small fixes

README.md

@@ -198,14 +198,17 @@ polarIFy is still in an early stage of development and doesn't support the full
 - assignments (like `x = 1`)
 - polars expressions (like `pl.col("x")`, TODO)
 - side-effect free functions that return a polars expression (can be generated by `@polarify`) (TODO)
+- `match` statements
 
 ### Unsupported operations
 
 - `for` loops
 - `while` loops
 - `break` statements
 - `:=` walrus operator
-- `match ... case` statements (TODO)
+- dictionary mappings in `match` statements
+- list matching in `match` statements
+- star patterns in `match statements
 - functions with side-effects (`print`, `pl.write_csv`, ...)
 
 ## 🚀 Benchmarks

polarify/main.py

@@ -51,13 +51,6 @@ def build_polars_when_then_otherwise(body: Sequence[ResolvedCase], orelse: ast.e
 
     assert body or orelse, "No when-then cases provided."
 
-    if not body:
-        """
-        When a match statement has no valid cases (i.e., all cases except catch-all pattern are ignored),
-        we return the orelse expression but the test setup does not work with literal expressions.
-        """
-        raise ValueError("No valid cases provided.")
-
     for test, then in body:
         when_node = ast.Call(
             func=ast.Attribute(
@@ -375,6 +368,10 @@ def transform_tree_into_expr(node: State) -> ast.expr:
     if isinstance(node.node, ReturnState):
         return node.node.expr
     elif isinstance(node.node, ConditionalState):
+        if not node.node.body:
+            # this happens if none of the cases will ever match or exist
+            # in these cases we just need to return the orelse body
+            return transform_tree_into_expr(node.node.orelse)
         return build_polars_when_then_otherwise(
             [
                 ResolvedCase(case.test, transform_tree_into_expr(case.state))

tests/functions.py

@@ -3,11 +3,10 @@
 import sys
 
 if sys.version_info >= (3, 10):
-    from .functions_310 import functions_310, unsupported_functions_310, xfail_functions_310
+    from .functions_310 import functions_310, unsupported_functions_310
 else:
     functions_310 = []
     unsupported_functions_310 = []
-    xfail_functions_310 = []
 
 
 def signum(x):
@@ -317,7 +316,6 @@ def global_variable(x):
     different_type_assignments,
     star_assignments,
     global_variable,
-    *xfail_functions_310,
 ]
 
 unsupported_functions = [

tests/functions_310.py

@@ -233,28 +233,40 @@ def match_guarded_match_as(x):
     return 3
 
 
-def match_sequence_padded_length_no_case(x):
+def match_sequence_unmatchable_case_smaller(x):
     y = 2
     z = None
 
     match x, y, z:
         case 1, 2:
             return 1
         case _:
-            return -1
+            return x
+
+
+def match_sequence_unmatchable_case_larger(x):
+    y = 2
+    z = None
+
+    match x, y:
+        case 1, 2, 3:
+            return 1
+        case _:
+            return x * 2
 
 
-def match_sequence_padded_length_return(x):
+def match_sequence_unmatchable_case_smaller_return(x):
     y = 1
     z = 2
 
     match x, y, z:
         case 1, 2:
+            x = 4
             return 1
-    return -1
+    return x
 
 
-def match_sequence_padded_length(x):
+def match_sequence_unmatchable_case(x):
     y = 1
     z = 2
 
@@ -294,17 +306,15 @@ def match_guard_no_assignation(x):
     match_with_assignment_hard,
     match_complex_subject,
     match_guarded_match_as,
-    match_sequence_padded_length,
     match_guard_no_assignation,
-]
-
-xfail_functions_310 = [
-    match_mapping,
-    match_sequence_padded_length_no_case,
-    match_sequence_padded_length_return,
+    match_sequence_unmatchable_case,
+    match_sequence_unmatchable_case_smaller,
+    match_sequence_unmatchable_case_smaller_return,
+    match_sequence_unmatchable_case_larger,
 ]
 
 unsupported_functions_310 = [
+    (match_mapping, "ast.MatchMapping"),
     (match_sequence_star, "starred patterns are not supported."),
     (match_sequence, "Matching lists is not supported."),
     (match_sequence_with_brackets, "Matching lists is not supported."),