Merge branch 'bjorn/compiler/map-core-syntax/OTP-12454'

* bjorn/compiler/map-core-syntax/OTP-12454:
  Make the syntax for map pairs readable

3 files changed, 17 insertions, 19 deletions

diff --git a/lib/compiler/src/core_parse.yrl b/lib/compiler/src/core_parse.yrl
index 849f801a11..8bdb6bc37d 100644
--- a/lib/compiler/src/core_parse.yrl
+++ b/lib/compiler/src/core_parse.yrl
@@ -58,7 +58,8 @@ Terminals
 
 %% Separators
 
-'(' ')' '{' '}' '[' ']' '|' ',' '->' '=' '/' '<' '>' ':' '-|' '#' '~' '::'
+'(' ')' '{' '}' '[' ']' '|' ',' '->' '=' '/' '<' '>' ':' '-|' '#'
+'~' '=>' ':='
 
 %% Keywords (atoms are assumed to always be single-quoted).
 
@@ -189,8 +190,9 @@ map_pattern -> '~' '{' map_pair_patterns '}' '~' :
 map_pair_patterns -> map_pair_pattern : ['$1'].
 map_pair_patterns -> map_pair_pattern ',' map_pair_patterns : ['$1' | '$3'].
 
-map_pair_pattern -> '~' '<' anno_expression ',' anno_pattern '>' :
-			#c_map_pair{op=#c_literal{val=exact},key='$3',val='$5'}.
+map_pair_pattern -> anno_expression ':=' anno_pattern :
+			#c_map_pair{op=#c_literal{val=exact},
+				    key='$1',val='$3'}.
 
 cons_pattern -> '[' anno_pattern tail_pattern :
 		    c_cons('$2', '$3').
@@ -295,10 +297,10 @@ map_pairs -> map_pair ',' map_pairs : ['$1' | '$3'].
 map_pair -> map_pair_assoc : '$1'.
 map_pair -> map_pair_exact : '$1'.
 
-map_pair_assoc -> '::' '<' anno_expression ',' anno_expression'>' :
-		#c_map_pair{op=#c_literal{val=assoc},key='$3',val='$5'}.
-map_pair_exact -> '~' '<' anno_expression ',' anno_expression'>' :
-		#c_map_pair{op=#c_literal{val=exact},key='$3',val='$5'}.
+map_pair_assoc -> anno_expression '=>' anno_expression :
+		#c_map_pair{op=#c_literal{val=assoc},key='$1',val='$3'}.
+map_pair_exact -> anno_expression ':=' anno_expression :
+		#c_map_pair{op=#c_literal{val=exact},key='$1',val='$3'}.
 
 cons -> '[' anno_expression tail : c_cons('$2', '$3').
 
diff --git a/lib/compiler/src/core_pp.erl b/lib/compiler/src/core_pp.erl
index 01922c3fdf..662ef6c83f 100644
--- a/lib/compiler/src/core_pp.erl
+++ b/lib/compiler/src/core_pp.erl
@@ -183,15 +183,9 @@ format_1(#c_map{arg=Var,es=Es}, Ctxt) ->
      "}~"
     ];
 format_1(#c_map_pair{op=#c_literal{val=assoc},key=K,val=V}, Ctxt) ->
-    ["::<",
-     format_map_pair(K, V, Ctxt),
-     ">"
-    ];
+    format_map_pair("=>", K, V, Ctxt);
 format_1(#c_map_pair{op=#c_literal{val=exact},key=K,val=V}, Ctxt) ->
-    ["~<",
-     format_map_pair(K, V, Ctxt),
-     ">"
-    ];
+    format_map_pair(":=", K, V, Ctxt);
 format_1(#c_cons{hd=H,tl=T}, Ctxt) ->
     Txt = ["["|format(H, add_indent(Ctxt, 1))],
     [Txt|format_list_tail(T, add_indent(Ctxt, width(Txt, Ctxt)))];
@@ -448,11 +442,11 @@ format_list_tail(#c_cons{anno=[],hd=H,tl=T}, Ctxt) ->
 format_list_tail(Tail, Ctxt) ->
     ["|",format(Tail, add_indent(Ctxt, 1)),"]"].
 
-format_map_pair(K, V, Ctxt0) ->
+format_map_pair(Op, K, V, Ctxt0) ->
     Ctxt1 = add_indent(Ctxt0, 1),
     Txt = format(K, set_class(Ctxt1, expr)),
     Ctxt2 = add_indent(Ctxt0, width(Txt, Ctxt1)),
-    [Txt,",",format(V, Ctxt2)].
+    [Txt,Op,format(V, Ctxt2)].
 
 indent(Ctxt) -> indent(Ctxt#ctxt.indent, Ctxt).
 
diff --git a/lib/compiler/src/core_scan.erl b/lib/compiler/src/core_scan.erl
index b7799b373a..8ab20b1982 100644
--- a/lib/compiler/src/core_scan.erl
+++ b/lib/compiler/src/core_scan.erl
@@ -271,8 +271,10 @@ scan1("->" ++ Cs, Toks, Pos) ->
     scan1(Cs, [{'->',Pos}|Toks], Pos);
 scan1("-|" ++ Cs, Toks, Pos) ->
     scan1(Cs, [{'-|',Pos}|Toks], Pos);
-scan1("::" ++ Cs, Toks, Pos) ->
-    scan1(Cs, [{'::',Pos}|Toks], Pos);
+scan1(":=" ++ Cs, Toks, Pos) ->
+    scan1(Cs, [{':=',Pos}|Toks], Pos);
+scan1("=>" ++ Cs, Toks, Pos) ->
+    scan1(Cs, [{'=>',Pos}|Toks], Pos);
 scan1([C|Cs], Toks, Pos) ->				%Punctuation character
     P = list_to_atom([C]),
     scan1(Cs, [{P,Pos}|Toks], Pos);