adding catalog table function interface (#1955)

* view diff

* adding catalog table

---------

Co-authored-by: James Cor <james@dolthub.com>

sql/planbuilder/from.go

@@ -514,6 +514,13 @@ func (b *Builder) buildTableFunc(inScope *scope, t *ast.TableFuncExpr) (outScope
 		b.handleErr(err)
 	}
 
+	if ctf, isCTF := newInstance.(sql.CatalogTableFunction); isCTF {
+		newInstance, err = ctf.WithCatalog(b.cat)
+		if err != nil {
+			b.handleErr(err)
+		}
+	}
+
 	// Table Function must always have an alias, pick function name as alias if none is provided
 	var newAlias *plan.TableAlias
 	if t.Alias.IsEmpty() {

sql/tables.go

@@ -14,7 +14,9 @@
 
 package sql
 
-import "fmt"
+import (
+	"fmt"
+)
 
 // Table is a SQL table.
 type Table interface {
@@ -41,6 +43,14 @@ type TableFunction interface {
 	NewInstance(ctx *Context, db Database, args []Expression) (Node, error)
 }
 
+// CatalogTableFunction is a table function that can be used as a table factor in many SQL queries.
+type CatalogTableFunction interface {
+	TableFunction
+
+	// WithCatalog returns a new instance of the table function with the given catalog
+	WithCatalog(c Catalog) (TableFunction, error)
+}
+
 // TemporaryTable allows tables to declare that they are temporary (created by CREATE TEMPORARY TABLE).
 // Only used for validation of certain DDL operations -- in almost all respects TemporaryTables are indistinguishable
 // from persisted tables to the engine.