How to replace pairs tags with regexp

[Ali Çehreli via Digitalmars-d-learn]

On 07/20/2017 06:39 AM, Suliman wrote:
> I have got next code:
>
> import std.stdio;
> import std.regex;
> import std.file;
>
> void main()
> {
>     auto text = readText("book.txt");
>
>     auto inlineCodeBlock = regex("`([^`\n]+)`");
>     auto bigCodeBlock = regex(r"`{3}[\s\S]*?`{3}");
>
>     foreach(t; text.matchAll(bigCodeBlock))
>     {
>         string t1 = t.hit.replaceFirst(regex("`"),`<code>`);
>         string t2 = t1.replaceFirst(regex("`"),`</code>`);
>     }
>
> }
>
> Here I am replacing `foo` to <code>foo</code>. But got replaced data as
> copy, not in original document. But I need to get replacing in original
> document.
>
> replaceAll is not suitable for it because it's not clear how to get open
> and close tags (<code> and </code>).

It's not guaranteed that the original document have space for the 
modifications. I recommend outputting to a new place. This one build the 
output in memory, hoping that it will fit:

import std.stdio;
import std.regex;
import std.array;

void main()
{
     auto text = q"END
first line
```
void main() {
}
```
last line
END";

     auto bigCodeBlock = regex(r"`{3}([\s\S]*?)`{3}");

     auto result = appender!string;
     replaceAllInto(result, text, bigCodeBlock, "<code>$1</code>");
     writeln(result.data);
}

Outputs:

first line
<code>
void main() {
}
</code>
last line

Ali