Refs gar1t#19: Add flow_control.erl for pattern matching

Author: Kevin C. Baird

examples/flow_control.erl

@@ -0,0 +1,26 @@
+-module(flow_control).
+-export([report_result/1, report_result_via_case/1]).
+-include_lib("eunit/include/eunit.hrl").
+
+% An example with case
+report_result_via_case(Response) -> 
+  case Response of
+    {ok,    Msg} -> report_success(Msg);
+    {error, Msg} -> report_failure(Msg)
+  end.
+
+% An example with pattern matching
+report_result({ok,    Msg}) -> report_success(Msg);
+report_result({error, Msg}) -> report_failure(Msg).
+
+% private/hidden functions
+% Real code would do something meaningful with the argument.
+report_success(_Msg) -> success.
+report_failure(_Msg) -> failure.
+
+%% TESTS
+success_via_case_test() -> ?assertEqual(success, report_result_via_case({ok,    anything})).
+failure_via_case_test() -> ?assertEqual(failure, report_result_via_case({error, anything})).
+
+success_via_pm_test() -> ?assertEqual(success, report_result({ok,    anything})).
+failure_via_pm_test() -> ?assertEqual(failure, report_result({error, anything})).