parse chains of binary ~ as a macro call to @~. closes JuliaLang#4882

NEWS.md

@@ -9,8 +9,6 @@ New language features
   * Tuples (of integers, symbols, or bools) can now be used as type
     parameters ([#5164]).
 
-  * `import module: name1, name2, ...` ([#5214]).
-
   * Default "inner" constructors now accept any arguments. Constructors that
     look like `MyType(a, b) = new(a, b)` can and should be removed ([#4026]).
 
@@ -21,6 +19,9 @@ New language features
   * When reloading code, types whose definitions have not changed can be
     ignored in some cases.
 
+  * Binary `~` now parses as a vararg macro call to `@~`.
+    For example `x~y~z` => `@~ x y z` ([#4882]).
+
 New library functions
 ---------------------
 
@@ -110,7 +111,6 @@ Deprecated or removed
 
 [#4042]: https://github.com/JuliaLang/julia/issues/4042
 [#5164]: https://github.com/JuliaLang/julia/issues/5164
-[#5214]: https://github.com/JuliaLang/julia/issues/5214
 [#4026]: https://github.com/JuliaLang/julia/issues/4026
 [#4799]: https://github.com/JuliaLang/julia/issues/4799
 [#4862]: https://github.com/JuliaLang/julia/issues/4862
@@ -139,6 +139,7 @@ Deprecated or removed
 [#987]: https://github.com/JuliaLang/julia/issues/987
 [#2345]: https://github.com/JuliaLang/julia/issues/2345
 [#5330]: https://github.com/JuliaLang/julia/issues/5330
+[#4882]: https://github.com/JuliaLang/julia/issues/4882
 
 Julia v0.2.0 Release Notes
 ==========================
@@ -190,6 +191,8 @@ New language features
   * Methods can be added to functions in other modules using dot syntax,
     as in `Foo.bar(x) = 0`.
 
+  * `import module: name1, name2, ...` ([#5214]).
+
   * A semicolon is now allowed after an `import` or `using` statement ([#4130]).
 
   * In an interactive session (REPL), you can use `;cmd` to run `cmd` via an interactive
@@ -512,6 +515,7 @@ Too numerous to mention.
 [#4235]: https://github.com/JuliaLang/julia/issues/4235
 [#4284]: https://github.com/JuliaLang/julia/issues/4284
 [#4412]: https://github.com/JuliaLang/julia/issues/4412
+[#5214]: https://github.com/JuliaLang/julia/issues/5214
 
 [packages chapter]: http://docs.julialang.org/en/latest/manual/packages/
 [sorting functions]: http://docs.julialang.org/en/latest/stdlib/sort/

src/julia-parser.scm

@@ -445,9 +445,9 @@
 ; parse right-to-left binary operator
 ; produces structures like (= a (= b (= c d)))
 (define (parse-RtoL s down ops)
-  (let ((ex (down s))
-	(t   (peek-token s))
-	(spc (ts:space? s)))
+  (let loop ((ex  (down s))
+	     (t   (peek-token s))
+	     (spc (ts:space? s)))
     (if (not (memq t ops))
 	ex
 	(begin (take-token s)
@@ -457,6 +457,14 @@
 		      ex)
 		     ((syntactic-op? t)
 		      (list t ex (parse-RtoL s down ops)))
+		     ((eq? t '~)
+		      (let ((args (parse-chain s down '~)))
+			(if (memq (peek-token s) ops)
+			    `(macrocall @~ ,ex ,@(butlast args)
+					,(loop (last args)
+					       (peek-token s)
+					       (ts:space? s)))
+			    `(macrocall @~ ,ex ,@args))))
 		     (else
 		      (list 'call t ex (parse-RtoL s down ops))))))))