7 +2,7 @@ use crate::{
     decode::Decode,
     encode::{Encode, IsNull},
     error::BoxDynError,
-    postgres::{PgArgumentBuffer, PgTypeInfo, PgValueFormat, PgValueRef, Postgres},
+    postgres::{PgArgumentBuffer, PgHasArrayType, PgTypeInfo, PgValueFormat, PgValueRef, Postgres},
     types::Type,
 };
 use bit_vec::BitVec;
@@ -19,26 +19,16 @@ impl Type<Postgres> for BitVec {
     }
 }
 
-impl Type<Postgres> for [BitVec] {
-    fn type_info() -> PgTypeInfo {
+impl PgHasArrayType for BitVec {
+    fn array_type_info() -> PgTypeInfo {
         PgTypeInfo::VARBIT_ARRAY
     }
 
-    fn compatible(ty: &PgTypeInfo) -> bool {
+    fn array_compatible(ty: &PgTypeInfo) -> bool {
         *ty == PgTypeInfo::BIT_ARRAY || *ty == PgTypeInfo::VARBIT_ARRAY
     }
 }
 
-impl Type<Postgres> for Vec<BitVec> {
-    fn type_info() -> PgTypeInfo {
-        <[BitVec] as Type<Postgres>>::type_info()
-    }
-
-    fn compatible(ty: &PgTypeInfo) -> bool {
-        <[BitVec] as Type<Postgres>>::compatible(ty)
-    }
-}
-
 impl Encode<'_, Postgres> for BitVec {
     fn encode_by_ref(&self, buf: &mut PgArgumentBuffer) -> IsNull {
         buf.extend(&(self.len() as i32).to_be_bytes());

sqlx-core/src/postgres/types/bool.rs

@@ -1,7 +1,9 @@
 use crate::decode::Decode;
 use crate::encode::{Encode, IsNull};
 use crate::error::BoxDynError;
-use crate::postgres::{PgArgumentBuffer, PgTypeInfo, PgValueFormat, PgValueRef, Postgres};
+use crate::postgres::{
+    PgArgumentBuffer, PgHasArrayType, PgTypeInfo, PgValueFormat, PgValueRef, Postgres,
+};
 use crate::types::Type;
 
 impl Type<Postgres> for bool {
@@ -10,18 +12,12 @@ impl Type<Postgres> for bool {
     }
 }
 
-impl Type<Postgres> for [bool] {
-    fn type_info() -> PgTypeInfo {
+impl PgHasArrayType for bool {
+    fn array_type_info() -> PgTypeInfo {
         PgTypeInfo::BOOL_ARRAY
     }
 }
 
-impl Type<Postgres> for Vec<bool> {
-    fn type_info() -> PgTypeInfo {
-        <[bool] as Type<Postgres>>::type_info()
-    }
-}
-
 impl Encode<'_, Postgres> for bool {
     fn encode_by_ref(&self, buf: &mut PgArgumentBuffer) -> IsNull {
         buf.push(*self as u8);

sqlx-core/src/postgres/types/bytes.rs

@@ -1,41 +1,25 @@
 use crate::decode::Decode;
 use crate::encode::{Encode, IsNull};
 use crate::error::BoxDynError;
-use crate::postgres::{PgArgumentBuffer, PgTypeInfo, PgValueFormat, PgValueRef, Postgres};
+use crate::postgres::{
+    PgArgumentBuffer, PgHasArrayType, PgTypeInfo, PgValueFormat, PgValueRef, Postgres,
+};
 use crate::types::Type;
 
-impl Type<Postgres> for [u8] {
-    fn type_info() -> PgTypeInfo {
+impl PgHasArrayType for u8 {
+    fn array_type_info() -> PgTypeInfo {
         PgTypeInfo::BYTEA
     }
 }
 
-impl Type<Postgres> for Vec<u8> {
-    fn type_info() -> PgTypeInfo {
-        <[u8] as Type<Postgres>>::type_info()
-    }
-}
-
-impl Type<Postgres> for [&'_ [u8]] {
-    fn type_info() -> PgTypeInfo {
+impl PgHasArrayType for &'_ [u8] {
+    fn array_type_info() -> PgTypeInfo {
         PgTypeInfo::BYTEA_ARRAY
     }
 }
 
-impl Type<Postgres> for [Vec<u8>] {
-    fn type_info() -> PgTypeInfo {
-        <[&[u8]] as Type<Postgres>>::type_info()
-    }
-}
-
-impl Type<Postgres> for Vec<&'_ [u8]> {
-    fn type_info() -> PgTypeInfo {
-        <[&[u8]] as Type<Postgres>>::type_info()
-    }
-}
-
-impl Type<Postgres> for Vec<Vec<u8>> {
-    fn type_info() -> PgTypeInfo {
+impl PgHasArrayType for Vec<u8> {
+    fn array_type_info() -> PgTypeInfo {
         <[&[u8]] as Type<Postgres>>::type_info()
     }
 }

sqlx-core/src/postgres/types/chrono/date.rs

@@ -1,7 +1,9 @@
 use crate::decode::Decode;
 use crate::encode::{Encode, IsNull};
 use crate::error::BoxDynError;
-use crate::postgres::{PgArgumentBuffer, PgTypeInfo, PgValueFormat, PgValueRef, Postgres};
+use crate::postgres::{
+    PgArgumentBuffer, PgHasArrayType, PgTypeInfo, PgValueFormat, PgValueRef, Postgres,
+};
 use crate::types::Type;
 use chrono::{Duration, NaiveDate};
 use std::mem;
@@ -12,18 +14,12 @@ impl Type<Postgres> for NaiveDate {
     }
 }
 
