CODEWITHSUNDEEP
c++regexstringvisual-studio-2012
3Dave
3Dave

Reputation: 29051

Faking raw strings in VS2012?

Is there any convenient way to fake raw strings in VS2012? (I'm thinking using a preprocessor macro, but am open to suggestions.)

My use case is a fairly long, but static, list of regular expressions, that are nearly unreadable with all of the escaped \'s.

The alternative to having code that looks like this:

p[TokenType::Comment       ] = "(/\\*([^*]|[\\r\\n]|(\\*+([^*/]|[\\r\\n])))*\\*+/)|(//.*)";
p[TokenType::Float         ] = "[0-9]+\\.[0-9^(A-Za-z)]*";
p[TokenType::Integer       ] = "[0-9]+";
p[TokenType::String        ] = "\\\"([^\\\"\\\\\\\\]|\\\\\\\\.)*\\\"";
p[TokenType::Identifier    ] = "[a-zA-Z_][a-zA-Z0-9_]*";
p[TokenType::Operator      ] = "\\^|\\*|\\/|\\+|\\-|\\=";
p[TokenType::BinaryOperator] = "(\\=\\=)|(\\+\\=)|(\\-\\=)|(\\*\\=)|(\\/\\=)";
p[TokenType::WhiteSpace    ] = "\\s+";

p[TokenType::EndOfStatement] = ";";
p[TokenType::ListStart     ] = "\\(";
p[TokenType::ListDelimiter ] = "\\,";
p[TokenType::ListEnd       ] = "\\)";
p[TokenType::BlockStart    ] = "\\{";
p[TokenType::BlockEnd      ] = "\\}";

(which is just plain ugly, and difficult to maintain.)

I've found is to put everything in a text file and load it at runtime, but I'd rather not have to distribute that. Suggestions?

Upvotes: 0

Views: 120

Answers (2)

Dmitry Ilukhin
Dmitry Ilukhin

Reputation: 498

A simple answer is: put strings into resources, then load them at run time.

Upvotes: 2

Matteo Italia
Matteo Italia

Reputation: 126887

Write a code generator that takes the input file in a simple format and outputs the escaped .cpp, then add it to your pre-build steps.

In Python, assuming an input file like this:

Comment=(/\*([^*]|[\r\n]|(\*+([^*/]|[\r\n])))*\*+/)|(//.*)
Float=[0-9]+\.[0-9^(A-Za-z)]*

the whole thing would boil down to something like:

def c_escape(s):
    result = ''
    for c in s:
        if not (32 <= ord(c) < 127) or c in ('\\', '"'):
            result += '\\%03o' % ord(c)
        else:
            result += c
    return result

import sys
inFile = open(sys.args[1])
outFile = open(sys.args[2], 'w')
for l in inFile:
    idx = l.find('=')
    k,v = l[0:idx], c_escape(l[idx+1:])
    outFile.write('p[TokenType::%s]="%s";\n' % (k, v)

Upvotes: 5

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