compiler: Change Maps Core Format

Ex.

Instead of:

    M~{~<K,V>}~

The format is now:

    ~{~<K,V>|M}~

This also removes a shift/reduce warning.

The changes in core_pp now requires compiler-5.0 to compile
because of is_map/1 guard, i.e. a need for a compiler with Maps know-how.

1 files changed, 10 insertions, 4 deletions

diff --git a/lib/compiler/src/core_pp.erl b/lib/compiler/src/core_pp.erl
index faa26ec6df..ada556a970 100644
--- a/lib/compiler/src/core_pp.erl
+++ b/lib/compiler/src/core_pp.erl
@@ -118,6 +118,12 @@ format_1(#c_literal{val=Tuple}, Ctxt) when is_tuple(Tuple) ->
 format_1(#c_literal{anno=A,val=Bitstring}, Ctxt) when is_bitstring(Bitstring) ->
     Segs = segs_from_bitstring(Bitstring),
     format_1(#c_binary{anno=A,segments=Segs}, Ctxt);
+format_1(#c_literal{anno=A,val=M},Ctxt) when is_map(M) ->
+    Pairs = maps:to_list(M),
+    Cpairs = [#c_map_pair{op=#c_literal{val=assoc},
+			  key=#c_literal{val=V},
+			  val=#c_literal{val=K}} || {K,V} <- Pairs],
+	format_1(#c_map{anno=A,var=#c_literal{val=#{}},es=Cpairs},Ctxt);
 format_1(#c_var{name={I,A}}, _) ->
     [core_atom(I),$/,integer_to_list(A)];
 format_1(#c_var{name=V}, _) ->
@@ -161,15 +167,15 @@ format_1(#c_tuple{es=Es}, Ctxt) ->
      format_hseq(Es, ",", add_indent(Ctxt, 1), fun format/2),
      $}
     ];
-format_1(#c_map{var=#c_var{}=Var,es=Es}, Ctxt) ->
-    [format_1(Var, Ctxt),
-     "~{",
+format_1(#c_map{var=#c_literal{val=M},es=Es}, Ctxt) when is_map(M),map_size(M)=:=0 ->
+    ["~{",
      format_hseq(Es, ",", add_indent(Ctxt, 1), fun format/2),
      "}~"
     ];
-format_1(#c_map{es=Es}, Ctxt) ->
+format_1(#c_map{var=Var,es=Es}, Ctxt) ->
     ["~{",
      format_hseq(Es, ",", add_indent(Ctxt, 1), fun format/2),
+     "|",format(Var, add_indent(Ctxt, 1)),
      "}~"
     ];
 format_1(#c_map_pair{op=#c_literal{val=assoc},key=K,val=V}, Ctxt) ->