More stuff

test.nim

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+import unittest, patty
+
+
+suite "adt construction":
+  test "basic creation":
+    adt Shape:
+      Circle(r: float, x: float, y: float)
+      Rectangle(w: float, h: float)
+      Square(side: int)
+
+    let c = Shape(kind: Circle, r: 4, x: 2, y: 0)
+    check c.r == 4.0
+
+  test "allowing empty objects":
+    adt Shape:
+      Circle(r: float, x: float, y: float)
+      Rectangle(w: float, h: float)
+      Square(side: int)
+      UnitCircle
+
+    let r = Shape(kind: Rectangle, w: 2, h: 5)
+    check r.h == 5.0
+
+
+suite "pattern matching":
+  type
+    ShapeKind = enum
+      Circle, Rectangle
+    Shape = object
+      case kind: ShapeKind
+      of Circle:
+        x, y, r: float
+      of Rectangle:
+        w, h: float
+
+  test "basic matching":
+    let c = Shape(kind: Circle, r: 4, x: 2, y: 0)
+    var res: float = 0
+    match c:
+      Circle(x: x, y: y, r: r):
+        res = r
+      Rectangle(w: w, h: h):
+        res = 1
+    check res == 4.0
+
+  test "binding to different variable names":
+    let c = Shape(kind: Circle, r: 4, x: 2, y: 0)
+    var res: float = 0
+    match c:
+      Circle(x: x, y: y, r: someNumber):
+        res = someNumber
+      Rectangle(w: w, h: h):
+        res = 1
+    check res == 4.0
+
+  test "binding a complex expression":
+    proc makeRect(w, h: float): Shape =
+      Shape(kind: Rectangle, w: w, h: h)
+
+    var res: float = 0
+    match makeRect(3, 4):
+      Circle(x: x, y: y, r: r):
+        res = r
+      Rectangle(w: w, h: h):
+        res = w + h
+    check res == 7.0
+
+  test "ignoring _ bindings":
+    let c = Shape(kind: Circle, r: 4, x: 2, y: 0)
+    var res: float = 0
+    match c:
+      Circle(x: _, y: _, r: r):
+        res = r
+      Rectangle(w: w, h: h):
+        res = w + h
+    check res == 4.0