Cast dialect clean up.

internal/jet/cast.go

@@ -76,8 +76,8 @@ func (b *castExpression) serialize(statement StatementType, out *SqlBuilder, opt
 	expression := b.expression
 	castType := b.cast
 
-	if castOverride := out.Dialect.CastOverride(); castOverride != nil {
+	if castOverride := out.Dialect.SerializeOverride("CAST"); castOverride != nil {
-		return castOverride(expression, castType)(statement, out, options...)
+		return castOverride(expression, String(castType))(statement, out, options...)
 	}
 
 	out.WriteString("CAST(")

internal/jet/dialects.go

@@ -18,7 +18,6 @@ type Dialect interface {
 	Name() string
 	PackageName() string
 	SerializeOverride(operator string) SerializeOverride
-	CastOverride() CastOverride
 	AliasQuoteChar() byte
 	IdentifierQuoteChar() byte
 	ArgumentPlaceholder() QueryPlaceholderFunc
@@ -31,14 +30,12 @@ type SerializeOverride func(expressions ...Expression) SerializeFunc
 
 type QueryPlaceholderFunc func(ord int) string
 
-type CastOverride func(expression Expression, castType string) SerializeFunc
 type UpdateAssigmentFunc func(columns []IColumn, values []Clause, out *SqlBuilder) (err error)
 
 type DialectParams struct {
 	Name                string
 	PackageName         string
 	SerializeOverrides  map[string]SerializeOverride
-	CastOverride        CastOverride
 	AliasQuoteChar      byte
 	IdentifierQuoteChar byte
 	ArgumentPlaceholder QueryPlaceholderFunc
@@ -52,7 +49,6 @@ func NewDialect(params DialectParams) Dialect {
 		name:                params.Name,
 		packageName:         params.PackageName,
 		serializeOverrides:  params.SerializeOverrides,
-		castOverride:        params.CastOverride,
 		aliasQuoteChar:      params.AliasQuoteChar,
 		identifierQuoteChar: params.IdentifierQuoteChar,
 		argumentPlaceholder: params.ArgumentPlaceholder,
@@ -65,7 +61,6 @@ type dialectImpl struct {
 	name                string
 	packageName         string
 	serializeOverrides  map[string]SerializeOverride
-	castOverride        CastOverride
 	aliasQuoteChar      byte
 	identifierQuoteChar byte
 	argumentPlaceholder QueryPlaceholderFunc
@@ -86,10 +81,6 @@ func (d *dialectImpl) SerializeOverride(operator string) SerializeOverride {
 	return d.serializeOverrides[operator]
 }
 
-func (d *dialectImpl) CastOverride() CastOverride {
-	return d.castOverride
-}
-
 func (d *dialectImpl) AliasQuoteChar() byte {
 	return d.aliasQuoteChar
 }

postgres/dialect.go

@@ -13,11 +13,11 @@ func NewDialect() jet.Dialect {
 
 	serializeOverrides := map[string]jet.SerializeOverride{}
 	serializeOverrides["REGEXP_LIKE"] = postgres_REGEXP_LIKE_function
+	serializeOverrides["CAST"] = postgresCAST
 
 	dialectParams := jet.DialectParams{
 		Name:                "PostgreSQL",
 		PackageName:         "postgres",
-		CastOverride:        castFunc,
 		SerializeOverrides:  serializeOverrides,
 		AliasQuoteChar:      '"',
 		IdentifierQuoteChar: '"',
@@ -31,8 +31,26 @@ func NewDialect() jet.Dialect {
 	return jet.NewDialect(dialectParams)
 }
 
-func castFunc(expression jet.Expression, castType string) jet.SerializeFunc {
+func postgresCAST(expressions ...jet.Expression) jet.SerializeFunc {
 	return func(statement jet.StatementType, out *jet.SqlBuilder, options ...jet.SerializeOption) error {
+		if len(expressions) < 2 {
+			return errors.New("jet: invalid number of expressions for operator")
+		}
+
+		expression := expressions[0]
+
+		litExpr, ok := expressions[1].(jet.LiteralExpression)
+
+		if !ok {
+			return errors.New("jet: cast invalid cast type")
+		}
+
+		castType, ok := litExpr.Value().(string)
+
+		if !ok {
+			return errors.New("jet: cast type is not string")
+		}
+
 		if err := jet.Serialize(expression, statement, out, options...); err != nil {
 			return err
 		}