From 53c86cf72c1326539fe2bfce523c1dce1bdb81c0 Mon Sep 17 00:00:00 2001
From: Andreas Gerstmayr <andreas@gerstmayr.me>
Date: Mon, 3 Feb 2025 23:35:52 +0100
Subject: [PATCH 1/2] Support GROUP BY for links and tags

Currently, `[...] GROUP BY links` throws the following exception:

    beanquery.compiler.CompilationError: GROUP-BY a non-hashable type is not supported: "Column(name='links')"

because `set` is not hashable. `frozenset` is hashable, and can be used
for the `links` and `tags` which don't need to be mutable.
---
 beanquery/query_execute_test.py | 28 ++++++++++++++++++++++++++++
 beanquery/sources/beancount.py  |  8 ++++----
 2 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/beanquery/query_execute_test.py b/beanquery/query_execute_test.py
index 0358d632..facdd4c3 100644
--- a/beanquery/query_execute_test.py
+++ b/beanquery/query_execute_test.py
@@ -1086,6 +1086,34 @@ def test_aggregated_group_by_invisible_order_by_aggregate_invisible(self):
                 (2,),
                 ])
 
+    def test_aggregated_group_by_links(self):
+        self.check_query(
+            """
+            2010-02-21 * "doctor" "appointment" ^2010-reimbursement-doc1
+              Assets:Bank:Checking               -1000.00 USD
+              Assets:AccountsReceivable:Pending   1000.00 USD
+
+            2010-02-22 * "insurance" "partial reimbursement" ^2010-reimbursement-doc1
+              Assets:Bank:Checking                100.00 USD
+              Assets:AccountsReceivable:Pending  -100.00 USD
+            """,
+            """
+            SELECT FIRST(date) as date, FIRST(payee) AS payee, FIRST(narration) AS narration, links, SUM(position) AS balance
+            WHERE account ~ 'Assets:AccountsReceivable:Pending'
+            GROUP BY links
+            ORDER BY balance DESC
+            """,
+            [
+                ('date', datetime.date),
+                ('payee', str),
+                ('narration', str),
+                ('links', frozenset),
+                ('balance', inventory.Inventory),
+            ],
+            [
+                (datetime.date(2010, 2, 21), 'doctor', 'appointment', {'2010-reimbursement-doc1'}, I('900.00 USD')),
+            ])
+
     def test_aggregated_group_by_with_having(self):
         self.check_query(
             """
diff --git a/beanquery/sources/beancount.py b/beanquery/sources/beancount.py
index e388b6c6..b4d131ef 100644
--- a/beanquery/sources/beancount.py
+++ b/beanquery/sources/beancount.py
@@ -357,12 +357,12 @@ def description(entry):
             return None
         return ' | '.join(filter(None, [entry.payee, entry.narration]))
 
-    @columns.register(set)
+    @columns.register(frozenset)
     def tags(entry):
         """The set of tags of the transaction."""
         return getattr(entry, 'tags', None)
 
-    @columns.register(set)
+    @columns.register(frozenset)
     def links(entry):
         """The set of links of the transaction."""
         return getattr(entry, 'links', None)
@@ -493,12 +493,12 @@ def description(context):
         """A combination of the payee + narration for the transaction of this posting."""
         return ' | '.join(filter(None, [context.entry.payee, context.entry.narration]))
 
-    @columns.register(set)
+    @columns.register(frozenset)
     def tags(context):
         """The set of tags of the parent transaction for this posting."""
         return context.entry.tags
 
-    @columns.register(set)
+    @columns.register(frozenset)
     def links(context):
         """The set of links of the parent transaction for this posting."""
         return context.entry.links

From 2adaf1409bb8d4c80c5b36665b0d3b7080f82ece Mon Sep 17 00:00:00 2001
From: Andreas Gerstmayr <andreas@gerstmayr.me>
Date: Sun, 9 Feb 2025 15:51:35 +0100
Subject: [PATCH 2/2] add renderer for frozenset

---
 beanquery/query_render.py      | 4 ++++
 beanquery/query_render_test.py | 7 +++++++
 2 files changed, 11 insertions(+)

diff --git a/beanquery/query_render.py b/beanquery/query_render.py
index ebcfbcae..d1063f02 100644
--- a/beanquery/query_render.py
+++ b/beanquery/query_render.py
@@ -147,6 +147,10 @@ def format(self, value):
         return self.sep.join(str(x) for x in sorted(value))
 
 
+class FrozensetRenderer(SetRenderer):
+    dtype = frozenset
+
+
 class DateRenderer(ColumnRenderer):
     dtype = datetime.date
 
diff --git a/beanquery/query_render_test.py b/beanquery/query_render_test.py
index 4f55b42a..11a9375c 100644
--- a/beanquery/query_render_test.py
+++ b/beanquery/query_render_test.py
@@ -100,6 +100,13 @@ def test_set_str(self):
             'bb  ccc',
         ])
 
+    def test_frozenset_str(self):
+        self.assertEqual(self.render(frozenset, [frozenset({}), frozenset({'aaaa'}), frozenset({'bb', 'ccc'})]), [
+            '       ',
+            'aaaa   ',
+            'bb  ccc',
+        ])
+
     def test_date(self):
         self.assertEqual(self.render(datetime.date, [datetime.date(2014, 10, 3)]), [
             '2014-10-03'