Bump to Rust 1.22

No changes in the parser. One small bugfix to let `|_||x, y| x+y` be
parsed as a valid closure returning a closure.

Author: harpocrates

sample-sources/expressions.rs

@@ -23,7 +23,8 @@ fn main() {
   loop { break; }
   'l: loop { break 'l 1; }
   match x { _ => () }
-  let x = move |a,b,c| { a + b + c }; 
+  let x = move |a,b,c| { a + b + c };
+  let f = |_||x, y| x+y;
   let x = { 1 };
   let x = unsafe { 1 };
   a = 1;

src/Language/Rust/Parser/Internal.y

@@ -348,6 +348,16 @@ gt :: { () }
            _                   -> pushToken (Spanned tok s)
     }
 
+-- This should precede any '|' token which could be absorbed in a '||' token. This works in the same
+-- way as 'gt'.
+pipe :: { () }
+  : {- empty -}   {%% \(Spanned tok s) -> 
+      let s' = nudge 1 0 s; s'' = nudge 0 (-1) s
+      in case tok of
+           PipePipe -> pushToken (Spanned Pipe s') *> pushToken (Spanned Pipe s'')
+           _        -> pushToken (Spanned tok s)
+    }
+
 -------------
 -- Utility --
 -------------
@@ -1133,7 +1143,7 @@ lambda_expr_block :: { Expr Span }
 -- Lambda expression arguments block
 lambda_args :: { Spanned [Arg Span] }
   : '||'                                                { Spanned [] (spanOf $1) }
-  | '|' sep_byT(lambda_arg,',') '|'                     { Spanned $2 ($1 # $3) }
+  | '|' sep_byT(lambda_arg,',') pipe '|'                { Spanned $2 ($1 # $4) }
 
 
 -- Struct expression literal

test/rustc-tests/Main.hs

@@ -33,7 +33,7 @@ import Test.Framework.Providers.API
 main :: IO ()
 main = do
   -- Check last time `rustc` version was bumped
-  let lastDay = fromGregorian 2017 8 21
+  let lastDay = fromGregorian 2017 9 25
   today <- utctDay <$> getCurrentTime
   when (diffDays today lastDay > 32) $
     putStrLn $ "\x1b[33m" ++ "\nThe version of `rustc' the tests will try to use is older than 1 month" ++ "\x1b[0m"