Fix "char" and array types for system functions and tables

server/ast/resolvable_type_reference.go

@@ -74,13 +74,13 @@ func nodeResolvableTypeReference(typ tree.ResolvableTypeReference) (*vitess.Conv
 				}
 			case oid.T_char:
 				width := uint32(columnType.Width())
-				if width > pgtypes.StringMaxLength {
-					return nil, nil, fmt.Errorf("length for type char cannot exceed %d", pgtypes.StringMaxLength)
+				if width > pgtypes.InternalCharLength {
+					return nil, nil, fmt.Errorf("length for type \"char\" cannot exceed %d", pgtypes.InternalCharLength)
 				}
 				if width == 0 {
 					width = 1
 				}
-				resolvedType = pgtypes.CharType{Length: width}
+				resolvedType = pgtypes.InternalChar
 			case oid.T_date:
 				resolvedType = pgtypes.Date
 			case oid.T_float4:

server/cast/char.go

@@ -33,6 +33,13 @@ func initChar() {
 
 // charExplicit registers all explicit casts. This comprises only the "From" types.
 func charExplicit() {
+	framework.MustAddExplicitTypeCast(framework.TypeCast{
+		FromType: pgtypes.BpChar,
+		ToType:   pgtypes.InternalChar,
+		Function: func(ctx *sql.Context, val any, targetType pgtypes.DoltgresType) (any, error) {
+			return targetType.IoInput(ctx, val.(string))
+		},
+	})
 	framework.MustAddExplicitTypeCast(framework.TypeCast{
 		FromType: pgtypes.BpChar,
 		ToType:   pgtypes.Int32,
@@ -58,6 +65,13 @@ func charImplicit() {
 			return targetType.IoInput(ctx, val.(string))
 		},
 	})
+	framework.MustAddImplicitTypeCast(framework.TypeCast{
+		FromType: pgtypes.BpChar,
+		ToType:   pgtypes.InternalChar,
+		Function: func(ctx *sql.Context, val any, targetType pgtypes.DoltgresType) (any, error) {
+			return targetType.IoInput(ctx, val.(string))
+		},
+	})
 	framework.MustAddImplicitTypeCast(framework.TypeCast{
 		FromType: pgtypes.BpChar,
 		ToType:   pgtypes.Name,

server/cast/init.go

@@ -23,6 +23,7 @@ func Init() {
 	initInt16()
 	initInt32()
 	initInt64()
+	initInternalChar()
 	initJson()
 	initJsonB()
 	initName()

