feat!: remove Python constraint type

this feature was only partially implemented (parsing) and the syntax was not ideal so this commit removes it entirely

gen/python.py

@@ -44,11 +44,6 @@ class BaseType:
     args: tuple[MidasType, ...]
 
 
-class ConstraintType:
-    type: MidasType
-    constraint: ast.expr
-
-
 class FrameColumn:
     name: Optional[str]
     type: Optional[MidasType]

midas/ast/printer/python_ast.py

@@ -18,14 +18,6 @@ class PythonAstPrinter(
             self._write_line(f"base: {node.base}")
             self._write_sequence("args", node.args, last=True)
 
-    def visit_constraint_type(self, node: p.ConstraintType) -> None:
-        self._write_line("ConstraintType")
-        with self._child_level():
-            self._write_line("type")
-            with self._child_level(single=True):
-                node.type.accept(self)
-            self._write_line(f"constraint: {ast.unparse(node.constraint)}", last=True)
-
     def visit_frame_column(self, node: p.FrameColumn) -> None:
         self._write_line("FrameColumn")
         with self._child_level():

midas/ast/python.py

@@ -52,9 +52,6 @@ class MidasType(ABC):
         @abstractmethod
         def visit_base_type(self, node: BaseType) -> T: ...
 
-        @abstractmethod
-        def visit_constraint_type(self, node: ConstraintType) -> T: ...
-
         @abstractmethod
         def visit_frame_column(self, node: FrameColumn) -> T: ...
 
@@ -71,15 +68,6 @@ class BaseType(MidasType):
         return visitor.visit_base_type(self)
 
 
-@dataclass(frozen=True)
-class ConstraintType(MidasType):
-    type: MidasType
-    constraint: ast.expr
-
-    def accept(self, visitor: MidasType.Visitor[T]) -> T:
-        return visitor.visit_constraint_type(self)
-
-
 @dataclass(frozen=True)
 class FrameColumn(MidasType):
     name: Optional[str]

midas/checker/python.py

@@ -985,10 +985,6 @@ class PythonTyper(
             return self.types.apply_generic(base, args)
         return base
 
-    def visit_constraint_type(self, node: p.ConstraintType) -> Type:
-        self.reporter.warning(node.location, "ConstraintType not yet supported")
-        return UnknownType()
-
     def visit_frame_column(self, node: p.FrameColumn) -> ColumnType:
         return ColumnType(
             type=(

midas/checker/types.py

@@ -437,8 +437,8 @@ def to_annotation(type: Type) -> str:
         case AppliedType(name=name, args=args):
             return f"{name}[{', '.join(map(to_annotation, args))}]"
 
-        case ConstraintType():
+        case ConstraintType(type=base):
-            return str(type)
+            return to_annotation(base)
 
         case TupleType(items=items):
             return f"Tuple[{', '.join(map(to_annotation, items))}]"

midas/cli/highlighter.py

@@ -138,10 +138,6 @@ class PythonHighlighter(
             self.wrap(arg, "arg")
             arg.accept(self)
 
-    def visit_constraint_type(self, node: p.ConstraintType) -> None:
-        self.wrap(node, "constraint-type")
-        node.type.accept(self)
-
     def visit_frame_column(self, node: p.FrameColumn) -> None:
         self.wrap(node, "frame-column")
         if node.type is not None:

midas/cli/hl_python.css

@@ -7,10 +7,6 @@ span {
         --col: 103, 192, 224;
     }
 
-    &.constraint-type {
-        --col: 174, 200, 195;
-    }
-
     &.frame-column {
         --col: 216, 231, 81;
     }

midas/parser/python.py

@@ -9,7 +9,6 @@ from midas.ast.python import (
     CallExpr,
     CastExpr,
     CompareExpr,
-    ConstraintType,
     DictExpr,
     Expr,
     ExpressionStmt,
@@ -337,30 +336,6 @@ class PythonParser:
                     args=(),
                 )
 
