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.

3 files changed, 26 insertions, 14 deletions

diff --git a/lib/compiler/src/core_parse.yrl b/lib/compiler/src/core_parse.yrl
index b8db0f683a..8d07ab42b0 100644
--- a/lib/compiler/src/core_parse.yrl
+++ b/lib/compiler/src/core_parse.yrl
@@ -21,7 +21,7 @@
 %% Have explicit productions for annotated phrases named anno_XXX.
 %% This just does an XXX and adds the annotation.
 
-Expect 1.
+Expect 0.
 
 Nonterminals
 
@@ -285,9 +285,9 @@ tuple -> '{' '}' : c_tuple([]).
 tuple -> '{' anno_expressions '}' : c_tuple('$2').
 
 map_expr -> '~' '{' '}' '~' : #c_map{es=[]}.
-map_expr -> '~' '{' map_pairs  '}' '~' : #c_map{es='$3'}.
-map_expr -> variable '~' '{' '}' '~' : #c_map{var='$1',es=[]}.
-map_expr -> variable '~' '{' map_pairs  '}' '~' : #c_map{var='$1',es='$4'}.
+map_expr -> '~' '{' map_pairs '}' '~' : #c_map{es='$3'}.
+map_expr -> '~' '{' map_pairs '|' variable '}' '~' : #c_map{var='$5',es='$3'}.
+map_expr -> '~' '{' map_pairs '|' map_expr '}' '~' : #c_map{var='$5',es='$3'}.
 
 map_pairs -> map_pair : ['$1'].
 map_pairs -> map_pair ',' map_pairs : ['$1' | '$3'].
diff --git a/lib/compiler/src/core_pp.erl b/lib/compiler/src/core_pp.erl
index faa26ec6df..ada556a970 100644
--- a/lib/compiler/src/core_pp.erl
+++ b/lib/compiler/src/core_pp.erl
@@ -118,6 +118,12 @@ format_1(#c_literal{val=Tuple}, Ctxt) when is_tuple(Tuple) ->
 format_1(#c_literal{anno=A,val=Bitstring}, Ctxt) when is_bitstring(Bitstring) ->
     Segs = segs_from_bitstring(Bitstring),
     format_1(#c_binary{anno=A,segments=Segs}, Ctxt);
+format_1(#c_literal{anno=A,val=M},Ctxt) when is_map(M) ->
+    Pairs = maps:to_list(M),
+    Cpairs = [#c_map_pair{op=#c_literal{val=assoc},
+			  key=#c_literal{val=V},
+			  val=#c_literal{val=K}} || {K,V} <- Pairs],
+	format_1(#c_map{anno=A,var=#c_literal{val=#{}},es=Cpairs},Ctxt);
 format_1(#c_var{name={I,A}}, _) ->
     [core_atom(I),$/,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) ->
diff --git a/lib/compiler/src/v3_kernel_pp.erl b/lib/compiler/src/v3_kernel_pp.erl
index b4e486f97c..b33eba50eb 100644
--- a/lib/compiler/src/v3_kernel_pp.erl
+++ b/lib/compiler/src/v3_kernel_pp.erl
@@ -104,20 +104,26 @@ format_1(#k_tuple{es=Es}, Ctxt) ->
      format_hseq(Es, ",", ctxt_bump_indent(Ctxt, 1), fun format/2),
      $}
     ];
-format_1(#k_map{var=#k_var{}=Var,es=Es}, Ctxt) ->
-    [$~,${,
+format_1(#k_map{var=#k_literal{val=M},op=assoc,es=Es}, Ctxt) when is_map(M), map_size(M) =:= 0 ->
+    ["~{",
      format_hseq(Es, ",", ctxt_bump_indent(Ctxt, 1), fun format/2),
-     " | ",format_1(Var, Ctxt),
-     $},$~
+     "}~"
     ];
-format_1(#k_map{op=assoc,es=Es}, Ctxt) ->
+format_1(#k_map{var=#k_literal{val=M},op=exact,es=Es}, Ctxt) when is_map(M), map_size(M) =:= 0 ->
+    ["::{",
+     format_hseq(Es, ",", ctxt_bump_indent(Ctxt, 1), fun format/2),
+     "}::"
+    ];
+format_1(#k_map{var=Var,op=assoc,es=Es}, Ctxt) ->
     ["~{",
      format_hseq(Es, ",", ctxt_bump_indent(Ctxt, 1), fun format/2),
+     " | ",format_1(Var, Ctxt),
      "}~"
     ];
-format_1(#k_map{es=Es}, Ctxt) ->
+format_1(#k_map{var=Var,op=exact,es=Es}, Ctxt) ->
     ["::{",
      format_hseq(Es, ",", ctxt_bump_indent(Ctxt, 1), fun format/2),
+     " | ",format_1(Var, Ctxt),
      "}::"
     ];
 format_1(#k_map_pair{key=K,val=V}, Ctxt) ->