server/cast/internal_char.go

@@ -0,0 +1,129 @@
+// Copyright 2024 Dolthub, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cast
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+	"unicode"
+
+	"github.com/dolthub/go-mysql-server/sql"
+
+	"github.com/dolthub/doltgresql/server/functions/framework"
+	pgtypes "github.com/dolthub/doltgresql/server/types"
+)
+
+// initInternalChar handles all casts that are built-in. This comprises only the "From" types.
+func initInternalChar() {
+	internalCharExplicit()
+	internalCharImplicit()
+}
+
+// internalCharExplicit registers all explicit casts. This comprises only the "From" types.
+func internalCharExplicit() {
+	framework.MustAddExplicitTypeCast(framework.TypeCast{
+		FromType: pgtypes.InternalChar,
+		ToType:   pgtypes.BpChar,
+		Function: func(ctx *sql.Context, val any, targetType pgtypes.DoltgresType) (any, error) {
+			return targetType.IoInput(ctx, val.(string))
+		},
+	})
+	framework.MustAddExplicitTypeCast(framework.TypeCast{
+		FromType: pgtypes.InternalChar,
+		ToType:   pgtypes.Int32,
+		Function: func(ctx *sql.Context, val any, targetType pgtypes.DoltgresType) (any, error) {
+			s := val.(string)
+			if len(s) == 0 {
+				return int32(0), nil
+			}
+			if unicode.IsLetter(rune(s[0])) {
+				return int32(s[0]), nil
+			}
+			i, err := strconv.ParseInt(s, 10, 32)
+			if err != nil {
+				return 0, err
+			}
+			return int32(i), nil
+		},
+	})
+	framework.MustAddExplicitTypeCast(framework.TypeCast{
+		FromType: pgtypes.InternalChar,
+		ToType:   pgtypes.Name,
+		Function: func(ctx *sql.Context, val any, targetType pgtypes.DoltgresType) (any, error) {
+			return handleStringCast(val.(string), targetType)
+		},
+	})
+	framework.MustAddExplicitTypeCast(framework.TypeCast{
+		FromType: pgtypes.InternalChar,
+		ToType:   pgtypes.Text,
+		Function: func(ctx *sql.Context, val any, targetType pgtypes.DoltgresType) (any, error) {
+			return val, nil
+		},
+	})
+	framework.MustAddExplicitTypeCast(framework.TypeCast{
+		FromType: pgtypes.InternalChar,
+		ToType:   pgtypes.VarChar,
+		Function: func(ctx *sql.Context, val any, targetType pgtypes.DoltgresType) (any, error) {
+			return handleStringCast(val.(string), targetType)
+		},
+	})
+}
+
+// internalCharImplicit registers all implicit casts. This comprises only the "From" types.
+func internalCharImplicit() {
+	framework.MustAddImplicitTypeCast(framework.TypeCast{
+		FromType: pgtypes.InternalChar,
+		ToType:   pgtypes.BpChar,
+		Function: func(ctx *sql.Context, val any, targetType pgtypes.DoltgresType) (any, error) {
+			return targetType.IoInput(ctx, val.(string))
+		},
+	})
+	framework.MustAddImplicitTypeCast(framework.TypeCast{
+		FromType: pgtypes.InternalChar,
+		ToType:   pgtypes.Int32,
+		Function: func(ctx *sql.Context, val any, targetType pgtypes.DoltgresType) (any, error) {
+			out, err := strconv.ParseInt(strings.TrimSpace(val.(string)), 10, 32)
+			if err != nil {
+				return nil, fmt.Errorf("invalid input syntax for type %s: %q", targetType.String(), val.(string))
+			}
+			if out > 2147483647 || out < -2147483648 {
+				return nil, fmt.Errorf("value %q is out of range for type %s", val.(string), targetType.String())
+			}
+			return int32(out), nil
+		},
+	})
+	framework.MustAddImplicitTypeCast(framework.TypeCast{
+		FromType: pgtypes.InternalChar,
+		ToType:   pgtypes.Name,
+		Function: func(ctx *sql.Context, val any, targetType pgtypes.DoltgresType) (any, error) {
+			return handleStringCast(val.(string), targetType)
+		},
+	})
+	framework.MustAddImplicitTypeCast(framework.TypeCast{
+		FromType: pgtypes.InternalChar,
+		ToType:   pgtypes.Text,
+		Function: func(ctx *sql.Context, val any, targetType pgtypes.DoltgresType) (any, error) {
+			return val, nil
+		},
+	})
+	framework.MustAddImplicitTypeCast(framework.TypeCast{
+		FromType: pgtypes.InternalChar,
+		ToType:   pgtypes.VarChar,
+		Function: func(ctx *sql.Context, val any, targetType pgtypes.DoltgresType) (any, error) {
+			return handleStringCast(val.(string), targetType)
+		},
+	})
+}

server/cast/name.go

@@ -36,6 +36,13 @@ func nameAssignment() {
 			return handleStringCast(val.(string), targetType)
 		},
 	})
+	framework.MustAddAssignmentTypeCast(framework.TypeCast{
+		FromType: pgtypes.Name,
+		ToType:   pgtypes.InternalChar,
+		Function: func(ctx *sql.Context, val any, targetType pgtypes.DoltgresType) (any, error) {
+			return handleStringCast(val.(string), targetType)
+		},
+	})
 	framework.MustAddAssignmentTypeCast(framework.TypeCast{
 		FromType: pgtypes.Name,
 		ToType:   pgtypes.VarChar,

