Format and raw strings ignore escape characters

[michaeljklein]

Aim

Attempted to use escape characters in format or raw strings

Expected Behavior

1. reject invalid escape character \999..
2. convert escaped characters to expected values, e.g. \n becoming a newline
3. the same behavior between the different string types, besides exceptions for formatting and #'s

Bug

Format strings f".." and raw strings r".." currently ignore \n, and other escaped characters.

For example:

    print(f"hello world!\n \0 \99999999");
    print(r#"hello world!\n \0 \99999999"#);

nargo execute gives:

hello world!\n \0 \99999999[name_of_program] Circuit witness successfully solved

To Reproduce

1. put one of the print's above into a test file
2. nargo execute

Project Impact

None

Impact Context

No response

Workaround

Yes

Workaround Description

use regular strings for escaped characters and format strings for formatting, like so:

  print(f"hi there, {name}!");
  print("\n");

Additional Context

No response

Installation Method

Binary (noirup default)

Nargo Version

No response

NoirJS Version

0.24.0+722dc969e8b09e5a6fd56b094b6939e9330233f6

Would you like to submit a PR for this Issue?

None

Support Needs

No response

[asterite]

This will be fixed by #6703

I'm commenting this because it will only "fix" it for fmtstring. Raw strings seem to work well... or at least in Rust if you do "\n" inside a raw string, it prints "\n", not a newline, and it seems escape chars don't work inside raw strings.