I am processing an input format that can use either @ or \ to introduce inline directives. when a literal @ or \ is in the input, either character can be used to escape either character. IE: @@ or \@ or \\ or @\

Currently, I replace the escape sequences with place holders, then extract directives, then replace the placeholders with the intended literal occurrences of @ and \ in the string. 

    s/(?<![\\\@])[\\\@]\@/\x11/g;
    s/(?<![\\\@])[\\\@]\\/\x12/g;
    while (/[\\\@]([_A-Za-z]+)/)
    {
        print "Extracted code '$1'\n";
        s/[\\\@]$1//;
    }
    s/\x11/\@/g;
    s/\x12/\\/g;

[download]

I'm sure there's a better way, but my search-foo is lacking. And so is my regex-foo. (And there's likely an input file that will break this.)

(and no, it's not LaTeX, despite the similarities)

In reply to better way to escape escapes by RonW

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