server/cast/text.go

@@ -36,6 +36,13 @@ func textAssignment() {
 			return handleStringCast(val.(string), targetType)
 		},
 	})
+	framework.MustAddAssignmentTypeCast(framework.TypeCast{
+		FromType: pgtypes.Text,
+		ToType:   pgtypes.InternalChar,
+		Function: func(ctx *sql.Context, val any, targetType pgtypes.DoltgresType) (any, error) {
+			return handleStringCast(val.(string), targetType)
+		},
+	})
 }
 
 // textImplicit registers all implicit casts. This comprises only the "From" types.
@@ -47,6 +54,13 @@ func textImplicit() {
 			return handleStringCast(val.(string), targetType)
 		},
 	})
+	framework.MustAddImplicitTypeCast(framework.TypeCast{
+		FromType: pgtypes.Text,
+		ToType:   pgtypes.InternalChar,
+		Function: func(ctx *sql.Context, val any, targetType pgtypes.DoltgresType) (any, error) {
+			return handleStringCast(val.(string), targetType)
+		},
+	})
 	framework.MustAddImplicitTypeCast(framework.TypeCast{
 		FromType: pgtypes.Text,
 		ToType:   pgtypes.Name,

server/cast/utils.go

@@ -44,6 +44,9 @@ func handleStringCast(str string, targetType pgtypes.DoltgresType) (string, erro
 				return str, nil
 			}
 		}
+	case pgtypes.InternalCharType:
+		str, _ := truncateString(str, pgtypes.InternalCharLength)
+		return str, nil
 	case pgtypes.NameType:
 		// Name seems to never throw an error, regardless of the context or how long the input is
 		str, _ := truncateString(str, targetType.Length)

server/cast/varchar.go

@@ -36,6 +36,13 @@ func varcharAssignment() {
 			return handleStringCast(val.(string), targetType)
 		},
 	})
+	framework.MustAddAssignmentTypeCast(framework.TypeCast{
+		FromType: pgtypes.VarChar,
+		ToType:   pgtypes.InternalChar,
+		Function: func(ctx *sql.Context, val any, targetType pgtypes.DoltgresType) (any, error) {
+			return handleStringCast(val.(string), targetType)
+		},
+	})
 }
 
 // varcharImplicit registers all implicit casts. This comprises only the "From" types.
@@ -47,6 +54,13 @@ func varcharImplicit() {
 			return handleStringCast(val.(string), targetType)
 		},
 	})
+	framework.MustAddImplicitTypeCast(framework.TypeCast{
+		FromType: pgtypes.VarChar,
+		ToType:   pgtypes.InternalChar,
+		Function: func(ctx *sql.Context, val any, targetType pgtypes.DoltgresType) (any, error) {
+			return handleStringCast(val.(string), targetType)
+		},
+	})
 	framework.MustAddImplicitTypeCast(framework.TypeCast{
 		FromType: pgtypes.VarChar,
 		ToType:   pgtypes.Name,

