Add support for sigils containing integers (#13448)

Author: starbelly

lib/elixir/pages/getting-started/sigils.md

@@ -235,6 +235,6 @@ iex> ~i(42)n
 -42
 ```
 
-Custom sigils may be either a single lowercase character or several uppercase characters.
+Custom sigils may be either a single lowercase character, or an uppercase character followed by more uppercase characters and digits.
 
 Sigils can also be used to do compile-time work with the help of macros. For example, regular expressions in Elixir are compiled into an efficient representation during compilation of the source code, therefore skipping this step at runtime. If you're interested in the subject, you can learn more about macros and check out how sigils are implemented in the `Kernel` module (where the `sigil_*` functions are defined).

lib/elixir/src/elixir_import.erl

@@ -157,7 +157,10 @@ is_sigil({Name, 2}) ->
       case Letters of
         [L] when L >= $a, L =< $z -> true;
         [] -> false;
-        Letters -> lists:all(fun(L) -> L >= $A andalso L =< $Z end, Letters)
+        [H|T] when H >= $A, H =< $Z ->
+              lists:all(fun(L) -> (L >= $0 andalso L =< $9)
+                                  orelse (L>= $A andalso L =< $Z)
+                        end, T)
       end;
     _ ->
       false

lib/elixir/src/elixir_tokenizer.erl

@@ -1559,20 +1559,33 @@ tokenize_sigil([$~ | T], Line, Column, Scope, Tokens) ->
   end.
 
 % A one-letter sigil is ok both as upcase as well as downcase.
-tokenize_sigil_name([S | T], [], Line, Column, Scope, Tokens) when ?is_upcase(S) orelse ?is_downcase(S) ->
-  tokenize_sigil_name(T, [S], Line, Column + 1, Scope, Tokens);
+tokenize_sigil_name([S | T], [], Line, Column, Scope, Tokens) when ?is_downcase(S) ->
+  tokenize_lower_sigil_name(T, [S], Line, Column + 1, Scope, Tokens);
+tokenize_sigil_name([S | T], [], Line, Column, Scope, Tokens) when ?is_upcase(S) ->
+    tokenize_upper_sigil_name(T, [S], Line, Column + 1, Scope, Tokens).
+
+tokenize_lower_sigil_name([S | _T] = Original, [_ | _] = NameAcc, _Line, _Column, _Scope, _Tokens) when ?is_downcase(S) ->
+  SigilName = lists:reverse(NameAcc) ++ Original,
+  {error, sigil_name_error(), [$~] ++ SigilName};
+tokenize_lower_sigil_name(T, NameAcc, Line, Column, Scope, Tokens) ->
+  {ok, lists:reverse(NameAcc), T, Line, Column, Scope, Tokens}.
+
 % If we have an uppercase letter, we keep tokenizing the name.
-tokenize_sigil_name([S | T], NameAcc, Line, Column, Scope, Tokens) when ?is_upcase(S) ->
-  tokenize_sigil_name(T, [S | NameAcc], Line, Column + 1, Scope, Tokens);
+% A digit is allowed but an uppercase letter or digit must proceed it.
+tokenize_upper_sigil_name([S | T], NameAcc, Line, Column, Scope, Tokens) when ?is_upcase(S); ?is_digit(S) ->
+  tokenize_upper_sigil_name(T, [S | NameAcc], Line, Column + 1, Scope, Tokens);
 % With a lowercase letter and a non-empty NameAcc we return an error.
-tokenize_sigil_name([S | _T] = Original, [_ | _] = NameAcc, _Line, _Column, _Scope, _Tokens) when ?is_downcase(S) ->
-  Message = "invalid sigil name, it should be either a one-letter lowercase letter or a" ++
-            " sequence of uppercase letters only, got: ",
-  {error, Message, [$~] ++ lists:reverse(NameAcc) ++ Original};
+tokenize_upper_sigil_name([S | _T] = Original, [_ | _] = NameAcc, _Line, _Column, _Scope, _Tokens) when ?is_downcase(S) ->
+  SigilName = lists:reverse(NameAcc) ++ Original,
+  {error,  sigil_name_error(), [$~] ++ SigilName};
 % We finished the letters, so the name is over.
-tokenize_sigil_name(T, NameAcc, Line, Column, Scope, Tokens) ->
+tokenize_upper_sigil_name(T, NameAcc, Line, Column, Scope, Tokens) ->
   {ok, lists:reverse(NameAcc), T, Line, Column, Scope, Tokens}.
 
+sigil_name_error() ->
+  "invalid sigil name, it should be either a one-letter lowercase letter or an " ++
+  "uppercase letter optionally followed by uppercase letters and digits, got: ".
+
 tokenize_sigil_contents([H, H, H | T] = Original, [S | _] = SigilName, Line, Column, Scope, Tokens)
     when ?is_quote(H) ->
   case extract_heredoc_with_interpolation(Line, Column, Scope, ?is_downcase(S), T, H) of

lib/elixir/test/elixir/kernel/parser_test.exs

@@ -165,13 +165,26 @@ defmodule Kernel.ParserTest do
       meta = [delimiter: "\"\"\"", line: 1]
       args = {:sigil_MAT, meta, [{:<<>>, [indentation: 0, line: 1], ["1,2,3\n"]}, []]}
       assert string_to_quoted.("~MAT\"\"\"\n1,2,3\n\"\"\"") == args
+
+      args = {:sigil_FOO1, meta, [{:<<>>, [indentation: 0, line: 1], ["1,2,3\n"]}, []]}
+      assert string_to_quoted.("~FOO1\"\"\"\n1,2,3\n\"\"\"") == args
+
+      args = {:sigil_BAR321, meta, [{:<<>>, [indentation: 0, line: 1], ["1,2,3\n"]}, []]}
+      assert string_to_quoted.("~BAR321\"\"\"\n1,2,3\n\"\"\"") == args
+
+      args = {:sigil_I18N, meta, [{:<<>>, [indentation: 0, line: 1], ["1,2,3\n"]}, []]}
+      assert string_to_quoted.("~I18N\"\"\"\n1,2,3\n\"\"\"") == args
     end
 
     test "invalid multi-letter sigils" do
       msg =
-        ~r/invalid sigil name, it should be either a one-letter lowercase letter or a sequence of uppercase letters only/
+        ~r/invalid sigil name, it should be either a one-letter lowercase letter or an uppercase letter optionally followed by uppercase letters and digits/
 
       assert_syntax_error(["nofile:1:1:", msg], "~Regex/foo/")
+
+      assert_syntax_error(["nofile:1:1:", msg], "~FOo1{bar]")
+
+      assert_syntax_error(["nofile:1:1:", msg], "~foo1{bar]")
     end
 
     test "sigil newlines" do