Problem parsing square brackets in string literals

[khjklujn]

Cobra 0.7.3, Mono 1.2.6

The following program fails with "error: Expecting an expression" in line 3.

class Program
    def main is shared
        t = '0123['
        print t.indexOf('[')

The workaround I am using is:

class Program
    def main is shared
        t as String = sharp' "0123[" '
        print t.indexOf(sharp' "[" ')

[Dafra]

I've got the same problem each time there is a square bracket in a string. Maybe Cobra believes they are regexs ?
I use ns'123[' (no substitution) or r'123[' (raw). You should try both because I don't know the difference.

[dennis]

Rather than a regex, I think Cobra is probably looking for a variable substitution:

print 'Value: [foo]'

This works, for example:

a = '456'
b = '123[a]789'

I also tried escaping the bracket with a backslash or doubling the bracket. Neither worked.

t = '0123\[' # Nope
t = '0123[[' # Nope

So I think r'0123[' or ns'0123[' are the correct way.

This works, BTW (it gives '0123['):

s = '12'
t = '0[s]' + r'3['

[Charles]

You are correct that square brackets are used for interpolation. Also, you can have any kind of expression. And you can use : followed by a .NET formatting code:

print '[person.lastName], [person.firstName]'
print '[amount:N2]'

If you search for "C# string formatting" or such you'll find info on the formatting codes.

ns stands for "no substitution". It still respects \n \r \t etc. as meaning newline, carriage return, tab etc.

r stands for "raw" which is like Python's r'aoeu' and C#'s @"aoeu". All characters are literal including backslashes and brackets. Most often used for regular expressions where backslashes are common.

I've wanted \[ to work for awhile, but just haven't gotten to it. I also see that a better error message could be given to guide people.