server/functions/framework/cast.go

@@ -139,6 +139,10 @@ func GetExplicitCast(fromType pgtypes.DoltgresTypeBaseID, toType pgtypes.Doltgre
 	if fromType == toType && toType.GetTypeCategory() != pgtypes.TypeCategory_StringTypes && fromType.GetTypeCategory() != pgtypes.TypeCategory_StringTypes {
 		return identityCast
 	}
+	// The "char" type is an exception to the built-in explicit cast for string types below
+	if fromType.GetRepresentativeType() == pgtypes.InternalChar || toType.GetRepresentativeType() == pgtypes.InternalChar {
+		return nil
+	}
 	// All types have a built-in explicit cast to string types: https://www.postgresql.org/docs/15/sql-createcast.html
 	if toType.GetTypeCategory() == pgtypes.TypeCategory_StringTypes {
 		return func(ctx *sql.Context, val any, targetType pgtypes.DoltgresType) (any, error) {
@@ -177,7 +181,7 @@ func GetAssignmentCast(fromType pgtypes.DoltgresTypeBaseID, toType pgtypes.Doltg
 	}
 	// We check for the identity after checking the maps, as the identity may be overridden (such as for types that have
 	// parameters). If the "to" type is a string type, then we do not use the identity, and use the I/O conversion below.
-	if fromType == toType && fromType.GetTypeCategory() != pgtypes.TypeCategory_StringTypes {
+	if fromType == toType {
 		return identityCast
 	}
 	// All types have a built-in assignment cast from string types: https://www.postgresql.org/docs/15/sql-createcast.html

server/tables/information_schema/columns_table.go

@@ -300,6 +300,9 @@ func getDataAndUdtType(colType sql.Type, colName string) (string, string) {
 	dgType, ok := colType.(pgtypes.DoltgresType)
 	if ok {
 		udtName = dgType.BaseName()
+		if udtName == `"char"` {
+			udtName = "char"
+		}
 		if t, ok := partypes.OidToType[oid.Oid(dgType.OID())]; ok {
 			dataType = t.SQLStandardName()
 		}

server/tables/pgcatalog/pg_aggregate.go

@@ -58,7 +58,7 @@ func (p PgAggregateHandler) Schema() sql.PrimaryKeySchema {
 // pgAggregateSchema is the schema for pg_aggregate.
 var pgAggregateSchema = sql.Schema{
 	{Name: "aggfnoid", Type: pgtypes.Text, Default: nil, Nullable: false, Source: PgAggregateName}, // TODO: regproc type
-	{Name: "aggkind", Type: pgtypes.BpChar, Default: nil, Nullable: false, Source: PgAggregateName},
+	{Name: "aggkind", Type: pgtypes.InternalChar, Default: nil, Nullable: false, Source: PgAggregateName},
 	{Name: "aggnumdirectargs", Type: pgtypes.Int16, Default: nil, Nullable: false, Source: PgAggregateName},
 	{Name: "aggtransfn", Type: pgtypes.Text, Default: nil, Nullable: false, Source: PgAggregateName},     // TODO: regproc type
 	{Name: "aggfinalfn", Type: pgtypes.Text, Default: nil, Nullable: false, Source: PgAggregateName},     // TODO: regproc type

server/tables/pgcatalog/pg_am.go

@@ -60,7 +60,7 @@ var pgAmSchema = sql.Schema{
 	{Name: "oid", Type: pgtypes.Oid, Default: nil, Nullable: false, Source: PgAmName},
 	{Name: "amname", Type: pgtypes.Name, Default: nil, Nullable: false, Source: PgAmName},
 	{Name: "amhandler", Type: pgtypes.Text, Default: nil, Nullable: false, Source: PgAmName}, // TODO: type regproc
-	{Name: "amtype", Type: pgtypes.BpChar, Default: nil, Nullable: false, Source: PgAmName},
+	{Name: "amtype", Type: pgtypes.InternalChar, Default: nil, Nullable: false, Source: PgAmName},
 }
 
 // pgAmRowIter is the sql.RowIter for the pg_am table.

server/tables/pgcatalog/pg_amop.go

@@ -62,7 +62,7 @@ var pgAmopSchema = sql.Schema{
 	{Name: "amoplefttype", Type: pgtypes.Oid, Default: nil, Nullable: false, Source: PgAmopName},
 	{Name: "amoprighttype", Type: pgtypes.Oid, Default: nil, Nullable: false, Source: PgAmopName},
 	{Name: "amopstrategy", Type: pgtypes.Int16, Default: nil, Nullable: false, Source: PgAmopName},
-	{Name: "amoppurpose", Type: pgtypes.BpChar, Default: nil, Nullable: false, Source: PgAmopName},
+	{Name: "amoppurpose", Type: pgtypes.InternalChar, Default: nil, Nullable: false, Source: PgAmopName},
 	{Name: "amopopr", Type: pgtypes.Oid, Default: nil, Nullable: false, Source: PgAmopName},
 	{Name: "amopmethod", Type: pgtypes.Oid, Default: nil, Nullable: false, Source: PgAmopName},
 	{Name: "amopsortfamily", Type: pgtypes.Oid, Default: nil, Nullable: false, Source: PgAmopName},

