From bc725eaa131b621bec7a8af084f631c1d31c0bf8 Mon Sep 17 00:00:00 2001
From: Araq <rumpf_a@web.de>
Date: Thu, 10 Sep 2015 13:18:11 +0200
Subject: documented void context

---
 doc/manual/stmts.txt | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

(limited to 'doc/manual/stmts.txt')

diff --git a/doc/manual/stmts.txt b/doc/manual/stmts.txt
index 062c08d7c..a833d7b7d 100644
--- a/doc/manual/stmts.txt
+++ b/doc/manual/stmts.txt
@@ -60,6 +60,24 @@ An empty ``discard`` statement is often used as a null statement:
     else: discard
 
 
+Void context
+------------
+
+In a list of statements every expression except the last one needs to have the
+type ``void``. In addition to this rule an assignment to the builtin ``result``
+symbol also triggers a ``void`` context:
+
+.. code-block:: nim
+  proc invalid*(): string =
+    result = "foo"
+    "invalid"  # Error: value of type 'string' has to be discarded
+
+.. code-block:: nim
+  proc valid*(): string =
+    let x = 317
+    "valid"
+
+
 Var statement
 -------------
 
-- 
cgit 1.4.1-2-gfad0