RE: cc-mode help - how to support literal strings in C# syntax?

[dino chiesa <dpchiesa@hotmail.com>]

Andreas, thanks for the reply. 
The mode is available at: 
http://www.emacswiki.org/emacs/csharp-mode.el
 
 
And here is a source code module that exhibits the problem:
//========================================
using System;
using System.Collections.Generic;

namespace Example.LiteralStrings
{
    public class Pippo
    {
        // Problem: when the final char in an "escaped" string literal is a
        // slash, indenting and fontification breaks.
        List<string> directories = new List<string> {
            // string #1 in the list
            @"C:\Temp\sub1\",
                    // The emacs parser thinks the string has not ended.
                    // This comment is fontified and indented as if it is in
                    // the middle of a string literal.
            // string #2
                    @"C:\Temp\sub2\",
            // Because we have another \" at the end of a string,
            // emacs now thinks we're "out" of the string literal.
            // This comment is now indented and fontified correctly.
            // string #3
            @"C:\Home\"
                    // A third \", and now emacs thinks we're back inside the string literal.
                    // The rest of the code will be treated as if it were inside the string literal.
                };  // this is indented wrongly
// and the incorrect indenting continues all the way through
            protected void Page_Load(object sender, EventArgs e)
            {
                Console.WriteLine("Hello {0}", "world");
            }
        }
    }

//========================================
 
 
I will check out the beg-end.el as well, to see if I can figure out how to use it in cc-mode. 
(csharp-mode).
 
I'll be interested to see what you find. 
 
 
-Dino
 


> Date: Tue, 29 Dec 2009 11:43:58 +0100
> From: andreas.roehler@online.de
> To: dpchiesa@hotmail.com
> CC: emacs-devel@gnu.org; bug-cc-mode@gnu.org
> Subject: Re: cc-mode help - how to support literal strings in C# syntax?
> 
> dino chiesa wrote:
>> 
>> I'm improving the csharp-mode from http://www.emacswiki.org/emacs/CSharpMode . In case you're not aware, it's derived from cc-mode, something like Java, but with a few different syntactic quirks. 
>> 
>> The existing csharp-mode.el is pretty good. 
>> There were a couple things I fixed: 
>> 
>> - #if/else/endif was not being properly recognized, 
>> was indenting and fontifying strangely
>> 
>> - a struct was not being treated as a class - indenting inside the block was broken.
>> 
>> - class definitions that derived from other classes were not being parsed as a class. 
>> 
>> These are all minor things I was able to resolve by using c-lang-defconst on various constants: c-typeless-decl-kwds, c-other-block-decl-kwds, c-cpp-message-directives, c-cpp-expr-directives, c-colon-type-list-kwds, c-symbol-chars, c-block-prefix-disallowed-chars, and a few others.
>> 
>> There's one think I haven't been able to resolve. In C# syntax, strings can be specified as they are in C - surrounded by quotes. There's also a special form of literal string that begins with @, n which all characters in the string are to be treated as "escaped". In other words 
>> 
>> @"\usr\bin" == "\\usr\\bin"
>> 
>> The problem happens when the literal string ends in a slash. Eg @"\usr\bin\" The cc-mode syntax engine sees that as an unterminated string, the \" is an escaped double-quote. On the other hand the C# compiler sees it as a string of 9 chars. 
>> 
>> Because it isn't parsed correctly, the fontification and indenting is wrong after a @-prefixed string that ends in a slash. 
>> 
>> 
>> How can I get the prefixed strings to be treated correctly? 
>> 
> 
> Made a beg-end.el for this kind of parsings.
> Would try it with your problem.
> Feel free to send me your mode as far its done.
> Maybe some larger test-code too.
> 
> Should you want to try it yourself, get beg-end.el at
> 
> https://code.launchpad.net/s-x-emacs-werkstatt/
> 
> 
> Andreas
> 
> 
> 
> 
>> 
>> Defining a special c-in-literal seems not to be it. That function uses parse-partial-sexp , which apparently determines if the point is within a string or not. 
>> 
>> Modifying the syntax table to insert @ as a special prefix is also not it. 
>> 
>> Any suggestions? 
>> 
>> dpchiesa@hotmail.com
>> 
>> _________________________________________________________________
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>> 
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