server/tables/pgcatalog/pg_attribute.go

@@ -86,14 +86,14 @@ var pgAttributeSchema = sql.Schema{
 	{Name: "atttypmod", Type: pgtypes.Int32, Default: nil, Nullable: false, Source: PgAttributeName},
 	{Name: "attndims", Type: pgtypes.Int16, Default: nil, Nullable: false, Source: PgAttributeName},
 	{Name: "attbyval", Type: pgtypes.Bool, Default: nil, Nullable: false, Source: PgAttributeName},
-	{Name: "attalign", Type: pgtypes.BpChar, Default: nil, Nullable: false, Source: PgAttributeName},
-	{Name: "attstorage", Type: pgtypes.BpChar, Default: nil, Nullable: false, Source: PgAttributeName},
-	{Name: "attcompression", Type: pgtypes.BpChar, Default: nil, Nullable: false, Source: PgAttributeName},
+	{Name: "attalign", Type: pgtypes.InternalChar, Default: nil, Nullable: false, Source: PgAttributeName},
+	{Name: "attstorage", Type: pgtypes.InternalChar, Default: nil, Nullable: false, Source: PgAttributeName},
+	{Name: "attcompression", Type: pgtypes.InternalChar, Default: nil, Nullable: false, Source: PgAttributeName},
 	{Name: "attnotnull", Type: pgtypes.Bool, Default: nil, Nullable: false, Source: PgAttributeName},
 	{Name: "atthasdef", Type: pgtypes.Bool, Default: nil, Nullable: false, Source: PgAttributeName},
 	{Name: "atthasmissing", Type: pgtypes.Bool, Default: nil, Nullable: false, Source: PgAttributeName},
-	{Name: "attidentity", Type: pgtypes.BpChar, Default: nil, Nullable: false, Source: PgAttributeName},
-	{Name: "attgenerated", Type: pgtypes.BpChar, Default: nil, Nullable: false, Source: PgAttributeName},
+	{Name: "attidentity", Type: pgtypes.InternalChar, Default: nil, Nullable: false, Source: PgAttributeName},
+	{Name: "attgenerated", Type: pgtypes.InternalChar, Default: nil, Nullable: false, Source: PgAttributeName},
 	{Name: "attisdropped", Type: pgtypes.Bool, Default: nil, Nullable: false, Source: PgAttributeName},
 	{Name: "attislocal", Type: pgtypes.Bool, Default: nil, Nullable: false, Source: PgAttributeName},
 	{Name: "attinhcount", Type: pgtypes.Int16, Default: nil, Nullable: false, Source: PgAttributeName},

server/tables/pgcatalog/pg_cast.go

@@ -61,8 +61,8 @@ var pgCastSchema = sql.Schema{
 	{Name: "castsource", Type: pgtypes.Oid, Default: nil, Nullable: false, Source: PgCastName},
 	{Name: "casttarget", Type: pgtypes.Oid, Default: nil, Nullable: false, Source: PgCastName},
 	{Name: "castfunc", Type: pgtypes.Oid, Default: nil, Nullable: false, Source: PgCastName},
-	{Name: "castcontext", Type: pgtypes.BpChar, Default: nil, Nullable: false, Source: PgCastName},
-	{Name: "castmethod", Type: pgtypes.BpChar, Default: nil, Nullable: false, Source: PgCastName},
+	{Name: "castcontext", Type: pgtypes.InternalChar, Default: nil, Nullable: false, Source: PgCastName},
+	{Name: "castmethod", Type: pgtypes.InternalChar, Default: nil, Nullable: false, Source: PgCastName},
 }
 
