Add support for OFFSET

lang/resources/org/partiql/type-domains/partiql.ion

@@ -121,7 +121,8 @@
                 (group (? group_by))
                 (having (? expr))
                 (order (? order_by))
-                (limit (? expr))))
+                (limit (? expr))
+                (offset (? expr))))
         // end of sum expr
 
         // Time

lang/src/org/partiql/lang/eval/visitors/GroupByPathExpressionVisitorTransform.kt

@@ -103,6 +103,7 @@ class GroupByPathExpressionVisitorTransform(
         val groupBy = unshadowedTransformer.transformExprSelect_group(node)
         val having = currentAndUnshadowedTransformer.transformExprSelect_having(node)
         val order = currentAndUnshadowedTransformer.transformExprSelect_order(node)
+        val offset = unshadowedTransformer.transformExprSelect_offset(node)
         val limit = unshadowedTransformer.transformExprSelect_limit(node)
         val metas = unshadowedTransformer.transformExprSelect_metas(node)
 
@@ -116,6 +117,7 @@ class GroupByPathExpressionVisitorTransform(
                 group = groupBy,
                 having = having,
                 order = order,
+                offset = offset,
                 limit = limit,
                 metas = metas)
         }

lang/src/org/partiql/lang/eval/visitors/VisitorTransformBase.kt

@@ -41,6 +41,7 @@ abstract class VisitorTransformBase : PartiqlAst.VisitorTransform() {
         val setq = transformExprSelect_setq(node)
         val project = transformExprSelect_project(node)
         val order = transformExprSelect_order(node)
+        val offset = transformExprSelect_offset(node)
         val limit = transformExprSelect_limit(node)
         val metas = transformExprSelect_metas(node)
         return PartiqlAst.build {
@@ -53,6 +54,7 @@ abstract class VisitorTransformBase : PartiqlAst.VisitorTransform() {
                 group = group,
                 having = having,
                 order = order,
+                offset = offset,
                 limit = limit,
                 metas = metas)
         }