-            case ast.BinOp(left=left_expr, op=ast.Add(), right=right_expr):
-                left = self._parse_type(left_expr)
-                match left:
-                    # If chained constraints, separate base type and rebuild constraint
-                    case ConstraintType(type=left_type, constraint=left_constraint):
-                        constraint = ast.BinOp(
-                            left=left_constraint,
-                            op=ast.Add(),
-                            right=right_expr,
-                        )
-                        ast.copy_location(constraint, type_expr)
-                        return ConstraintType(
-                            location=loc,
-                            type=left_type,
-                            constraint=constraint,
-                        )
-
-                    case _:
-                        return ConstraintType(
-                            location=loc,
-                            type=left,
-                            constraint=right_expr,
-                        )
-
             case ast.Constant(value=None):
                 return BaseType(
                     location=loc,

tests/cases/checker/01_simple_types.py

@@ -5,7 +5,7 @@ from __future__ import annotations
 df: Frame[
     verified: bool,
     birth_year: int,
-    height: float + ( _ > 0 ) + ( _ < 250 ),
+    height: float,
     name: str,
     date: datetime,
     float,

tests/cases/checker/01_simple_types.py.ref.json

@@ -1,19 +1,5 @@
 {
   "diagnostics": [
-    {
-      "type": "Warning",
-      "location": {
-        "start": [
-          8,
-          12
-        ],
-        "end": [
-          8,
-          43
-        ]
-      },
-      "message": "ConstraintType not yet supported"
-    },
     {
       "type": "Warning",
       "location": {

tests/cases/python-parser/01_simple_types.py

@@ -5,7 +5,7 @@ from __future__ import annotations
 df: Frame[
     verified: bool,
     birth_year: int,
-    height: float + ( _ > 0 ) + ( _ < 250 ),
+    height: float,
     name: str,
     date: datetime,
     float,

tests/cases/python-parser/01_simple_types.py.ref.json

@@ -40,13 +40,9 @@
             "_type": "FrameColumn",
             "name": "height",
             "type": {
-              "_type": "ConstraintType",
+              "_type": "BaseType",
-              "type": {
+              "base": "float",
-                "_type": "BaseType",
+              "args": []
-                "base": "float",
-                "args": []
-              },
-              "constraint": "(_ > 0) + (_ < 250)"
             }
           },
           {

tests/cases/python-parser/02_custom_types.py

@@ -16,10 +16,6 @@ lat2: Latitude = lat[1]
 lat_diff: Difference[Latitude] = lat2 - lat1
 
 df2: Frame[
-    age: int + (_ >= 0),
+    age: int,
-    height: float + (_ >= 0),
+    height: float,
-]
-df2_bis: Frame[
-    age: int + Positive,
-    height: float + Positive,
 ]

tests/cases/python-parser/02_custom_types.py.ref.json

@@ -227,61 +227,18 @@
             "_type": "FrameColumn",
             "name": "age",
             "type": {
-              "_type": "ConstraintType",
+              "_type": "BaseType",
-              "type": {
+              "base": "int",
-                "_type": "BaseType",
+              "args": []
-                "base": "int",
-                "args": []
-              },
-              "constraint": "_ >= 0"
             }
           },
           {
             "_type": "FrameColumn",
             "name": "height",
             "type": {
-              "_type": "ConstraintType",
+              "_type": "BaseType",
-              "type": {
+              "base": "float",
-                "_type": "BaseType",
+              "args": []
-                "base": "float",
-                "args": []
-              },
-              "constraint": "_ >= 0"
-            }
-          }
-        ]
-      }
-    },
-    {
-      "_type": "TypeAssign",
-      "name": "df2_bis",
-      "type": {
-        "_type": "FrameType",
-        "columns": [
-          {
-            "_type": "FrameColumn",
-            "name": "age",
-            "type": {
-              "_type": "ConstraintType",
-              "type": {
-                "_type": "BaseType",
-                "base": "int",
-                "args": []
-              },
-              "constraint": "Positive"
-            }
-          },
-          {
-            "_type": "FrameColumn",
-            "name": "height",
-            "type": {
-              "_type": "ConstraintType",
-              "type": {
-                "_type": "BaseType",
-                "base": "float",
-                "args": []
-              },
-              "constraint": "Positive"
             }
           }
         ]