 // pgCastRowIter is the sql.RowIter for the pg_cast table.

server/tables/pgcatalog/pg_class.go

@@ -127,8 +127,8 @@ var pgClassSchema = sql.Schema{
 	{Name: "reltoastrelid", Type: pgtypes.Oid, Default: nil, Nullable: false, Source: PgClassName},
 	{Name: "relhasindex", Type: pgtypes.Bool, Default: nil, Nullable: false, Source: PgClassName},
 	{Name: "relisshared", Type: pgtypes.Bool, Default: nil, Nullable: false, Source: PgClassName},
-	{Name: "relpersistence", Type: pgtypes.BpChar, Default: nil, Nullable: false, Source: PgClassName},
-	{Name: "relkind", Type: pgtypes.BpChar, Default: nil, Nullable: false, Source: PgClassName},
+	{Name: "relpersistence", Type: pgtypes.InternalChar, Default: nil, Nullable: false, Source: PgClassName},
+	{Name: "relkind", Type: pgtypes.InternalChar, Default: nil, Nullable: false, Source: PgClassName},
 	{Name: "relnatts", Type: pgtypes.Int16, Default: nil, Nullable: false, Source: PgClassName},
 	{Name: "relchecks", Type: pgtypes.Int16, Default: nil, Nullable: false, Source: PgClassName},
 	{Name: "relhasrules", Type: pgtypes.Bool, Default: nil, Nullable: false, Source: PgClassName},
@@ -137,7 +137,7 @@ var pgClassSchema = sql.Schema{
 	{Name: "relrowsecurity", Type: pgtypes.Bool, Default: nil, Nullable: false, Source: PgClassName},
 	{Name: "relforcerowsecurity", Type: pgtypes.Bool, Default: nil, Nullable: false, Source: PgClassName},
 	{Name: "relispopulated", Type: pgtypes.Bool, Default: nil, Nullable: false, Source: PgClassName},
-	{Name: "relreplident", Type: pgtypes.BpChar, Default: nil, Nullable: false, Source: PgClassName},
+	{Name: "relreplident", Type: pgtypes.InternalChar, Default: nil, Nullable: false, Source: PgClassName},
 	{Name: "relispartition", Type: pgtypes.Bool, Default: nil, Nullable: false, Source: PgClassName},
 	{Name: "relrewrite", Type: pgtypes.Oid, Default: nil, Nullable: false, Source: PgClassName},
 	{Name: "relfrozenxid", Type: pgtypes.Xid, Default: nil, Nullable: false, Source: PgClassName},

server/tables/pgcatalog/pg_collation.go

@@ -61,7 +61,7 @@ var PgCollationSchema = sql.Schema{
 	{Name: "collname", Type: pgtypes.Name, Default: nil, Nullable: false, Source: PgCollationName},
 	{Name: "collnamespace", Type: pgtypes.Oid, Default: nil, Nullable: false, Source: PgCollationName},
 	{Name: "collowner", Type: pgtypes.Oid, Default: nil, Nullable: false, Source: PgCollationName},
-	{Name: "collprovider", Type: pgtypes.BpChar, Default: nil, Nullable: false, Source: PgCollationName},
+	{Name: "collprovider", Type: pgtypes.InternalChar, Default: nil, Nullable: false, Source: PgCollationName},
 	{Name: "collisdeterministic", Type: pgtypes.Bool, Default: nil, Nullable: false, Source: PgCollationName},
 	{Name: "collencoding", Type: pgtypes.Int32, Default: nil, Nullable: false, Source: PgCollationName},
 	{Name: "collcollate", Type: pgtypes.Text, Default: nil, Nullable: true, Source: PgCollationName},   // TODO: collation C