added lox test files

lox.t/logical_operator/and.lox

@@ -0,0 +1,19 @@
+// Note: These tests implicitly depend on ints being truthy.
+
+// Return the first non-true argument.
+print false and 1; // expect: false
+print true and 1; // expect: 1
+print 1 and 2 and false; // expect: false
+
+// Return the last argument if all are true.
+print 1 and true; // expect: true
+print 1 and 2 and 3; // expect: 3
+
+// Short-circuit at the first false argument.
+var a = "before";
+var b = "before";
+(a = true) and
+    (b = false) and
+    (a = "bad");
+print a; // expect: true
+print b; // expect: false

lox.t/logical_operator/and_truth.lox

@@ -0,0 +1,8 @@
+// False and nil are false.
+print false and "bad"; // expect: false
+print nil and "bad"; // expect: nil
+
+// Everything else is true.
+print true and "ok"; // expect: ok
+print 0 and "ok"; // expect: ok
+print "" and "ok"; // expect: ok

lox.t/logical_operator/or.lox

@@ -0,0 +1,19 @@
+// Note: These tests implicitly depend on ints being truthy.
+
+// Return the first true argument.
+print 1 or true; // expect: 1
+print false or 1; // expect: 1
+print false or false or true; // expect: true
+
+// Return the last argument if all are false.
+print false or false; // expect: false
+print false or false or false; // expect: false
+
+// Short-circuit at the first true argument.
+var a = "before";
+var b = "before";
+(a = false) or
+    (b = true) or
+    (a = "bad");
+print a; // expect: false
+print b; // expect: true

lox.t/logical_operator/or_truth.lox

@@ -0,0 +1,8 @@
+// False and nil are false.
+print false or "ok"; // expect: ok
+print nil or "ok"; // expect: ok
+
+// Everything else is true.
+print true or "ok"; // expect: true
+print 0 or "ok"; // expect: 0
+print "s" or "ok"; // expect: s