# String

`String` is the primitive type constraint for string values.

A string literal is enclosed in `"`.

```dcdl
"hello"
"line 1\nline 2"
```

`$`, `{`, and `}` have no special meaning inside a string; Decodal does not perform string interpolation.

## Examples

```dcdl
name = String;
greeting = String default "hello";
```

## Constraint composition

`String` can be composed with string constraints.

```dcdl
message = String & /Hello! .*/;
```

Enable regex-constraint validation with the Rust crate's `regex` feature.
Without that feature, a regex constraint cannot be validated against a concrete string and produces a diagnostic.