# Strings and Text Formatting

## String literals

- Maybe it's the backtick quote?
- Should we have a `r"some\nliteral\tstring"` ala rust?
- Should we have something like python's triple double quotes like `"""` which helps with multi-line strings and also does string literal things?

## String interpolation

String interpolation uses either double quotes or single quotes with a preceding dollar sign. However, when using double quotes, you have to be aware that escapes will be recognized and interpreted.

### Example:

```nu
let name = "Nushell"
print $"My favorite shell is ($name)"
```

There are a couple things to be aware of in the above example.

1. The trigger to recognize a string interpolated string is the `$` sign.
2. Double quotes are used here, but single quotes could be as well. Be aware of escapes when using double quotes.
3. Accessed variable names need to be in parentheses as `$name` is in the example.

### Executing String Interpolated strings

Sometimes you need to build a path to execute external commands or build command arguments.

#### Example:

```nu
let path1 = "/part1"
let path2 = "/part2"
let fn = "filename"
let arguments = ["arg1", "-a", "arg2"]

^$"($path1)($path2)($fn)" ...$arguments
```

The caret `^` before the string interpolation symbol `$` allows that external command to be executed.

## String Quoting

### Double quotes

Double quotes are used as you would normal quotes, except for one thing: escapes can be recognized and interpreted with double quotes.

Example:

```nu
"\e[31mHello\e[35m Nushell\e[0m"
```

This would be interpreted as a red foreground `Hello` and a magenta/purple foreground `Nushell` because:

1. `\e` means insert an `escape` character
2. `[31m` means use whatever is defined as `red` foreground in your terminal
3. `[35m` means use whatever is defined as `magenta/purple` foreground in your terminal.
4. `[0m` means reset all ANSI escape sequences.

There are other escapes defined by Nushell found in [parser.rs](https://github.com/nushell/nushell/blob/main/crates/nu-parser/src/parser.rs#L2496) around line 2500 in the `unescape_string` function.

Recognized Nushell escapes:

- `"` - Double quote
- `'` - Single quote
- `\` - Back slash
- `/` - Forward slash
- `(` - Left parenthesis
- `)` - Right parenthesis
- `{` - Left brace
- `}` - Right brace
- `$` - Dollar sign
- `^` - Caret symbol
- `#` - Hash / pound sign
- `|` - Pipe character
- `~` - Tilde
- `a` - Bel
- `b` - Bs aka Backspace