tests/cases/python-parser/03_functions.py

@@ -4,11 +4,10 @@ from __future__ import annotations
 
 
 def func(
-    col1: Column[float + (0 <= _ <= 1)],
+    col1: Column[float],
-    col2: Column[float + (0 <= _ <= 1)],
+    col2: Column[float],
-) -> Column[float + (0 <= _ <= 2)]:
+) -> Column[float]:
-    result: Column[float + (0 <= _ <= 2)] = col1 + col2
+    return col1 + col2
-    return result
 
 
 def func2(a: int, /, b: float, *, c: str):

tests/cases/python-parser/03_functions.py.ref.json

@@ -26,13 +26,9 @@
               "base": "Column",
               "args": [
                 {
-                  "_type": "ConstraintType",
+                  "_type": "BaseType",
-                  "type": {
+                  "base": "float",
-                    "_type": "BaseType",
+                  "args": []
-                    "base": "float",
-                    "args": []
-                  },
-                  "constraint": "0 <= _ <= 1"
                 }
               ]
             },
@@ -45,13 +41,9 @@
               "base": "Column",
               "args": [
                 {
-                  "_type": "ConstraintType",
+                  "_type": "BaseType",
-                  "type": {
+                  "base": "float",
-                    "_type": "BaseType",
+                  "args": []
-                    "base": "float",
-                    "args": []
-                  },
-                  "constraint": "0 <= _ <= 1"
                 }
               ]
             },
@@ -65,44 +57,15 @@
         "base": "Column",
         "args": [
           {
-            "_type": "ConstraintType",
+            "_type": "BaseType",
-            "type": {
+            "base": "float",
-              "_type": "BaseType",
+            "args": []
-              "base": "float",
-              "args": []
-            },
-            "constraint": "0 <= _ <= 2"
           }
         ]
       },
       "body": [
         {
-          "_type": "TypeAssign",
+          "_type": "ReturnStmt",
-          "name": "result",
-          "type": {
-            "_type": "BaseType",
-            "base": "Column",
-            "args": [
-              {
-                "_type": "ConstraintType",
-                "type": {
-                  "_type": "BaseType",
-                  "base": "float",
-                  "args": []
-                },
-                "constraint": "0 <= _ <= 2"
-              }
-            ]
-          }
-        },
-        {
-          "_type": "AssignStmt",
-          "targets": [
-            {
-              "_type": "VariableExpr",
-              "name": "result"
-            }
-          ],
           "value": {
             "_type": "BinaryExpr",
             "left": {
@@ -115,13 +78,6 @@
               "name": "col2"
             }
           }
-        },
-        {
-          "_type": "ReturnStmt",
-          "value": {
-            "_type": "VariableExpr",
-            "name": "result"
-          }
         }
       ]
     },

tests/serializer/python.py

@@ -8,7 +8,6 @@ from midas.ast.python import (
     CallExpr,
     CastExpr,
     CompareExpr,
-    ConstraintType,
     DictExpr,
     Expr,
     ExpressionStmt,
@@ -106,13 +105,6 @@ class PythonAstJsonSerializer(
             "args": self._serialize_list(node.args),
         }
 
-    def visit_constraint_type(self, node: ConstraintType) -> dict:
-        return {
-            "_type": "ConstraintType",
-            "type": node.type.accept(self),
-            "constraint": ast.unparse(node.constraint),
-        }
-
     def visit_frame_column(self, node: FrameColumn) -> dict:
         return {
             "_type": "FrameColumn",