-impl Type<Postgres> for [NaiveDate] {
-    fn type_info() -> PgTypeInfo {
+impl PgHasArrayType for NaiveDate {
+    fn array_type_info() -> PgTypeInfo {
         PgTypeInfo::DATE_ARRAY
     }
 }
 
-impl Type<Postgres> for Vec<NaiveDate> {
-    fn type_info() -> PgTypeInfo {
-        <[NaiveDate] as Type<Postgres>>::type_info()
-    }
-}
-
 impl Encode<'_, Postgres> for NaiveDate {
     fn encode_by_ref(&self, buf: &mut PgArgumentBuffer) -> IsNull {
         // DATE is encoded as the days since epoch

sqlx-core/src/postgres/types/chrono/datetime.rs

@@ -1,7 +1,9 @@
 use crate::decode::Decode;
 use crate::encode::{Encode, IsNull};
 use crate::error::BoxDynError;
-use crate::postgres::{PgArgumentBuffer, PgTypeInfo, PgValueFormat, PgValueRef, Postgres};
+use crate::postgres::{
+    PgArgumentBuffer, PgHasArrayType, PgTypeInfo, PgValueFormat, PgValueRef, Postgres,
+};
 use crate::types::Type;
 use chrono::{
     DateTime, Duration, FixedOffset, Local, NaiveDate, NaiveDateTime, Offset, TimeZone, Utc,
@@ -20,30 +22,18 @@ impl<Tz: TimeZone> Type<Postgres> for DateTime<Tz> {
     }
 }
 
-impl Type<Postgres> for [NaiveDateTime] {
-    fn type_info() -> PgTypeInfo {
+impl PgHasArrayType for NaiveDateTime {
+    fn array_type_info() -> PgTypeInfo {
         PgTypeInfo::TIMESTAMP_ARRAY
     }
 }
 
-impl<Tz: TimeZone> Type<Postgres> for [DateTime<Tz>] {
-    fn type_info() -> PgTypeInfo {
+impl<Tz: TimeZone> PgHasArrayType for DateTime<Tz> {
+    fn array_type_info() -> PgTypeInfo {
         PgTypeInfo::TIMESTAMPTZ_ARRAY
     }
 }
 
-impl Type<Postgres> for Vec<NaiveDateTime> {
-    fn type_info() -> PgTypeInfo {
-        <[NaiveDateTime] as Type<Postgres>>::type_info()
-    }
-}
-
-impl<Tz: TimeZone> Type<Postgres> for Vec<DateTime<Tz>> {
-    fn type_info() -> PgTypeInfo {
-        <[DateTime<Tz>] as Type<Postgres>>::type_info()
-    }
-}
-
 impl Encode<'_, Postgres> for NaiveDateTime {
     fn encode_by_ref(&self, buf: &mut PgArgumentBuffer) -> IsNull {
         // FIXME: We should *really* be returning an error, Encode needs to be fallible

sqlx-core/src/postgres/types/chrono/time.rs

@@ -1,7 +1,9 @@
 use crate::decode::Decode;
 use crate::encode::{Encode, IsNull};
 use crate::error::BoxDynError;
-use crate::postgres::{PgArgumentBuffer, PgTypeInfo, PgValueFormat, PgValueRef, Postgres};
+use crate::postgres::{
+    PgArgumentBuffer, PgHasArrayType, PgTypeInfo, PgValueFormat, PgValueRef, Postgres,
+};
 use crate::types::Type;
 use chrono::{Duration, NaiveTime};
 use std::mem;
@@ -12,18 +14,12 @@ impl Type<Postgres> for NaiveTime {
     }
 }
 
-impl Type<Postgres> for [NaiveTime] {
-    fn type_info() -> PgTypeInfo {
+impl PgHasArrayType for NaiveTime {
+    fn array_type_info() -> PgTypeInfo {
         PgTypeInfo::TIME_ARRAY
     }
 }
 
-impl Type<Postgres> for Vec<NaiveTime> {
-    fn type_info() -> PgTypeInfo {
-        <[NaiveTime] as Type<Postgres>>::type_info()
-    }
-}
-
 impl Encode<'_, Postgres> for NaiveTime {
     fn encode_by_ref(&self, buf: &mut PgArgumentBuffer) -> IsNull {
         // TIME is encoded as the microseconds since midnight

sqlx-core/src/postgres/types/decimal.rs

@@ -9,7 +9,9 @@ use crate::decode::Decode;
 use crate::encode::{Encode, IsNull};
 use crate::error::BoxDynError;
 use crate::postgres::types::numeric::{PgNumeric, PgNumericSign};
-use crate::postgres::{PgArgumentBuffer, PgTypeInfo, PgValueFormat, PgValueRef, Postgres};
+use crate::postgres::{
+    PgArgumentBuffer, PgHasArrayType, PgTypeInfo, PgValueFormat, PgValueRef, Postgres,
+};
 use crate::types::Type;
 
 impl Type<Postgres> for Decimal {
@@ -18,18 +20,12 @@ impl Type<Postgres> for Decimal {
     }
 }
 
-impl Type<Postgres> for [Decimal] {
-    fn type_info() -> PgTypeInfo {
+impl PgHasArrayType for Decimal {
+    fn array_type_info() -> PgTypeInfo {
         PgTypeInfo::NUMERIC_ARRAY
     }
 }
 
-impl Type<Postgres> for Vec<Decimal> {
-    fn type_info() -> PgTypeInfo {
-        <[Decimal] as Type<Postgres>>::type_info()
-    }
-}
-
 impl TryFrom<PgNumeric> for Decimal {
     type Error = BoxDynError;