In a lot of my string manipulation functions I need the flexibility of passing a string but other times I need to pass a char[] so that I can change the contents of the string in the function.  Because the string data type is immutable I get errors if I pass it as a parameter and try to change it in the function.

Can I overload a function to work for either a char[] or a string?

Many of the library functions that I need to call require string arguments such as the replace below.

I believe I can create a wrapper function for it like this to still get at the functionality. But this seems like a lot of work for every function.

I'm almost sorry that the the string datatype was created because then probably all the library string handling would have been written for char[].

Are there any alternate libraries for D that have a mutable string datatype or is there a way to override the immutable characteristic of the string datatype by reallocating it or something?

I realize that the reduced memory reallocation in string handling is probably a major reason that D is faster than other more dynamic languages like Python but

Maybe the functions in std.string could be overloaded into a std.mutablestring library at some point to eliminate emulate the functionality of more dynamic languages for those programs that need it.

	char[] ReplaceAllSubstrings(inout char[] Original,
                                    in char[] SearchString,
                                    in char[] Substring)
	{
	    string SOriginal = Original.dup;
	    string SSearchString = SearchString.dup;
	    string SSubstring = Substring.dup;
	    SOriginal.replace(SSearchString, SSubstring);
            return Original.dup;
        }

On Sunday, 30 March 2014 at 15:58:52 UTC, Gary Miller wrote:

> Are there any alternate libraries for D that have a mutable string datatype or is there a way to override the immutable characteristic of the string datatype by reallocating it or something?

string.dup property does a copy of original array(! note that this is array property and would work for any other arrays and slices).

you can have overloaded variant for strings but i think compiler would optimize to call everything as string variant, you can figure this out on your own.

Gary Miller:

> 	char[] ReplaceAllSubstrings(inout char[] Original,
>                                     in char[] SearchString,
>                                     in char[] Substring)
> 	{
> 	    string SOriginal = Original.dup;
> 	    string SSearchString = SearchString.dup;
> 	    string SSubstring = Substring.dup;
> 	    SOriginal.replace(SSearchString, SSubstring);
>             return Original.dup;
>         }

Here if you care for some efficiency you need to dup only SOriginal. And at the end you can call assumeUnique if you want to return a string (or you can use a less efficient idup).

Note that in D string/function names start with a lowercase.

It's also better to use "auto" instead of "string" in that function, because the result of dup is not a string.

Bye,
bearophile