Format errors_test.exs

Author: José Valim

.formatter.exs

@@ -11,6 +11,9 @@
     assert_same: 1,
     assert_same: 2,
 
+    # Errors tests
+    assert_eval_raise: 3,
+
     # Mix tests
     in_fixture: 2,
     in_tmp: 2

lib/elixir/src/elixir.erl

@@ -280,6 +280,7 @@ string_to_tokens(String, StartLine, File, Opts) when is_integer(StartLine), is_b
 
 tokens_to_quoted(Tokens, File, Opts) ->
   handle_parsing_opts(File, Opts),
+
   try elixir_parser:parse(Tokens) of
     {ok, Forms} -> {ok, Forms};
     {error, {{Line, _, _}, _, [Error, Token]}} -> {error, {Line, to_binary(Error), to_binary(Token)}};

lib/elixir/src/elixir_errors.erl

@@ -98,6 +98,15 @@ parse_error(Line, File, {ErrorPrefix, ErrorSuffix}, Token) when is_binary(ErrorP
   Message = <<ErrorPrefix/binary, Token/binary, ErrorSuffix/binary >>,
   raise(Line, File, 'Elixir.SyntaxError', Message);
 
+%% Misplaced char tokens (e.g., {char, _, 97}) are translated by Erlang into
+%% the char literal (i.e., the token in the previous example becomes $a),
+%% because {char, _, _} is a valid Erlang token for an Erlang char literal. We
+%% want to represent that token as ?a in the error, according to the Elixir
+%% syntax.
+parse_error(Line, File, <<"syntax error before: ">>, <<$$, Char/binary>>) ->
+  Message = <<"syntax error before: ?", Char/binary>>,
+  raise(Line, File, 'Elixir.SyntaxError', Message);
+
 %% Everything else is fine as is
 parse_error(Line, File, Error, Token) when is_binary(Error), is_binary(Token) ->
   Message = <<Error/binary, Token/binary >>,

lib/elixir/src/elixir_parser.yrl

@@ -40,7 +40,7 @@ Terminals
   capture_op rel_op
   'true' 'false' 'nil' 'do' eol ';' ',' '.'
   '(' ')' '[' ']' '{' '}' '<<' '>>' '%{}' '%'
-  int float
+  int float char
   .
 
 Rootsymbol grammar.
@@ -263,6 +263,7 @@ access_expr -> max_expr : '$1'.
 
 %% Augment integer literals with representation format if formatter_metadata option is true
 number -> int : handle_literal(number_value('$1'), '$1', [{original, ?exprs('$1')}]).
+number -> char : handle_literal(?exprs('$1'), '$1', [{original, number_value('$1')}]).
 number -> float : handle_literal(number_value('$1'), '$1', [{original, ?exprs('$1')}]).
 
 %% Aliases and properly formed calls. Used by map_expr.

lib/elixir/src/elixir_tokenizer.erl

@@ -215,7 +215,7 @@ tokenize([$~, S, H | _] = Original, Line, Column, _Scope, Tokens) when ?is_upcas
 
 tokenize([$?, $\\, H | T], Line, Column, Scope, Tokens) ->
   Char = elixir_interpolation:unescape_map(H),
-  Token = {int, {Line, {Column, Column + 3}, Char}, [$?, $\\, H]},
+  Token = {char, {Line, {Column, Column + 3}, [$?, $\\, H]}, Char},
   tokenize(T, Line, Column + 3, Scope, [Token | Tokens]);
 
 tokenize([$?, Char | T], Line, Column, Scope, Tokens) ->
@@ -227,7 +227,7 @@ tokenize([$?, Char | T], Line, Column, Scope, Tokens) ->
     false ->
       ok
   end,
-  Token = {int, {Line, {Column, Column + 2}, Char}, [$?, Char]},
+  Token = {char, {Line, {Column, Column + 2}, [$?, Char]}, Char},
   tokenize(T, Line, Column + 2, Scope, [Token | Tokens]);
 
 % Heredocs