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digitalmars.D.learn - Convert user input string to Regex

reply Ky-Anh Huynh <saigon example.net> writes:
Hi,

Is there a way to transform user input string to a regular 
expression? For example, I want to write a `grep`-like program

```
mygrep -E '/pattern/i' file.txt
```

and here the user's parameter `/pattern/i` would be converted to 
a Regex object.

Fyi, in Ruby, `to_regexp` is a useful gem: 
https://rubygems.org/gems/to_regexp

Thanks a lot.
Sep 15
parent reply Adam D. Ruppe <destructionator gmail.com> writes:
On Saturday, 16 September 2017 at 03:18:31 UTC, Ky-Anh Huynh 
wrote:
 Is there a way to transform user input string to a regular 
 expression? For example, I want to write a `grep`-like program
import std.regex; auto re = regex(user_pattern, user_flags); You'll probably want to split it on the '/' to split the pattern and the flags since they are two separate variables to the regex function, but that's all you need to do. http://dpldocs.info/experimental-docs/std.regex.regex.2.html
Sep 15
parent Ky-Anh Huynh <saigon example.net> writes:
On Saturday, 16 September 2017 at 03:23:14 UTC, Adam D. Ruppe 
wrote:
 On Saturday, 16 September 2017 at 03:18:31 UTC, Ky-Anh Huynh 
 wrote:
 Is there a way to transform user input string to a regular 
 expression? For example, I want to write a `grep`-like program
import std.regex; auto re = regex(user_pattern, user_flags); You'll probably want to split it on the '/' to split the pattern and the flags since they are two separate variables to the regex function, but that's all you need to do. http://dpldocs.info/experimental-docs/std.regex.regex.2.html
Thanks Adam. I will give it a try.
Sep 16