Re: with and shadowing variables

[Anonymouse via Digitalmars-d]

On Monday, 23 July 2018 at 12:01:19 UTC, Jim Balter wrote:
Do you have an actual case where it was a problem, as opposed 
to a contrived example with semantically empty identifiers? I 
recently saw another comment objecting to `with` altogether as 
being obfuscating because you can't tell which symbols are 
qualified by the symbol in the with clause, when the 
obfuscation was  clearly due to the meaningless names in the 
poster's example.

Copy/pasted but changed some bits for clarity.

struct IRCServer
{
    // ...
    string prefixchars;
    string prefixes;  // <--
}

struct IRCBot
{
    // ...
    IRCServer server;
}

struct IRCParser
{
    // ...
    IRCBot bot;
}

IRCParser parser;

// string content == "EXCEPTS INVEX PREFIX=(Yqaohv)!~&@%+";

foreach (entry; content.splitter(" "))
{
    // Roughly rewritten splitting
    auto split = entry.findSplit("=");
    string key = split[0];
    string value = split[2];

    with (parser.bot.server)
    switch (key)
    {
    case "PREFIX":
        // PREFIX=(Yqaohv)!~&@%+
        import std.format : formattedRead;

        string modes;
        string prefixes;  // <--
        value.formattedRead("(%s)%s", modes, prefixes);

        foreach (immutable i; 0..modes.length)
        {
            prefixchars[prefixes[i]] = modes[i];  // 
parser.bot.server.prefixchars
            prefixes ~= modes[i];  // <-- accidental local 
prefixes instead of parser.bot.server.prefixes
        }
        break;

    // ...

    default:
        break;
}

https://github.com/zorael/kameloso/blob/93002da193eac2dfbfeb6c8756feb2d74a345530/source/kameloso/irc.d#L1887