From 2357813f49c3de64d3a3f984111a2b804a0dc40c Mon Sep 17 00:00:00 2001
From: Tobias Lindahl <tobias@happihacking.se>
Date: Fri, 7 Jun 2019 13:09:54 +0200
Subject: [PATCH] Introduce typereps

---
 include/aeb_fate_data.hrl      |  3 ++-
 src/aeb_fate_asm.erl           |  8 +++++++-
 src/aeb_fate_asm_scan.template |  1 +
 src/aeb_fate_data.erl          |  4 ++++
 src/aeb_fate_encoding.erl      | 21 +++++++++++++++++++--
 5 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/include/aeb_fate_data.hrl b/include/aeb_fate_data.hrl
index 6218244..db11d0b 100644
--- a/include/aeb_fate_data.hrl
+++ b/include/aeb_fate_data.hrl
@@ -39,6 +39,7 @@
                                 andalso is_tuple(element(4, X))
                                ))).
 -define(IS_FATE_BOOLEAN(X), is_boolean(X)).
+-define(IS_FATE_TYPEREP(X), (is_tuple(X) andalso tuple_size(X) =:= 2 andalso element(1, X) =:= typerep)).
 
 -define(FATE_UNIT,         {tuple, {}}).
 -define(FATE_TUPLE(T),     {tuple, T}).
@@ -50,7 +51,7 @@
 -define(FATE_NAME(X),      {name, X}).
 -define(FATE_CHANNEL(X),   {channel, X}).
 -define(FATE_BITS(B),      {bits, B}).
-
+-define(FATE_TYPEREP(T),   {typerep, T}).
 
 -define(FATE_INTEGER_VALUE(X), (X)).
 -define(FATE_BOOLEAN_VALUE(X), (X)).
diff --git a/src/aeb_fate_asm.erl b/src/aeb_fate_asm.erl
index e9d70ee..82de00b 100644
--- a/src/aeb_fate_asm.erl
+++ b/src/aeb_fate_asm.erl
@@ -304,6 +304,10 @@ to_bytecode([{start_variant,_line}|_] = Tokens, Address, Env, Code, Opts) ->
     {Arities, Tag, Values, Rest} = parse_variant(Tokens),
     Variant = aeb_fate_data:make_variant(Arities, Tag, Values),
     to_bytecode(Rest, Address, Env, [{immediate, Variant}|Code], Opts);
+to_bytecode([{typerep,_line}|Rest], Address, Env, Code, Opts) ->
+    {Type, Rest1} = to_type(Rest),
+    TypeRep = aeb_fate_data:make_typerep(Type),
+    to_bytecode(Rest1, Address, Env, [{immediate, TypeRep}|Code], Opts);
 to_bytecode([{bits,_line, Bits}|Rest], Address, Env, Code, Opts) ->
     to_bytecode(Rest, Address, Env,
                 [{immediate, aeb_fate_data:make_bits(Bits)}|Code], Opts);
@@ -403,7 +407,9 @@ parse_value([{object,_line, {channel, Address}} | Rest]) ->
 parse_value([{hash,_line, Hash} | Rest]) ->
     {aeb_fate_data:make_hash(Hash), Rest};
 parse_value([{signature,_line, Hash} | Rest]) ->
-    {aeb_fate_data:make_signature(Hash), Rest}.
+    {aeb_fate_data:make_signature(Hash), Rest};
+parse_value([{typerep,_line} | Rest]) ->
+    to_type(Rest).
 
 to_fun_def([{id, _, Name}, {'(', _} | Rest]) ->
     {ArgsType, [{'to', _} | Rest2]} = to_arg_types(Rest),
diff --git a/src/aeb_fate_asm_scan.template b/src/aeb_fate_asm_scan.template
index bd67d28..ec7a6e8 100644
--- a/src/aeb_fate_asm_scan.template
+++ b/src/aeb_fate_asm_scan.template
@@ -75,6 +75,7 @@ FUNCTION       : {token, {function, TokenLine, 'FUNCTION' }}.
 \{  : {token, {'{', TokenLine}}.
 \}  : {token, {'}', TokenLine}}.
 \|  : {token, {'|', TokenLine}}.
+\'  : {token, {typerep, TokenLine}}.
 
