finish DEMO-3

src/renkon/core/model/type/__init__.py

@@ -2,21 +2,6 @@
 #
 # SPDX-License-Identifier: BSD-3-Clause
 
-from renkon.core.model.type.base import (
-    Bool,
-    Bottom,
-    Float,
-    Int,
-    String,
-    Type,
-    Union,
-    rk_bool,
-    rk_bottom,
-    rk_float,
-    rk_int,
-    rk_str,
-    rk_union,
-)
 
 __all__ = [
     "Type",
@@ -32,4 +17,23 @@
     "rk_bool",
     "rk_union",
     "rk_bottom",
+    "renkon_type_to_polars_type",
+    "polars_type_to_renkon_type",
 ]
+
+from renkon.core.model.type.base import (
+    Bool,
+    Bottom,
+    Float,
+    Int,
+    String,
+    Type,
+    Union,
+    rk_bool,
+    rk_bottom,
+    rk_float,
+    rk_int,
+    rk_str,
+    rk_union
+)
+from renkon.core.model.type.convert import renkon_type_to_polars_type, polars_type_to_renkon_type

src/renkon/core/model/type/base.py

@@ -19,7 +19,7 @@ class Type(BaseModel, ABC, Hashable):
     class Config:
         frozen = True
 
-    _parser: ClassVar[Lark] = Lark(grammar, parser="lalr")
+    _parser: ClassVar[Lark] = Lark(grammar, lexer="standard", parser="lalr")
 
     @abstractmethod
     def is_equal(self, other: Type) -> bool:
@@ -361,5 +361,4 @@ def union(self, types: list[Type]) -> Union:
     def paren(self, type_: list[Type]) -> Type:
         return type_[0]
 
-
 # endregion

src/renkon/core/model/type/convert.py

@@ -1,3 +1,47 @@
 # SPDX-FileCopyrightText: 2024-present Dylan Lukes <[email protected]>
 #
 # SPDX-License-Identifier: BSD-3-Clause
+
+import polars as pl
+
+from renkon.core.model.type import rk_int
+from renkon.core.model.type.base import Type as RenkonType, rk_float, rk_str, rk_bool
+
+
+def polars_type_to_renkon_type(rk_ty: pl.PolarsDataType) -> RenkonType:
+    """
+    Convert a Polars data type to a Renkon data type.
+    """
+    if rk_ty.is_integer():
+        return rk_int
+
+    if rk_ty.is_float():
+        return rk_float
+
+    if rk_ty.is_(pl.String):
+        return rk_str
+
+    if rk_ty.is_(pl.Boolean):
+        return rk_bool
+
+    raise ValueError(f"Unsupported Polars data type: {rk_ty}")
+
+
+def renkon_type_to_polars_type(rk_ty: RenkonType) -> pl.PolarsDataType:
+    """
+    Convert a Renkon data type to a Polars data type.
+    """
+
+    if rk_ty.is_equal(rk_int):
+        return pl.Int64
+
+    if rk_ty.is_equal(rk_float) or rk_ty.is_equal(rk_int | rk_float):
+        return pl.Float64
+
+    if rk_ty.is_equal(rk_str):
+        return pl.Utf8
+
+    if rk_ty.is_equal(rk_bool):
+        return pl.Boolean
+
+    raise ValueError(f"Unsupported Renkon data type: {rk_ty}")

tests/renkon/core/model/test_convert.py

@@ -0,0 +1,28 @@
+# SPDX-FileCopyrightText: 2024-present Dylan Lukes <[email protected]>
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+import polars as pl
+import pytest
+
+import renkon.core.model.type as rkty
+from renkon.core.model.type import polars_type_to_renkon_type, renkon_type_to_polars_type
+
+
+def test_polars_type_to_renkon_type():
+    assert polars_type_to_renkon_type(pl.Int64) == rkty.rk_int
+    assert polars_type_to_renkon_type(pl.Float64) == rkty.rk_float
+    assert polars_type_to_renkon_type(pl.Utf8) == rkty.rk_str
+    assert polars_type_to_renkon_type(pl.Boolean) == rkty.rk_bool
+
+    with pytest.raises(ValueError):
+        polars_type_to_renkon_type(pl.Date)
+        polars_type_to_renkon_type(pl.Time)
+        polars_type_to_renkon_type(pl.Datetime)
+
+
+def test_renkon_type_to_polars_type():
+    assert renkon_type_to_polars_type(rkty.rk_int) == pl.Int64
+    assert renkon_type_to_polars_type(rkty.rk_float) == pl.Float64
+    assert renkon_type_to_polars_type(rkty.rk_str) == pl.Utf8
+    assert renkon_type_to_polars_type(rkty.rk_bool) == pl.Boolean

tests/renkon/core/model/test_type.py

@@ -154,7 +154,7 @@ def test_comparable():
 
 
 def test_type_parser():
-    parser = Lark(grammar, parser='lalr', transformer=TreeToType())
+    parser = Lark(grammar, parser='lalr', lexer="standard", transformer=TreeToType())
 
     assert parser.parse("int") == rk_int
     assert parser.parse("float") == rk_float