[Haskell-cafe] mistake in Gentle Introduction

[Simon Marlow]

On 22 September 2005 10:05, Christian Maeder wrote:

> Michael Vanier wrote:
>> On this page:
>> 
>> http://www.haskell.org/tutorial/modules.html
>> 
>> it refers to the process of hiding imported names from a module and
>> gives the example: 
>> 
>>   import Prelude hiding length
> 
> The error message on this is really poor: parse error on input
> `length' 
> 
> An addition like "expecting '('" might be more helpful.

Not easy to do - some significant work on Happy would be required (or
rewriting GHC's parser, which is even more unlikely).

However we *would* like to do some simple error recovery in the parser
at some point.  The main reason for doing this is to get better results
from checking partially complete modules in Visual Haskell or hIDE.

Cheers,
	Simon