Move templates outside the source .mk filestemplates

Templates now no longer use Make variables for substitution
but instead replace strings with their equivalent:

  template_name: Corresponds to n=template_name
  project_name:  Corresponds to $(PROJECT) or in=project_name

This allows defining templates outside of Makefiles. For
example an external plugin could define their templates
in templates/my_template.erl and then have the following
in the included Makefile:

  tpl_my_template = $(file < $(THIS)/templates/my_template.erl)

By default the created file will be in src/template_name.erl.
This can be overriden with the tplp_* variable:

  tplp_my_template = src/model/my_template.erl

Substitution is applied both to the template contents and
to its path.

In addition, attempting to overwrite an existing file when
creating a template will result in failure.

1 files changed, 42 insertions, 0 deletions

diff --git a/templates/gen_statem.erl b/templates/gen_statem.erl
new file mode 100644
index 0000000..afdf20f
--- /dev/null
+++ b/templates/gen_statem.erl
@@ -0,0 +1,42 @@
+-module(template_name).
+-behaviour(gen_statem).
+
+%% API.
+-export([start_link/0]).
+
+%% gen_statem.
+-export([callback_mode/0]).
+-export([init/1]).
+-export([state_name/3]).
+-export([handle_event/4]).
+-export([terminate/3]).
+-export([code_change/4]).
+
+-record(state, {
+}).
+
+%% API.
+
+-spec start_link() -> {ok, pid()}.
+start_link() ->
+	gen_statem:start_link(?MODULE, [], []).
+
+%% gen_statem.
+
+callback_mode() ->
+	state_functions.
+
+init([]) ->
+	{ok, state_name, #state{}}.
+
+state_name(_EventType, _EventData, StateData) ->
+	{next_state, state_name, StateData}.
+
+handle_event(_EventType, _EventData, StateName, StateData) ->
+	{next_state, StateName, StateData}.
+
+terminate(_Reason, _StateName, _StateData) ->
+	ok.
+
+code_change(_OldVsn, StateName, StateData, _Extra) ->
+	{ok, StateName, StateData}.