require else after catch

Author: simeonschaub

src/julia-parser.scm

@@ -1515,7 +1515,7 @@
             (cond
              ((eq? nxt 'end)
               (list* 'try try-block (or catchv '(false))
-                     (or catchb (if (or finalb elseb) '(false) (error "try without catch, else or finally")))
+                     (or catchb (if finalb '(false) (error "try without catch or finally")))
                      (cond (elseb  (list (or finalb '(false)) elseb))
                            (finalb (list finalb))
                            (else   '()))))
@@ -1561,6 +1561,8 @@
                       elseb)))
              ((and (eq? nxt 'else)
                    (not elseb))
+              (if (or (not catchb) finalb)
+                  (error "else inside try block needs to be immediately after catch"))
               (let ((eb (if (eq? (require-token s) '(catch finally))
                             '(block)
                             (parse-block s))))

test/syntax.jl

@@ -2983,9 +2983,15 @@ end
     @test fails(error)
     @test !fails(() -> 1 + 2)
 
+    @test_throws ParseError Meta.parse("try foo() else bar() end")
+    @test_throws ParseError Meta.parse("try foo() else bar() catch; baz() end")
+    @test_throws ParseError Meta.parse("try foo() catch; baz() finally foobar() else bar() end")
+    @test_throws ParseError Meta.parse("try foo() finally foobar() else bar() catch; baz() end")
+
     err = try
         try
             1 + 2
+        catch
         else
             error("foo")
         end
@@ -2998,6 +3004,7 @@ end
     err = try
         try
             1 + 2
+        catch
         else
             error("foo")
         finally
@@ -3009,21 +3016,6 @@ end
     @test err == ErrorException("foo")
     @test x == 1
 
-    x = 0
-    err = try
-        try
-            1 + 2
-        else
-            3 + 4
-        finally
-            x += 1
-        end
-    catch e
-        e
-    end
-    @test err == 3 + 4
-    @test x == 1
-
     x = 0
     err = try
         try