Add a VERSION file at the top level and go from there

VERSION

@@ -0,0 +1 @@
+2.0.0

docs/aeso_compiler.md

@@ -15,7 +15,7 @@ returns the compiled module in a map which can then be loaded.
 ``` erlang
 contract_string() = string() | binary()
 contract_map() = #{bytecode => binary(),
-                   compiler_version => string(),
+                   compiler_version => binary(),
                    contract_souce => string(),
                    type_info => type_info()}
 type_info()
@@ -75,12 +75,12 @@ Types
 
 Get the type representation of a type declaration.
 
-#### version() -> Version
+#### version() -> {ok, Version} | {error, term()}
 
 Types
 
 ``` erlang
-Version = integer()
+Version = binary()
 ```
 
 Get the current version of the Sophia compiler.

src/aeso_compiler.erl

@@ -39,14 +39,24 @@
              , options/0
              ]).
 
--define(COMPILER_VERSION_1, 1).
--define(COMPILER_VERSION_2, 2).
-
--define(COMPILER_VERSION, ?COMPILER_VERSION_2).
-
--spec version() -> pos_integer().
+-spec version() -> {ok, binary()} | {error, term()}.
 version() ->
-    ?COMPILER_VERSION.
+    case lists:keyfind(aesophia, 1, application:loaded_applications()) of
+        false ->
+            case application:load(aesophia) of
+                ok ->
+                    case application:get_key(aesophia, vsn) of
+                        {ok, VsnString} ->
+                            {ok, list_to_binary(VsnString)};
+                        undefined ->
+                            {error, failed_to_load_aesophia}
+                    end;
+                Err = {error, _} ->
+                    Err
+            end;
+        {_App, _Des, VsnString} ->
+            {ok, list_to_binary(VsnString)}
+    end.
 
 -spec file(string()) -> {ok, map()} | {error, binary()}.
 file(Filename) ->
@@ -75,8 +85,9 @@ from_string(ContractString, Options) ->
         ByteCodeList = to_bytecode(Assembler, Options),
         ByteCode = << << B:8 >> || B <- ByteCodeList >>,
         pp_bytecode(ByteCode, Options),
+        {ok, Version} = version(),
         {ok, #{byte_code => ByteCode,
-               compiler_version => version(),
+               compiler_version => Version,
                contract_source => ContractString,
                type_info => TypeInfo
               }}

src/aesophia.app.src

@@ -1,6 +1,6 @@
 {application, aesophia,
  [{description, "Contract Language for Aethernity"},
-  {vsn, "1.2.0"},
+  {vsn, {cmd, "cat VERSION | tr -d '[:space:]'"}},
   {registered, []},
   {applications,
    [kernel,

src/aesophia.erl

@@ -4,6 +4,7 @@
 
 -define(OPT_SPEC,
     [ {src_file, undefined, undefined, string, "Sophia source code file"}
+    , {version, $V, "version", undefined, "Print compiler version"}
     , {verbose, $v, "verbose", undefined, "Verbose output"}
     , {help, $h, "help", undefined, "Show this message"}
     , {outfile, $o, "out", string, "Output file (experimental)"} ]).
@@ -14,11 +15,13 @@ usage() ->
 main(Args) ->
     case getopt:parse(?OPT_SPEC, Args) of
         {ok, {Opts, []}} ->
-            case proplists:get_value(help, Opts, false) of
-                false ->
-                    compile(Opts);
-                true ->
-                    usage()
+            case Opts of
+                [version] ->
+                    print_vsn();
+                [help] ->
+                    usage();
+                _ ->
+                    compile(Opts)
             end;
 
         {ok, {_, NonOpts}} ->
@@ -69,3 +72,7 @@ write_outfile(Out, ResMap)  ->
     %% Lazy approach
     file:write_file(Out, term_to_binary(ResMap)),
     io:format("Output written to: ~s\n", [Out]).
+
+print_vsn() ->
+    {ok, Vsn} = aeso_compiler:version(),
+    io:format("Compiler version: ~s\n", [Vsn]).