Merge pull request #144 from csicar/patch-1

chexxor · web-flow · commit 37e28fbc51b4 · 2017-12-13T22:05:02.000-06:00
add documentation for IncorrectAnonymousArgument
diff --git a/errors/IncorrectAnonymousArgument.md b/errors/IncorrectAnonymousArgument.md
@@ -3,19 +3,35 @@
 ## Example
 
 ```purescript
-module ShortFailingExample where
+module Example where
 
-...
+add = (_ + _)
+
+mapArray = map _ [1, 2, 3]
 ```
 
 ## Cause
 
-Explain why a user might see this error.
+In an [operator section](https://github.com/purescript/documentation/blob/fc4a9db4b128aa3331e5f990cb1860e59077af31/language/Syntax.md#operator-sections), like `(_ + 1)`, an anonymous argument can be used only once.
+
 
 ## Fix
 
-- Suggest possible solutions.
+In the case of multiple arguments, give them names:
+```purescript
+add a b = (a + b)
+```
+or in the case of a normal function: Write the function [as an operator](https://github.com/purescript/documentation/blob/fc4a9db4b128aa3331e5f990cb1860e59077af31/language/Syntax.md#functions-as-operators) using backticks:
+```purescript
+mapArray = _ `map` [1, 2, 3]
+```
+
 
 ## Notes
 
-- Additional notes.
+- While `_ + _` will give this error; `\a -> a + _` will not
+
+- If you really want to have multiple anonymous arguments, it can be achieved like this:
+```purescript
+add = (((+) $ _) $ _)
+```
