feat(trino): implement existing json functionality (#8963)

Implement existing JSON functionality for the Trino backend.

ibis/backends/tests/test_json.py

@@ -64,7 +64,7 @@ def test_json_getitem_array(json_t):
 @pytest.mark.notyet(["bigquery", "sqlite"], reason="doesn't support maps")
 @pytest.mark.notyet(["postgres"], reason="only supports map<string, string>")
 @pytest.mark.notyet(
-    ["pyspark", "trino", "flink"], reason="should work but doesn't deserialize JSON"
+    ["pyspark", "flink"], reason="should work but doesn't deserialize JSON"
 )
 def test_json_map(backend, json_t):
     expr = json_t.js.map.name("res")
@@ -87,7 +87,7 @@ def test_json_map(backend, json_t):
 @pytest.mark.notimpl(["dask", "mysql", "pandas", "risingwave"])
 @pytest.mark.notyet(["sqlite"], reason="doesn't support arrays")
 @pytest.mark.notyet(
-    ["pyspark", "trino", "flink"], reason="should work but doesn't deserialize JSON"
+    ["pyspark", "flink"], reason="should work but doesn't deserialize JSON"
 )
 @pytest.mark.notyet(["bigquery"], reason="doesn't allow null in arrays")
 def test_json_array(backend, json_t):

ibis/backends/trino/compiler.py

@@ -447,3 +447,23 @@ def visit_RegexpExtract(self, op, *, arg, pattern, index):
         # sqlglot doesn't support the third `group` argument for trino so work
         # around that limitation using an anonymous function
         return self.f.anon.regexp_extract(arg, pattern, index)
+
+    def visit_ToJSONMap(self, op, *, arg):
+        return self.cast(
+            self.f.json_parse(
+                self.f.json_query(
+                    self.f.json_format(arg), 'strict $?($.type() == "object")'
+                )
+            ),
+            dt.Map(dt.string, dt.json),
+        )
+
+    def visit_ToJSONArray(self, op, *, arg):
+        return self.cast(
+            self.f.json_parse(
+                self.f.json_query(
+                    self.f.json_format(arg), 'strict $?($.type() == "array")'
+                )
+            ),
+            dt.Array(dt.json),
+        )