add scala-like syntax

pampy/pampy_scala.py

@@ -0,0 +1,57 @@
+from pampy import match, _
+from pampy.helpers import NoDefault
+
+
+class Case:
+    def __init__(self, case):
+        self.case = case
+
+    def __rshift__(self, then):
+        self.then = then
+
+        return self
+
+    def pair(self):
+        return self.case, self.then
+
+
+class Match:
+    """
+    Wrapper to improve the pattern matching syntax (Scala-like style).
+    Usage example:
+
+        from pampy import Match
+
+        def fibonacci(n):
+
+            return Match(n).of(
+                Case(1) >> 0,
+                Case(2) >> 1,
+                Case(_) >> ( lambda x: fibonacci(x-1) + fibonacci(x-2) )
+            )
+
+    To add a default:
+
+        Match(n).with_default(42).of(
+            Case(1) >> 0,
+            ...
+        )
+    """
+
+    def __init__(self, v):
+        self.value = v
+        self.default = None
+
+    def with_default(self, default):
+        self.default = default
+
+        return self
+
+    def of(self, *cases):
+        pairs = [c.pair() for c in cases]
+
+        return match(
+            self.value,
+            *[v for tp in pairs for v in tp],
+            default=self.default if self.default else NoDefault
+        )