Simplify cardinality expression render (#65)

opvious/model/ast.py

@@ -291,8 +291,17 @@ class _CardinalityExpression(Expression):
     domain: Domain
 
     def render(self, _precedence=0) -> str:
-        with local_formatting_scope(self.domain.quantifiers):
-            return f"\\lvert \\{{ {self.domain.render()} \\}} \\rvert"
+        qs = self.domain.quantifiers
+        with local_formatting_scope(qs):
+            if len(qs) == 1 and self.domain.mask is None:
+                key = _quantifier_grouping_key(qs[0])
+                if isinstance(key, tuple):
+                    sp = render_identifier(key[0], *key[1])
+                else:
+                    sp = key.render()
+            else:
+                sp = f"\\{{ {self.domain.render()} \\}}"
+            return f"\\lvert {sp} \\rvert"
 
 
 @dataclasses.dataclass(frozen=True)

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "poetry.core.masonry.api"
 
 [tool.poetry]
 name = "opvious"
-version = "0.12.0rc23"
+version = "0.12.0rc24"
 description = "Opvious Python SDK"
 authors = ["Opvious Engineering <[email protected]>"]
 readme = "README.md"

tests/test_model.py

@@ -183,7 +183,7 @@ def one_value_per_box(self):
 
 class BinPacking(om.Model):
     items = om.Dimension()
-    bins = om.interval(0, om.size(items), name="B")
+    bins = om.interval(1, om.size(items))
 
     weight = om.Parameter.non_negative(items)
     bin_max_weight = om.Parameter.non_negative()