rustdoc: Add ifaces to demo module

Author: brson

src/rustdoc/demo.rs

@@ -98,4 +98,73 @@ mod blade_runner {
 ")]
 resource bored(bored: bool) {
     log(error, bored);
+}
+
+#[doc(
+    brief = "The Shunned House",
+    desc = "
+
+From even the greatest of horrors irony is seldom absent. Sometimes it
+enters directly into the composition of the events, while sometimes it
+relates only to their fortuitous position among persons and
+places. The latter sort is splendidly exemplified by a case in the
+ancient city of Providence, where in the late forties Edgar Allan Poe
+used to sojourn often during his unsuccessful wooing of the gifted
+poetess, Mrs.  Whitman. Poe generally stopped at the Mansion House in
+Benefit Street--the renamed Golden Ball Inn whose roof has sheltered
+Washington, Jefferson, and Lafayette--and his favorite walk led
+northward along the same street to Mrs. Whitman's home and the
+neighboring hillside churchyard of St. John's, whose hidden expanse of
+Eighteenth Century gravestones had for him a peculiar fascination.
+
+")]
+iface the_shunned_house {
+    #[doc(
+        desc = "
+
+    Now the irony is this. In this walk, so many times repeated, the
+    world's greatest master of the terrible and the bizarre was
+    obliged to pass a particular house on the eastern side of the
+    street; a dingy, antiquated structure perched on the abruptly
+    rising side hill, with a great unkempt yard dating from a time
+    when the region was partly open country. It does not appear that
+    he ever wrote or spoke of it, nor is there any evidence that he
+    even noticed it. And yet that house, to the two persons in
+    possession of certain information, equals or outranks in horror
+    the wildest fantasy of the genius who so often passed it
+    unknowingly, and stands starkly leering as a symbol of all that is
+    unutterably hideous.
+
+    ",
+        args(
+            a =
+            "A yard dating from a time when the region was partly
+             open country"
+    ))]
+    fn dingy_house(unkempt_yard: int);
+
+    #[doc(
+        desc = "
+
+    The house was--and for that matter still is--of a kind to attract
+    the attention of the curious. Originally a farm or semi-farm
+    building, it followed the average New England colonial lines of
+    the middle Eighteenth Century--the prosperous peaked-roof sort,
+    with two stories and dormerless attic, and with the Georgian
+    doorway and interior panelling dictated by the progress of taste
+    at that time. It faced south, with one gable end buried to the
+    lower windows in the eastward rising hill, and the other exposed
+    to the foundations toward the street. Its construction, over a
+    century and a half ago, had followed the grading and straightening
+    of the road in that especial vicinity; for Benefit Street--at
+    first called Back Street--was laid out as a lane winding amongst
+    the graveyards of the first settlers, and straightened only when
+    the removal of the bodies to the North Burial Ground made it
+    decently possible to cut through the old family plots.
+
+    ",
+        return = "A dingy house with an unkempt yard",
+        failure = "Will fail if bodies are removed from premises"
+    )]
+    fn construct() -> bool;
 }