 ;;.* :
  {token, {comment, TokenLine, drop_prefix($;, TokenChars)}}.
diff --git a/src/aeb_fate_data.erl b/src/aeb_fate_data.erl
index 1b6f6ae..7567dfb 100644
--- a/src/aeb_fate_data.erl
+++ b/src/aeb_fate_data.erl
@@ -95,6 +95,7 @@
         , make_channel/1
         , make_bits/1
         , make_unit/0
+        , make_typerep/1
         ]).
 -export([
          elt/2
@@ -122,6 +123,7 @@ make_bits(I)    when is_integer(I) -> ?FATE_BITS(I).
 make_string(S)  when is_list(S) ->
     ?FATE_STRING(iolist_to_binary(S));
 make_string(S)  when is_binary(S) -> ?FATE_STRING(S).
+make_typerep(T) -> ?FATE_TYPEREP(T).
 
 %% Tag points to the selected variant (zero based)
 %% The arity of this variant is read from the list of provided arities
@@ -177,6 +179,8 @@ format(?FATE_NAME(X))       ->
     ["@", aeser_api_encoder:encode(name, X)];
 format(?FATE_CHANNEL(X))    ->
     ["@", aeser_api_encoder:encode(channel, X)];
+format(?FATE_TYPEREP(X))    ->
+    ["'", io_lib:format("~p", [X])];
 format(V) -> exit({not_a_fate_type, V}).
 
 format_bits(0, Acc) -> Acc;
diff --git a/src/aeb_fate_encoding.erl b/src/aeb_fate_encoding.erl
index c324124..f58779f 100644
--- a/src/aeb_fate_encoding.erl
+++ b/src/aeb_fate_encoding.erl
@@ -115,6 +115,18 @@
 -define(OTYPE_NAME,      5).
 -define(OTYPE_CHANNEL,   6).
 
+-define(IS_TYPE_TAG(X), (X =:= ?TYPE_INTEGER orelse
+                         X =:= ?TYPE_BOOLEAN orelse
+                         X =:= ?TYPE_ANY orelse
+                         X =:= ?TYPE_VAR orelse
+                         X =:= ?TYPE_LIST orelse
+                         X =:= ?TYPE_TUPLE orelse
+                         X =:= ?TYPE_OBJECT orelse
+                         X =:= ?TYPE_BITS orelse
+                         X =:= ?TYPE_MAP orelse
+                         X =:= ?TYPE_STRING orelse
+                         X =:= ?TYPE_VARIANT)).
+
 %% --------------------------------------------------
 %% Serialize
 %% Serialized a Fate data value into a sequence of bytes
@@ -200,7 +212,9 @@ serialize(?FATE_VARIANT(Arities, Tag, Values)) ->
                       (serialize(?FATE_TUPLE(Values)))/binary
                     >>
             end
-    end.
+    end;
+serialize(?FATE_TYPEREP(T)) ->
+    iolist_to_binary(serialize_type(T)).
 
 
 %% -----------------------------------------------------
@@ -424,7 +438,10 @@ deserialize2(<<?VARIANT, Rest/binary>>) ->
                true ->
                     {?FATE_VARIANT(Arities, Tag, T), Rest3}
             end
-    end.
+    end;
+deserialize2(<<TypeTag, _/binary>> = Bin) when ?IS_TYPE_TAG(TypeTag) ->
+    {Type, Rest} = deserialize_type(Bin),
+    {?FATE_TYPEREP(Type), Rest}.
 
 insert_kv([]) -> [];
 insert_kv([K, V | R]) -> [{K, V} | insert_kv(R)].